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Uehara Y, Komatsu T, Sasaki K, Abe S, Nakashima S, Yamamoto T, Kim JE, Cho KH. Cuban policosanol improves high-density lipoprotein cholesterol efflux capacity in healthy Japanese subjects. Front Nutr 2024; 10:1297008. [PMID: 38260075 PMCID: PMC10800607 DOI: 10.3389/fnut.2023.1297008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/18/2023] [Indexed: 01/24/2024] Open
Abstract
Policosanol supplementation has been reported to increase high-density lipoprotein (HDL)-cholesterol (HDL-C). However, the association between Cuban policosanol supplementation and HDL cholesterol efflux capacity (CEC), an important function of HDL, remains unclear. We performed a lipoprotein analysis investigating 32 Japanese healthy participants (placebo, n = 17 or policosanol supplementation for 12 weeks, n = 15) from a randomized Cuban policosanol clinical trial. First, HDL CEC and HDL-related factors were measured before and after policosanol supplementation. Then, through electron microscopy after ultracentrifugation and high-performance liquid chromatography, HDL morphology and subclass were analyzed, respectively. Finally, the effects of policosanol supplementation regarding HDL function, HDL-related factors, and HDL morphology/component were examined. Cuban policosanol considerably increased the HDL CEC and HDL-C and apolipoprotein A-I (ApoA-I) levels. Furthermore, policosanol supplementation led to larger HDL particles, increased cholesterol content in larger HDL particles, and reduced triglyceride content in smaller HDL particles. In participants with high baseline HDL-C levels, the policosanol effects for HDL CEC are observed. HDL CEC fluctuation induced by policosanol was highly associated with HDL-C and ApoA-I changes. In conclusion, for the first time, we demonstrated that policosanol supplementation increased the HDL CEC in healthy participants.
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Affiliation(s)
- Yoshinari Uehara
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
- Research Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
- Center for Preventive, Anti-aging and Regenerative Medicine, Fukuoka University Hospital, Fukuoka, Japan
| | - Tomohiro Komatsu
- Research Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
- Center for Preventive, Anti-aging and Regenerative Medicine, Fukuoka University Hospital, Fukuoka, Japan
| | - Kei Sasaki
- Center for Preventive, Anti-aging and Regenerative Medicine, Fukuoka University Hospital, Fukuoka, Japan
| | - Satomi Abe
- Research Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
| | - Shihoko Nakashima
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
| | - Taiki Yamamoto
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
| | - Ji-Eun Kim
- Raydel Research Institute, Medical Innovation Complex, Daegu, Republic of Korea
| | - Kyung-Hyun Cho
- Raydel Research Institute, Medical Innovation Complex, Daegu, Republic of Korea
- LipoLab, Yeungnam University, Gyeongsan, Republic of Korea
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Komatsu T, Abe S, Nakashima S, Sasaki K, Higaki Y, Saku K, Miura SI, Uehara Y. Dipeptidyl Peptidase-4 Inhibitor Sitagliptin Phosphate Accelerates Cellular Cholesterol Efflux in THP-1 Cells. Biomolecules 2023; 13:biom13020228. [PMID: 36830597 PMCID: PMC9953524 DOI: 10.3390/biom13020228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
Cholesterol efflux is a major atheroprotective function of high-density lipoproteins (HDLs) which removes cholesterol from the foam cells of lipid-rich plaques in Type 2 diabetes. The dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin phosphate increases plasma glucagon-like peptide-1 (GLP-1) concentrations and is used to treat Type 2 diabetes. GLP-1 plays an important role in regulating insulin secretion and expression via the GLP-1 receptor (GLP-1R), which is expressed in pancreatic islets as well as freshly isolated human monocytes and THP-1 cells. Here, we identified a direct role of GLP-1 and DPP-4 inhibition in HDL function. Cholesterol efflux was measured in cultivated phorbol 12-myristate 13-acetate-treated THP-1 cells radiolabeled with 3H-cholesterol and stimulated with liver X receptor/retinoid X receptor agonists. Contrary to vildagliptin, sitagliptin phosphate together with GLP-1 significantly (p < 0.01) elevated apolipoprotein (apo)A1-mediated cholesterol efflux in a dose-dependent manner. The sitagliptin-induced increase in cholesterol efflux did not occur in the absence of GLP-1. In contrast, adenosine triphosphate-binding cassette transporter A1 (ABCA1) mRNA and protein expressions in the whole cell fraction were not changed by sitagliptin in the presence of GLP-1, although sitagliptin treatment significantly increased ABCA1 protein expression in the membrane fraction. Furthermore, the sitagliptin-induced, elevated efflux in the presence of GLP-1 was significantly decreased by a GLP-1R antagonist, an effect that was not observed with a protein kinase A inhibitor. To our knowledge, the present study reports for the first time that sitagliptin elevates cholesterol efflux in cultivated macrophages and may exert anti-atherosclerotic actions that are independent of improvements in glucose metabolism. Our results suggest that sitagliptin enhances HDL function by inducing a de novo HDL synthesis via cholesterol efflux.
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Affiliation(s)
- Tomohiro Komatsu
- Research Institute for Physical Activity, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Center for Preventive, Anti-Aging and Regenerative Medicine, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Satomi Abe
- Research Institute for Physical Activity, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Shihoko Nakashima
- Faculty of Sports and Health Science, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Kei Sasaki
- Center for Preventive, Anti-Aging and Regenerative Medicine, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Yasuki Higaki
- Research Institute for Physical Activity, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Faculty of Sports and Health Science, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Keijiro Saku
- Department of Cardiology, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Shin-ichiro Miura
- Department of Cardiology, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
| | - Yoshinari Uehara
- Research Institute for Physical Activity, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Center for Preventive, Anti-Aging and Regenerative Medicine, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Faculty of Sports and Health Science, Fukuoka University, 8-19-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Department of Cardiology, Fukuoka University Hospital, 7-45-1 Nanakuma, Johnan-ku, Fukuoka 814-0180, Japan
- Correspondence: ; Tel.: +81-92-871-6631
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Kotlyarov S, Kotlyarova A. Clinical significance of polyunsaturated fatty acids in the prevention of cardiovascular diseases. Front Nutr 2022; 9:998291. [PMID: 36276836 PMCID: PMC9582942 DOI: 10.3389/fnut.2022.998291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular diseases are one of the most important problems of modern medicine. They are associated with a large number of health care visits, hospitalizations and mortality. Prevention of atherosclerosis is one of the most effective strategies and should start as early as possible. Correction of lipid metabolism disorders is associated with definite clinical successes, both in primary prevention and in the prevention of complications of many cardiovascular diseases. A growing body of evidence suggests a multifaceted role for polyunsaturated fatty acids. They demonstrate a variety of functions in inflammation, both participating directly in a number of cellular processes and acting as a precursor for subsequent biosynthesis of lipid mediators. Extensive clinical data also support the importance of polyunsaturated fatty acids, but all questions have not been answered to date, indicating the need for further research.
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Affiliation(s)
| | - Anna Kotlyarova
- Department of Pharmacy Management and Economics, Ryazan State Medical University, Ryazan, Russia
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Sztolsztener K, Harasim-Symbor E, Chabowski A, Konstantynowicz-Nowicka K. The influence of dexamethasone on hepatic fatty acids metabolism and transport in human steatotic HepG2 cell line exposed to palmitate. Biochem Biophys Res Commun 2021; 585:132-138. [PMID: 34801933 DOI: 10.1016/j.bbrc.2021.11.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 11/25/2022]
Abstract
Dexamethasone (DEX) is a synthetic glucocorticoid with anti-inflammatory properties. We evaluated a potentially protective dexamethasone influence on hepatocellular lipid metabolism and fatty acid (FA) transporters expression. The HepG2 cells were incubated with palmitic acid (PA) and/or dexamethasone in two different time expositions (16 h and 40 h). Intracellular and extracellular lipid and sphingolipid concentrations were estimated by the gas-liquid chromatography and high-performance liquid chromatography, respectively. The protein expression involved in FA uptake and lipid metabolism was determined by immunoblotting. The treatment of HepG2 with dexamethasone and palmitate enhanced lipid transport to the cell via increased especially FABPpm expression and resulted in the increased triacylglycerol (TAG), diacylglycerol (DAG) and ceramide deposition. Dexamethasone with palmitate treatment altered FA composition resulting in the elevated n-3 polyunsaturated fatty acid (PUFA) activity in DAG and TAG and the diminished n-6 PUFA activity in DAG after prolonged exposure. We may speculate that although protective lipid secretion into media and decrease in inflammatory FA precursors dexamethasone treatment exacerbated lipotoxicity in HepG2 cells.
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Affiliation(s)
- Klaudia Sztolsztener
- Department of Physiology, Medical University of Bialystok, Mickiewicz Str. 2C, 15-222, Bialystok, Poland.
| | - Ewa Harasim-Symbor
- Department of Physiology, Medical University of Bialystok, Mickiewicz Str. 2C, 15-222, Bialystok, Poland.
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Mickiewicz Str. 2C, 15-222, Bialystok, Poland.
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Moradi S, Tavilani H, Saidijam M, Hashemnia M, Vaisi-Raygani A. Kiwifruit supplementation increases the gene expression of ATP-binding cassette transporter A1 and Liver X receptor α in liver and intestine of hamsters fed with high-fat diet. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2021. [DOI: 10.3233/mnm-200467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND: Liver X receptor α (LXRα) and ATP-binding cassette transporter A1 (ABCA1) as a lipid transporter play an important role in cholesterol efflux from cells. OBJECTIVE: This study was aimed to determine the effect of kiwifruit supplementation on LXRα and ABCA1 gene expressions in liver and intestine of hamsters fed with high-fat diet (HFD). METHODS: 36 Golden Syrian male hamsters were divided into 6 groups (n = 6) including, group 1 received chow diet (control normal), group 2 and 3 received chow diet plus 1.86 and 3.73 g/kg kiwifruit, group 4 received HFD, group 5 and 6 received HFD plus 1.86 and 3.73 g/kg kiwifruit for 8 weeks. RESULTS: ABCA1 gene expression were significantly decreased in the liver (p < 0.01) and the intestine (p < 0.05) of HFD group compared with control normal. The gene expression levels of ABCA1 from liver and intestine were increased in HFD treated with kiwifruit compare to untreated HFD group (p < 0.05). LXRα gene expression of intestine was increased in all of the kiwifruit treated groups compared with untreated groups (p < 0.05). CONCLUSIONS: Consumption of kiwifruit in in hamsters receiving HFD can improve cholesterol efflux from liver and intestine by increase the gene expression of ABCA1 and LXRα.
