51
|
Garbacz WG, Uppal H, Yan J, Xu M, Ren S, Stolz DB, Huang M, Xie W. Chronic Activation of Liver X Receptor Sensitizes Mice to High Cholesterol Diet-Induced Gut Toxicity. Mol Pharmacol 2018; 94:1145-1154. [PMID: 30045953 DOI: 10.1124/mol.118.112672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/16/2018] [Indexed: 11/22/2022] Open
Abstract
Cholesterol is essential for numerous biologic functions and processes, but an excess of intracellular cholesterol can be toxic. Intestinal cholesterol absorption is a major determinant of plasma cholesterol level. The liver X receptor (LXR) is a nuclear receptor known for its activity in cholesterol efflux and reverse cholesterol transport. In this study, we uncovered a surprising function of LXR in intestinal cholesterol absorption and toxicity. Genetic or pharmacologic activation of LXRα-sensitized mice to a high-cholesterol diet (HCD) induced intestinal toxicity and tissue damage, including the disruption of enterocyte tight junctions, whereas the same HCD caused little toxicity in the absence of LXR activation. The gut toxicity in HCD-fed LXR-KI mice may have been accounted for by the increased intestinal cholesterol absorption and elevation of enterocyte and systemic levels of free cholesterol. The increased intestinal cholesterol absorption preceded the gut toxicity, suggesting that the increased absorption was not secondary to tissue damage. The heightened sensitivity to HCD in the HCD-fed LXRα-activated mice appeared to be intestine-specific because the liver was not affected despite activation of the same receptor in this tissue. Moreover, heightened sensitivity to HCD cannot be reversed by ezetimibe, a Niemann-Pick C1-like 1 inhibitor that inhibits intestinal cholesterol absorption, suggesting that the increased cholesterol absorption in LXR-activated intestine is mediated by a mechanism that has yet to be defined.
Collapse
Affiliation(s)
- Wojciech G Garbacz
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Hirdesh Uppal
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Jiong Yan
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Meishu Xu
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Songrong Ren
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Donna B Stolz
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Min Huang
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences (W.G.G., H.U., J.Y., M.X., S.R., W.X.), Departments of Cell Biology and Physiology (D.B.S.) and Pharmacology and Chemical Biology (W.X.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Institute of Clinical Pharmacology and Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-Sen University, Guangzhou, China (M.H.)
| |
Collapse
|
52
|
Huang J, Wang Y, Ying C, Liu L, Lou Z. Effects of mulberry leaf on experimental hyperlipidemia rats induced by high-fat diet. Exp Ther Med 2018; 16:547-556. [PMID: 30116313 PMCID: PMC6090255 DOI: 10.3892/etm.2018.6254] [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: 10/02/2017] [Accepted: 03/09/2018] [Indexed: 12/25/2022] Open
Abstract
Hypercholesterolemia is a major risk factor for cardiovascular disease. Mulberry leaf (ML) is a Traditional Chinese Medicine used to treat hyperlipidemia in clinical settings. The aim of the present study was to identify the potential effect and possible target of ML in anti-hypercholesterolemia. Male Sprague-Dawley rats were fed with a high-fat diet and treated with ML for 5 weeks. Blood lipid levels, total cholesterol (TC) and total bile acid (TBA) in the liver and feces were measured to assess the effects of ML on hypercholesterolemia. Harris's hematoxylin staining and oil red O staining was applied to observe the pathological change and lipid accumulation in the liver. Immunohistochemical assay was performed to observe the location of expressions of scavenger receptor class B type I and low-density lipoprotein (LDL) receptor (-R), and western blotting was applied to determine the protein expression of ATP-binding cassette transporter G5/G8 (ABCG5/8), nuclear transcription factor peroxisome proliferator-activated receptor-α (PPARα), farnesoid-X receptor (FXR) and cholesterol 7α-hydroxylase 1 (CYP7A1). The results demonstrated that ML treatment reduced serum TC and LDL-cholesterol levels, and liver TC and TBA contents; increased serum HDL-C levels, and fecal TC and TBA contents; and alleviated hepatocyte lipid degeneration. In addition, ML treatment inhibited liver LDL-R, PPARα and FXR protein expression, promoted protein expression of CYP7A1, and maintained the ratio of ABCG5/ABCG8. The findings of the present study provide a positive role of ML on cholesterol clearance via promoting cholesterol and TBA execration via FXR- and CYP7A1-mediated pathways; RCT regulation may be a potential mechanism of ML on anti-hypercholesterolemia.
Collapse
Affiliation(s)
- Jianbo Huang
- Department of Basic Theory of Traditional Chinese Medicine, College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Yangpeng Wang
- Department of Basic Theory of Traditional Chinese Medicine, College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Chao Ying
- Institute of Materia Medica, College of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China
| | - Lei Liu
- Department of Basic Theory of Traditional Chinese Medicine, College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Zhaohuan Lou
- Institute of Materia Medica, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| |
Collapse
|
53
|
Krishna SM, Moxon JV, Jose RJ, Li J, Sahebkar A, Jaafari MR, Hatamipour M, Liu D, Golledge J. Anionic nanoliposomes reduced atherosclerosis progression in Low Density Lipoprotein Receptor (LDLR) deficient mice fed a high fat diet. J Cell Physiol 2018; 233:6951-6964. [PMID: 29741759 DOI: 10.1002/jcp.26610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/22/2018] [Indexed: 12/28/2022]
Abstract
Atherosclerosis is a systemic disease characterized by the deposition of cholesterol and inflammatory cells within the arterial wall. Removal of cholesterol from the vessel wall may have an impact on the size and composition of atherosclerotic lesions. Anionic phospholipids or liposome vesicles composed of a lipid bilayer such as nanoliposomes have been suggested as treatments for dyslipidemia. In this study, we investigated the effect of anionic nanoliposomes on atherosclerosis in a mouse model. Low-density lipoprotein receptor knockout mice (Ldlr-/- ) were fed with an atherosclerosis promoting high fat and cholesterol (HFC) diet for 12 weeks. Anionic nanoliposomes including hydrogenated soy phosphatidylcholine (HSPC) and distearoyl phosphatidylglycerol (DSPG) (molar ratio: 1:3) were injected intravenously into HFC-fed Ldlr-/- mice once a week for 4 weeks. Mice receiving nanoliposomes had significantly reduced atherosclerosis within the aortic arch as assessed by Sudan IV staining area (p = 0.007), and reduced intima/media ratio (p = 0.030) and greater collagen deposition within atherosclerosis plaques within the brachiocephalic artery (p = 0.007), compared to control mice. Administration of nanoliposomes enhanced markers of reverse cholesterol transport (RCT) and increased markers of plaque stability in HFC-fed Ldlr-/- mice. Reduced cholesterol accumulation was observed in the liver along with the up-regulation of the major genes involved in the efflux of cholesterol such as hepatic ATP-binding cassette transporters (ABC) including Abc-a1, Abc-g1, Abc-g5, and Abc-g8, Scavenger receptor class B, member 1 (Scarb1), and Liver X receptor alpha (Lxr)-α. Lecithin Cholesterol Acyltransferase activity within the plasma was also increased in mice receiving nanoliposomes. Anionic nanoliposome administration reduced atherosclerosis in HFC-fed Ldlr-/- mice by promoting RCT and upregulating the ABC-A1/ABC-G1 pathway.
Collapse
Affiliation(s)
- Smriti M Krishna
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Joseph V Moxon
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Roby J Jose
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Jiaze Li
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - 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.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud R Jaafari
- Nanotechnology Research Centre, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahdi Hatamipour
- Nanotechnology Research Centre, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Dawie Liu
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia
| | - Jonathan Golledge
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia.,Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Queensland, Australia
| |
Collapse
|
54
|
Patel SB, Graf GA, Temel RE. ABCG5 and ABCG8: more than a defense against xenosterols. J Lipid Res 2018; 59:1103-1113. [PMID: 29728459 DOI: 10.1194/jlr.r084244] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/17/2018] [Indexed: 12/14/2022] Open
Abstract
The elucidation of the molecular basis of the rare disease, sitosterolemia, has revolutionized our mechanistic understanding of how dietary sterols are excreted and how cholesterol is eliminated from the body. Two proteins, ABCG5 and ABCG8, encoded by the sitosterolemia locus, work as obligate dimers to pump sterols out of hepatocytes and enterocytes. ABCG5/ABCG8 are key in regulating whole-body sterol trafficking, by eliminating sterols via the biliary tree as well as the intestinal tract. Importantly, these transporters keep xenosterols from accumulating in the body. The sitosterolemia locus has been genetically associated with lipid levels and downstream atherosclerotic disease, as well as formation of gallstones and the risk of gallbladder cancer. While polymorphic variants raise or lower the risks of these phenotypes, loss of function of this locus leads to more dramatic phenotypes, such as premature atherosclerosis, platelet dysfunction, and thrombocytopenia, and, perhaps, increased endocrine disruption and liver dysfunction. Whether small amounts of xenosterol exposure over a lifetime cause pathology in normal humans with polymorphic variants at the sitosterolemia locus remains largely unexplored. The purpose of this review will be to summarize the current state of knowledge, but also highlight key conceptual and mechanistic issues that remain to be explored.
Collapse
Affiliation(s)
- Shailendra B Patel
- Division of Endocrinology, Diabetes, and Metabolism, University of Cincinnati, Cincinnati, OH 45219
| | - Gregory A Graf
- Department of Pharmaceutical Sciences and Saha Cardiovascular Research Center and University of Kentucky, Lexington, KY 40536
| | - Ryan E Temel
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536
| |
Collapse
|
55
|
Hiebl V, Ladurner A, Latkolik S, Dirsch VM. Natural products as modulators of the nuclear receptors and metabolic sensors LXR, FXR and RXR. Biotechnol Adv 2018; 36:1657-1698. [PMID: 29548878 DOI: 10.1016/j.biotechadv.2018.03.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/02/2018] [Accepted: 03/08/2018] [Indexed: 01/25/2023]
Abstract
Nuclear receptors (NRs) represent attractive targets for the treatment of metabolic syndrome-related diseases. In addition, natural products are an interesting pool of potential ligands since they have been refined under evolutionary pressure to interact with proteins or other biological targets. This review aims to briefly summarize current basic knowledge regarding the liver X (LXR) and farnesoid X receptors (FXR) that form permissive heterodimers with retinoid X receptors (RXR). Natural product-based ligands for these receptors are summarized and the potential of LXR, FXR and RXR as targets in precision medicine is discussed.
Collapse
Affiliation(s)
- Verena Hiebl
- University of Vienna, Department of Pharmacognosy, Althanstrasse 14, 1090 Vienna, Austria
| | - Angela Ladurner
- University of Vienna, Department of Pharmacognosy, Althanstrasse 14, 1090 Vienna, Austria.
| | - Simone Latkolik
- University of Vienna, Department of Pharmacognosy, Althanstrasse 14, 1090 Vienna, Austria
| | - Verena M Dirsch
- University of Vienna, Department of Pharmacognosy, Althanstrasse 14, 1090 Vienna, Austria
| |
Collapse
|
56
|
de Boer JF, Kuipers F, Groen AK. Cholesterol Transport Revisited: A New Turbo Mechanism to Drive Cholesterol Excretion. Trends Endocrinol Metab 2018; 29:123-133. [PMID: 29276134 DOI: 10.1016/j.tem.2017.11.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 11/26/2017] [Accepted: 11/29/2017] [Indexed: 12/31/2022]
Abstract
A fine-tuned balance between cholesterol uptake and excretion by the body is pivotal to maintain health and to remain free from the deleterious consequences of cholesterol accumulation such as cardiovascular disease. The pathways involved in intracellular and extracellular cholesterol transport are a subject of intense investigation and are being unraveled in increasing detail. In addition, insight into the complex interactions between cholesterol and bile acid metabolism has increased considerably in the last couple of years. This review provides an overview of the mechanisms involved in cholesterol uptake and excretion, with a particular emphasis on the most recent progress in this field. Special attention is given to the transintestinal cholesterol excretion (TICE) pathway, which was recently demonstrated to have a remarkably high transport capacity and to be sensitive to pharmacological modulation.
