1
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Deng Y, Wang J, Wang R, Wang Y, Shu X, Wang P, Chen C, Zhang F. Limosilactobacillus fermentum TY-S11 ameliorates hypercholesterolemia via promoting cholesterol excretion and regulating gut microbiota in high-cholesterol diet-fed apolipoprotein E-deficient mice. Heliyon 2024; 10:e32059. [PMID: 38882320 PMCID: PMC11180314 DOI: 10.1016/j.heliyon.2024.e32059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024] Open
Abstract
Hypercholesterolemia is a metabolic disease characterized by elevated cholesterol level in the blood, which is a risk factor for many diseases. Probiotic intervention may be one of the ways to improve hypercholesterolemia. In this study, three strains with better cholesterol removal ability were selected from 60 strains of lactic acid bacteria, and were orally administered to apolipoprotein E-deficient mice on a high-cholesterol diet. Among the three strains, only Limosilactobacillus fermentum TY-S11, which was isolated from the intestine of a longevity person, significantly improved serum and liver lipid levels in hypercholesterolemic mice. Further study found that L. fermentum TY-S11 promoted the excretion of cholesterol in the feces and inhibited the absorption of cholesterol in the small intestine. As for gut microbiota, the results showed that L. fermentum TY-S11 not only prevented the reduction of diversity caused by high-cholesterol diet, but also increased the contents of short-chain fatty acids in feces. These results confirmed the ameliorative effect of L. fermentum TY-S11 on hypercholesterolemia.
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Affiliation(s)
- Yadan Deng
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
| | - Jing Wang
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
| | - Ran Wang
- Department of Nutrition and Health, Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Government, China Agricultural University, Beijing, 100190, China
| | - Yuying Wang
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
| | - Xi Shu
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
| | - Pengjie Wang
- Department of Nutrition and Health, Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Government, China Agricultural University, Beijing, 100190, China
| | - Chong Chen
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
| | - Feng Zhang
- Key Laboratory of Conservation, Exploration and Utilization of Southwest Characteristic Bacterial Germplasm Resources, Chongqing Tianyou Dairy Co., Ltd., Chongqing, 401120, China
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2
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Xu C, Fu F, She Y, Xu C. NPC1L1 Plays a Novel Role in Nonalcoholic Fatty Liver Disease. ACS OMEGA 2023; 8:48586-48589. [PMID: 38162748 PMCID: PMC10753569 DOI: 10.1021/acsomega.3c07337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 11/24/2023] [Accepted: 11/28/2023] [Indexed: 01/03/2024]
Abstract
Niemann-Pick C1-Like 1 (NPC1L1) is a key protein in the transport of cholesterol, which exists in the brush marginal membrane of the intestinal epithelial cells and the timid duct membrane of the liver. It affects cholesterol absorption and plasma low-density lipoprotein levels. Cholesterol is both an important component of the cell membrane and a precursor of bile acid and steroid hormone synthesis. Abnormal cholesterol metabolism is closely related to nonalcoholic steatohepatitis (NASH). NASH can progress to fibrosis and cirrhosis, with serious consequences. NPC1L1 is involved in the regulation of cholesterol and lipid metabolism and plays an important role in maintaining the balance of cholesterol metabolism in the body. It also plays an important role in some metabolic diseases such as nonalcoholic fatty liver disease, obesity, and hypercholesterolemia. Therefore, it is necessary to elucidate the molecular pathological mechanism of NPC1L1 in the regulation of cholesterol metabolism and the occurrence and development of NASH, which can provide a target for the development of novel drugs for the treatment of NASH and other diseases. More importantly, it helps to accelerate the development of drugs that regulate lipid metabolism at multiple levels and reduce liver steatosis, which is extremely important for the prevention and treatment of NASH and related severe metabolic diseases.