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Affiliation(s)
- Saba Moradi
- Department of Clinical Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Heidar Tavilani
- Department of Clinical Biochemistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Massoud Saidijam
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Hashemnia
- Departments of Pathobiology, Veterinary Medicine Faculty, Razi University, Kermanshah, Iran
| | - Asad Vaisi-Raygani
- Fertility and Infertility Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Rozhkova AV, Dmitrieva VG, Nosova EV, Dergunov AD, Limborska SA, Dergunova LV. Genomic Variants and Multilevel Regulation of ABCA1, ABCG1, and SCARB1 Expression in Atherogenesis. J Cardiovasc Dev Dis 2021; 8:jcdd8120170. [PMID: 34940525 PMCID: PMC8707585 DOI: 10.3390/jcdd8120170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022] Open
Abstract
Atheroprotective properties of human plasma high-density lipoproteins (HDLs) are determined by their involvement in reverse cholesterol transport (RCT) from the macrophage to the liver. ABCA1, ABCG1, and SR-BI cholesterol transporters are involved in cholesterol efflux from macrophages to lipid-free ApoA-I and HDL as a first RCT step. Molecular determinants of RCT efficiency that may possess diagnostic and therapeutic meaning remain largely unknown. This review summarizes the progress in studying the genomic variants of ABCA1, ABCG1, and SCARB1, and the regulation of their function at transcriptional and post-transcriptional levels in atherosclerosis. Defects in the structure and function of ABCA1, ABCG1, and SR-BI are caused by changes in the gene sequence, such as single nucleotide polymorphism or various mutations. In the transcription initiation of transporter genes, in addition to transcription factors, long noncoding RNA (lncRNA), transcription activators, and repressors are also involved. Furthermore, transcription is substantially influenced by the methylation of gene promoter regions. Post-transcriptional regulation involves microRNAs and lncRNAs, including circular RNAs. The potential biomarkers and targets for atheroprotection, based on molecular mechanisms of expression regulation for three transporter genes, are also discussed in this review.
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Affiliation(s)
- Alexandra V. Rozhkova
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.V.R.); (V.G.D.); (E.V.N.); (S.A.L.); (L.V.D.)
| | - Veronika G. Dmitrieva
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.V.R.); (V.G.D.); (E.V.N.); (S.A.L.); (L.V.D.)
| | - Elena V. Nosova
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.V.R.); (V.G.D.); (E.V.N.); (S.A.L.); (L.V.D.)
| | - Alexander D. Dergunov
- Laboratory of Structural Fundamentals of Lipoprotein Metabolism, National Medical Research Center for Therapy and Preventive Medicine, 101990 Moscow, Russia
- Correspondence:
| | - Svetlana A. Limborska
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.V.R.); (V.G.D.); (E.V.N.); (S.A.L.); (L.V.D.)
| | - Liudmila V. Dergunova
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics of National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.V.R.); (V.G.D.); (E.V.N.); (S.A.L.); (L.V.D.)
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7
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Dakroub H, Nowak M, Benoist JF, Noël B, Vedie B, Paul JL, Fournier N. Eicosapentaenoic acid membrane incorporation stimulates ABCA1-mediated cholesterol efflux from human THP-1 macrophages. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:159016. [PMID: 34332075 DOI: 10.1016/j.bbalip.2021.159016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 06/28/2021] [Accepted: 07/25/2021] [Indexed: 12/16/2022]
Abstract
A high intake in polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) (C20:5 n-3), is cardioprotective. Dietary PUFAs incorporate into membrane phospholipids, which may modify the function of membrane proteins. We investigated the consequences of the membrane incorporation of several PUFAs on the key antiatherogenic ABCA1-mediated cholesterol efflux pathway. Human THP-1 macrophages were incubated with EPA, arachidonic acid (AA) (C20:4 n-6) or docosahexaenoic acid (DHA) (C22:6 n-3) for a long time to mimic a chronic exposure. EPA 70 μM, but not AA 50 μM or DHA 15 μM, increased ABCA1-mediated cholesterol efflux to apolipoprotein (apo) AI by 28% without altering aqueous diffusion. No variation in ABCA1 expression or localization was observed after EPA treatment. EPA incorporation did not affect the phenotype of THP-1 macrophages. The membrane phospholipids composition of EPA cells displayed higher levels of both EPA and its elongation product docosapentaenoic acid, which was associated with drastic lower levels of AA. Treatment by EPA increased the ATPase activity of the transporter, likely through a PKA-dependent mechanism. Eicosanoids were not involved in the stimulated ABCA1-mediated cholesterol efflux from EPA-enriched macrophages. In addition, EPA supplementation increased the apo AI binding capacity from macrophages by 38%. Moreover, the increased apo AI binding in EPA-enriched macrophages can be competed. In conclusion, EPA membrane incorporation increased ABCA1 functionality in cholesterol-normal human THP-1 macrophages, likely through a combination of different mechanisms. This beneficial in vitro effect may partly contribute to the cardioprotective effect of a diet enriched with EPA highlighted by several recent clinical trials.
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Affiliation(s)
- Hani Dakroub
- Lip(Sys) (2) - EA 7357, Athérosclérose et macrophages: impact des phospholipides et des fonctions mitochondriales sur le trafic et l'efflux du cholestérol, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France
| | - Maxime Nowak
- Lip(Sys) (2) - EA 7357, Athérosclérose et macrophages: impact des phospholipides et des fonctions mitochondriales sur le trafic et l'efflux du cholestérol, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France
| | - Jean-François Benoist
- Lip(Sys) (2) - EA 7357, Athérosclérose et macrophages: impact des phospholipides et des fonctions mitochondriales sur le trafic et l'efflux du cholestérol, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France; Laboratoire de Biochimie métabolique, AP-HP (Assistance Publique-Hôpitaux de Paris), Hôpital Necker, 75015 Paris, France
| | - Benoît Noël
- Allergie, Immunotoxicologie et Immunopathologie, INSERM UMR 996, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France
| | - Benoît Vedie
- Laboratoire de Biochimie, AP-HP (Assistance Publique-Hôpitaux de Paris), Hôpital Européen Georges Pompidou, 75015 Paris, France
| | - Jean-Louis Paul
- Lip(Sys) (2) - EA 7357, Athérosclérose et macrophages: impact des phospholipides et des fonctions mitochondriales sur le trafic et l'efflux du cholestérol, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France; Laboratoire de Biochimie, AP-HP (Assistance Publique-Hôpitaux de Paris), Hôpital Européen Georges Pompidou, 75015 Paris, France
| | - Natalie Fournier
- Lip(Sys) (2) - EA 7357, Athérosclérose et macrophages: impact des phospholipides et des fonctions mitochondriales sur le trafic et l'efflux du cholestérol, Université Paris-Saclay, UFR de Pharmacie, 92296 Châtenay-Malabry, France; Laboratoire de Biochimie, AP-HP (Assistance Publique-Hôpitaux de Paris), Hôpital Européen Georges Pompidou, 75015 Paris, France.
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Soltani S, Boozari M, Cicero AFG, Jamialahmadi T, Sahebkar A. Effects of phytochemicals on macrophage cholesterol efflux capacity: Impact on atherosclerosis. Phytother Res 2021; 35:2854-2878. [PMID: 33464676 DOI: 10.1002/ptr.6991] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/19/2020] [Accepted: 12/11/2020] [Indexed: 12/24/2022]
Abstract
High-density lipoprotein cholesterol (HDL) is the major promoter of reverse cholesterol transport and efflux of excess cellular cholesterol. The functions of HDL, such as cholesterol efflux, are associated with cardiovascular disease rather than HDL levels. We have reviewed the evidence base on the major classes of phytochemicals, including polyphenols, alkaloids, carotenoids, phytosterols, and fatty acids, and their effects on macrophage cholesterol efflux and its major pathways. Phytochemicals show the potential to improve the efficiency of each of these pathways. The findings are mainly in preclinical studies, and more clinical research is warranted in this area to develop novel clinical applications.
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Affiliation(s)
- Saba Soltani
- Department of Pharmacognosy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Motahareh Boozari
- Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Arrigo F G Cicero
- Hypertension and Cardiovascular Risk Factors Research Center, Medical and Surgical Sciences Department, University of Bologna, Bologna, Italy
| | - Tannaz Jamialahmadi
- Department of Food Science and Technology, Quchan Branch, Islamic Azad University, Quchan, Iran.,Department of Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Halal Research Center of IRI, FDA, Tehran, Iran.,Polish Mother's Memorial Hospital Research Institute (PMMHRI), Lodz, Poland
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Wang Y, Xiao S, Zhou S, Zhang R, Liu H, Lin Y, Yu P. High Glucose Aggravates Cholesterol Accumulation in Glomerular Endothelial Cells Through the LXRs/LncRNAOR13C9/ABCA1 Regulatory Network. Front Physiol 2020; 11:552483. [PMID: 33192550 PMCID: PMC7604427 DOI: 10.3389/fphys.2020.552483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/17/2020] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The underlying mechanisms by which diabetes and dyslipidemia contribute to diabetic nephropathy (DN) are not fully understood. In this study, we aimed to investigate the role of high glucose (HG) on intracellular cholesterol accumulation in glomerular endothelial cells (GEnCs) and its potential mechanism. METHODS Oil red O staining, RT-qPCR, Western blotting, and immunocytofluorescence analyses were used to determine cholesterol accumulation and the expressions of LXRs and ABCA1 in GEnCs under high cholesterol (HC) and/or HG conditions, and the effect of these treatments was compared to that of low glucose without adding cholesterol. LncRNA microarrays were used to identify a long non-coding RNA (LncRNA OR13C9), of which levels increased in cells treated with the LXR agonist, GW3965. Fluorescence in situ hybridization (FISH) was conducted to confirm subcellular localization of LncOR13C9 and a bioinformatics analysis was used to identify competing endogenous RNA (ceRNA) regulatory networks between LncOR13C9 and microRNA-23a-5p (miR-23a-5p). Gain and loss of function, rescue assay approaches, and dual-luciferase reporter assay were conducted to study interactions between LncOR13C9, miR-23a-5p, and ABCA1. RESULTS We showed that HG could decrease the response ability of GEnCs to cholesterol load, specifically that HG could downregulate LXRs expression in GEnCs under cholesterol load and that the decrease in LXRs expression suppressed ABCA1 expression and increased cholesterol accumulation. We focused on the targets of LXRs and identified a long non-coding RNA (LncOR13C9) that was downregulated in GEnCs grown in HG and HC conditions, compared with that grown in HC conditions. We speculated that LncRNAOR13C9 was important for LXRs to increase cholesterol efflux via ABCA1 under HC. Furthermore, using gain of function, loss of function, and rescue assay approaches, we showed that LncOR13C9 could regulate ABCA1 by inhibiting the action of miR-23a-5p in the LXR pathway. Furthermore, dual-luciferase reporter assay was conducted to study the interaction of LncOR13C9 with miR-23a-5p. CONCLUSION Overall, our study identified the LXRs/LncOR13C9/miR23A-5p/ABCA1 regulatory network in GEnCs, which may be helpful to better understand the effect of HG on cholesterol accumulation in GEnCs under cholesterol load and to explore new therapeutic tools for the management of DN patients.
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Affiliation(s)
| | | | | | | | | | | | - Pei Yu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
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10
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Analysis of Low Molecular Weight Substances and Related Processes Influencing Cellular Cholesterol Efflux. Pharmaceut Med 2020; 33:465-498. [PMID: 31933239 PMCID: PMC7101889 DOI: 10.1007/s40290-019-00308-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cholesterol efflux is the key process protecting the vascular system from the development of atherosclerotic lesions. Various extracellular and intracellular events affect the ability of the cell to efflux excess cholesterol. To explore the possible pathways and processes that promote or inhibit cholesterol efflux, we applied a combined cheminformatic and bioinformatic approach. We performed a comprehensive analysis of published data on the various substances influencing cholesterol efflux and found 153 low molecular weight substances that are included in the Chemical Entities of Biological Interest (ChEBI) database. Pathway enrichment was performed for substances identified within the Reactome database, and 45 substances were selected in 93 significant pathways. The most common pathways included the energy-dependent processes related to active cholesterol transport from the cell, lipoprotein metabolism and lipid transport, and signaling pathways. The activators and inhibitors of cholesterol efflux were non-uniformly distributed among the different pathways: the substances influencing ‘biological oxidations’ activate cholesterol efflux and the substances influencing ‘Signaling by GPCR and PTK6’ inhibit efflux. This analysis may be used in the search and design of efflux effectors for therapies targeting structural and functional high-density lipoprotein deficiency.