Collapse
Affiliation(s)
- Jan Freark de Boer
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Folkert Kuipers
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Vascular Medicine, University of Amsterdam Academic Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
57
|
Abstract
PURPOSE OF REVIEW To discuss recent insights into the measurement and cellular basis of transintestinal cholesterol excretion (TICE) in humans and to explore TICE as a therapeutic target for increasing reverse cholesterol transport. RECENT FINDINGS TICE is the net effect of cholesterol excretion by the enterocyte into the intestinal lumen and is the balance between input and output fluxes through the enterocytes. These fluxes are: cholesterol excretion into the intestinal lumen mainly via ATP-binding cassette (ABC) G5/8, cholesterol absorption from the intestine by Niemann-Pick C1 like protein 1, the uptake of plasma lipoproteins by enterocytes at the basolateral membrane, and the excretion of cholesterol in chylomicrons into the lymph. Multiple studies have shown that TICE contributes to fecal neutral sterol (FNS) excretion in humans. TICE can be targeted with plant sterols, liver X receptor agonists, bile acids, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors. SUMMARY TICE contributes significantly to FNS excretion in humans, independently of the biliary pathway. Knowledge about its underlying cellular mechanisms surges through in-vivo and in-vitro studies in mice and humans. TICE might be an interesting therapeutic target for increasing cholesterol disposal with the feces. Albeit multiple therapeutic options are available, studies showing clinical benefit are still needed.
Collapse
Affiliation(s)
| | | | - Albert K Groen
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| |
Collapse
|
58
|
Herbert KE, Erridge C. Regulation of low-density lipoprotein cholesterol by intestinal inflammation and the acute phase response. Cardiovasc Res 2017; 114:226-232. [DOI: 10.1093/cvr/cvx237] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/29/2017] [Indexed: 02/07/2023] Open
Abstract
AbstractSystemic inflammation, induced by disease or experimental intervention, is well established to result in elevated levels of circulating triglycerides, and reduced levels of high-density lipoprotein-cholesterol (HDL-C), in most mammalian species. However, the relationship between inflammation and low-density lipoprotein-cholesterol (LDL-C) concentrations is less clear. Most reports indicate that systemic inflammation, as observed during sepsis or following high dose experimental endotoxaemia, lowers total, and LDL-C in man. However, isolated reports have suggested that certain inflammatory conditions are associated with increased LDL-C. In this review, we summarize the emerging evidence that low-grade inflammation specifically of intestinal origin may be associated with increased serum LDL-C levels. Preliminary insights into potential mechanisms that may mediate these effects, including those connecting inflammation to trans-intestinal cholesterol efflux (TICE), are considered. We conclude that this evidence supports the potential downregulation of major mediators of TICE by inflammatory mediators in vitro and during intestinal inflammation in vivo. The TICE-inflammation axis therefore merits further study in terms of its potential to regulate serum LDL-C, and as a readily druggable target for hypercholesterolaemia.
Collapse
Affiliation(s)
- Karl E Herbert
- Department of Cardiovascular Sciences, Glenfield Hospital, University of Leicester, Groby Road, Leicester, Leicestershire, LE3 9QP, UK
| | - Clett Erridge
- Department of Cardiovascular Sciences, Glenfield Hospital, University of Leicester, Groby Road, Leicester, Leicestershire, LE3 9QP, UK
- Department of Biomedical and Forensic Sciences, Anglia Ruskin University, East Road, Cambridge, Cambridgeshire, CB1 1PT, UK
| |
Collapse
|
59
|
Riedlinger T, Dommerholt MB, Wijshake T, Kruit JK, Huijkman N, Dekker D, Koster M, Kloosterhuis N, Koonen DP, de Bruin A, Baker D, Hofker MH, van Deursen J, Jonker JW, Schmitz ML, van de Sluis B. NF-κB p65 serine 467 phosphorylation sensitizes mice to weight gain and TNFα-or diet-induced inflammation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1785-1798. [DOI: 10.1016/j.bbamcr.2017.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/23/2017] [Accepted: 07/14/2017] [Indexed: 01/04/2023]
|
60
|
Blanchard C, Moreau F, Ayer A, Toque L, Garçon D, Arnaud L, Borel F, Aguesse A, Croyal M, Krempf M, Prieur X, Neunlist M, Cariou B, Le May C. Roux-en-Y gastric bypass reduces plasma cholesterol in diet-induced obese mice by affecting trans-intestinal cholesterol excretion and intestinal cholesterol absorption. Int J Obes (Lond) 2017; 42:552-560. [PMID: 29135972 DOI: 10.1038/ijo.2017.232] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 08/10/2017] [Accepted: 08/27/2017] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Bariatric surgery appears as the most efficient therapeutic alternative in morbidly obese patients. In addition to its efficiency to decrease body weight, it also improves metabolic complications associated to morbid obesity, including dyslipidemia. Although the cholesterol-lowering effect varies with the bariatric procedures, the underlying molecular mechanisms remain poorly defined. This study aims to assess the consequence of both restrictive (sleeve gastrectomy; SG) and malabsorptive (Roux-en-Y gastric bypass; RYGB) procedures on cholesterol metabolism in mice. SUBJECTS Ten-week-old C57BL6/J males were fed with a high-fat diet for 8-14 weeks before sleeve or RYGB surgery. RESULTS SG has a modest and transient effect on plasma cholesterol levels, linked to a reduction in food intake. In contrast, modified RYGB led to a sustained ≈35% reduction in plasma cholesterol concentrations with a drastic increase in fecal cholesterol output. Mechanistically, RYGB exerts a synergystic effect on cholesterol metabolism by inducing the trans-intestinal cholesterol efflux and reducing the intestinal cholesterol absorption. CONCLUSIONS In mice, RYGB, but not sleeve, strongly favors plasma cholesterol elimination by concomitantly increasing trans-intestinal cholesterol excretion and by decreasing intestinal cholesterol absorption. Our models open new perspective for deciphering the hypocholesterolemic effects of bariatric procedures.
Collapse
Affiliation(s)
- C Blanchard
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France.,Service de Clinique de Chirurgie Digestive et Endocrinienne, CHU de Nantes, Nantes, France
| | - F Moreau
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - A Ayer
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - L Toque
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - D Garçon
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - L Arnaud
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - F Borel
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France.,Service de Clinique de Chirurgie Digestive et Endocrinienne, CHU de Nantes, Nantes, France
| | - A Aguesse
- Physiologie des Adaptations Nutritionnelles, CHU Hôtel-Dieu, Nantes, France.,CRNHO, West Human Nutrition Research Center, CHU, Nantes, France
| | - M Croyal
- Physiologie des Adaptations Nutritionnelles, CHU Hôtel-Dieu, Nantes, France.,CRNHO, West Human Nutrition Research Center, CHU, Nantes, France
| | - M Krempf
- Physiologie des Adaptations Nutritionnelles, CHU Hôtel-Dieu, Nantes, France.,CRNHO, West Human Nutrition Research Center, CHU, Nantes, France
| | - X Prieur
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - M Neunlist
- 5 INSERM UMR 1235, Nantes France.,CHU Nantes, Institut des Maladies de l'Appareil Digestif, Nantes, France
| | - B Cariou
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France.,l'institut du thorax, CHU Nantes, Department of Endocrinology, Nantes, France
| | - C Le May
- l'institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| |
Collapse
|
61
|
Dimova LG, de Boer JF, Plantinga J, Plösch T, Hoekstra M, Verkade HJ, Tietge UJF. Inhibiting Cholesterol Absorption During Lactation Programs Future Intestinal Absorption of Cholesterol in Adult Mice. Gastroenterology 2017; 153:382-385.e3. [PMID: 28438611 DOI: 10.1053/j.gastro.2017.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 04/06/2017] [Accepted: 04/18/2017] [Indexed: 01/26/2023]
Abstract
In nematodes, the intestine senses and integrates early life dietary cues that lead to lifelong epigenetic adaptations to a perceived nutritional environment-it is not clear whether this process occurs in mammals. We aimed to establish a mouse model of reduced dietary cholesterol availability from maternal milk and investigate the consequences of decreased milk cholesterol availability, early in life, on the metabolism of cholesterol in adult mice. We blocked intestinal absorption of cholesterol in milk fed to newborn mice by supplementing the food of dams (for 3 weeks between birth and weaning) with ezetimibe, which is secreted into milk. Ezetimibe interacts with the intestinal cholesterol absorption transporter NPC1l1 to block cholesterol uptake into enterocytes. Characterization of these offspring at 24 weeks of age showed a 27% decrease in cholesterol absorption (P < .001) and reduced levels of Npc1l1 messenger RNA and protein, but not other cholesterol transporters, in the proximal small intestine. We observed increased histone H3K9me3 methylation at positions -423 to -607 of the proximal Npc1l1 promoter in small intestine tissues from 24-week-old offspring fed ezetimibe during lactation, compared with controls. These findings show that the early postnatal mammalian intestine functions as an environmental sensor of nutritional conditions, responding to conditions such as low cholesterol levels by epigenetic modifications of genes. Further studies are needed to determine how decreased sterol absorption for a defined period might activate epigenetic regulators; the findings of our study might have implications for human infant nutrition and understanding and preventing cardiometabolic disease.
Collapse
Affiliation(s)
- Lidiya G Dimova
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Freark de Boer
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Josee Plantinga
- Department of Obstetrics and Gynecology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Torsten Plösch
- Department of Obstetrics and Gynecology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Menno Hoekstra
- Department of Biopharmaceutics, Leiden Academic Center for Drug Research, Leiden, The Netherlands
| | - Henkjan J Verkade
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| |
Collapse
|
62
|
Ducheix S, Montagner A, Polizzi A, Lasserre F, Régnier M, Marmugi A, Benhamed F, Bertrand-Michel J, Mselli-Lakhal L, Loiseau N, Martin PG, Lobaccaro JM, Ferrier L, Postic C, Guillou H. Dietary oleic acid regulates hepatic lipogenesis through a liver X receptor-dependent signaling. PLoS One 2017; 12:e0181393. [PMID: 28732092 PMCID: PMC5521785 DOI: 10.1371/journal.pone.0181393] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/22/2017] [Indexed: 12/13/2022] Open
Abstract
Olive oil consumption is beneficial for health as it is associated with a decreased prevalence of cancer and cardiovascular diseases. Oleic acid is, by far, the most abundant component of olive oil. Since it can be made through de novo synthesis in animals, it is not an essential fatty acid. While it has become clear that dietary oleic acid regulates many biological processes, the signaling pathway involved in these regulations remains poorly defined. In this work we tested the impact of an oleic acid-rich diet on hepatic gene expression. We were particularly interested in addressing the contribution of Liver X Receptors (LXR) in the control of genes involved in hepatic lipogenesis, an essential process in whole body energy homeostasis. We used wild-type mice and transgenic mice deficient for both α and β Liver X Receptor isoforms (LXR-/-) fed a control or an oleate enriched diet. We observed that hepatic-lipid accumulation was enhanced as well as the expression of lipogenic genes in the liver of wild-type mice fed the oleate enriched diet. In contrast, none of these changes occurred in the liver of LXR-/- mice. Strikingly, oleate-rich diet reduced cholesterolemia in wild-type mice and induced signs of liver inflammation and damage in LXR-/- mice but not in wild-type mice. This work suggests that dietary oleic acid reduces cholesterolemia while promoting LXR-dependent hepatic lipogenesis without detrimental effects to the liver.
Collapse
Affiliation(s)
- Simon Ducheix
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Alexandra Montagner
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Arnaud Polizzi
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Frédéric Lasserre
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Marion Régnier
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Alice Marmugi
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Fadila Benhamed
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France
| | | | - Laila Mselli-Lakhal
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Nicolas Loiseau
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Pascal G Martin
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Jean-Marc Lobaccaro
- Clermont Université, Université Blaise Pascal, Génétique Reproduction et Développement, Clermont-Ferrand, France.,CNRS, UMR 6293, GReD, Aubière, France.,INSERM, U1103, GReD, Aubière, France.,Centre de Recherche en Nutrition Humaine d'Auvergne, Clermont-Ferrand, France
| | - Laurent Ferrier
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Catherine Postic
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Hervé Guillou
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| |
Collapse
|
63
|
Kim B, Bae M, Park YK, Ma H, Yuan T, Seeram NP, Lee JY. Blackcurrant anthocyanins stimulated cholesterol transport via post-transcriptional induction of LDL receptor in Caco-2 cells. Eur J Nutr 2017; 57:405-415. [PMID: 28718016 DOI: 10.1007/s00394-017-1506-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 07/07/2017] [Indexed: 12/13/2022]
Abstract
PURPOSES We previously showed that polyphenol-rich blackcurrant extract (BCE) showed a hypocholesterolemic effect in mice fed a high fat diet. As direct cholesterol removal from the body via the intestine has been recently appreciated, we investigated the effect of BCE on the modulation of genes involved in intestinal cholesterol transport using Caco-2 cells as an in vitro model. METHODS Caco-2 cells were treated with BCE to determine its effects on mRNA and protein expression of genes important for intestinal cholesterol transport, low-density lipoprotein (LDL) uptake, cellular cholesterol content, and cholesterol transport from basolateral to apical membrane of Caco-2 cell monolayers. Cells were also treated with anthocyanin-rich or -poor fraction of BCE to determine the role of anthocyanin on BCE effects. RESULTS BCE significantly increased protein levels of LDL receptor (LDLR) without altering its mRNA, which consequently increased LDL uptake into Caco-2 cells. This post-transcriptional induction of LDLR by BCE was markedly attenuated in the presence of rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1). In addition, BCE altered genes involved in cholesterol transport in the enterocytes, including apical and basolateral cholesterol transporters, in such a way that could enhance cholesterol flux from the basolateral to apical side of the enterocytes. Indeed, BCE significantly increased the flux of LDL-derived cholesterol from the basolateral to the apical chamber of Caco-2 monolayer. LDLR protein levels were markedly increased by anthocyanin-rich fraction, but not by anthocyanin-free fraction. CONCLUSION mTORC1-dependent post-transcriptional induction of LDLR by BCE anthocyanins drove the transport of LDL-derived cholesterol to the apical side of the enterocytes. This may represent a potential mechanism for the hypocholesterolemic effect of BCE.