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Affiliation(s)
- ChongLi Xu
- College
of Medical Technology, Chongqing Medical
and Pharmaceutical College, 82 Daxuecheng Road, Chongqing 401331, PR China
| | - Fengyang Fu
- College
of Medical Technology, Chongqing Medical
and Pharmaceutical College, 82 Daxuecheng Road, Chongqing 401331, PR China
| | - Yuhan She
- College
of Medical Technology, Chongqing Medical
and Pharmaceutical College, 82 Daxuecheng Road, Chongqing 401331, PR China
| | - ChongBo Xu
- School
of Biology and Agriculture, Shaoguan University, Shaoguan 512005, PR China
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3
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Jiang W, Xu Y, Fu Z, Hu M, Wu Q, Ji Y, Li JZ, Gong Y, Zhou H. Genetic analysis and functional study of a novel ABCG5 mutation in sitosterolemia with hematologic disease. Gene 2023; 879:147596. [PMID: 37390873 DOI: 10.1016/j.gene.2023.147596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/24/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023]
Abstract
Sitosterolemia is a rare autosomal recessive hereditary disease caused by loss-of-function genetic mutations in either ATP-binding cassette subfamily G member 5 or member 8 (ABCG5 or ABCG8). Here, we investigate novel variants in ABCG5 and ABCG8 that are associated with the sitosterolemia phenotype. We describe a 32-year-old woman with hypercholesterolemia, tendon and hip xanthomas, autoimmune hemolytic anemia and macrothrombocytopenia from early life, which make us highly suspicious of the possibility of sitosterolemia. A novel homozygous variant in ABCG5 (c.1769C>A, p.S590X) was identified by genomic sequencing. We also examined the lipid profile, especially plant sterols levels, using gas chromatography-mass spectrometry. Functional studies, including western blotting and immunofluorescence staining, showed that the nonsense mutation ABCG5 1769C>A hinders the formation of ABCG5 and ABCG8 heterodimers and the function of transporting sterols. Our study expands the knowledge of variants in sitosterolemia and provides diagnosis and treatment recommendations.
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Affiliation(s)
- Wanzi Jiang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Yiwen Xu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Zhenzhen Fu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Moran Hu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Qinyi Wu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China
| | - Yong Ji
- Key Laboratory of Cardiovascular and Cerebrovascular Medicine, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Suzhou, China
| | - John Zhong Li
- The Key Laboratory of Rare Metabolic Disease, Department of Biochemistry and Molecular Biology, The Key Laboratory of Human Functional Genomics of Jiangsu Province, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China
| | - Yingyun Gong
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China.
| | - Hongwen Zhou
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University and Jiangsu Province Hospital, Nanjing, China.
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4
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Jia L, Ma Y, Haywood J, Jiang L, Xue B, Shi H, Dawson PA, Yu L. NPC1L1 Deficiency Suppresses Ileal Fibroblast Growth Factor 15 Expression and Increases Bile Acid Pool Size in High-Fat-Diet-Fed Mice. Cells 2021; 10:3468. [PMID: 34943976 PMCID: PMC8700447 DOI: 10.3390/cells10123468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 02/04/2023] Open
Abstract
Niemann-Pick C1-like 1 (NPC1L1) mediates intestinal uptake of dietary and biliary cholesterol and is the target of ezetimibe, a cholesterol absorption inhibitor used to treat hypercholesterolemia. Genetic deletion of NPC1L1 or ezetimibe treatment protects mice from high-fat diet (HFD)-induced obesity; however, the molecular mechanisms responsible for this therapeutic benefit remain unknown. A major metabolic fate of cholesterol is its conversion to bile acids. We found that NPC1L1 knockout (L1-KO) mice fed an HFD had increased energy expenditure, bile acid pool size, and fecal bile acid excretion rates. The elevated bile acid pool in the HFD-fed L1-KO mice was enriched with tauro-β-muricholic acid. These changes in the L1-KO mice were associated with reduced ileal mRNA expression of fibroblast growth factor 15 (FGF15) and increased hepatic mRNA expression of cholesterol 7α-hydroxylase (Cyp7A1) and mitochondrial sterol 27-hydroxylase (Cyp27A1). In addition, mRNA expression of the membrane bile acid receptor Takeda G protein-coupled receptor 5 (TGR5) and type 2 iodothyronine deiodinase (Dio2) were elevated in brown adipose tissue of L1-KO mice, which is known to promote energy expenditure. Thus, altered bile acid homeostasis and signaling may play a role in protecting L1-KO mice against HFD-induced obesity.