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11
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Srivastava N, Cefalu AB, Averna M, Srivastava RAK. Rapid degradation of ABCA1 protein following cAMP withdrawal and treatment with PKA inhibitor suggests ABCA1 is a short-lived protein primarily regulated at the transcriptional level. J Diabetes Metab Disord 2020; 19:363-371. [PMID: 32550187 DOI: 10.1007/s40200-020-00517-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 03/12/2020] [Indexed: 01/08/2023]
Abstract
Objectives ATP-binding cassette transporter A1 (ABCA1) is a key player in the reverse cholesterol transport (RCT) and HDL biogenesis. Since RCT is compromised as a result of ABCA1 dysfunction in diabetic state, the objective of this study was to investigate the regulation of ABCA1 in a stably transfected 293 cells expressing ABCA1 under the control of cAMP response element. Methods To delineate transcriptional and posttranscriptional regulation of ABCA1, 293 cells were stably transfected with the full length ABCA1 cDNA under the control of CMV promoter harboring cAMP response element. cAMP-mediated regulation of ABCA1 and cholesterol efflux were studied in the presence of 8-Br-cAMP and after withdrawal of 8-Br-cAMP. The mechanism of cAMP-mediated transcriptional induction of the ABCA1 gene was studied in protein kinase A (PKA) inhibitors-treated cells. Results The transfected 293 cells expressed high levels of ABCA1, while non-transfected wild-type 293 cells showed very low levels of ABCA1. Treatments of transfected cells with 8-Br-cAMP increased ABCA1 protein by 10-fold and mRNA by 20-fold. Cholesterol efflux also increased in parallel. Withdrawal of 8-Br-cAMP caused time-dependent rapid diminution of ABCA1 protein and mRNA, suggesting ABCA1 regulation at the transcriptional level. Treatment with PKA inhibitors abolished the cAMP-mediated induction of the ABCA1 mRNA and protein, resulting dampening of ABCA1-dependent cholesterol efflux. Conclusions These results demonstrate that transfected cell line mimics cAMP response similar to normal cells with natural ABCA1 promoter and suggest that ABCA1 is a short-lived protein primarily regulated at the transcriptional level to maintain cellular cholesterol homeostasis.
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12
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Generoso G, Bensenor IM, Santos RD, Staniak HL, Sharovsky R, Santos IS, Goulart AC, Jones SR, Kulkarni KR, Blaha MJ, Toth PP, Lotufo PA, Bittencourt MS. High-density Lipoprotein-cholesterol Subfractions and Coronary Artery Calcium: The ELSA-Brasil Study. Arch Med Res 2019; 50:362-367. [DOI: 10.1016/j.arcmed.2019.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/25/2019] [Accepted: 10/18/2019] [Indexed: 01/16/2023]
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13
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Zhang X, van den Munckhof ICL, Rutten JHW, Netea MG, Groen AK, Zwinderman AH. Association of hemoglobin A1C with circulating metabolites in Dutch with European, African Surinamese and Ghanaian background. Nutr Diabetes 2019; 9:15. [PMID: 31040268 PMCID: PMC6491479 DOI: 10.1038/s41387-019-0082-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/28/2019] [Accepted: 04/11/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The prevalence of type 2 diabetes mellitus (T2DM) varies significantly across ethnic groups. A better understanding of the mechanisms underlying the variation in different ethnic groups may help to elucidate the pathophysiology of T2DM. The present work aims to generate a hypothesis regarding "why do subjects with African background have excess burden of T2DM?". METHODS In the current study, we performed metabolite profiling of plasma samples derived from 773 subjects of three ethnic groups (Dutch with European, Ghanaian and African Surinamese background). We performed Bayesian lognormal regression analyses to assess associations between HbA1c and circulating metabolites. RESULTS Here we show that subjects with African Surinamese and Ghanaian background had similar associations of HbA1c with circulating amino acids and triglyceride-rich lipoproteins as subjects with European background. In contrast, subjects with Ghanaian and African Surinamese background had different associations of HbA1c with acetoacetate, small LDL particle and small HDL particle concentrations, compared to the subjects with European background. CONCLUSIONS On the basis of the observations, we hypothesize that the excess burden of T2DM in subjects with African background may be due to impaired cholesterol efflux capacity or abnormal cholesterol uptake.
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Affiliation(s)
- Xiang Zhang
- Department of Experimental Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | | | - Joost H W Rutten
- Department of Internal Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Mihai G Netea
- Department of Internal Medicine, Radboud university medical center, Nijmegen, The Netherlands
- Radboud Center for Infectious Diseases, Radboud university medical Center, Nijmegen, The Netherlands
- Department for Genomics & Immunoregulation, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Albert K Groen
- Department of Experimental Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Aeilko H Zwinderman
- Clinical Epidemiology, Biostatistics, and Bioinformatics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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14
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Cholesterol Efflux: Does It Contribute to Aortic Stiffening? J Cardiovasc Dev Dis 2018; 5:jcdd5020023. [PMID: 29724005 PMCID: PMC6023341 DOI: 10.3390/jcdd5020023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 04/20/2018] [Accepted: 04/25/2018] [Indexed: 12/12/2022] Open
Abstract
Aortic stiffness during cardiac contraction is defined by the rigidity of the aorta and the elastic resistance to deformation. Recent studies suggest that aortic stiffness may be associated with changes in cholesterol efflux in endothelial cells. This alteration in cholesterol efflux may directly affect endothelial function, extracellular matrix composition, and vascular smooth muscle cell function and behavior. These pathological changes favor an aortic stiffness phenotype. Among all of the proteins participating in the cholesterol efflux process, ATP binding cassette transporter A1 (ABCA1) appears to be the main contributor to arterial stiffness changes in terms of structural and cellular function. ABCA1 is also associated with vascular inflammation mediators implicated in aortic stiffness. The goal of this mini review is to provide a conceptual hypothesis of the recent advancements in the understanding of ABCA1 in cholesterol efflux and its role and association in the development of aortic stiffness, with a particular emphasis on the potential mechanisms and pathways involved.
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15
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Yeh YT, Chiang AN, Hsieh SC. Chinese Olive (Canarium album L.) Fruit Extract Attenuates Metabolic Dysfunction in Diabetic Rats. Nutrients 2017; 9:nu9101123. [PMID: 29036927 PMCID: PMC5691739 DOI: 10.3390/nu9101123] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/11/2017] [Accepted: 10/12/2017] [Indexed: 02/06/2023] Open
Abstract
Hyperglycemia and dysregulation of lipid metabolism play a crucial role in metabolic dysfunction. The aims of present study were to evaluate the ameliorative effect of the ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc) on high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic rats. CO-EtOAc, rich in gallic acid and ellagic acid, could markedly decreased the body weight and epididymal adipose mass. In addition, CO-EtOAc increased serum HDL-C levels, hepatic GSH levels, and antioxidant enzyme activities; lowered blood glucose, serum levels of total cholesterol (TC), triglycerides (TG), bile acid, and tumor necrosis factor alpha (TNFα); and reduced TC and TG in liver. We further demonstrated that CO-EtOAc mildly suppressed hepatic levels of phosphorylated IRS-1, TNF-α, and IL-6, but enhanced Akt phosphorylation. The possible mechanisms of cholesterol metabolism were assessed by determining the expression of genes involved in cholesterol transportation, biosynthesis, and degradation. It was found that CO-EtOAc not only inhibited mRNA levels of SREBP-2, HMG-CoAR, SR-B1, and CYP7A1 but also increased the expression of genes, such as ABCA1 and LDLR that governed cholesterol efflux and cholesterol uptake. Moreover, the protein expressions of ABCA1 and LDLR were also significantly increased in the liver of rats supplemented with CO-EtOAc. We suggest that Chinese olive fruit may ameliorate metabolic dysfunction in diabetic rats under HFD challenge.
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Affiliation(s)
- Yu-Te Yeh
- Institute of Food Science and Technology, National Taiwan University, Taipei 106, Taiwan.
| | - An-Na Chiang
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan.
| | - Shu-Chen Hsieh
- Institute of Food Science and Technology, National Taiwan University, Taipei 106, Taiwan.
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16
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Tsujita M, Hossain MA, Lu R, Tsuboi T, Okumura-Noji K, Yokoyama S. Exposure to High Glucose Concentration Decreases Cell Surface ABCA1 and HDL Biogenesis in Hepatocytes. J Atheroscler Thromb 2017; 24:1132-1149. [PMID: 28428480 PMCID: PMC5684479 DOI: 10.5551/jat.39156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Aim: To study atherosclerosis risk in diabetes, we investigated ATP-binding cassette transporter A1 (ABCA1) expression and high-density lipoprotein (HDL) biogenesis in the liver and hepatocytes under hyperglycemic conditions. Methods and Results: In streptozotocin-induced diabetic mice, plasma HDL decreased while ABCA1 protein increased without changing its mRNA in the liver, only in the animals that responded to the treatment to show hypoinsulinemia and fasting hyperglycemia but not in the poor responders not showing those. To study the mechanism for this finding, hepatocytes were isolated from the control and diabetic mice, and they showed no difference in expression of ABCA1 protein, its mRNA, and HDL biogenesis in 1 g/l d-glucose but showed decreased HDL biogenesis in 4.5 g/l d-glucose although ABCA1 protein increased without change in its mRNA. Similar findings were confirmed in HepG2 cells with d-glucose but not with l-glucose. Thus, these cell models reproduced the in vivo findings in hyperglycemia. Labeling of cell surface protein revealed that surface ABCA1 decreased in high concentration of d-glucose in HepG2 cells despite the increase of cellular ABCA1 while not with l-glucose. Immunostaining of ABCA1 in HepG2 cells demonstrated the decrease of surface ABCA1 but increase of intracellular ABCA1 with high d-glucose. Clearance of ABCA1 was retarded both in primary hepatocytes and HepG2 cells exposed to high d-glucose but not to l-glucose, being consistent with the decrease of surface ABCA1. Conclusions: It is suggested that localization of ABCA1 to the cell surface is decreased in hepatocytes in hyperglycemic condition to cause decrease of HDL biogenesis.