Collapse
Affiliation(s)
- Bohkyung Kim
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, 06269-4017, USA
| | - Minkyung Bae
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, 06269-4017, USA
| | - Young-Ki Park
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, 06269-4017, USA
| | - Hang Ma
- Bioactive Botanical Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, 02881, USA
| | - Tao Yuan
- Bioactive Botanical Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, 02881, USA
| | - Navindra P Seeram
- Bioactive Botanical Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, 02881, USA
| | - Ji-Young Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, 06269-4017, USA.
| |
Collapse
|
64
|
Fessler MB. The challenges and promise of targeting the Liver X Receptors for treatment of inflammatory disease. Pharmacol Ther 2017; 181:1-12. [PMID: 28720427 DOI: 10.1016/j.pharmthera.2017.07.010] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Liver X Receptors (LXRs) are oxysterol-activated transcription factors that upregulate a suite of genes that together promote coordinated mobilization of excess cholesterol from cells and from the body. The LXRs, like other nuclear receptors, are anti-inflammatory, inhibiting signal-dependent induction of pro-inflammatory genes by nuclear factor-κB, activating protein-1, and other transcription factors. Synthetic LXR agonists have been shown to ameliorate atherosclerosis and a wide range of inflammatory disorders in preclinical animal models. Although this has suggested potential for application to human disease, systemic LXR activation is complicated by hepatic steatosis and hypertriglyceridemia, consequences of lipogenic gene induction in the liver by LXRα. The past several years have seen the development of multiple advanced LXR therapeutics aiming to avoid hepatic lipogenesis, including LXRβ-selective agonists, tissue-selective agonists, and transrepression-selective agonists. Although several synthetic LXR agonists have made it to phase I clinical trials, none have progressed due to unforeseen adverse reactions or undisclosed reasons. Nonetheless, several sophisticated pharmacologic strategies, including structure-guided drug design, cell-specific drug targeting, as well as non-systemic drug routes have been initiated and remain to be comprehensively explored. In addition, recent studies have identified potential utility for targeting the LXRs during therapy with other agents, such as glucocorticoids and rexinoids. Despite the pitfalls encountered to date in translation of LXR agonists to human disease, it appears likely that this accelerating field will ultimately yield effective and safe applications for LXR targeting in humans.
Collapse
Affiliation(s)
- Michael B Fessler
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, P.O. Box 12233, MD D2-01, Research Triangle Park, NC 27709, United States.
| |
Collapse
|
65
|
Paalvast Y, de Boer JF, Groen AK. Developments in intestinal cholesterol transport and triglyceride absorption. Curr Opin Lipidol 2017; 28:248-254. [PMID: 28338522 DOI: 10.1097/mol.0000000000000415] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW To discuss recent advances in research focused on intestinal lipid handling. RECENT FINDINGS An important strategy in reducing atherosclerosis and risk of cardiovascular events is to increase the rate of reverse cholesterol transport, including its final step; cholesterol excretion from the body. The rate of removal is determined by a complex interplay between the factors involved in regulation of intestinal cholesterol absorption. One of these factors is a process known as transintestinal cholesterol excretion. This pathway comprises transport of cholesterol directly from the blood, through the enterocyte, into the intestinal lumen. In humans, this pathway accounts for 35% of cholesterol excretion in the feces. Mechanistic studies in mice revealed that, activation of the bile acid receptor farnesoid X receptor increases cholesterol removal via the transintestinal cholesterol excretion pathway as well as decreases plasma cholesterol and triglyceride providing an interesting target for treatment of dyslipidemia in humans. The physical chemical properties of bile acids are under control of farnesoid X receptor and determine intestinal cholesterol and triglyceride solubilization as well as absorption, providing a direct link between these two important factors in the pathogenesis of cardiovascular disease. Besides bile acids, intestinal phospholipids are important for luminal lipid solubilization. Interestingly, phospholipid remodeling through LPCAT3 was shown to be pivotal for uptake of fatty acids by enterocytes, which may provide a mechanistic handle for therapeutic intervention. SUMMARY The importance of the intestine in control of cholesterol and triglyceride homeostasis is increasingly recognized. Recently, novel factors involved in regulation of cholesterol excretion and intestinal triglyceride and fatty acid uptake have been reported and are discussed in this short review.
Collapse
Affiliation(s)
- Yared Paalvast
- aDepartment of Pediatrics bDepartment of Laboratory Medicine, University of Groningen, University Medical Center Groningen cDepartment of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | | |
Collapse
|
66
|
Hirata H, Uto-Kondo H, Ogura M, Ayaori M, Shiotani K, Ota A, Tsuchiya Y, Ikewaki K. Xanthohumol, a hop-derived prenylated flavonoid, promotes macrophage reverse cholesterol transport. J Nutr Biochem 2017; 47:29-34. [PMID: 28501703 DOI: 10.1016/j.jnutbio.2017.04.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 04/09/2017] [Accepted: 04/14/2017] [Indexed: 12/27/2022]
Abstract
Xanthohumol, a prominent prenyl flavonoid from the hop plant (Humulus lupulus L.), is suggested to be antiatherogenic since it reportedly increases high-density lipoprotein (HDL) cholesterol levels. It is not clear whether xanthohumol promotes reverse cholesterol transport (RCT), the most important antiatherogenic property of HDL; therefore, we investigated the effects of xanthohumol on macrophage-to-feces RCT using a hamster model as a CETP-expressing species. In vivo RCT experiments showed that xanthohumol significantly increased fecal appearance of the tracer derived from intraperitoneally injected [3H]-cholesterol-labeled macrophages. Ex vivo experiments were then employed to investigate the detailed mechanism by which xanthohumol enhanced RCT. Cholesterol efflux capacity from macrophages was 1.5-fold higher in xanthohumol-fed hamsters compared with the control group. In addition, protein expression and lecithin-cholesterol acyltransferase activity in the HDL fraction were significantly higher in xanthohumol-fed hamsters compared with the control, suggesting that xanthohumol promoted HDL maturation. Hepatic transcript analysis revealed that xanthohumol increased mRNA expression of abcg8 and cyp7a1. In addition, protein expressions of liver X receptor α and bile pump export protein were increased in the liver by xanthohumol administration when compared with the control, implying that it stimulated bile acid synthesis and cholesterol excretion to feces. In conclusion, our data demonstrate that xanthohumol improves RCT in vivo through cholesterol efflux from macrophages and excretion to feces, leading to antiatherosclerosis effects. It remains to be elucidated whether enhancement of RCT by xanthohumol could prove valuable in humans.
Collapse
Affiliation(s)
- Hiroshi Hirata
- Frontier Laboratories for Value Creation, SAPPORO HOLDINGS LTD., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan.
| | - Harumi Uto-Kondo
- Division of Neurology, Anti-Aging, and Vascular Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Masatsune Ogura
- Division of Neurology, Anti-Aging, and Vascular Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Makoto Ayaori
- Tokorozawa Heart Center, 1-4-1-101 Midoricho, Tokorozawa, Saitama 359-1111, Japan
| | - Kazusa Shiotani
- Division of Neurology, Anti-Aging, and Vascular Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Ami Ota
- Frontier Laboratories for Value Creation, SAPPORO HOLDINGS LTD., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
| | - Youichi Tsuchiya
- Frontier Laboratories for Value Creation, SAPPORO HOLDINGS LTD., 10 Okatome, Yaizu, Shizuoka 425-0013, Japan
| | - Katsunori Ikewaki
- Division of Neurology, Anti-Aging, and Vascular Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| |
Collapse
|
67
|
Cedó L, Santos D, Ludwig IA, Silvennoinen R, García-León A, Kaipiainen L, Carbó JM, Valledor AF, Gylling H, Motilva MJ, Kovanen PT, Lee-Rueckert M, Blanco-Vaca F, Escolà-Gil JC. Phytosterol-mediated inhibition of intestinal cholesterol absorption in mice is independent of liver X receptor. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201700055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Lídia Cedó
- Institut d'Investigacions Biomèdiques (IIB) Sant Pau; Barcelona Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas; CIBERDEM, Hospitalet de Llobregat Spain
| | - David Santos
- Institut d'Investigacions Biomèdiques (IIB) Sant Pau; Barcelona Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas; CIBERDEM, Hospitalet de Llobregat Spain
| | - Iziar A. Ludwig
- Food Technology Department, UTPV-XaRTA, Agrotecnio Center; University of Lleida; Lleida Spain
| | | | - Annabel García-León
- Institut d'Investigacions Biomèdiques (IIB) Sant Pau; Barcelona Spain
- Departament de Bioquímica, Biología Molecular i Biomedicina; Universitat Autònoma de Barcelona; Barcelona Spain
| | - Leena Kaipiainen
- University of Helsinki and Helsinki University Central Hospital; Department of Internal Medicine; Helsinki Finland
| | - José M. Carbó
- Department of Cellular Biology, Physiology and Immunology; School of Biology, University of Barcelona; Barcelona Spain
| | - Annabel F. Valledor
- Department of Cellular Biology, Physiology and Immunology; School of Biology, University of Barcelona; Barcelona Spain
| | - Helena Gylling
- University of Helsinki and Helsinki University Central Hospital; Department of Internal Medicine; Helsinki Finland
| | - Maria-José Motilva
- Food Technology Department, UTPV-XaRTA, Agrotecnio Center; University of Lleida; Lleida Spain
| | | | | | - Francisco Blanco-Vaca
- Institut d'Investigacions Biomèdiques (IIB) Sant Pau; Barcelona Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas; CIBERDEM, Hospitalet de Llobregat Spain
- Departament de Bioquímica, Biología Molecular i Biomedicina; Universitat Autònoma de Barcelona; Barcelona Spain
| | - Joan Carles Escolà-Gil
- Institut d'Investigacions Biomèdiques (IIB) Sant Pau; Barcelona Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas; CIBERDEM, Hospitalet de Llobregat Spain
- Departament de Bioquímica, Biología Molecular i Biomedicina; Universitat Autònoma de Barcelona; Barcelona Spain
| |
Collapse
|
68
|
de Boer JF, Schonewille M, Dikkers A, Koehorst M, Havinga R, Kuipers F, Tietge UJ, Groen AK. Transintestinal and Biliary Cholesterol Secretion Both Contribute to Macrophage Reverse Cholesterol Transport in Rats—Brief Report. Arterioscler Thromb Vasc Biol 2017; 37:643-646. [DOI: 10.1161/atvbaha.116.308558] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/08/2017] [Indexed: 11/16/2022]
Abstract
Objective—
Reverse cholesterol transport comprises efflux of cholesterol from macrophages and its subsequent removal from the body with the feces and thereby protects against formation of atherosclerotic plaques. Because of lack of suitable animal models that allow for evaluation of the respective contributions of biliary cholesterol secretion and transintestinal cholesterol excretion (TICE) to macrophage reverse cholesterol transport under physiological conditions, the relative importance of both pathways in this process has remained controversial.
Approach and Results—
To separate cholesterol traffic via the biliary route from TICE, bile flow was mutually diverted between rats, continuously, for 3 days. Groups of 2 weight-matched rats were designated as a pair, and both rats were equipped with cannulas in the bile duct and duodenum. Bile from rat 1 was diverted to the duodenum of rat 2, whereas bile from rat 2 was rerouted to the duodenum of rat 1. Next, rat 1 was injected with [
3
H]cholesterol-loaded macrophages. [
3
H]Cholesterol secreted via the biliary route was consequently diverted to rat 2 and could thus be quantified from the feces of that rat. On the other hand, [
3
H]cholesterol tracer in the feces of rat 1 reflected macrophage-derived cholesterol excreted via TICE. Using this setup, we found that 63% of the label secreted with the fecal neutral sterols had travelled via the biliary route, whereas 37% was excreted via TICE.