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Affiliation(s)
- Lin Jia
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (L.J.); (Y.M.); (J.H.); (P.A.D.)
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
- Department of Biological Sciences, The University of Texas at Dallas, 800 W, Campbell Road, Richardson, TX 75080, USA
| | - Yinyan Ma
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (L.J.); (Y.M.); (J.H.); (P.A.D.)
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Jamie Haywood
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (L.J.); (Y.M.); (J.H.); (P.A.D.)
| | - Long Jiang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Bingzhong Xue
- Department of Endocrinology and Metabolism, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA;
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
| | - Hang Shi
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA;
- Internal Medicine Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Paul A. Dawson
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (L.J.); (Y.M.); (J.H.); (P.A.D.)
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, Emory University, Atlanta, GA 30322, USA
| | - Liqing Yu
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (L.J.); (Y.M.); (J.H.); (P.A.D.)
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
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Sitosterolemia: Four Cases of an Uncommon Cause of Hemolytic Anemia (Mediterranean Stomatocytosis with Macrothrombocytopenia). Indian J Hematol Blood Transfus 2021; 37:157-161. [PMID: 33707850 DOI: 10.1007/s12288-020-01346-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/28/2020] [Indexed: 10/23/2022] Open
Abstract
Sitosterolemia is a rare autosomal recessively inherited lipid metabolic disorder that is characterized by hyper absorption of plant sterols from the intestinal mucosa leading to toxic levels in the blood. Four patients of age ranging from 11 to 29 years presented to the outpatient department with clinical features of hemolytic anemia. There were no features of hypercholesterolemia in any of the patients. Peripheral smear examination of all four patients showed stomatocytes and macrothrombocytopenia. Qualitative testing for plant sterols was performed in one case. Next generation sequencing revealed a compound heterozygous mutation in ABCG5 gene (c.1222C>T and c.1255C>T) in one case and homozygous mutations in ABCG5 gene (c.727C>T), (c.332G>A (p.G111E)), (c.1222C>T) in the other three cases. Ezetimibe (10 mg/day) was administered in one case, with complete resolution of symptoms. All patients were advised a low plant sterol diet and regular monitoring of hemoglobin and lipid profile. Our cases highlight a rare but important cause of hemolytic anemia that can be suspected from careful peripheral blood examination but only conclusively established by molecular genetic diagnosis.
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Williams K, Segard A, Graf GA. Sitosterolemia: Twenty Years of Discovery of the Function of ABCG5ABCG8. Int J Mol Sci 2021; 22:2641. [PMID: 33807969 PMCID: PMC7961684 DOI: 10.3390/ijms22052641] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/19/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023] Open
Abstract
Sitosterolemia is a lipid disorder characterized by the accumulation of dietary xenosterols in plasma and tissues caused by mutations in either ABCG5 or ABCG8. ABCG5 ABCG8 encodes a pair of ABC half transporters that form a heterodimer (G5G8), which then traffics to the surface of hepatocytes and enterocytes and promotes the secretion of cholesterol and xenosterols into the bile and the intestinal lumen. We review the literature from the initial description of the disease, the discovery of its genetic basis, current therapy, and what has been learned from animal, cellular, and molecular investigations of the transporter in the twenty years since its discovery. The genomic era has revealed that there are far more carriers of loss of function mutations and likely pathogenic variants of ABCG5 ABCG8 than previously thought. The impact of these variants on G5G8 structure and activity are largely unknown. We propose a classification system for ABCG5 ABCG8 mutants based on previously published systems for diseases caused by defects in ABC transporters. This system establishes a framework for the comprehensive analysis of disease-associated variants and their impact on G5G8 structure-function.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 5/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 5/history
- ATP Binding Cassette Transporter, Subfamily G, Member 5/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 8/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 8/history
- ATP Binding Cassette Transporter, Subfamily G, Member 8/metabolism
- Animals
- Cholesterol/metabolism
- Enterocytes/metabolism
- Enterocytes/pathology
- Hepatocytes/metabolism
- Hepatocytes/pathology
- History, 21st Century
- Humans
- Hypercholesterolemia/genetics
- Hypercholesterolemia/history
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Intestinal Diseases/genetics
- Intestinal Diseases/history
- Intestinal Diseases/metabolism
- Intestinal Diseases/pathology
- Lipid Metabolism, Inborn Errors/genetics
- Lipid Metabolism, Inborn Errors/history
- Lipid Metabolism, Inborn Errors/metabolism
- Lipid Metabolism, Inborn Errors/pathology
- Lipoproteins/genetics
- Lipoproteins/history
- Lipoproteins/metabolism
- Mutation
- Phytosterols/adverse effects
- Phytosterols/genetics
- Phytosterols/history
- Phytosterols/metabolism
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Affiliation(s)
- Kori Williams
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
| | - Allison Segard
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
| | - Gregory A. Graf
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA; (K.W.); (A.S.)