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Affiliation(s)
- Maki Tsujita
- Biochemistry, Nagoya City University Graduate School of Medical Sciences
| | | | - Rui Lu
- Nutritional Health Science Research Center, Chubu University
| | - Tomoe Tsuboi
- Nutritional Health Science Research Center, Chubu University
| | | | - Shinji Yokoyama
- Nutritional Health Science Research Center, Chubu University
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17
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Quach D, Vitali C, La FM, Xiao AX, Millar JS, Tang C, Rader DJ, Phillips MC, Lyssenko NN. Cell lipid metabolism modulators 2-bromopalmitate, D609, monensin, U18666A and probucol shift discoidal HDL formation to the smaller-sized particles: implications for the mechanism of HDL assembly. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1968-1979. [PMID: 27671775 DOI: 10.1016/j.bbalip.2016.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/27/2016] [Accepted: 09/23/2016] [Indexed: 12/17/2022]
Abstract
ATP-binding cassette transporter A1 (ABCA1) mediates formation of disc-shaped high-density lipoprotein (HDL) from cell lipid and lipid-free apolipoprotein A-I (apo A-I). Discoidal HDL particles are heterogeneous in physicochemical characteristics for reasons that are understood incompletely. Discoidal lipoprotein particles similar in characteristics and heterogeneity to cell-formed discoidal HDL can be reconstituted from purified lipids and apo A-I by cell-free, physicochemical methods. The heterogeneity of reconstituted HDL (rHDL) is sensitive to the lipid composition of the starting lipid/apo A-I mixture. To determine whether the heterogeneity of cell-formed HDL is similarly sensitive to changes in cell lipids, we investigated four compounds that have well-established effects on cell lipid metabolism and ABCA1-mediated cell cholesterol efflux. 2-Bromopalmitate, D609, monensin and U18666A decreased formation of the larger-sized, but dramatically increased formation of the smaller-sized HDL. 2-Bromopalmitate did not appear to affect ABCA1 activity, subcellular localization or oligomerization, but induced dissolution of the cholesterol-phospholipid complexes in the plasma membrane. Arachidonic and linoleic acids shifted HDL formation to the smaller-sized species. Tangier disease mutations and inhibitors of ABCA1 activity wheat germ agglutinin and AG 490 reduced formation of both larger-sized and smaller-sized HDL. The effect of probucol was similar to the effect of 2-bromopalmitate. Taking rHDL formation as a paradigm, we propose that ABCA1 mutations and activity inhibitors reduce the amount of cell lipid available for HDL formation, and the compounds in the 2-bromopalmitate group and the polyunsaturated fatty acids change cell lipid composition from one that favors formation of the larger-sized HDL particles to one that favors formation of the smaller-sized species.
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Affiliation(s)
- Duyen Quach
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Cecilia Vitali
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Fiona M La
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Angel X Xiao
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - John S Millar
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Chongren Tang
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Daniel J Rader
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Michael C Phillips
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Nicholas N Lyssenko
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
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18
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Zou X, Meng J, Li L, Han W, Li C, Zhong R, Miao X, Cai J, Zhang Y, Zhu D. Acetoacetate Accelerates Muscle Regeneration and Ameliorates Muscular Dystrophy in Mice. J Biol Chem 2015; 291:2181-95. [PMID: 26645687 DOI: 10.1074/jbc.m115.676510] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 11/06/2022] Open
Abstract
Acetoacetate (AA) is a ketone body and acts as a fuel to supply energy for cellular activity of various tissues. Here, we uncovered a novel function of AA in promoting muscle cell proliferation. Notably, the functional role of AA in regulating muscle cell function is further evidenced by its capability to accelerate muscle regeneration in normal mice, and it ameliorates muscular dystrophy in mdx mice. Mechanistically, our data from multiparameter analyses consistently support the notion that AA plays a non-metabolic role in regulating muscle cell function. Finally, we show that AA exerts its function through activation of the MEK1-ERK1/2-cyclin D1 pathway, revealing a novel mechanism in which AA serves as a signaling metabolite in mediating muscle cell function. Our findings highlight the profound functions of a small metabolite as signaling molecule in mammalian cells.
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Affiliation(s)
- Xiaoting Zou
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Jiao Meng
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Li Li
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Wanhong Han
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Changyin Li
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Ran Zhong
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Xuexia Miao
- the Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jun Cai
- the Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yong Zhang
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
| | - Dahai Zhu
- From the State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 and
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19
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Kardassis D, Gafencu A, Zannis VI, Davalos A. Regulation of HDL genes: transcriptional, posttranscriptional, and posttranslational. Handb Exp Pharmacol 2015; 224:113-179. [PMID: 25522987 DOI: 10.1007/978-3-319-09665-0_3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
HDL regulation is exerted at multiple levels including regulation at the level of transcription initiation by transcription factors and signal transduction cascades; regulation at the posttranscriptional level by microRNAs and other noncoding RNAs which bind to the coding or noncoding regions of HDL genes regulating mRNA stability and translation; as well as regulation at the posttranslational level by protein modifications, intracellular trafficking, and degradation. The above mechanisms have drastic effects on several HDL-mediated processes including HDL biogenesis, remodeling, cholesterol efflux and uptake, as well as atheroprotective functions on the cells of the arterial wall. The emphasis is on mechanisms that operate in physiologically relevant tissues such as the liver (which accounts for 80% of the total HDL-C levels in the plasma), the macrophages, the adrenals, and the endothelium. Transcription factors that have a significant impact on HDL regulation such as hormone nuclear receptors and hepatocyte nuclear factors are extensively discussed both in terms of gene promoter recognition and regulation but also in terms of their impact on plasma HDL levels as was revealed by knockout studies. Understanding the different modes of regulation of this complex lipoprotein may provide useful insights for the development of novel HDL-raising therapies that could be used to fight against atherosclerosis which is the underlying cause of coronary heart disease.
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Affiliation(s)
- Dimitris Kardassis
- Department of Biochemistry, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology of Hellas, Heraklion, Crete, 71110, Greece,
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20
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Vollenweider P, von Eckardstein A, Widmann C. HDLs, diabetes, and metabolic syndrome. Handb Exp Pharmacol 2015; 224:405-21. [PMID: 25522996 DOI: 10.1007/978-3-319-09665-0_12] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The prevalence of type 2 diabetes mellitus and of the metabolic syndrome is rising worldwide and reaching epidemic proportions. These pathologies are associated with significant morbidity and mortality, in particular with an excess of cardiovascular deaths. Type 2 diabetes mellitus and the cluster of pathologies including insulin resistance, central obesity, high blood pressure, and hypertriglyceridemia that constitute the metabolic syndrome are associated with low levels of HDL cholesterol and the presence of dysfunctional HDLs. We here review the epidemiological evidence and the potential underlying mechanisms of this association. We first discuss the well-established association of type 2 diabetes mellitus and insulin resistance with alterations of lipid metabolism and how these alterations may lead to low levels of HDL cholesterol and the occurrence of dysfunctional HDLs. We then present and discuss the evidence showing that HDL modulates insulin sensitivity, insulin-independent glucose uptake, insulin secretion, and beta cell survival. A dysfunction in these actions could play a direct role in the pathogenesis of type 2 diabetes mellitus.
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Affiliation(s)
- Peter Vollenweider
- Department of Internal Medicine, University Hospital Center (CHUV) and University of Lausanne, Lausanne, Switzerland
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21
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Saccenti E, Suarez-Diez M, Luchinat C, Santucci C, Tenori L. Probabilistic Networks of Blood Metabolites in Healthy Subjects As Indicators of Latent Cardiovascular Risk. J Proteome Res 2014; 14:1101-11. [DOI: 10.1021/pr501075r] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Edoardo Saccenti
- Laboratory
of Systems and Synthetic Biology, Wageningen University and Research Center, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Maria Suarez-Diez
- Laboratory
of Systems and Synthetic Biology, Wageningen University and Research Center, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Claudio Luchinat
- Magnetic
Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
- Department
of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Claudio Santucci
- Magnetic
Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Leonardo Tenori
- FiorGen Foundation, Via L. Sacconi
6, 50019 Sesto Fiorentino, Italy
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22
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Uehara Y, Saku K. High-density lipoprotein and atherosclerosis: Roles of lipid transporters. World J Cardiol 2014; 6:1049-1059. [PMID: 25349649 PMCID: PMC4209431 DOI: 10.4330/wjc.v6.i10.1049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 02/10/2014] [Accepted: 08/31/2014] [Indexed: 02/06/2023] Open
Abstract
Various previous studies have found a negative correlation between the risk of cardiovascular events and serum high-density lipoprotein (HDL) cholesterol levels. The reverse cholesterol transport, a pathway of cholesterol from peripheral tissue to liver which has several potent antiatherogenic properties. For instance, the particles of HDL mediate to transport cholesterol from cells in arterial tissues, particularly from atherosclerotic plaques, to the liver. Both ATP-binding cassette transporters (ABC) A1 and ABCG1 are membrane cholesterol transporters and have been implicated in mediating cholesterol effluxes from cells in the presence of HDL and apolipoprotein A-I, a major protein constituent of HDL. Previous studies demonstrated that ABCA1 and ABCG1 or the interaction between ABCA1 and ABCG1 exerted antiatherosclerotic effects. As a therapeutic approach for increasing HDL cholesterol levels, much focus has been placed on increasing HDL cholesterol levels as well as enhancing HDL biochemical functions. HDL therapies that use injections of reconstituted HDL, apoA-I mimetics, or full-length apoA-I have shown dramatic effectiveness. In particular, a novel apoA-I mimetic peptide, Fukuoka University ApoA-I Mimetic Peptide, effectively removes cholesterol via specific ABCA1 and other transporters, such as ABCG1, and has an antiatherosclerotic effect by enhancing the biological functions of HDL without changing circulating HDL cholesterol levels. Thus, HDL-targeting therapy has significant atheroprotective potential, as it uses lipid transporter-targeting agents, and may prove to be a therapeutic tool for atherosclerotic cardiovascular diseases.
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23
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Soffientini U, Caridis AM, Dolan S, Graham A. Intracellular cholesterol transporters and modulation of hepatic lipid metabolism: Implications for diabetic dyslipidaemia and steatosis. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1842:1372-82. [PMID: 25014273 DOI: 10.1016/j.bbalip.2014.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/13/2014] [Accepted: 07/01/2014] [Indexed: 01/22/2023]
Abstract
AIMS/HYPOTHESES To examine hepatic expression of cholesterol-trafficking proteins, mitochondrial StarD1 and endosomal StarD3, and their relationship with dyslipidaemia and steatosis in Zucker (fa/fa) genetically obese rats, and to explore their functional role in lipid metabolism in rat McArdle RH-7777 hepatoma cells. METHODS Expression of StarD1 and StarD3 in rat liver and hepatoma samples were determined by Q-PCR and/or immunoblotting; lipid mass by colorimetric assays; radiolabelled precursors were utilised to measure lipid synthesis and secretion, and lipidation of exogenous apolipoprotein A-I. RESULTS Hepatic expression of StarD3 protein was repressed by genetic obesity in (fa/fa) Zucker rats, compared with lean (Fa/?) controls, suggesting a link with storage or export of lipids from the liver. Overexpression of StarD1 and StarD3, and knockdown of StarD3, in rat hepatoma cells, revealed differential effects on lipid metabolism. Overexpression of StarD1 increased utilisation of exogenous (preformed) fatty acids for triacylglycerol synthesis and secretion, but impacted minimally on cholesterol homeostasis. By contrast, overexpression of StarD3 increased lipidation of exogenous apoA-I, and facilitated de novo biosynthetic pathways for neutral lipids, potentiating triacylglycerol accumulation but possibly offering protection against lipotoxicity. Finally, StarD3 overexpression altered expression of genes which impact variously on hepatic insulin resistance, inducing Ppargcla, Cyp2e1, Nr1h4, G6pc and Irs1, and repressing expression of Scl2a1, Igfbp1, Casp3 and Serpine 1. CONCLUSIONS/INTERPRETATION Targeting StarD3 may increase circulating levels of HDL and protect the liver against lipotoxicity; loss of hepatic expression of this protein, induced by genetic obesity, may contribute to the pathogenesis of dyslipidaemia and steatosis.