Conclusions—
TICE and biliary cholesterol secretion contribute to macrophage reverse cholesterol transport in rats. The majority of macrophage-derived cholesterol is however excreted via the hepatobiliary route.
Collapse
Affiliation(s)
- Jan Freark de Boer
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Marleen Schonewille
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Arne Dikkers
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Martijn Koehorst
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Rick Havinga
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Folkert Kuipers
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Uwe J.F. Tietge
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| | - Albert K. Groen
- From the Departments of Pediatrics (J.F.d.B., M.S., A.D., M.K., R.H., F.K., U.J.F.T., A.K.G.) and Laboratory Medicine (F.K., A.K.G.), University of Groningen, University Medical Center Groningen, The Netherlands
| |
Collapse
|
69
|
de Boer JF, Schonewille M, Boesjes M, Wolters H, Bloks VW, Bos T, van Dijk TH, Jurdzinski A, Boverhof R, Wolters JC, Kuivenhoven JA, van Deursen JM, Oude Elferink RPJ, Moschetta A, Kremoser C, Verkade HJ, Kuipers F, Groen AK. Intestinal Farnesoid X Receptor Controls Transintestinal Cholesterol Excretion in Mice. Gastroenterology 2017; 152:1126-1138.e6. [PMID: 28065787 DOI: 10.1053/j.gastro.2016.12.037] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 12/03/2016] [Accepted: 12/23/2016] [Indexed: 01/17/2023]
Abstract
BACKGROUND & AIMS The role of the intestine in the maintenance of cholesterol homeostasis increasingly is recognized. Fecal excretion of cholesterol is the last step in the atheroprotective reverse cholesterol transport pathway, to which biliary and transintestinal cholesterol excretion (TICE) contribute. The mechanisms controlling the flux of cholesterol through the TICE pathway, however, are poorly understood. We aimed to identify mechanisms that regulate and stimulate TICE. METHODS We performed studies with C57Bl/6J mice, as well as with mice with intestine-specific knockout of the farnesoid X receptor (FXR), mice that express an FXR transgene specifically in the intestine, and ABCG8-knockout mice. Mice were fed a control diet or a diet supplemented with the FXR agonist PX20606, with or without the cholesterol absorption inhibitor ezetimibe. Some mice with intestine-specific knockout of FXR were given daily injections of fibroblast growth factor (FGF)19. To determine fractional cholesterol absorption, mice were given intravenous injections of cholesterol D5 and oral cholesterol D7. Mice were given 13C-acetate in drinking water for measurement of cholesterol synthesis. Bile cannulations were performed and biliary cholesterol secretion rates were assessed. In a separate set of experiments, bile ducts of male Wistar rats were exteriorized, allowing replacement of endogenous bile by a model bile. RESULTS In mice, we found TICE to be regulated by intestinal FXR via induction of its target gene Fgf15 (FGF19 in rats and human beings). Stimulation of this pathway caused mice to excrete up to 60% of their total cholesterol content each day. PX20606 and FGF19 each increased the ratio of muricholate:cholate in bile, inducing a more hydrophilic bile salt pool. The altered bile salt pool stimulated robust secretion of cholesterol into the intestinal lumen via the sterol-exporting heterodimer adenosine triphosphate binding cassette subfamily G member 5/8 (ABCG5/G8). Of note, the increase in TICE induced by PX20606 was independent of changes in cholesterol absorption. CONCLUSIONS Hydrophilicity of the bile salt pool, controlled by FXR and FGF15/19, is an important determinant of cholesterol removal via TICE. Strategies that alter bile salt pool composition might be developed for the prevention of cardiovascular disease. Transcript profiling: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=irsrayeohfcntqx&acc=GSE74101.
Collapse
Affiliation(s)
- Jan Freark de Boer
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Marleen Schonewille
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marije Boesjes
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Henk Wolters
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Vincent W Bloks
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Trijnie Bos
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Angelika Jurdzinski
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Renze Boverhof
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Justina C Wolters
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan A Kuivenhoven
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan M van Deursen
- Department of Pediatric and Adolescent Medicine, Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Ronald P J Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Department of Hepatology and Gastroenterology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Antonio Moschetta
- Department of Interdisciplinary Medicine, University of Bari, IRCCS Istituto Tumori "Giovanni Paolo II," Bari, Italy
| | | | - Henkjan J Verkade
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Folkert Kuipers
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| |
Collapse
|
70
|
Mistry RH, Verkade HJ, Tietge UJF. Absence of intestinal microbiota increases ß-cyclodextrin stimulated reverse cholesterol transport. Mol Nutr Food Res 2017; 61. [PMID: 28087885 DOI: 10.1002/mnfr.201600674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 11/07/2022]
Abstract
SCOPE Non-digestible oligosaccharides are used as prebiotics for perceived health benefits, among these modulating lipid metabolism. However, the mechanisms of action are incompletely understood. The present study characterized the impact of dietary ß-cyclodextrin (ßCD, 10%, w/w), a cyclic oligosaccharide, on sterol metabolism and reverse cholesterol transport (RCT) in conventional and also germ-free mice to establish dependency on metabolism by intestinal bacteria. METHODS AND RESULTS In conventional ßCD-fed C57BL/6J wild-type mice plasma cholesterol decreased significantly (-40%, p < 0.05), largely within HDL, while fecal neutral sterol excretion increased (3-fold, p < 0.01) and fecal bile acid excretion was unchanged. Hepatic cholesterol levels and biliary cholesterol secretion were unaltered. Changes in cholesterol metabolism translated into increased macrophage-to-feces RCT in ßCD-administered mice (1.5-fold, p < 0.05). In germ-free C57BL/6J mice ßCD similarly lowered plasma cholesterol (-40%, p < 0.05). However, ßCD increased fecal neutral sterol excretion (7.5-fold, p < 0.01), bile acid excretion (2-fold, p < 0.05) and RCT (2.5-fold, p < 0.01) even more substantially in germ-free mice compared with the effect in conventional mice. CONCLUSION In summary, this study demonstrates that ßCD lowers plasma cholesterol levels and increases fecal cholesterol excretion from a RCT-relevant pool. Intestinal bacteria decrease the impact of ßCD on RCT. These data suggest that dietary ßCD might have cardiovascular health benefits.
Collapse
Affiliation(s)
- Rima H Mistry
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Henkjan J Verkade
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| |
Collapse
|
71
|
Dimova LG, Zlatkov N, Verkade HJ, Uhlin BE, Tietge UJF. High-cholesterol diet does not alter gut microbiota composition in mice. Nutr Metab (Lond) 2017; 14:15. [PMID: 28239402 PMCID: PMC5314487 DOI: 10.1186/s12986-017-0170-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/05/2017] [Indexed: 02/07/2023] Open
Abstract
Introduction Western diet containing both saturated fat and cholesterol impairs cardio-metabolic health partly by modulating diversity and function of the microbiota. While diet containing only high fat has comparable effects, it is unclear how diets only enriched in cholesterol impact the microbiota. Therefore, we aimed to characterize the response of host and microbiota to a high cholesterol (HC) diet in mice susceptible to cardio-metabolic disease. Methods LDLR knockout mice received either 1.25% HC or no cholesterol containing control diet (NC) for 12 weeks before characterizing host cholesterol metabolism and intestinal microbiota composition (next generation sequencing). Results HC diet substantially increased plasma (1.6-fold) and liver cholesterol levels (21-fold), biliary cholesterol secretion (4.5-fold) and fecal neutral sterol excretion (68-fold, each p < 0.001) but not fecal bile acid excretion. Interestingly, despite the profound changes in intestinal cholesterol homeostasis no differences in microbial composition between control and HC-fed mice were detected. In both groups the main phyla were Bacteroidetes (55%), Firmicutes (27%) and Verrucomicrobia (14%). Conclusion Our results demonstrate that in mice HC diet alone does not alter the microbiota composition despite inducing substantial adaptive changes in whole body cholesterol homeostasis. The impact of Western diet on intestinal microbiota thus appears to be mediated exclusively by its high fat content. Electronic supplementary material The online version of this article (doi:10.1186/s12986-017-0170-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lidiya G Dimova
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Nikola Zlatkov
- Laboratory for Molecular Infection Medicine Sweden (MIMS) and Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Henkjan J Verkade
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Bernt Eric Uhlin
- Laboratory for Molecular Infection Medicine Sweden (MIMS) and Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Uwe J F Tietge
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
72
|
Dugardin C, Briand O, Touche V, Schonewille M, Moreau F, Le May C, Groen AK, Staels B, Lestavel S. Retrograde cholesterol transport in the human Caco-2/TC7 cell line: a model to study trans-intestinal cholesterol excretion in atherogenic and diabetic dyslipidemia. Acta Diabetol 2017; 54:191-199. [PMID: 27796655 DOI: 10.1007/s00592-016-0936-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022]
Abstract
AIMS The dyslipidemia associated with type 2 diabetes is a major risk factor for the development of atherosclerosis. Trans-intestinal cholesterol excretion (TICE) has recently been shown to contribute, together with the classical hepatobiliary route, to fecal cholesterol excretion and cholesterol homeostasis. The aim of this study was to develop an in vitro cell model to investigate enterocyte-related processes of TICE. METHODS Differentiated Caco-2/TC7 cells were grown on transwells and incubated basolaterally (blood side) with human plasma and apically (luminal side) with lipid micelles. Radioactive and fluorescent cholesterol tracers were used to investigate cholesterol uptake at the basolateral membrane, intracellular distribution and apical excretion. RESULTS Our results show that cholesterol is taken up at the basolateral membrane, accumulates intracellularly as lipid droplets and undergoes a cholesterol acceptor-facilitated and progressive excretion through the apical membrane of enterocytes. The overall process is abolished at 4 °C, suggesting a biologically active phenomenon. Moreover, this trans-enterocytic retrograde cholesterol transport displays some TICE features like modulation by PCSK9 and an ABCB1 inhibitor. Finally, we highlight the involvement of microtubules in the transport of plasma cholesterol from basolateral to apical pole of enterocytes. CONCLUSIONS The human Caco-2/TC7 cell line appears a good in vitro model to investigate the enterocytic molecular mechanisms of TICE, which may help to identify intestinal molecular targets to enhance reverse cholesterol transport and fight against dyslipidemia.
Collapse
Affiliation(s)
- Camille Dugardin
- Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France
| | - Olivier Briand
- Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France
| | - Véronique Touche
- Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France
| | - Marleen Schonewille
- University Medical Center Groningen, Department of Pediatrics, University of Groningen, Groningen, The Netherlands
| | | | - Cédric Le May
- INSERM, UMR 1087, CNRS UMR 6291, 44000, Nantes, France
| | - Albert K Groen
- University Medical Center Groningen, Department of Pediatrics, University of Groningen, Groningen, The Netherlands
- Academic Medical Center, Amsterdam, The Netherlands
| | - Bart Staels
- Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France.
| | - Sophie Lestavel
- Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Univ. Lille, 59000, Lille, France
| |
Collapse
|
73
|
Jakulj L, van Dijk TH, de Boer JF, Kootte RS, Schonewille M, Paalvast Y, Boer T, Bloks VW, Boverhof R, Nieuwdorp M, Beuers UHW, Stroes ESG, Groen AK. Transintestinal Cholesterol Transport Is Active in Mice and Humans and Controls Ezetimibe-Induced Fecal Neutral Sterol Excretion. Cell Metab 2016; 24:783-794. [PMID: 27818259 DOI: 10.1016/j.cmet.2016.10.001] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 05/09/2016] [Accepted: 09/30/2016] [Indexed: 01/10/2023]
Abstract
Except for conversion to bile salts, there is no major cholesterol degradation pathway in mammals. Efficient excretion from the body is therefore a crucial element in cholesterol homeostasis. Yet, the existence and importance of cholesterol degradation pathways in humans is a matter of debate. We quantified cholesterol fluxes in 15 male volunteers using a cholesterol balance approach. Ten participants repeated the protocol after 4 weeks of treatment with ezetimibe, an inhibitor of intestinal and biliary cholesterol absorption. Under basal conditions, about 65% of daily fecal neutral sterol excretion was bile derived, with the remainder being contributed by direct transintestinal cholesterol excretion (TICE). Surprisingly, ezetimibe induced a 4-fold increase in cholesterol elimination via TICE. Mouse studies revealed that most of ezetimibe-induced TICE flux is mediated by the cholesterol transporter Abcg5/Abcg8. In conclusion, TICE is active in humans and may serve as a novel target to stimulate cholesterol elimination in patients at risk for cardiovascular disease.