- Saha Cardiovascular Research Center, Lexington, KY 40536, USA
- Barnstable Brown Diabetes and Obesity Center, Lexington, KY 40536, USA
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7
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Jiang X, Pan D, Zhang T, Liu C, Zhang J, Su M, Wu Z, Zeng X, Sun Y, Guo Y. Novel milk casein–derived peptides decrease cholesterol micellar solubility and cholesterol intestinal absorption in Caco-2 cells. J Dairy Sci 2020; 103:3924-3936. [DOI: 10.3168/jds.2019-17586] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/01/2020] [Indexed: 12/15/2022]
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8
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Poongavanam V, Kongsted J, Wüstner D. Computational Modeling Explains the Multi Sterol Ligand Specificity of the N-Terminal Domain of Niemann-Pick C1-Like 1 Protein. ACS OMEGA 2019; 4:20894-20904. [PMID: 31867479 PMCID: PMC6921270 DOI: 10.1021/acsomega.9b01668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Niemann-Pick C1 like 1 (NPC1L1) is a sterol transporter expressed in the apical membrane of enterocytes and hepatocytes. NPC1L1 resembles the lysosomal NPC1 protein including an N-terminal domain (NTD), which binds a variety of sterols. The molecular mechanisms underlying this multiligand specificity of the NTD of NPC1L1 (NPC1L1-NTD) are not known. On the basis of the crystal structure of NPC1L1-NTD, we have investigated the structural details of protein-sterol interactions using molecular mechanics Poisson Boltzmann surface area calculations here. We found a good agreement between experimental and calculated binding affinities with similar ranking of various sterol ligands. We defined hydrogen bonding of sterol ligands via the 3'-β-hydroxy group inside the binding pose as instrumental in stabilizing the interaction. A leucine residue (LEU213) at the mouth of the binding pocket transiently opens to allow for the access of sterol into the binding pose. Our calculations also predict that NPC1L1-NTD binds polyene sterols, such as dehydroergosterol or cholestatrienol with high affinity, which validates their use in future experiments as close intrinsically fluorescent cholesterol analogs. A free energy decomposition and computational mutation analysis revealed that the binding of various sterols to NPC1L1-NTD depends critically on specific amino acid residues within the binding pocket. Some of these residues were previously detected as being relevant for intestinal cholesterol absorption. We show that clinically known mutations in the NPC1L1-NTD associated with lowered risk of coronary heart disease result in strongly reduced binding energies, providing a molecular explanation for the clinical phenotype.