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Affiliation(s)
- Ugo Soffientini
- Diabetes Research Group, Institute for Applied Health Research and the Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Anna-Maria Caridis
- Diabetes Research Group, Institute for Applied Health Research and the Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Sharron Dolan
- Diabetes Research Group, Institute for Applied Health Research and the Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Annette Graham
- Diabetes Research Group, Institute for Applied Health Research and the Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK.
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Kawashima RL, Medh JD. Down-regulation of lipoprotein lipase increases ABCA1-mediated cholesterol efflux in THP-1 macrophages. Biochem Biophys Res Commun 2014; 450:1416-21. [PMID: 25017912 DOI: 10.1016/j.bbrc.2014.07.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/17/2022]
Abstract
The ATP-binding cassette transporter A1 (ABCA1) mediates the efflux of excess cholesterol from foam cells to lipid-poor apolipoprotein A-I, in a process called reverse cholesterol transport. Lipoprotein lipase (LPL) is a lipolytic enzyme expressed by macrophages within atherosclerotic lesions. Lentivirus-mediated RNA interference was used to genetically knock-down (KD) the expression of LPL in THP-1 macrophages. Silencing of the LPL gene was confirmed by end-point PCR, real time PCR, and protein analysis. Suppression of LPL expression correlated with a 1.6-fold up-regulation of ABCA1 mRNA levels, and resulted in a 4.5-fold increase in ABCA1-dependent cholesterol efflux. Replenishing LPL by addition of purified bovine LPL to the cell culture media resulted in down-regulation of ABCA1-mediated cholesterol efflux in both wild-type and LPL knockdown cells. These findings suggest an inverse correlation between macrophage LPL levels and ABCA1 cholesterol transport activity.
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Affiliation(s)
- Ryoko L Kawashima
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262, United States
| | - Jheem D Medh
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262, United States.
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25
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Shalia K, Saranath D, Shah VK. Peripheral Blood Mononuclear Cell ABCA1 Transcripts and Protein Expression in Acute Myocardial Infarction. J Clin Lab Anal 2014; 29:242-9. [PMID: 24796288 DOI: 10.1002/jcla.21757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 03/03/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND ATP binding cassette transporter-A1 (ABCA1) facilitates the formation of high density lipoprotein (HDL). HDL due to its anti-atherosclerotic, anti-inflammatory and anti-thrombotic activities provides protection against atherothrombosis or myocardial infarction (MI). The aim was to investigate the role of peripheral blood mononuclear cell (PBMNC) ABCA1 expression in MI. METHODS The participants comprised 29 males with acute MI (AMI) and 20 healthy controls. AMI patients were normotensive, not on statins, with triglycerides < 200mg/dl and categorized into AMI with type 2 diabetes (T2DM) (N = 12) and without T2DM (N = 17). The PBMNC ABCA1 mRNA transcripts were analysed by quantitative real-time polymerase chain reaction (qRTPCR) and protein by enzyme linked immunosorbent assay (ELISA). RESULTS PBMNC ABCA1 mRNA transcript and protein levels were not significantly different in AMI patients or when sub-grouped into with/without T2DM, as compared to controls. ABCA1 protein correlated positively with HDL-cholesterol (r = 0.655, p = 0.021) in AMI patients with T2DM and negatively with age (r = - 0.525, p = 0.031) in AMI patients without T2DM and it was more strongly associated in latter group with smoking and alcohol habit. CONCLUSION In the present study, the effects of metabolites of diabetes and ischemia were observed on PBMNC ABCA1 protein and thus on HDL-C in AMI patients. Further influence of risk factors such as smoking and alcohol consumption observed in the present study can be evaluated in larger sample size. The control of these cardiovascular associated risk factors may increase stability of PBMNC ABCA1 protein and thus HDL-C levels.
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Affiliation(s)
- Kavita Shalia
- Sir H. N. Medical Research Society, Sir H. N. Hospital and Research Centre, Mumbai, India
| | | | - Vinod K Shah
- Sir H. N. Hospital and Research Centre, Mumbai, India
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Reyes-Quiroz ME, Alba G, Saenz J, Santa-María C, Geniz I, Jiménez J, Ramírez R, Martín-Nieto J, Pintado E, Sobrino F. Oleic acid modulates mRNA expression of liver X receptor (LXR) and its target genes ABCA1 and SREBP1c in human neutrophils. Eur J Nutr 2014; 53:1707-17. [PMID: 24722912 DOI: 10.1007/s00394-014-0677-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 02/19/2014] [Indexed: 01/04/2023]
Abstract
PURPOSE Regulation of liver X receptors (LXRs) is essential for cholesterol homeostasis and inflammation. The present study was conducted to determine whether oleic acid (OA) could regulate mRNA expression of LXRα and LXRα-regulated genes and to assess the potential promotion of oxidative stress by OA in neutrophils. METHODS Human neutrophils were treated with OA at different doses and LXR target gene expression, oxidative stress production, lipid efflux and inflammation state were analyzed. RESULTS We describe that mRNA synthesis of both LXRα and ABCA1 (a reverse cholesterol transporter) was induced by OA in human neutrophils. This fatty acid enhanced the effects of LXR ligands on ABCA1 and LXR expression, but it decreased the mRNA levels of sterol regulatory element-binding protein 1c (a transcription factor that regulates the synthesis of triglycerides). Although OA elicited a slight oxidative stress in the short term (15-30 min) in neutrophils, it is unlikely that this is relevant for the modulation of transcription in our experimental conditions, which involve longer incubation time (i.e., 6 h). Of physiological importance is our finding that OA depresses intracellular lipid levels and that markers of inflammation, such as ERK1/2 and p38 mitogen-activated protein kinase phosphorylation, were decreased by OA treatment. In addition, 200 μM OA reduced the migration of human neutrophils, another marker of the inflammatory state. However, OA did not affect lipid peroxidation induced by pro-oxidant agents. CONCLUSIONS This work presents for the first time evidence that human neutrophils are highly sensitive to OA and provides novel data in support of a protective role of this monounsaturated acid against the activation of neutrophils during inflammation.
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Affiliation(s)
- María Edith Reyes-Quiroz
- Departamento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Avda. Sánchez Pizjuán 4, 41009, Sevilla, Spain
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27
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Harvatine KJ, Boisclair YR, Bauman DE. Liver x receptors stimulate lipogenesis in bovine mammary epithelial cell culture but do not appear to be involved in diet-induced milk fat depression in cows. Physiol Rep 2014; 2:e00266. [PMID: 24760520 PMCID: PMC4002246 DOI: 10.1002/phy2.266] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abstract Milk fat synthesis of ruminants can be inhibited by intermediates of ruminal fatty acid biohydrogenation including trans-10, cis-12 conjugated linoleic acid (CLA). These biohydrogenation intermediates signal a coordinated downregulation of genes involved in mammary FA synthesis, transport, and esterification. We have previously reported decreased mammary expression of sterol response element-binding protein 1 (SREBP1), SREBP1-activating proteins, and thyroid hormone-responsive spot 14 (S14) in the cow during diet-induced milk fat depression (MFD), and treatment with trans-10, cis-12 CLA. Liver x receptors (LXR) and retinoid x receptors (RXR) regulate lipogenesis and are known to bind polyunsaturated FA and LXR agonist increases lipid synthesis in mammary epithelial cell culture. The current studies investigated if biohydrogenation products of rumen origin inhibit mammary lipogenesis through LXR and/or RXR. Expression of LXRs was not different in lactating compared to nonlactating bovine mammary tissue, and expression of LXRs, RXRα, and selected LXR and RXR target genes was not changed in mammary tissue during diet-induced or CLA-induced MFD in the cow. In bovine mammary epithelial cell culture, LXR agonist stimulated lipogenesis and expression of LXRß, ATP-binding cassette 1 (ABCA1), SREBP1c, and S14, but LXR activation did not overcome CLA inhibition of lipogenesis and downregulation of LXRß, SREBP1c, and S14 expression. Lastly, expression of the LXR-regulated carbohydrate-responsive element-binding protein (ChREBP) was higher in lactating than nonlactating tissue and was decreased during CLA-induced MFD. We conclude that changes in mammary LXR expression in dairy cows are not involved in MFD and that trans-10, cis-12 CLA inhibition of lipogenesis and diet-induced MFD appears independent of direct LXR signaling.
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Affiliation(s)
- Kevin J Harvatine
- Department of Animal Science, Penn State University, University Park, Pennsylvania
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Afonso MDS, Castilho G, Lavrador MSF, Passarelli M, Nakandakare ER, Lottenberg SA, Lottenberg AM. The impact of dietary fatty acids on macrophage cholesterol homeostasis. J Nutr Biochem 2014; 25:95-103. [DOI: 10.1016/j.jnutbio.2013.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 09/11/2013] [Accepted: 10/03/2013] [Indexed: 11/16/2022]
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Röhrl C, Eigner K, Winter K, Korbelius M, Obrowsky S, Kratky D, Kovacs WJ, Stangl H. Endoplasmic reticulum stress impairs cholesterol efflux and synthesis in hepatic cells. J Lipid Res 2013; 55:94-103. [PMID: 24179149 PMCID: PMC3927476 DOI: 10.1194/jlr.m043299] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Metabolic disorders such as type 2 diabetes cause hepatic endoplasmic reticulum (ER) stress, which affects neutral lipid metabolism. However, the role of ER stress in cholesterol metabolism is incompletely understood. Here, we show that induction of acute ER stress in human hepatic HepG2 cells reduced ABCA1 expression and caused ABCA1 redistribution to tubular perinuclear compartments. Consequently, cholesterol efflux to apoA-I, a key step in nascent HDL formation, was diminished by 80%. Besides ABCA1, endogenous apoA-I expression was reduced upon ER stress induction, which contributed to reduced cholesterol efflux. Liver X receptor, a key regulator of ABCA1 in peripheral cells, was not involved in this process. Despite reduced cholesterol efflux, cellular cholesterol levels remained unchanged during ER stress. This was due to impaired de novo cholesterol synthesis by reduction of HMG-CoA reductase activity by 70%, although sterol response element-binding protein-2 activity was induced. In mice, ER stress induction led to a marked reduction of hepatic ABCA1 expression. However, HDL cholesterol levels were unaltered, presumably because of scavenger receptor class B, type I downregulation under ER stress. Taken together, our data suggest that ER stress in metabolic disorders reduces HDL biogenesis due to impaired hepatic ABCA1 function.
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Affiliation(s)
- Clemens Röhrl
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
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Differential regulation of ABCA1 and macrophage cholesterol efflux by elaidic and oleic acids. Lipids 2013; 48:757-67. [PMID: 23800855 DOI: 10.1007/s11745-013-3808-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/04/2013] [Indexed: 12/11/2022]
Abstract
Trans fatty acid consumption is associated with an increased risk of coronary heart disease. This increased risk has been attributed to decreased levels of HDL cholesterol and increased levels of LDL cholesterol. However, the mechanism by which trans fatty acid modulates cholesterol transit remains poorly defined. ATP-binding cassette transporter A1 (ABCA1)-mediated macrophage cholesterol efflux is the rate-limiting step initiating apolipoprotein A-I lipidation. In this study, elaidic acid, the most abundant trans fatty acid in partially hydrogenated vegetable oil, was shown to stabilize macrophage ABCA1 protein levels in comparison to that of its cis fatty acid isomer, oleic acid. The mechanism responsible for the disparate effects of oleic and elaidic acid on ABCA1 levels was through accelerated ABCA1 protein degradation in cells treated with oleic acid. In contrast, no apparent differences were observed in ABCA1 mRNA levels, and only minor changes were observed in Liver X receptor/Retinoic X receptor promoter activity in cells treated with elaidic and oleic acid. Efflux of both tracers and cholesterol mass revealed that elaidic acid slightly increased ABCA1-mediated cholesterol efflux, while oleic acid led to decreased ABCA1-mediated efflux. In conclusion, these studies show that cis and trans structural differences in 18 carbon n-9 monoenoic fatty acids variably impact cholesterol efflux through disparate effects on ABCA1 protein degradation.