Collapse
Affiliation(s)
- Lily Jakulj
- Department of Vascular Medicine, Academic Medical Center, Amsterdam 1105AZ, the Netherlands
| | - Theo H van Dijk
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Jan Freark de Boer
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Ruud S Kootte
- Department of Vascular Medicine, Academic Medical Center, Amsterdam 1105AZ, the Netherlands
| | - Marleen Schonewille
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Yared Paalvast
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Theo Boer
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Vincent W Bloks
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Renze Boverhof
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands
| | - Max Nieuwdorp
- Department of Vascular Medicine, Academic Medical Center, Amsterdam 1105AZ, the Netherlands
| | - Ulrich H W Beuers
- Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam 1105AZ, the Netherlands
| | - Erik S G Stroes
- Department of Vascular Medicine, Academic Medical Center, Amsterdam 1105AZ, the Netherlands
| | - Albert K Groen
- Department of Vascular Medicine, Academic Medical Center, Amsterdam 1105AZ, the Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands; Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen 9713ZG, the Netherlands; Amsterdam Diabetes Research Center, Academic Medical Center, Amsterdam 1105AZ, the Netherlands; Groningen Center of Systems Biology, University Medical Center Groningen, Groningen 9713ZG, the Netherlands.
| |
Collapse
|
74
|
Panneerselvam S, Packirisamy RM, Bobby Z, Elizabeth Jacob S, Sridhar MG. Soy isoflavones ( Glycine max ) ameliorate hypertriglyceridemia and hepatic steatosis in high fat-fed ovariectomized Wistar rats (an experimental model of postmenopausal obesity). J Nutr Biochem 2016; 38:57-69. [DOI: 10.1016/j.jnutbio.2016.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 05/23/2016] [Accepted: 08/10/2016] [Indexed: 10/21/2022]
|
75
|
Ronda OAHO, van Dijk TH, Verkade HJ, Groen AK. Measurement of Intestinal and Peripheral Cholesterol Fluxes by a Dual-Tracer Balance Method. ACTA ACUST UNITED AC 2016; 6:408-434. [PMID: 27906461 DOI: 10.1002/cpmo.16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Long-term elevated plasma cholesterol levels put individuals at risk for developing atherosclerosis. Plasma cholesterol levels are determined by the balance between cholesterol input and output fluxes. Here we describe in detail the methodology to determine the different cholesterol fluxes in mice. The percentage of absorbed cholesterol is calculated from a stable isotope-based double-label method. Cholesterol synthesis is calculated from MIDA after 13 C-acetate enrichment. Cholesterol is removed from the body via the feces. The fecal excretion route is either biliary or non-biliary. The non-biliary route is dominated by trans-intestinal cholesterol efflux, or TICE. Biliary excretion of cholesterol is measured by collecting bile. Non-biliary excretion is calculated by computational modeling. In this article, we describe methods and procedures to measure and calculate dietary intake of cholesterol, fractional cholesterol absorption, fecal neutral sterol output, biliary cholesterol excretion, TICE, cholesterol synthesis, peripheral fluxes, and whole-body cholesterol balance. © 2016 by John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- Onne A H O Ronda
- Center for Liver, Digestive and Metabolic Diseases, Departments of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Laboratory Medicine, Center for Liver Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - H J Verkade
- Center for Liver, Digestive and Metabolic Diseases, Departments of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Laboratory Medicine, Center for Liver Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Amsterdam Diabetes Center, Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
76
|
Kikuchi T, Orihara K, Oikawa F, Han SI, Kuba M, Okuda K, Satoh A, Osaki Y, Takeuchi Y, Aita Y, Matsuzaka T, Iwasaki H, Yatoh S, Sekiya M, Yahagi N, Suzuki H, Sone H, Nakagawa Y, Yamada N, Shimano H. Intestinal CREBH overexpression prevents high-cholesterol diet-induced hypercholesterolemia by reducing Npc1l1 expression. Mol Metab 2016; 5:1092-1102. [PMID: 27818935 PMCID: PMC5081412 DOI: 10.1016/j.molmet.2016.09.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/06/2016] [Accepted: 09/10/2016] [Indexed: 12/12/2022] Open
Abstract
Objective The transcription factor cyclic AMP-responsive element-binding protein H (CREBH, encoded by Creb3l3) is highly expressed in the liver and small intestine. Hepatic CREBH contributes to glucose and triglyceride metabolism by regulating fibroblast growth factor 21 (Fgf21) expression. However, the intestinal CREBH function remains unknown. Methods To investigate the influence of intestinal CREBH on cholesterol metabolism, we compared plasma, bile, fecal, and tissue cholesterol levels between wild-type (WT) mice and mice overexpressing active human CREBH mainly in the small intestine (CREBH Tg mice) under different dietary conditions. Results Plasma cholesterol, hepatic lipid, and cholesterol crystal formation in the gallbladder were lower in CREBH Tg mice fed a lithogenic diet (LD) than in LD-fed WTs, while fecal cholesterol output was higher in the former. These results suggest that intestinal CREBH overexpression suppresses cholesterol absorption, leading to reduced plasma cholesterol, limited hepatic supply, and greater excretion. The expression of Niemann–Pick C1-like 1 (Npc1l1), a rate-limiting transporter mediating intestinal cholesterol absorption, was reduced in the small intestine of CREBH Tg mice. Adenosine triphosphate-binding cassette transporter A1 (Abca1), Abcg5/8, and scavenger receptor class B, member 1 (Srb1) expression levels were also reduced in CREBH Tg mice. Promoter assays revealed that CREBH directly regulates Npc1l1 expression. Conversely, CREBH null mice exhibited higher intestinal Npc1l1 expression, elevated plasma and hepatic cholesterol, and lower fecal output. Conclusion Intestinal CREBH regulates dietary cholesterol flow from the small intestine by controlling the expression of multiple intestinal transporters. We propose that intestinal CREBH could be a therapeutic target for hypercholesterolemia. Plasma cholesterol, hepatic lipid, and gallstones were lower in CREBH Tg mice. Expression of intestinal Npc1l1 was reduced in CREBH Tg mice. CREBH directly down-regulates mouse Npc1l1 promoter activity. Intestinal CREBH regulates dietary cholesterol flow from the small intestine.
Collapse
Key Words
- ABCG5/8, adenosine triphosphate-binding cassette transporter G5/G8
- ALT, alanine aminotransferase
- AST, aspartate aminotransferase
- Abca1, ATP-binding cassette, sub-family A1
- Apoa4, apolipoprotein A-IV
- CREBH
- CREBH, cyclic AMP-responsive element-binding protein H
- Cholesterol
- Cpt1a, carnitine palmitoyltransferase 1a, liver
- Cyp7a1, cytochrome P450, family 7, subfamily a, polypeptide 1
- ER, endoplasmic reticulum
- FGF21, fibroblast growth factor 21
- FXR, Farnesoid X receptor
- Intestine
- LD, lithogenic diet
- LPL, lipoprotein lipase
- LXR, liver X receptor
- NEFA, non-esterified fatty acids
- NPC1L1, Nieman Pick C1-like 1
- Npc1l1
- PPARα, proliferator activated receptor alpha
- RCT, reverse cholesterol transport
- SREBP, sterol regulatory element-binding protein
- Shp, small heterodimer partner
- Srb1, scavenger receptor class B, member 1
- Srebf, sterol regulatory element-binding factor
- TG, triglyceride
- WT, wild type
Collapse
Affiliation(s)
- Takuya Kikuchi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kana Orihara
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Fusaka Oikawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Song-Iee Han
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Motoko Kuba
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kanako Okuda
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Aoi Satoh
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshinori Osaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshinori Takeuchi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuichi Aita
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Takashi Matsuzaka
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Iwasaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Shigeru Yatoh
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Motohiro Sekiya
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Naoya Yahagi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroaki Suzuki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Hirohito Sone
- Department of Hematology, Endocrinology and Metabolism, Niigata University Faculty of Medicine, Niigata, Niigata 951-8510, Japan
| | - Yoshimi Nakagawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
| | - Nobuhiro Yamada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan; Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba 305-8577, Japan.
| |
Collapse
|
77
|
Stöger JL, Boshuizen MCS, Brufau G, Gijbels MJJ, Wolfs IMJ, van der Velden S, Pöttgens CCH, Vergouwe MN, Wijnands E, Beckers L, Goossens P, Kerksiek A, Havinga R, Müller W, Lütjohann D, Groen AK, de Winther MPJ. Deleting myeloid IL-10 receptor signalling attenuates atherosclerosis in LDLR-/- mice by altering intestinal cholesterol fluxes. Thromb Haemost 2016; 116:565-77. [PMID: 27358035 DOI: 10.1160/th16-01-0043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/25/2016] [Indexed: 12/27/2022]
Abstract
Inflammatory responses and cholesterol homeostasis are interconnected in atherogenesis. Interleukin (IL)-10 is an important anti-inflammatory cytokine, known to suppress atherosclerosis development. However, the specific cell types responsible for the atheroprotective effects of IL-10 remain to be defined and knowledge on the actions of IL-10 in cholesterol homeostasis is scarce. Here we investigated the functional involvement of myeloid IL-10-mediated atheroprotection. To do so, bone marrow from IL-10 receptor 1 (IL-10R1) wild-type and myeloid IL-10R1-deficient mice was transplanted to lethally irradiated female LDLR-/- mice. Hereafter, mice were given a high cholesterol diet for 10 weeks after which atherosclerosis development and cholesterol metabolism were investigated. In vitro, myeloid IL-10R1 deficiency resulted in a pro-inflammatory macrophage phenotype. However, in vivo significantly reduced lesion size and severity was observed. This phenotype was associated with lower myeloid cell accumulation and more apoptosis in the lesions. Additionally, a profound reduction in plasma and liver cholesterol was observed upon myeloid IL-10R1 deficiency, which was reflected in plaque lipid content. This decreased hypercholesterolaemia was associated with lowered very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) levels, likely as a response to decreased intestinal cholesterol absorption. In addition, IL-10R1 deficient mice demonstrated substantially higher faecal sterol loss caused by increased non-biliary cholesterol efflux. The induction of this process was linked to impaired ACAT2-mediated esterification of liver and plasma cholesterol. Overall, myeloid cells do not contribute to IL-10-mediated atheroprotection. In addition, this study demonstrates a novel connection between IL-10-mediated inflammation and cholesterol homeostasis in atherosclerosis. These findings make us reconsider IL-10 as a beneficial influence on atherosclerosis.
Collapse
MESH Headings
- Animals
- Apoptosis
- Atherosclerosis/etiology
- Atherosclerosis/metabolism
- Atherosclerosis/prevention & control
- Biological Transport, Active
- Cholesterol/metabolism
- Cholesterol, Dietary/administration & dosage
- Disease Models, Animal
- Female
- Hypercholesterolemia/prevention & control
- Inflammation/etiology
- Inflammation/metabolism
- Inflammation/pathology
- Intestinal Mucosa/metabolism
- Macrophages/metabolism
- Macrophages/pathology
- Mice
- Mice, Knockout
- Myeloid Cells/metabolism
- Myeloid Cells/pathology
- Plaque, Atherosclerotic/etiology
- Plaque, Atherosclerotic/metabolism
- Plaque, Atherosclerotic/pathology
- Receptors, Interleukin-10/deficiency
- Receptors, Interleukin-10/genetics
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Signal Transduction
- Sterol O-Acyltransferase/metabolism
- Sterol O-Acyltransferase 2
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Menno P J de Winther
- Prof. M. P. J. de Winther, PhD, Experimental Vascular Biology, Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands, Tel.: +31 20 5666762, E-mail:
| |
Collapse
|
78
|
Lavoie JM. Dynamics of hepatic and intestinal cholesterol and bile acid pathways: The impact of the animal model of estrogen deficiency and exercise training. World J Hepatol 2016; 8:961-975. [PMID: 27621762 PMCID: PMC4990760 DOI: 10.4254/wjh.v8.i23.961] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/25/2016] [Accepted: 07/18/2016] [Indexed: 02/06/2023] Open
Abstract
Plasma cholesterol level is determined by a complex dynamics that involves transport lipoproteins which levels are tightly dependent on how the liver and the intestine regulate cholesterol and biliary acid metabolism. Regulation of cholesterol and biliary acids by the liver and the intestine is in turn coupled to a large array of enzymes and transporters that largely influence the inflow and the outflow of cholesterol and biliary acids through these organs. The activity of the key regulators of cholesterol and biliary acids may be influenced by several external factors such as pharmacological drugs and the nutritional status. In recent years, more information has been gathered about the impact of estrogens on regulation of cholesterol in the body. Exposure to high levels of estrogens has been reported to promote cholesterol gallstone formation and women are twice as likely as men to develop cholesterol gallstones. The impact of estrogen withdrawal, such as experienced by menopausal women, is therefore of importance and more information on how the absence of estrogens influence cholesterol regulation is started to come out, especially through the use of animal models. An interesting alternative to metabolic deterioration due to estrogen deficiency is exercise training. The present review is intended to summarize the present information that links key regulators of cholesterol and biliary acid pathways in liver and intestine to the absence of estrogens in an animal model and to discuss the potential role of exercise training as an alternative.