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Affiliation(s)
- Vasanthanathan Poongavanam
- Department of Physics, Chemistry and Pharmacy and Department of Biochemistry and
Molecular Biology, University of Southern
Denmark, DK-5230 Odense M, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy and Department of Biochemistry and
Molecular Biology, University of Southern
Denmark, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Physics, Chemistry and Pharmacy and Department of Biochemistry and
Molecular Biology, University of Southern
Denmark, DK-5230 Odense M, Denmark
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Lifsey HC, Kaur R, Thompson BH, Bennett L, Temel RE, Graf GA. Stigmasterol stimulates transintestinal cholesterol excretion independent of liver X receptor activation in the small intestine. J Nutr Biochem 2019; 76:108263. [PMID: 31759199 DOI: 10.1016/j.jnutbio.2019.108263] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 10/14/2019] [Accepted: 10/29/2019] [Indexed: 02/09/2023]
Abstract
Despite advances in healthcare, cardiovascular disease (CVD) remains the leading cause of death in the United States. Elevated levels of plasma cholesterol are highly predictive of CVD and stroke and are the principal driver of atherosclerosis. Unfortunately, current cholesterol lowering agents, such as statins, are not known to reverse atherosclerotic disease once it has been established. In preclinical models, agonists of nuclear receptor, LXR, have been shown to reduce and reverse atherosclerosis. Phytosterols are bioactive non-cholesterol sterols that act as LXR agonists and regulate cholesterol metabolism and transport. We hypothesized that stigmasterol would act as an LXR agonist and alter intestinal cholesterol secretion to promote cholesterol elimination. Mice were fed a control diet, or a diet supplemented with stigmasterol (0.3% w/w) or T0901317 (0.015% w/w), a known LXR agonist. In this experiment we analyzed the sterol content of bile, intestinal perfusate, plasma, and feces. Additionally, the liver and small intestine were analyzed for relative levels of transcripts known to be regulated by LXR. We observed that T0901317 robustly promoted cholesterol elimination and acted as a strong LXR agonist. Stigmasterol promoted transintestinal cholesterol secretion through an LXR-independent pathway.
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Affiliation(s)
| | - Rupinder Kaur
- Department of Pharmaceutical Sciences, College of Pharmacy
| | | | - Lisa Bennett
- Department of Pharmaceutical Sciences, College of Pharmacy
| | - Ryan E Temel
- Department of Physiology, College of Medicine, University of Kentucky; Saha Cardiovascular Research Center
| | - Gregory A Graf
- Department of Pharmaceutical Sciences, College of Pharmacy; Saha Cardiovascular Research Center; Barnstable Brown Diabetes and Obesity Center.
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10
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Veit L, Allegri Machado G, Bürer C, Speer O, Häberle J. Sitosterolemia-10 years observation in two sisters. JIMD Rep 2019; 48:4-10. [PMID: 31392106 PMCID: PMC6607017 DOI: 10.1002/jmd2.12038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 12/26/2022] Open
Abstract
Familial hypercholesterolemia due to heterozygous low-density lipoprotein-receptor mutations is a common inborn errors of metabolism. Secondary hypercholesterolemia due to a defect in phytosterol metabolism is far less common and may escape diagnosis during the work-up of patients with dyslipidemias. Here we report on two sisters with the rare, autosomal recessive condition, sitosterolemia. This disease is caused by mutations in a defective adenosine triphosphate-binding cassette sterol excretion transporter, leading to highly elevated plant sterol concentrations in tissues and to a wide range of symptoms. After a delayed diagnosis, treatment with a diet low in plant lipids plus ezetimibe to block the absorption of sterols corrected most of the clinical and biochemical signs of the disease. We followed the two patients for over 10 years and report their initial presentation and long-term response to treatment.