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Luquain-Costaz C, Lefai E, Arnal-Levron M, Markina D, Sakaï S, Euthine V, Makino A, Guichardant M, Yamashita S, Kobayashi T, Lagarde M, Moulin P, Delton-Vandenbroucke I. Bis(monoacylglycero)phosphate accumulation in macrophages induces intracellular cholesterol redistribution, attenuates liver-X receptor/ATP-Binding cassette transporter A1/ATP-binding cassette transporter G1 pathway, and impairs cholesterol efflux. Arterioscler Thromb Vasc Biol 2013; 33:1803-11. [PMID: 23788762 DOI: 10.1161/atvbaha.113.301857] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Endosomal signature phospholipid bis(monoacylglycero)phosphate (BMP) has been involved in the regulation of cellular cholesterol homeostasis. Accumulation of BMP is a hallmark of lipid storage disorders and was recently reported as a noticeable feature of oxidized low-density lipoprotein-laden macrophages. This study was designed to delineate the consequences of macrophage BMP accumulation on intracellular cholesterol distribution, metabolism, and efflux and to unravel the underlying molecular mechanisms. APPROACH AND RESULTS We have developed an experimental design to specifically increase BMP content in RAW 264.7 macrophages. After BMP accumulation, cell cholesterol distribution was markedly altered, despite no change in low-density lipoprotein uptake and hydrolysis, cholesterol esterification, or total cell cholesterol content. The expression of cholesterol-regulated genes sterol regulatory element-binding protein 2 and hydroxymethylglutaryl-coenzyme A reductase was decreased by 40%, indicative of an increase of endoplasmic reticulum-associated cholesterol. Cholesterol delivery to plasma membrane was reduced as evidenced by the 20% decrease of efflux by cyclodextrin. Functionally, BMP accumulation reduced cholesterol efflux to both apolipoprotein A1 and high-density lipoprotein by 40% and correlated with a 40% decrease in mRNA contents of ATP-binding cassette transporter A1, ATP-binding cassette transporter G1, and liver-X receptor α and β. Foam cell formation induced by oxidized low-density lipoprotein exposure was exacerbated in BMP-enriched cells. CONCLUSIONS The present work shows for the first time a strong functional link between BMP and cholesterol-regulating genes involved in both intracellular metabolism and efflux. We propose that accumulation of cellular BMP might contribute to the deregulation of cholesterol homeostasis in atheromatous macrophages.
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Affiliation(s)
- Céline Luquain-Costaz
- Université de Lyon, UMR 1060 Inserm, CarMeN, Institut National des Sciences Appliquées-Lyon, Villeurbanne, France
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Uehara Y, Ando S, Yahiro E, Oniki K, Ayaori M, Abe S, Kawachi E, Zhang B, Shioi S, Tanigawa H, Imaizumi S, Miura SI, Saku K. FAMP, a novel apoA-I mimetic peptide, suppresses aortic plaque formation through promotion of biological HDL function in ApoE-deficient mice. J Am Heart Assoc 2013; 2:e000048. [PMID: 23709562 PMCID: PMC3698760 DOI: 10.1161/jaha.113.000048] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background Apolipoprotein (apo) A‐I is a major high‐density lipoprotein (HDL) protein that causes cholesterol efflux from peripheral cells through the ATP‐binding cassette transporter A1 (ABCA1), thus generating HDL and reversing the macrophage foam cell phenotype. Pre‐β1 HDL is the smallest subfraction of HDL, which is believed to represent newly formed HDL, and it is the most active acceptor of free cholesterol. Furthermore it has a possible protective function against cardiovascular disease (CVD). We developed a novel apoA‐I mimetic peptide without phospholipids (Fukuoka University ApoA‐I Mimetic Peptide, FAMP). Methods and Results FAMP type 5 (FAMP5) had a high capacity for cholesterol efflux from A172 cells and mouse and human macrophages in vitro, and the efflux was mainly dependent on ABCA1 transporter. Incubation of FAMP5 with human HDL or whole plasma generated small HDL particles, and charged apoA‐I‐rich particles migrated as pre‐β HDL on agarose gel electrophoresis. Sixteen weeks of treatment with FAMP5 significantly suppressed aortic plaque formation (scrambled FAMP, 31.3±8.9% versus high‐dose FAMP5, 16.2±5.0%; P<0.01) and plasma C‐reactive protein and monocyte chemoattractant protein‐1 in apoE‐deficient mice fed a high‐fat diet. In addition, it significantly enhanced HDL‐mediated cholesterol efflux capacity from the mice. Conclusions A newly developed apoA‐I mimetic peptide, FAMP, has an antiatherosclerotic effect through the enhancement of the biological function of HDL. FAMP may have significant atheroprotective potential and prove to be a new therapeutic tool for CVD.
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Placental ABC transporters, cellular toxicity and stress in pregnancy. Chem Biol Interact 2013; 203:456-66. [PMID: 23524238 DOI: 10.1016/j.cbi.2013.03.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/05/2013] [Accepted: 03/11/2013] [Indexed: 12/25/2022]
Abstract
The human placenta, in addition to its roles as a nutrient transfer and endocrine organ, functions as a selective barrier to protect the fetus against the harmful effects of exogenous and endogenous toxins. Members of the ATP-binding cassette (ABC) family of transport proteins limit the entry of xenobiotics into the fetal circulation via vectorial efflux from the placenta to the maternal circulation. Several members of the ABC family, including proteins from the ABCA, ABCB, ABCC and ABCG subfamilies, have been shown to be functional in the placenta with clinically significant roles in xenobiotic efflux. However, recent findings suggest that these transporters also protect placental tissue by preventing the cellular accumulation of cytotoxic compounds such as lipids, sterols and their derivatives. Such protective functions are likely to be particularly important in pregnancies complicated by inflammatory or oxidative stress, where the generation of toxic metabolites is enhanced. For example, ABC transporters have been shown to protect against the harmful effects of hypoxia and oxidative stress through increased expression and efflux of oxysterols and glutathione conjugated xenobiotics. However, this protective capacity may be diminished in response to the same stressors. Several studies in primary human trophoblast cells and animal models have demonstrated decreased expression and activity of placental ABC transporters with inflammatory, oxidative or metabolic stress. Several clinical studies in pregnancies complicated by inflammatory conditions such as preeclampsia and gestational diabetes support these findings, although further studies are required to determine the clinical relevance of the relationships between placental ABC transporter expression and activity, and placental function in stressed pregnancies. Such studies are necessary to fully understand the consequences of pregnancy disorders on placental function and viability in order to optimise pregnancy care and maximise fetal growth and health.
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Sorrenson B, Suetani RJ, Williams MJA, Bickley VM, George PM, Jones GT, McCormick SPA. Functional rescue of mutant ABCA1 proteins by sodium 4-phenylbutyrate. J Lipid Res 2012; 54:55-62. [PMID: 23087442 DOI: 10.1194/jlr.m027193] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations in the ATP-binding cassette transporter A1 (ABCA1) are a major cause of decreased HDL cholesterol (HDL-C), which infers an increased risk of cardiovascular disease (CVD). Many ABCA1 mutants show impaired localization to the plasma membrane. The aim of this study was to investigate whether the chemical chaperone, sodium 4-phenylbutyrate (4-PBA) could improve cellular localization and function of ABCA1 mutants. Nine different ABCA1 mutants (p.A594T, p.I659V, p.R1068H, p.T1512M, p.Y1767D, p.N1800H, p.R2004K, p.A2028V, p.Q2239N) expressed in HEK293 cells, displaying different degrees of mislocalization to the plasma membrane and discrete impacts on cholesterol efflux, were subject to treatment with 4-PBA. Treatment restored localization to the plasma membrane and increased cholesterol efflux function for the majority of mutants. Treatment with 4-PBA also increased ABCA1 protein expression in all transfected cell lines. In fibroblast cells obtained from low HDL-C subjects expressing two of the ABCA1 mutants (p.R1068H and p.N1800H), 4-PBA increased cholesterol efflux without any increase in ABCA1 expression. Our study is the first to investigate the effect of the chemical chaperone, 4-PBA on ABCA1 and shows that it is capable of restoring plasma membrane localization and enhancing the cholesterol efflux function of mutant ABCA1s both in vitro and ex vivo. These results suggest 4-PBA may warrant further investigation as a potential therapy for increasing cholesterol efflux and HDL-C levels.
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Affiliation(s)
- Brie Sorrenson
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Unsaturated fatty acids repress expression of ATP binding cassette transporter A1 and G1 in RAW 264.7 macrophages. J Nutr Biochem 2012; 23:1271-6. [DOI: 10.1016/j.jnutbio.2011.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 05/28/2011] [Accepted: 07/13/2011] [Indexed: 12/28/2022]
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Younis NN, Durrington PN. HDL functionality in diabetes mellitus: potential importance of glycation. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.60] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Wang XT, Li J, Liu L, Hu N, Jin S, Liu C, Mei D, Liu XD. Tissue cholesterol content alterations in streptozotocin-induced diabetic rats. Acta Pharmacol Sin 2012; 33:909-17. [PMID: 22705727 DOI: 10.1038/aps.2012.50] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
AIM Diabetes is associated with elevated serum total cholesterol level and disrupted lipoprotein subfractions. The aim of this study was to examine alterations in the tissue cholesterol contents closely related to diabetic complications. METHODS Intraperitoneal injection of streptozotocin was used to induce type 1 diabetes in adult male Sprague-Dawley rats. On d 35 after the injection, liver, heart, intestine, kidney, pancreas, cerebral cortex and hippocampus were isolated from the rats. The content of total and free cholesterol in the tissues was determined using HPLC. The ATP-binding cassette protein A1 (ABCA1) protein and ApoE mRNA were measured using Western blot and QT-PCR analyses, respectively. RESULTS In diabetic rats, the level of free cholesterol was significantly decreased in the peripheral tissues, but significantly elevated in hippocampus, as compared with those in the control rats. Diabetic rats showed a trend of decreasing the total cholesterol level in the peripheral tissues, but significant change was only found in kidney and liver. In diabetic rats, the level of the ABCA1 protein was significantly increased in the peripheral tissues and cerebral cortex; the expression of ApoE mRNA was slightly decreased in hippocampus and cerebral cortex, but the change had no statistical significance. CONCLUSION Type 1 diabetes decreases the free cholesterol content in the peripheral tissues and increases the free cholesterol content in hippocampus. The decreased free cholesterol level in the peripheral tissues may be partly due to the increased expression of the ABCA1 protein.