Collapse
|
79
|
Hypocholesterolaemic Activity of Lupin Peptides: Investigation on the Crosstalk between Human Enterocytes and Hepatocytes Using a Co-Culture System Including Caco-2 and HepG2 Cells. Nutrients 2016; 8:nu8070437. [PMID: 27455315 PMCID: PMC4963913 DOI: 10.3390/nu8070437] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/07/2016] [Accepted: 07/14/2016] [Indexed: 12/22/2022] Open
Abstract
Literature indicates that peptic and tryptic peptides derived from the enzymatic hydrolysis of lupin protein are able to modulate cholesterol metabolism in human hepatic HepG2 cells and that part of these peptides are absorbed in a small intestine model based on differentiated human Caco-2 cells. In this paper, a co-culture system, including Caco-2 and HepG2 cells, was investigated with two objectives: (a) to verify whether cholesterol metabolism in HepG2 cells was modified by the peptides absorption through Caco-2 cells; (b) to investigate how lupin peptides influence cholesterol metabolism in Caco-2 cells. The experiments showed that the absorbed peptides, not only maintained their bioactivity on HepG2 cells, but that this activity was improved by the crosstalk of the two cells systems in co-culture. In addition, lupin peptides showed a positive influence on cholesterol metabolism in Caco-2 cells, decreasing the proprotein convertase subtilisin/kexin type 9 (PCSK9) secretion.
Collapse
|
80
|
Sachdev V, Leopold C, Bauer R, Patankar JV, Iqbal J, Obrowsky S, Boverhof R, Doktorova M, Scheicher B, Goeritzer M, Kolb D, Turnbull AV, Zimmer A, Hoefler G, Hussain MM, Groen AK, Kratky D. Novel role of a triglyceride-synthesizing enzyme: DGAT1 at the crossroad between triglyceride and cholesterol metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1132-1141. [PMID: 27344248 PMCID: PMC4948681 DOI: 10.1016/j.bbalip.2016.06.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 06/13/2016] [Accepted: 06/22/2016] [Indexed: 12/13/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in triacylglycerol (TG) biosynthesis. Here we show that genetic deficiency and pharmacological inhibition of DGAT1 in mice alters cholesterol metabolism. Cholesterol absorption, as assessed by acute cholesterol uptake, was significantly decreased in the small intestine and liver upon DGAT1 deficiency/inhibition. Ablation of DGAT1 in the intestine (I-DGAT1−/−) alone is sufficient to cause these effects. Consequences of I-DGAT1 deficiency phenocopy findings in whole-body DGAT1−/− and DGAT1 inhibitor-treated mice. We show that deficiency/inhibition of DGAT1 affects cholesterol metabolism via reduced chylomicron size and increased trans-intestinal cholesterol excretion. These effects are independent of cholesterol uptake at the apical surface of enterocytes but mediated through altered dietary fatty acid metabolism. Our findings provide insight into a novel role of DGAT1 and identify a pathway by which intestinal DGAT1 deficiency affects whole-body cholesterol homeostasis in mice. Targeting intestinal DGAT1 may represent a novel approach for treating hypercholesterolemia.
Collapse
Affiliation(s)
- Vinay Sachdev
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Raimund Bauer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Jay V Patankar
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Jahangir Iqbal
- Department of Cell Biology, SUNY Downstate Medical Center, 11203 New York, United States
| | - Sascha Obrowsky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Renze Boverhof
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Marcela Doktorova
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Bernhard Scheicher
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Madeleine Goeritzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Dagmar Kolb
- Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, 8010 Graz, Austria
| | | | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria
| | - Gerald Hoefler
- Institute of Pathology, Medical University of Graz, 8010 Graz, Austria
| | - M Mahmood Hussain
- Department of Cell Biology, SUNY Downstate Medical Center, 11203 New York, United States
| | - Albert K Groen
- Departments of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria.
| |
Collapse
|
81
|
Schonewille M, de Boer JF, Mele L, Wolters H, Bloks VW, Wolters JC, Kuivenhoven JA, Tietge UJF, Brufau G, Groen AK. Statins increase hepatic cholesterol synthesis and stimulate fecal cholesterol elimination in mice. J Lipid Res 2016; 57:1455-64. [PMID: 27313057 DOI: 10.1194/jlr.m067488] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Indexed: 12/19/2022] Open
Abstract
Statins are competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme of cholesterol synthesis. Statins reduce plasma cholesterol levels, but whether this is actually caused by inhibition of de novo cholesterol synthesis has not been clearly established. Using three different statins, we investigated the effects on cholesterol metabolism in mice in detail. Surprisingly, direct measurement of whole body cholesterol synthesis revealed that cholesterol synthesis was robustly increased in statin-treated mice. Measurement of organ-specific cholesterol synthesis demonstrated that the liver is predominantly responsible for the increase in cholesterol synthesis. Excess synthesized cholesterol did not accumulate in the plasma, as plasma cholesterol decreased. However, statin treatment led to an increase in cholesterol removal via the feces. Interestingly, enhanced cholesterol excretion in response to rosuvastatin and lovastatin treatment was mainly mediated via biliary cholesterol secretion, whereas atorvastatin mainly stimulated cholesterol removal via the transintestinal cholesterol excretion pathway. Moreover, we show that plasma cholesterol precursor levels do not reflect cholesterol synthesis rates during statin treatment in mice. In conclusion, cholesterol synthesis is paradoxically increased upon statin treatment in mice. However, statins potently stimulate the excretion of cholesterol from the body, which sheds new light on possible mechanisms underlying the cholesterol-lowering effects of statins.
Collapse
Affiliation(s)
- Marleen Schonewille
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan Freark de Boer
- Department of Pediatrics, Section Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Laura Mele
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Henk Wolters
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Vincent W Bloks
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Justina C Wolters
- Department of Pediatrics, Section Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan A Kuivenhoven
- Department of Pediatrics, Section Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gemma Brufau
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Department of Laboratory Medicine, Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Amsterdam Diabetes Center, Department of Vascular Medicine, Academic Medical Center, The Netherlands
| |
Collapse
|
82
|
Meriwether D, Sulaiman D, Wagner A, Grijalva V, Kaji I, Williams KJ, Yu L, Fogelman S, Volpe C, Bensinger SJ, Anantharamaiah GM, Shechter I, Fogelman AM, Reddy ST. Transintestinal transport of the anti-inflammatory drug 4F and the modulation of transintestinal cholesterol efflux. J Lipid Res 2016; 57:1175-93. [PMID: 27199144 DOI: 10.1194/jlr.m067025] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Indexed: 01/28/2023] Open
Abstract
The site and mechanism of action of the apoA-I mimetic peptide 4F are incompletely understood. Transintestinal cholesterol efflux (TICE) is a process involved in the clearance of excess cholesterol from the body. While TICE is responsible for at least 30% of the clearance of neutral sterols from the circulation into the intestinal lumen, few pharmacological agents have been identified that modulate this pathway. We show first that circulating 4F selectively targets the small intestine (SI) and that it is predominantly transported into the intestinal lumen. This transport of 4F into the SI lumen is transintestinal in nature, and it is modulated by TICE. We also show that circulating 4F increases reverse cholesterol transport from macrophages and cholesterol efflux from lipoproteins via the TICE pathway. We identify the cause of this modulation of TICE either as 4F being a cholesterol acceptor with respect to enterocytes, from which 4F enhances cholesterol efflux, or as 4F being an intestinal chaperone with respect to TICE. Our results assign a novel role for 4F as a modulator of the TICE pathway and suggest that the anti-inflammatory functions of 4F may be a partial consequence of the codependent intestinal transport of both 4F and cholesterol.
Collapse
Affiliation(s)
- David Meriwether
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA Department of Medical and Molecular Pharmacology, University of California Los Angeles, Los Angeles, CA
| | - Dawoud Sulaiman
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA Molecular Toxicology Interdepartmental Degree Program, University of California Los Angeles, Los Angeles, CA
| | - Alan Wagner
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Victor Grijalva
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Izumi Kaji
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Kevin J Williams
- Department of Medical and Molecular Pharmacology, University of California Los Angeles, Los Angeles, CA
| | - Liqing Yu
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD
| | - Spencer Fogelman
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Carmen Volpe
- Division of Laboratory Animal Medicine, University of California Los Angeles, Los Angeles, CA
| | - Steven J Bensinger
- Department of Medical and Molecular Pharmacology, University of California Los Angeles, Los Angeles, CA Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA
| | - G M Anantharamaiah
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Ishaiahu Shechter
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Alan M Fogelman
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Srinivasa T Reddy
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA Department of Medical and Molecular Pharmacology, University of California Los Angeles, Los Angeles, CA Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| |
Collapse
|
83
|
Zhao D. Challenges associated with elucidating the mechanisms of the hypocholesterolaemic activity of saponins. J Funct Foods 2016. [DOI: 10.1016/j.jff.2016.02.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
|
84
|
Marsch E, Demandt JAF, Theelen TL, Tullemans BME, Wouters K, Boon MR, van Dijk TH, Gijbels MJ, Dubois LJ, Meex SJR, Mazzone M, Hung G, Fisher EA, Biessen EAL, Daemen MJAP, Rensen PCN, Carmeliet P, Groen AK, Sluimer JC. Deficiency of the oxygen sensor prolyl hydroxylase 1 attenuates hypercholesterolaemia, atherosclerosis, and hyperglycaemia. Eur Heart J 2016; 37:2993-2997. [PMID: 27125949 PMCID: PMC5081036 DOI: 10.1093/eurheartj/ehw156] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/04/2016] [Accepted: 03/23/2016] [Indexed: 12/22/2022] Open
Abstract
AIMS Normalization of hypercholesterolaemia, inflammation, hyperglycaemia, and obesity are main desired targets to prevent cardiovascular clinical events. Here we present a novel regulator of cholesterol metabolism, which simultaneously impacts on glucose intolerance and inflammation. METHODS AND RESULTS Mice deficient for oxygen sensor HIF-prolyl hydroxylase 1 (PHD1) were backcrossed onto an atherogenic low-density lipoprotein receptor (LDLR) knockout background and atherosclerosis was studied upon 8 weeks of western-type diet. PHD1-/-LDLR-/- mice presented a sharp reduction in VLDL and LDL plasma cholesterol levels. In line, atherosclerotic plaque development, as measured by plaque area, necrotic core expansion and plaque stage was hampered in PHD1-/-LDLR-/- mice. Mechanistically, cholesterol-lowering in PHD1 deficient mice was a result of enhanced cholesterol excretion from blood to intestines and ultimately faeces. Additionally, flow cytometry of whole blood of these mice revealed significantly reduced counts of leucocytes and particularly of Ly6Chigh pro-inflammatory monocytes. In addition, when studying PHD1-/- in diet-induced obesity (14 weeks high-fat diet) mice were less glucose intolerant when compared with WT littermate controls. CONCLUSION Overall, PHD1 knockout mice display a metabolic phenotype that generally is deemed protective for cardiovascular disease. Future studies should focus on the efficacy, safety, and gender-specific effects of PHD1 inhibition in humans, and unravel the molecular actors responsible for PHD1-driven, likely intestinal, and regulation of cholesterol metabolism.
Collapse
Affiliation(s)
- Elke Marsch
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands
| | - Jasper A F Demandt
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands
| | - Thomas L Theelen
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands
| | - Bibian M E Tullemans
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands
| | - Kristiaan Wouters
- Department of Internal Medicine, CARIM, Maastricht University, Maastricht, The Netherlands
| | - Mariëtte R Boon
- Department of Human Biology, Maastricht University, Maastricht, The Netherlands.,Department of Medicine, Division of Endocrinology and Einthoven Laboratory for Experimental Vascular Medicine, LUMC, Leiden, The Netherlands
| | - Theo H van Dijk
- Department of Pediatrics/Laboratory Medicine, UMCG, Groningen, The Netherlands
| | - Marion J Gijbels
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands.,Department of Molecular Genetics, Maastricht University, Maastricht, The Netherlands.,Department of Medical Biochemistry, AMC, Amsterdam, The Netherlands
| | - Ludwig J Dubois
- Department of Radiation Oncology, MUMC, Maastricht, The Netherlands
| | - Steven J R Meex
- Department of Clinical Chemistry, MUMC, Maastricht, The Netherlands
| | - Massimiliano Mazzone
- Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, VIB, Leuven, Belgium.,Laboratory of Molecular Oncology and Angiogenesis, Vesalius Research Center, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Gene Hung
- ISIS Pharmaceuticals, Inc., Carlsbad, USA
| | | | - Erik A L Biessen
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands.,Institute for Cardiovascular Research, RWTH Aachen University, Aachen, Germany
| | | | - Patrick C N Rensen
- Department of Medicine, Division of Endocrinology and Einthoven Laboratory for Experimental Vascular Medicine, LUMC, Leiden, The Netherlands
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, VIB, Leuven, Belgium.,Laboratory of Angiogenesis and Neurovascular Link, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Albert K Groen
- Department of Pediatrics/Laboratory Medicine, UMCG, Groningen, The Netherlands
| | - Judith C Sluimer
- Department of Pathology, CARIM, MUMC, P. Debyelaan 25, Maastricht 6229 HX, The Netherlands
| |
Collapse
|
85
|
Lee-Rueckert M, Escola-Gil JC, Kovanen PT. HDL functionality in reverse cholesterol transport--Challenges in translating data emerging from mouse models to human disease. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:566-83. [PMID: 26968096 DOI: 10.1016/j.bbalip.2016.03.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 02/26/2016] [Accepted: 03/04/2016] [Indexed: 12/18/2022]
Abstract
Whereas LDL-derived cholesterol accumulates in atherosclerotic lesions, HDL particles are thought to facilitate removal of cholesterol from the lesions back to the liver thereby promoting its fecal excretion from the body. Because generation of cholesterol-loaded macrophages is inherent to atherogenesis, studies on the mechanisms stimulating the release of cholesterol from these cells and its ultimate excretion into feces are crucial to learn how to prevent lesion development or even induce lesion regression. Modulation of this key anti-atherogenic pathway, known as the macrophage-specific reverse cholesterol transport, has been extensively studied in several mouse models with the ultimate aim of applying the emerging knowledge to humans. The present review provides a detailed comparison and critical analysis of the various steps of reverse cholesterol transport in mouse and man. We attempt to translate this in vivo complex scenario into practical concepts, which could serve as valuable tools when developing novel HDL-targeted therapies.
Collapse
|
86
|
Warrier M, Zhang J, Bura K, Kelley K, Wilson MD, Rudel LL, Brown JM. Sterol O-Acyltransferase 2-Driven Cholesterol Esterification Opposes Liver X Receptor-Stimulated Fecal Neutral Sterol Loss. Lipids 2016; 51:151-7. [PMID: 26729489 PMCID: PMC5221701 DOI: 10.1007/s11745-015-4116-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/18/2015] [Indexed: 11/28/2022]
Abstract
Statin drugs have proven a successful and relatively safe therapy for the treatment of atherosclerotic cardiovascular disease (CVD). However, even with the substantial low-density lipoprotein (LDL) cholesterol lowering achieved with statin treatment, CVD remains the top cause of death in developed countries. Selective inhibitors of the cholesterol esterifying enzyme sterol-O acyltransferase 2 (SOAT2) hold great promise as effective CVD therapeutics. In mouse models, previous work has demonstrated that either antisense oligonucleotide (ASO) or small molecule inhibitors of SOAT2 can effectively reduce CVD progression, and even promote regression of established CVD. Although it is well known that SOAT2-driven cholesterol esterification can alter both the packaging and retention of atherogenic apoB-containing lipoproteins, here we set out to determine whether SOAT2-driven cholesterol esterification can also impact basal and liver X receptor (LXR)-stimulated fecal neutral sterol loss. These studies demonstrate that SOAT2 is a negative regulator of LXR-stimulated fecal neutral sterol loss in mice.
Collapse
Affiliation(s)
- Manya Warrier
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Jun Zhang
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Kanwardeep Bura
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Kathryn Kelley
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Martha D Wilson
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Lawrence L Rudel
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - J Mark Brown
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA.
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
| |
Collapse
|
87
|
Korach-André M, Gustafsson JÅ. Liver X receptors as regulators of metabolism. Biomol Concepts 2016; 6:177-90. [PMID: 25945723 DOI: 10.1515/bmc-2015-0007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 04/01/2015] [Indexed: 11/15/2022] Open
Abstract
The liver X receptors (LXR) are crucial regulators of metabolism. After ligand binding, they regulate gene transcription and thereby mediate changes in metabolic pathways. Modulation of LXR and their downstream targets has appeared to be a promising treatment for metabolic diseases especially atherosclerosis and cholesterol metabolism. However, the complexity of LXR action in various metabolic tissues and the liver side effect of LXR activation have slowed down the interest for LXR drugs. In this review, we summarized the role of LXR in the main metabolically active tissues with a special focus on obesity and associated diseases in mammals. We will also discuss the dual interplay between the two LXR isoforms suggesting that they may collaborate to establish a fine and efficient system for the maintenance of metabolism homeostasis.
Collapse
|
88
|
Dikkers A, de Boer JF, Groen AK, Tietge UJF. Hepatic ABCG5/G8 overexpression substantially increases biliary cholesterol secretion but does not impact in vivo macrophage-to-feces RCT. Atherosclerosis 2015; 243:402-6. [PMID: 26520893 DOI: 10.1016/j.atherosclerosis.2015.10.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 09/30/2015] [Accepted: 10/05/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND AIMS Biliary cholesterol secretion is important for reverse cholesterol transport (RCT). ABCG5/G8 contribute most cholesterol mass secretion into bile. We investigated the impact of hepatic ABCG5/G8 on cholesterol metabolism and RCT. METHODS Biliary and fecal sterol excretion (FSE) as well as RCT were determined using wild-type controls, Abcg8 knockout mice, Abcg8 knockouts with adenovirus-mediated hepatocyte-specific Abcg8 reinstitution and hepatic Abcg5/g8 overexpression in wild-types. RESULTS In Abcg8 knockouts, biliary cholesterol secretion was decreased by 75% (p < 0.001), while mass FSE and RCT were unchanged. Hepatic reinstitution of Abcg8 increased biliary cholesterol secretion 5-fold (p < 0.001) without changing FSE or overall RCT. Overexpression of both ABCG5/G8 elevated biliary cholesterol secretion 5-fold and doubled FSE (p < 0.001) without affecting overall RCT. CONCLUSIONS ABCG5/G8 mediate mass biliary cholesterol secretion but not from a RCT-relevant pool. Intervention strategies aiming at increasing hepatic Abcg5/g8 expression for enhancing RCT are not likely to be successful.
Collapse
Affiliation(s)
- Arne Dikkers
- Department of Pediatrics, The University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Freark de Boer
- Department of Pediatrics, The University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics, The University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, The University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics, The University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| |
Collapse
|
89
|
Lee SD, Tontonoz P. Liver X receptors at the intersection of lipid metabolism and atherogenesis. Atherosclerosis 2015; 242:29-36. [PMID: 26164157 PMCID: PMC4546914 DOI: 10.1016/j.atherosclerosis.2015.06.042] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Stephen D Lee
- Howard Hughes Medical Institute, Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA
| | - Peter Tontonoz
- Howard Hughes Medical Institute, Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA.
| |
Collapse
|
90
|
Temel RE, Brown JM. A new model of reverse cholesterol transport: enTICEing strategies to stimulate intestinal cholesterol excretion. Trends Pharmacol Sci 2015; 36:440-51. [PMID: 25930707 DOI: 10.1016/j.tips.2015.04.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 03/31/2015] [Accepted: 04/06/2015] [Indexed: 01/02/2023]
Abstract
Cardiovascular disease (CVD) remains the largest cause of mortality in most developed countries. Although recent failed clinical trials and Mendelian randomization studies have called into question the high-density lipoprotein (HDL) hypothesis, it remains well accepted that stimulating the process of reverse cholesterol transport (RCT) can prevent or even regress atherosclerosis. The prevailing model for RCT is that cholesterol from the artery wall must be delivered to the liver where it is secreted into bile before leaving the body through fecal excretion. However, many studies have demonstrated that RCT can proceed through a non-biliary pathway known as transintestinal cholesterol excretion (TICE). The goal of this review is to discuss the current state of knowledge of the TICE pathway, with emphasis on points of therapeutic intervention.
Collapse
Affiliation(s)
- Ryan E Temel
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536-0509, USA.
| | - J Mark Brown
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA.
| |
Collapse
|
91
|
ABCG5/G8 deficiency in mice reduces dietary triacylglycerol and cholesterol transport into the lymph. Lipids 2015; 50:371-9. [PMID: 25676339 DOI: 10.1007/s11745-015-3995-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/01/2015] [Indexed: 10/24/2022]
Abstract
The adenosine triphosphate-binding cassette (ABC) transporter G5/G8 is critical in protecting the body from accumulating dietary plant sterols. Expressed in the liver and small intestine, it transports plant sterols into the biliary and intestinal lumens, thus promoting their excretion. The extent to which G5/G8 regulates cholesterol absorption remains unclear. G5/G8 is also implicated in reducing the absorption of dietary triacylglycerols (TAG) by unknown mechanisms. We hypothesized that G5/G8 suppresses the production of chylomicrons, and its deficiency would enhance the absorption of both dietary TAG and cholesterol. The aim of this study was to investigate the effects of G5/G8 deficiency on lipid uptake and secretion into the lymph under steady-state conditions. Surprisingly, compared with wild-type mice (WT) (n = 9), G5/G8 KO (n = 13) lymph fistula mice given a continuous intraduodenal infusion of [3H]-TAG and [14C]-cholesterol showed a significant (P < 0.05) reduction in lymphatic transport of both [(3)H]-TAG and [(14)C]-cholesterol, concomitant with a significant (P < 0.05) increase of [(3)H]-TAG and [(14)C]-cholesterol accumulated in the intestinal lumen. There was no difference in the total amount of radiolabeled lipids retained in the intestinal mucosa between the two groups. G5/G8 KO mice given a bolus of TAG showed reduced intestinal TAG secretion compared with WT, suggesting an independent role for G5/G8 in facilitating intestinal TAG transport. Our data demonstrate that G5/G8 deficiency reduces the uptake and secretion of both dietary TAG and cholesterol by the intestine, suggesting a novel role for the sterol transporter in the formation and secretion of chylomicrons.
Collapse
|
92
|
Wang Y, Liu X, Pijut SS, Li J, Horn J, Bradford EM, Leggas M, Barrett TA, Graf GA. The combination of ezetimibe and ursodiol promotes fecal sterol excretion and reveals a G5G8-independent pathway for cholesterol elimination. J Lipid Res 2015; 56:810-20. [PMID: 25635125 DOI: 10.1194/jlr.m053454] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies suggest an interdependent relationship between liver and intestine for cholesterol elimination from the body. We hypothesized that a combination of ursodiol (Urso) and ezetimibe (EZ) could increase biliary secretion and reduce cholesterol reabsorption, respectively, to promote cholesterol excretion. Treatment with Urso increased hepatic ABCG5 ABCG8 (G5G8) protein and both biliary and fecal sterols in a dose-dependent manner. To determine whether the drug combination (Urso-EZ) further increased cholesterol excretion, mice were treated with Urso alone or in combination with two doses of EZ. EZ produced an additive and dose-dependent increase in fecal neutral sterol (FNS) elimination in the presence of Urso. Finally, we sequentially treated wide-type and G5G8-deficient mice with Urso and Urso-EZ to determine the extent to which these effects were G5G8 dependent. Although biliary and FNS were invariably lower in G5G8 KO mice, the relative increase in FNS following treatment with Urso alone or the Urso-EZ combination was not affected by genotype. In conclusion, Urso increases G5G8, biliary cholesterol secretion, and FNS and acts additively with EZ to promote fecal sterol excretion. However, the stimulatory effect of these agents was not G5G8 dependent.
Collapse
Affiliation(s)
- Yuhuan Wang
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Xiaoxi Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Sonja S Pijut
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Jianing Li
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Jamie Horn
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Emily M Bradford
- Division of Gastroenterology, University of Kentucky, Lexington, KY
| | - Markos Leggas
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY Center for Pharmaceutical Research and Innovation, University of Kentucky, Lexington, KY
| | | | - Gregory A Graf
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY
| |
Collapse
|
93
|
Warrier M, Shih DM, Burrows AC, Ferguson D, Gromovsky AD, Brown AL, Marshall S, McDaniel A, Schugar RC, Wang Z, Sacks J, Rong X, Vallim TDA, Chou J, Ivanova PT, Myers DS, Brown HA, Lee RG, Crooke RM, Graham MJ, Liu X, Parini P, Tontonoz P, Lusis AJ, Hazen SL, Temel RE, Brown JM. The TMAO-Generating Enzyme Flavin Monooxygenase 3 Is a Central Regulator of Cholesterol Balance. Cell Rep 2015; 10:326-338. [PMID: 25600868 DOI: 10.1016/j.celrep.2014.12.036] [Citation(s) in RCA: 286] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 11/24/2014] [Accepted: 12/16/2014] [Indexed: 12/15/2022] Open
Abstract
Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here, we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT) and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic endoplasmic reticulum (ER) stress and inflammation in part by decreasing hepatic oxysterol levels and subsequent LXR activation. FMO3 is thus identified as a central integrator of hepatic cholesterol and triacylglycerol metabolism, inflammation, and ER stress. These studies suggest that the gut microbiota-driven TMA/FMO3/TMAO pathway is a key regulator of lipid metabolism and inflammation.