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Tian L, Long S, Li C, Liu Y, Chen Y, Zeng Z, Fu M. High-density lipoprotein subclass and particle size in coronary heart disease patients with or without diabetes. Lipids Health Dis 2012; 11:54. [PMID: 22584085 PMCID: PMC3477075 DOI: 10.1186/1476-511x-11-54] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 04/27/2012] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND A higher prevalence of coronary heart disease (CHD) in people with diabetes. We investigated the high-density lipoprotein (HDL) subclass profiles and alterations of particle size in CHD patients with diabetes or without diabetes. METHODS Plasma HDL subclasses were quantified in CHD by 1-dimensional gel electrophoresis coupled with immunodetection. RESULTS Although the particle size of HDL tend to small, the mean levels of low density lipoprotein cholesterol(LDL-C) and total cholesterol (TC) have achieved normal or desirable for CHD patients with or without diabetes who administered statins therapy. Fasting plasma glucose (FPG), triglyceride (TG), TC, LDL-C concentrations, and HDL₃ (HDL(3b) and (3a)) contents along with Gensini Score were significantly higher; but those of HDL-C, HDL(2b+preβ2), and HDL(2a) were significantly lower in CHD patients with diabetes versus CHD patients without diabetes; The preβ₁-HDL contents did not differ significantly between these groups. Multivariate regression analysis revealed that Gensini Score was significantly and independently predicted by HDL(2a), and HDL(2b+preβ2). CONCLUSIONS The abnormality of HDL subpopulations distribution and particle size may contribute to CHD risk in diabetes patients. The HDL subclasses distribution may help in severity of coronary artery and risk stratification, especially in CHD patients with therapeutic LDL, TG and HDL levels.
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Affiliation(s)
- Li Tian
- Laboratory of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
- State Key Laboratory of Biotherapy, Sichuan University, New building 6, #16 Section 3, People South Road, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Shiyin Long
- Laboratory of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
- Department of Biochemistry and Molecular Biology, University of South China, Hengyang, Hunan, People’s Republic of China
| | - Chuanwei Li
- Cardiovascular department of West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Yinghui Liu
- Laboratory of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
- State Key Laboratory of Biotherapy, Sichuan University, New building 6, #16 Section 3, People South Road, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Yucheng Chen
- Cardiovascular department of West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Zhi Zeng
- Cardiovascular department of West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Mingde Fu
- Laboratory of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, People’s Republic of China
- State Key Laboratory of Biotherapy, Sichuan University, New building 6, #16 Section 3, People South Road, Chengdu, Sichuan, 610041, People’s Republic of China
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Liu HF, Cui KF, Wang JP, Zhang M, Guo YP, Li XY, Jiang C. Significance of ABCA1 in human carotid atherosclerotic plaques. Exp Ther Med 2012; 4:297-302. [PMID: 22970033 DOI: 10.3892/etm.2012.576] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 03/20/2012] [Indexed: 11/06/2022] Open
Abstract
The ATP-binding cassette transporter A1 (ABCA1) is an important effector in the regulation of cholesterol efflux from cells. In this study, we assessed the role of ABCA1 in human carotid atherosclerotic plaques (CAPs). We found that ABCA1 and retinoid X receptor α (RXRα) mRNAs were significantly increased in the atherosclerotic plaques compared to control arteries. The increased ABCA1 mRNA correlated with that of RXRα in plaques. According to the modified American Heart Association plaque classification, atherosclerotic specimens were assigned to three grades, and ABCA1 and RXRα mRNA levels were compared across plaques of different grades. Resultantly, plaques of grade II and III exhibited higher mRNA levels than grade I, but there was no difference in mRNA levels between plaques of grade II and III. By contrast, ABCA1 and RXRα protein levels were notably reduced in plaques relative to control tissues. Similarly, plaques of grade II and III exhibited lower ABCA1 and RXRα protein levels than grade I, and there was no difference in protein levels between plaques of grade II and III. Our findings suggest that decreased ABCA1 protein plays a key role in the pathogenesis of CAP; the regulation of ABCA1 may be mediated by RXRα and ABCA1 mRNA levels may serve as an indicator for plaque stability.
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Regulation of the expression of key genes involved in HDL metabolism by unsaturated fatty acids. Br J Nutr 2012; 108:1351-9. [PMID: 22221450 DOI: 10.1017/s0007114511006854] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The cardioprotective effects of HDL have been largely attributed to their role in the reverse cholesterol transport pathway, whose efficiency is affected by many proteins involved in the formation and remodelling of HDL. The aim of the present study was to determine the effects, and possible mechanisms of action, of unsaturated fatty acids on the expression of genes involved in HDL metabolism in HepG2 cells. The mRNA concentration of target genes was assessed by real-time PCR. Protein concentrations were determined by Western blot or immunoassays. PPAR and liver X receptor (LXR) activities were assessed in transfection experiments. Compared with the SFA palmitic acid (PA), the PUFA arachidonic acid (AA), EPA and DHA significantly decreased apoA-I, ATP-binding cassette A1 (ABCA1), lecithin-cholesterol acyltransferase (LCAT) and phospholipid transfer protein mRNA levels. EPA and DHA significantly lowered the protein concentration of apoA-I and LCAT in the media, as well as the cellular ABCA1 protein content. In addition, DHA repressed the apoA-I promoter activity. AA lowered only the protein concentration of LCAT in the media. The activity of PPAR was increased by DHA, while the activity of LXR was lowered by both DHA and AA, relative to PA. The regulation of these transcription factors by PUFA may explain some of the PUFA effects on gene expression. The observed n-3 PUFA-mediated changes in gene expression are predicted to reduce the rate of HDL particle formation and maturation.
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Kämmerer I, Ringseis R, Biemann R, Wen G, Eder K. 13-hydroxy linoleic acid increases expression of the cholesterol transporters ABCA1, ABCG1 and SR-BI and stimulates apoA-I-dependent cholesterol efflux in RAW264.7 macrophages. Lipids Health Dis 2011; 10:222. [PMID: 22129452 PMCID: PMC3248880 DOI: 10.1186/1476-511x-10-222] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 11/30/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Synthetic activators of peroxisome proliferator-activated receptors (PPARs) stimulate cholesterol removal from macrophages through PPAR-dependent up-regulation of liver × receptor α (LXRα) and subsequent induction of cholesterol exporters such as ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type 1 (SR-BI). The present study aimed to test the hypothesis that the hydroxylated derivative of linoleic acid (LA), 13-HODE, which is a natural PPAR agonist, has similar effects in RAW264.7 macrophages. METHODS RAW264.7 macrophages were treated without (control) or with LA or 13-HODE in the presence and absence of PPARα or PPARγ antagonists and determined protein levels of LXRα, ABCA1, ABCG1, SR-BI, PPARα and PPARγ and apolipoprotein A-I mediated lipid efflux. RESULTS Treatment of RAW264.7 cells with 13-HODE increased PPAR-transactivation activity and protein concentrations of LXRα, ABCA1, ABCG1 and SR-BI when compared to control treatment (P < 0.05). In addition, 13-HODE enhanced cholesterol concentration in the medium but decreased cellular cholesterol concentration during incubation of cells with the extracellular lipid acceptor apolipoprotein A-I (P < 0.05). Pre-treatment of cells with a selective PPARα or PPARγ antagonist completely abolished the effects of 13-HODE on cholesterol efflux and protein levels of genes investigated. In contrast to 13-HODE, LA had no effect on either of these parameters compared to control cells. CONCLUSION 13-HODE induces cholesterol efflux from macrophages via the PPAR-LXRα-ABCA1/SR-BI-pathway.
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Affiliation(s)
- Ines Kämmerer
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35390 Giessen, Germany
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Kanter JE, Tang C, Oram JF, Bornfeldt KE. Acyl-CoA synthetase 1 is required for oleate and linoleate mediated inhibition of cholesterol efflux through ATP-binding cassette transporter A1 in macrophages. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:358-64. [PMID: 22020260 DOI: 10.1016/j.bbalip.2011.10.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 09/30/2011] [Accepted: 10/01/2011] [Indexed: 12/31/2022]
Abstract
Diabetes and insulin resistance increase the risk of cardiovascular disease caused by atherosclerosis through mechanisms that are poorly understood. Lipid-loaded macrophages are key contributors to all stages of atherosclerosis. We have recently shown that diabetes associated with increased plasma lipids reduces cholesterol efflux and levels of the reverse cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) in mouse macrophages, which likely contributes to macrophage lipid accumulation in diabetes. Furthermore, we and others have shown that unsaturated fatty acids reduce ABCA1-mediated cholesterol efflux, and that this effect is mediated by the acyl-CoA derivatives of the fatty acids. We therefore investigated whether acyl-CoA synthetase 1 (ACSL1), a key enzyme mediating acyl-CoA synthesis in macrophages, could directly influence ABCA1 levels and cholesterol efflux in these cells. Mouse macrophages deficient in ACSL1 exhibited reduced sensitivity to oleate- and linoleate-mediated ABCA1 degradation, which resulted in increased ABCA1 levels and increased apolipoprotein A-I-dependent cholesterol efflux in the presence of these fatty acids, as compared with wildtype mouse macrophages. Conversely, overexpression of ACSL1 resulted in reduced ABCA1 levels and reduced cholesterol efflux in the presence of unsaturated fatty acids. Thus, the reduced ABCA1 and cholesterol efflux in macrophages subjected to conditions of diabetes and elevated fatty load may, at least in part, be mediated by ACSL1. These observations raise the possibility that ABCA1 levels could be increased by inhibition of acyl-CoA synthetase activity in vivo. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).
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Affiliation(s)
- Jenny E Kanter
- Department of Pathology, Diabetes and Obesity Center of Excellence, University of Washington School of Medicine, Seattle, WA 98109, USA
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Cruz-Garcia L, Sánchez-Gurmaches J, Gutiérrez J, Navarro I. Regulation of LXR by fatty acids, insulin, growth hormone and tumor necrosis factor-α in rainbow trout myocytes. Comp Biochem Physiol A Mol Integr Physiol 2011; 160:125-36. [DOI: 10.1016/j.cbpa.2011.05.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/15/2011] [Accepted: 05/17/2011] [Indexed: 01/27/2023]
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Zhang J, Grieger JA, Kris-Etherton PM, Thompson JT, Gillies PJ, Fleming JA, Vanden Heuvel JP. Walnut oil increases cholesterol efflux through inhibition of stearoyl CoA desaturase 1 in THP-1 macrophage-derived foam cells. Nutr Metab (Lond) 2011; 8:61. [PMID: 21871057 PMCID: PMC3180353 DOI: 10.1186/1743-7075-8-61] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 08/26/2011] [Indexed: 12/04/2022] Open
Abstract
Background Walnuts significantly decrease total and low-density lipoprotein cholesterol in normo- and hypercholesterolemic individuals. No study to date has evaluated the effects of walnuts on cholesterol efflux, the initial step in reverse cholesterol transport, in macrophage-derived foam cells (MDFC). The present study was conducted to investigate the mechanisms by which walnut oil affects cholesterol efflux. Methods The extract of English walnuts (walnut oil) was dissolved in DMSO and applied to cultured THP-1 MDFC cells (0.5 mg/mL). THP-1 MDFC also were treated with human sera (10%, v:v) taken from subjects in a walnut feeding study. Cholesterol efflux was examined by liquid scintillation counting. Changes in gene expression were quantified by real time PCR. Results Walnut oil treatment significantly increased cholesterol efflux through decreasing the expression of the lipogenic enzyme stearoyl CoA desaturase 1 (SCD1) in MDFC. Alpha-linolenic acid (ALA), the major n-3 polyunsaturated fatty acids found in walnuts, recaptured SCD1 reduction in MDFC, a mechanism mediated through activation of nuclear receptor farnesoid-X-receptor (FXR). Postprandial serum treatment also increased cholesterol efflux in MDFC. When categorized by baseline C-reactive protein (CRP; cut point of 2 mg/L), subjects in the lower CRP sub-group benefited more from dietary intervention, including a more increase in cholesterol efflux, a greater reduction in SCD1, and a blunted postprandial lipemia. Conclusion In conclusion, walnut oil contains bioactive molecules that significantly improve cholesterol efflux in MDFC. However, the beneficial effects of walnut intake may be reduced by the presence of a pro-inflammatory state. Trial Registration ClinicalTrials.gov: NCT00938340
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Affiliation(s)
- Jun Zhang
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
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Saito R, Matsuzaka T, Karasawa T, Sekiya M, Okada N, Igarashi M, Matsumori R, Ishii K, Nakagawa Y, Iwasaki H, Kobayashi K, Yatoh S, Takahashi A, Sone H, Suzuki H, Yahagi N, Yamada N, Shimano H. Macrophage Elovl6 deficiency ameliorates foam cell formation and reduces atherosclerosis in low-density lipoprotein receptor-deficient mice. Arterioscler Thromb Vasc Biol 2011; 31:1973-9. [PMID: 21817094 DOI: 10.1161/atvbaha.110.221663] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Elovl6, a long-chain fatty acid elongase, is a rate-limiting enzyme that elongates saturated and monounsaturated fatty acids and has been shown to be related to obesity-induced insulin resistance via modification of fatty acid composition. In this study, we investigated the roles of Elovl6 in foam cell formation in macrophages and atherosclerosis in mice. METHODS AND RESULTS To investigate the roles of Elovl6 in macrophages in the progression of atherosclerosis, we transplanted bone marrow cells of wild-type or Elovl6(-/-) mice into irradiated LDL-R(-/-) mice that were fed a western diet. Aortic atherosclerotic lesion areas and infiltration of macrophages were significantly smaller in Elovl6(-/-) bone marrow cells-transplanted LDL-R(-/-) mice than in wild-type. Accumulation of esterified cholesterol on exposure to acetylated-LDL was less severe in peritoneal macrophages from Elovl6(-/-) mice than those from wild-type. Cholesterol efflux and expression of cholesterol efflux transporters were increased in Elovl6(-/-) macrophages, although no difference in uptake of acetylated-LDL was found between the two groups. On analysis of fatty acid composition of the esterified cholesterol fraction in macrophages, n-6 polyunsaturated fatty acids were decreased by absence of Elovl6. CONCLUSIONS These findings suggest that Elovl6 in macrophages may contribute to foam cell formation and progression of atherosclerosis.
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Affiliation(s)
- Ryo Saito
- Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Patel DC, Albrecht C, Pavitt D, Paul V, Pourreyron C, Newman SP, Godsland IF, Valabhji J, Johnston DG. Type 2 diabetes is associated with reduced ATP-binding cassette transporter A1 gene expression, protein and function. PLoS One 2011; 6:e22142. [PMID: 21829447 PMCID: PMC3144880 DOI: 10.1371/journal.pone.0022142] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 06/16/2011] [Indexed: 01/05/2023] Open
Abstract
Objective Increasing plasma glucose levels are associated with increasing risk of vascular disease. We tested the hypothesis that there is a glycaemia-mediated impairment of reverse cholesterol transport (RCT). We studied the influence of plasma glucose on expression and function of a key mediator in RCT, the ATP binding cassette transporter-A1 (ABCA1) and expression of its regulators, liver X receptor-α (LXRα) and peroxisome proliferator-activated receptor–γ (PPARγ). Methods and Results Leukocyte ABCA1, LXRα and PPARγ expression was measured by polymerase chain reaction in 63 men with varying degrees of glucose homeostasis. ABCA1 protein concentrations were measured in leukocytes. In a sub-group of 25 men, ABCA1 function was quantified as apolipoprotein-A1-mediated cholesterol efflux from 2–3 week cultured skin fibroblasts. Leukocyte ABCA1 expression correlated negatively with circulating HbA1c and glucose (rho = −0.41, p<0.001; rho = −0.34, p = 0.006 respectively) and was reduced in Type 2 diabetes (T2DM) (p = 0.03). Leukocyte ABCA1 protein was lower in T2DM (p = 0.03) and positively associated with plasma HDL cholesterol (HDL-C) (rho = 0.34, p = 0.02). Apolipoprotein-A1-mediated cholesterol efflux correlated negatively with fasting glucose (rho = −0.50, p = 0.01) and positively with HDL-C (rho = 0.41, p = 0.02). It was reduced in T2DM compared with controls (p = 0.04). These relationships were independent of LXRα and PPARγ expression. Conclusions ABCA1 expression and protein concentrations in leukocytes, as well as function in cultured skin fibroblasts, are reduced in T2DM. ABCA1 protein concentration and function are associated with HDL-C levels. These findings indicate a glycaemia- related, persistent disruption of a key component of RCT.
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Affiliation(s)
- Dipesh C Patel
- Division of Medicine, Imperial College London, London, United Kingdom.
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Patel DC, Albrecht C, Pavitt D, Paul V, Pourreyron C, Newman SP, Godsland IF, Valabhji J, Johnston DG. Type 2 diabetes is associated with reduced ATP-binding cassette transporter A1 gene expression, protein and function. PLoS One 2011; 13:254-9. [PMID: 21829447 DOI: 10.2459/jcm.0b013e3283522422] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Increasing plasma glucose levels are associated with increasing risk of vascular disease. We tested the hypothesis that there is a glycaemia-mediated impairment of reverse cholesterol transport (RCT). We studied the influence of plasma glucose on expression and function of a key mediator in RCT, the ATP binding cassette transporter-A1 (ABCA1) and expression of its regulators, liver X receptor-α (LXRα) and peroxisome proliferator-activated receptor-γ (PPARγ). METHODS AND RESULTS Leukocyte ABCA1, LXRα and PPARγ expression was measured by polymerase chain reaction in 63 men with varying degrees of glucose homeostasis. ABCA1 protein concentrations were measured in leukocytes. In a sub-group of 25 men, ABCA1 function was quantified as apolipoprotein-A1-mediated cholesterol efflux from 2-3 week cultured skin fibroblasts. Leukocyte ABCA1 expression correlated negatively with circulating HbA1c and glucose (rho = -0.41, p<0.001; rho = -0.34, p = 0.006 respectively) and was reduced in Type 2 diabetes (T2DM) (p = 0.03). Leukocyte ABCA1 protein was lower in T2DM (p = 0.03) and positively associated with plasma HDL cholesterol (HDL-C) (rho = 0.34, p = 0.02). Apolipoprotein-A1-mediated cholesterol efflux correlated negatively with fasting glucose (rho = -0.50, p = 0.01) and positively with HDL-C (rho = 0.41, p = 0.02). It was reduced in T2DM compared with controls (p = 0.04). These relationships were independent of LXRα and PPARγ expression. CONCLUSIONS ABCA1 expression and protein concentrations in leukocytes, as well as function in cultured skin fibroblasts, are reduced in T2DM. ABCA1 protein concentration and function are associated with HDL-C levels. These findings indicate a glycaemia-related, persistent disruption of a key component of RCT.
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Affiliation(s)
- Dipesh C Patel
- Division of Medicine, Imperial College London, London, United Kingdom.
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Lee J, Park Y, Koo SI. ATP-binding cassette transporter A1 and HDL metabolism: effects of fatty acids. J Nutr Biochem 2011; 23:1-7. [PMID: 21684139 DOI: 10.1016/j.jnutbio.2011.03.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/14/2011] [Accepted: 03/18/2011] [Indexed: 01/08/2023]
Abstract
Ample evidence indicates that dietary fatty acids alter the plasma levels of high-density lipoprotein cholesterol (HDL-C). However, the mechanisms underlying the effects of fatty acids still remain elusive. Recent advances in our understanding of ATP-binding cassette transporter A1 (ABCA1) function and regulation have provided a valuable insight into the mechanisms by which fatty acids may affect plasma HDL-C levels. ABCA1 mediates the assembly of phospholipids and free cholesterol with apolipoprotein A-I, which is a critical step for HDL biogenesis. Studies have shown that unsaturated fatty acids, but not saturated fatty acids, repress the expression of ABCA1 in vitro. Although information on mechanisms for the fatty-acid-mediated regulation of ABCA1 expression is still limited and controversial, recent evidence suggests that unsaturated fatty acids inhibit the expression of ABCA1 at the transcriptional and posttranscriptional levels. The transcriptional repression of ABCA1 expression by unsaturated fatty acids is likely liver X receptor dependent. Evidence also suggests that histone deacetylation may play a role in the repression. Posttranscriptionally, unsaturated fatty acids may facilitate ABCA1 protein degradation, which may involve phosphorylation of ABCA1 by protein kinases. Further studies are warranted to better understand the role of dietary fatty acids in HDL metabolism and their effects on cardiovascular health.
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Affiliation(s)
- Jiyoung Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut 06269, USA.
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Ku CS, Rasmussen HE, Park Y, Jesch ED, Lee J. Unsaturated fatty acids repress the expression of ATP-binding cassette transporter A1 in HepG2 and FHs 74 Int cells. Nutr Res 2011; 31:278-85. [DOI: 10.1016/j.nutres.2011.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 03/12/2011] [Accepted: 03/15/2011] [Indexed: 01/03/2023]
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Pan J, Shilian P, Ishida B, Wu X, Kane JP, Malloy MJ, Charles MA. Effect of niacin on preβ-1 high-density lipoprotein levels in diabetes. Metabolism 2011; 60:292-7. [PMID: 20303127 DOI: 10.1016/j.metabol.2010.01.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 01/26/2010] [Indexed: 11/25/2022]
Abstract
Preβ-1 high-density lipoprotein (HDL) is an acceptor of peripheral free cholesterol and thus a participant in reverse cholesterol transport. Because patients with diabetes may have defects in reverse cholesterol transport, we hypothesized that (1) preβ-1 HDL might be decreased in diabetes and (2) because niacin improves reverse cholesterol transport and may stimulate preβ-1 HDL maturation, niacin would further decrease steady-state levels of preβ-1 HDL in diabetes. Absolute levels of preβ-1 HDL mass were measured using an isotopic dilution-ultrafiltration assay that measures apolipoprotein (apo) A-I after physically isolating preβ-1. Plasma apo A-I concentration and routine lipids were also evaluated in 11 diabetic patients. Diabetic subjects have a nearly 50% reduction of circulating levels of preβ-1 HDL to 36 ± 22 (1 SD) μg/mL compared with our previously published values of 73 ± 44 μg/mL in 136 healthy subjects. After niacin therapy, there was a further 17% reduction of preβ-1 HDL levels to 30 ± 26 μg/mL (P < .026) compared with baseline. The percentage of preβ-1 HDL in diabetic patients, as a percentage of total apo A-I, was about half of the normal value of 6.1% ± 3.6%; after niacin in diabetic patients, the percentage further decreased from 3.3% ± 2.1% to 2.3% ± 1.9% (P < .003). Absolute levels of apo A-I were similar in diabetic patients (1.14 ± 0.29) and healthy subjects (1.24 ± 0.24), and were unchanged by niacin in diabetic patients. We conclude with the novel observations that diabetes is associated with significantly reduced levels of preβ-1 HDL and that, after niacin treatment, a further lowering of preβ-1 HDL levels occur. Several altered mechanisms of RCT in diabetes are consistent with low levels of preβ-1 HDL both before and after niacin treatment.
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