Collapse
Affiliation(s)
- Manya Warrier
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Diana M Shih
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Amy C Burrows
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Daniel Ferguson
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Anthony D Gromovsky
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Amanda L Brown
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Stephanie Marshall
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Allison McDaniel
- Departments of Pathology and Biostatistics, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Rebecca C Schugar
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Zeneng Wang
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Jessica Sacks
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Xin Rong
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | | | - Jeff Chou
- Departments of Pathology and Biostatistics, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Pavlina T Ivanova
- Departments of Pharmacology and Biochemistry, The Vanderbilt Institute of Chemical Biology, Nashville, TN 37232, USA
| | - David S Myers
- Departments of Pharmacology and Biochemistry, The Vanderbilt Institute of Chemical Biology, Nashville, TN 37232, USA
| | - H Alex Brown
- Departments of Pharmacology and Biochemistry, The Vanderbilt Institute of Chemical Biology, Nashville, TN 37232, USA
| | - Richard G Lee
- Cardiovascular Group, Antisense Drug Discovery, Isis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Rosanne M Crooke
- Cardiovascular Group, Antisense Drug Discovery, Isis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Mark J Graham
- Cardiovascular Group, Antisense Drug Discovery, Isis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Xiuli Liu
- Department of Anatomical Pathology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Paolo Parini
- Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet at Huddinge University Hospital, 141 86 Stockholm, Sweden
| | - Peter Tontonoz
- Howard Hughes Medical Institute; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Aldon J Lusis
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stanley L Hazen
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Ryan E Temel
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536-0509, USA
| | - J Mark Brown
- Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA.
| |
Collapse
|
94
|
Hepatic farnesoid X-receptor isoforms α2 and α4 differentially modulate bile salt and lipoprotein metabolism in mice. PLoS One 2014; 9:e115028. [PMID: 25506828 PMCID: PMC4266635 DOI: 10.1371/journal.pone.0115028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 11/17/2014] [Indexed: 12/23/2022] Open
Abstract
The nuclear receptor FXR acts as an intracellular bile salt sensor that regulates synthesis and transport of bile salts within their enterohepatic circulation. In addition, FXR is involved in control of a variety of crucial metabolic pathways. Four FXR splice variants are known, i.e. FXRα1-4. Although these isoforms show differences in spatial and temporal expression patterns as well as in transcriptional activity, the physiological relevance hereof has remained elusive. We have evaluated specific roles of hepatic FXRα2 and FXRα4 by stably expressing these isoforms using liver-specific self-complementary adeno-associated viral vectors in total body FXR knock-out mice. The hepatic gene expression profile of the FXR knock-out mice was largely normalized by both isoforms. Yet, differential effects were also apparent; FXRα2 was more effective in reducing elevated HDL levels and transrepressed hepatic expression of Cyp8b1, the regulator of cholate synthesis. The latter coincided with a switch in hydrophobicity of the bile salt pool. Furthermore, FXRα2-transduction caused an increased neutral sterol excretion compared to FXRα4 without affecting intestinal cholesterol absorption. Our data show, for the first time, that hepatic FXRα2 and FXRα4 differentially modulate bile salt and lipoprotein metabolism in mice.
Collapse
|
95
|
Hijmans BS, Tiemann CA, Grefhorst A, Boesjes M, van Dijk TH, Tietge UJF, Kuipers F, van Riel NAW, Groen AK, Oosterveer MH. A systems biology approach reveals the physiological origin of hepatic steatosis induced by liver X receptor activation. FASEB J 2014; 29:1153-64. [PMID: 25477282 DOI: 10.1096/fj.14-254656] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 11/05/2014] [Indexed: 12/12/2022]
Abstract
Liver X receptor (LXR) agonists exert potent antiatherosclerotic actions but simultaneously induce excessive triglyceride (TG) accumulation in the liver. To obtain a detailed insight into the underlying mechanism of hepatic TG accumulation, we used a novel computational modeling approach called analysis of dynamic adaptations in parameter trajectories (ADAPT). We revealed that both input and output fluxes to hepatic TG content are considerably induced on LXR activation and that in the early phase of LXR agonism, hepatic steatosis results from only a minor imbalance between the two. It is generally believed that LXR-induced hepatic steatosis results from increased de novo lipogenesis (DNL). In contrast, ADAPT predicted that the hepatic influx of free fatty acids is the major contributor to hepatic TG accumulation in the early phase of LXR activation. Qualitative validation of this prediction showed a 5-fold increase in the contribution of plasma palmitate to hepatic monounsaturated fatty acids on acute LXR activation, whereas DNL was not yet significantly increased. This study illustrates that complex effects of pharmacological intervention can be translated into distinct patterns of metabolic regulation through state-of-the-art mathematical modeling.
Collapse
Affiliation(s)
- Brenda S Hijmans
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Christian A Tiemann
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Aldo Grefhorst
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Marije Boesjes
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Folkert Kuipers
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Natal A W van Riel
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| | - Maaike H Oosterveer
- Departments of *Pediatrics and Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Netherlands Consortium for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands; and Groningen Centre for Systems Biology, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
96
|
Wang J, Mitsche MA, Lütjohann D, Cohen JC, Xie XS, Hobbs HH. Relative roles of ABCG5/ABCG8 in liver and intestine. J Lipid Res 2014; 56:319-30. [PMID: 25378657 PMCID: PMC4306686 DOI: 10.1194/jlr.m054544] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABCG5 (G5) and ABCG8 (G8) form a sterol transporter that acts in liver and intestine to prevent accumulation of dietary sterols. Mutations in either G5 or G8 cause sitosterolemia, a recessive disorder characterized by sterol accumulation and premature coronary atherosclerosis. Hepatic G5G8 mediates cholesterol excretion into bile, but the function and relative importance of intestinal G5G8 has not been defined. To determine the role of intestinal G5G8, we developed liver-specific (L-G5G8(-/-)), intestine-specific (I-G5G8(-/-)), and total (G5G8(-/-)) KO mice. Tissue levels of sitosterol, the most abundant plant sterol, were >90-fold higher in G5G8(-/-) mice than in WT animals. Expression of G5G8 only in intestine or only in liver decreased tissue sterol levels by 90% when compared with G5G8(-/-) animals. Biliary sterol secretion was reduced in L-G5G8(-/-) and G5G8(-/-) mice, but not in I-G5G8(-/-) mice. Conversely, absorption of plant sterols was increased in I-G5G8(-/-) and G5G8(-/-) mice, but not in L-G5G8(-/-) mice. Reverse cholesterol transport, as assessed from the fraction of intravenously administered (3)H-cholesterol that appeared in feces, was reduced in G5G8(-/-), I-G5G8(-/-), and L-G5G8(-/-) mice. Thus, G5G8 expression in both the liver and intestine protects animals from sterol accumulation, and intestinal G5G8 contributes to extrahepatic cholesterol efflux in mice.
Collapse
Affiliation(s)
- Jin Wang
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Matthew A Mitsche
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Dieter Lütjohann
- Department of Clinical Pharmacology, University of Bonn, D-53105 Bonn, Germany
| | - Jonathan C Cohen
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Xiao-Song Xie
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Helen H Hobbs
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390 Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390 Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| |
Collapse
|
97
|
Blanchard C, Moreau F, Cariou B, Le May C. [Trans-intestinal cholesterol excretion (TICE): a new route for cholesterol excretion]. Med Sci (Paris) 2014; 30:896-901. [PMID: 25311025 DOI: 10.1051/medsci/20143010017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The small intestine plays a crucial role in dietary and biliary cholesterol absorption, as well as its lymphatic secretion as chylomicrons (lipoprotein exogenous way). Recently, a new metabolic pathway called TICE (trans-intestinal excretion of cholesterol) that plays a central role in cholesterol metabolism has emerged. TICE is an inducible way, complementary to the hepatobiliary pathway, allowing the elimination of the plasma cholesterol directly into the intestine lumen through the enterocytes. This pathway is poorly characterized but several molecular actors of TICE have been recently identified. Although it is a matter of debate, two independent studies suggest that TICE is involved in the anti-atherogenic reverse cholesterol transport pathway. Thus, TICE is an innovative drug target to reduce -cardiovascular diseases.
Collapse
Affiliation(s)
- Claire Blanchard
- IRS-UN, institut du thorax, unité Inserm UMR 1087/CNRS UMR 6291, 8, quai Moncousu, 44007 Nantes Cedex 1, France
| | - François Moreau
- IRS-UN, institut du thorax, unité Inserm UMR 1087/CNRS UMR 6291, 8, quai Moncousu, 44007 Nantes Cedex 1, France
| | - Bertrand Cariou
- IRS-UN, institut du thorax, unité Inserm UMR 1087/CNRS UMR 6291, 8, quai Moncousu, 44007 Nantes Cedex 1, France
| | - Cédric Le May
- IRS-UN, institut du thorax, unité Inserm UMR 1087/CNRS UMR 6291, 8, quai Moncousu, 44007 Nantes Cedex 1, France
| |
Collapse
|
98
|
Padmanabha D, Baker KD. Drosophila gains traction as a repurposed tool to investigate metabolism. Trends Endocrinol Metab 2014; 25:518-27. [PMID: 24768030 DOI: 10.1016/j.tem.2014.03.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 10/25/2022]
Abstract
The use of fruit flies has recently emerged as a powerful experimental paradigm to study the core aspects of energy metabolism. The fundamental need for lipid and carbohydrate processing and storage across species dictates that the central regulators that control metabolism are highly conserved through evolution. Accordingly, the Drosophila system is being used to identify human disease genes and has the potential to model successfully human disorders that center on excessive caloric intake and metabolic dysfunction, including diet-induced lipotoxicity and type 2 diabetes. We review here recent progress on this front and contend that increasing such efforts will yield unexpectedly high rates of experimental return, thereby leading to novel approaches in the treatment of obesity and its comorbidities.
Collapse
Affiliation(s)
- Divya Padmanabha
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, 1220 East Broad Street Room 2052, Richmond, VA 23298, USA
| | - Keith D Baker
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, 1220 East Broad Street Room 2052, Richmond, VA 23298, USA.
| |
Collapse
|
99
|
Abstract
PURPOSE OF REVIEW Proprotein convertase subtilisin/kexin type-9 (PCSK9) binds to LDL receptor (LDLR) and targets it for lysosomal degradation in cells. Decreased hepatic clearance of plasma LDL-cholesterol is the primary gauge of PCSK9 activity in humans; however, PCSK9's evolutionary role may extend to other lipoprotein classes and processes. This review highlights studies that are providing novel insights into physiological regulation of PCSK9 transcription and plasma PCSK9 activity. RECENT FINDINGS Recent studies indicate that circulating PCSK9 binds to apolipoprotein B100 on LDL particles, which in turn inhibits PCSK9's ability to bind to cell surface LDLRs. Negative feedback of secreted PCSK9 activity by LDL could serve to increase plasma excursion of triglyceride-rich lipoproteins and monitor lipoprotein remodeling. Recent findings have identified hepatocyte nuclear factor-1α as a key transcriptional regulator that cooperates with sterol regulatory element-binding protein-2 to control PCSK9 expression in hepatocytes in response to nutritional and hormonal inputs, as well as acute inflammation. SUMMARY PCSK9 is an established target for cholesterol-lowering therapies. Further study of PCSK9 regulatory mechanisms may identify additional control points for pharmacological inhibition of PCSK9-mediated LDLR degradation. PCSK9 function could reflect ancient roles in the fasting-feeding cycle and in linking lipoprotein metabolism with innate immunity.
Collapse
Affiliation(s)
- Thomas A Lagace
- Department of Pathology and Laboratory Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| |
Collapse
|
100
|
Ghosh S, Bie J, Wang J, Yuan Q, Ghosh SS. Cholesterol removal from plaques and elimination from the body: change in paradigm to reduce risk for heart disease. ACTA ACUST UNITED AC 2014. [DOI: 10.2217/clp.14.35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|