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Affiliation(s)
- Lara Veit
- Division of Metabolism and Children's Research CenterUniversity Children's Hospital ZurichZurichSwitzerland
| | - Gabriella Allegri Machado
- Division of Metabolism and Children's Research CenterUniversity Children's Hospital ZurichZurichSwitzerland
| | - Céline Bürer
- Division of Metabolism and Children's Research CenterUniversity Children's Hospital ZurichZurichSwitzerland
| | - Oliver Speer
- Division of Haematology and Children's Research CenterUniversity Children's Hospital ZurichZurichSwitzerland
- Institut für LabormedizinSpital Thurgau AGFrauenfeldSwitzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research CenterUniversity Children's Hospital ZurichZurichSwitzerland
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11
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Nunes VS, Cazita PM, Catanozi S, Nakandakare ER, Quintão ECR. Phytosterol containing diet increases plasma and whole body concentration of phytosterols in apoE-KO but not in LDLR-KO mice. J Bioenerg Biomembr 2019; 51:131-136. [PMID: 30739226 DOI: 10.1007/s10863-019-09786-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/28/2019] [Indexed: 12/21/2022]
Abstract
Phytosterol metabolism is unknown in the hypercholesterolemia of genetic origin. We investigated the metabolism of phytosterols in a cholesterol-free, phytosterol-containing standard diet in hypercholesterolemic mice knockouts for low density lipoprotein receptor (LDLR) and apolipoprotein E (apoE) mice compared to wild-type mice (controls). Phytosterols were measured in mice tissues by GCMS. ApoE-KO mice absorbed less phytosterols than LDLR-KO and the latter absorbed less phytosterols than control mice, because the intestinal campesterol content was low in both KO mice, and sitosterol was low in the intestine in apoE-KO mice as compared to LDLR-KO mice. Although the diet contained nine times more sitosterol than campesterol, the concentration of sitosterol was lower than that of campesterol in plasma in LDLR-KO, and in the liver in controls and in LDLR-KO, but only in apoE-KO. On the other hand, in the intestine sitosterol was higher than campesterol in controls, and in LDLR-KO but with a tendency only in apoE-KO. Because of the high dietary supply of sitosterol, sitosterol was better taken up by the intestine than campesterol, but the amount of sitosterol was lower than that of campesterol in the liver, while in the whole body the amounts of these phytosterols do not differ from each other. Therefore, via intestinal lymph less sitosterol than campesterol was transferred to the body. However, as compared to controls, in apoE-KO mice, but not in LDLR-KO mice, the increase in campesterol and sitosterol in plasma and in the whole body indicating that apoE-KO mice have a marked defect in the elimination of both phytosterols from the body.
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Affiliation(s)
- Valéria Sutti Nunes
- Laboratorio de Lipides, LIM-10, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 - room 3305, São Paulo, SP, CEP 01246-000, Brazil.
| | - Patrícia Miralda Cazita
- Laboratorio de Lipides, LIM-10, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 - room 3305, São Paulo, SP, CEP 01246-000, Brazil
| | - Sérgio Catanozi
- Laboratorio de Lipides, LIM-10, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 - room 3305, São Paulo, SP, CEP 01246-000, Brazil
| | - Edna Regina Nakandakare
- Laboratorio de Lipides, LIM-10, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 - room 3305, São Paulo, SP, CEP 01246-000, Brazil
| | - Eder Carlos Rocha Quintão
- Laboratorio de Lipides, LIM-10, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455 - room 3305, São Paulo, SP, CEP 01246-000, Brazil
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Nakano T, Inoue I, Murakoshi T. A Newly Integrated Model for Intestinal Cholesterol Absorption and Efflux Reappraises How Plant Sterol Intake Reduces Circulating Cholesterol Levels. Nutrients 2019; 11:nu11020310. [PMID: 30717222 PMCID: PMC6412963 DOI: 10.3390/nu11020310] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/27/2022] Open
Abstract
Cholesterol homeostasis is maintained through a balance of de novo synthesis, intestinal absorption, and excretion from the gut. The small intestine contributes to cholesterol homeostasis by absorbing and excreting it, the latter of which is referred to as trans-intestinal cholesterol efflux (TICE). Because the excretion efficiency of endogenous cholesterol is inversely associated with the development of atherosclerosis, TICE provides an attractive therapeutic target. Thus, elucidation of the mechanism is warranted. We have shown that intestinal cholesterol absorption and TICE are inversely correlated in intestinal perfusion experiments in mice. In this review, we summarized 28 paired data sets for absorption efficiency and fecal neutral sterol excretion, a surrogate marker of TICE, obtained from 13 available publications in a figure, demonstrating the inverse correlation were nearly consistent with the assumption. We then offer a bidirectional flux model that accommodates absorption and TICE occurring in the same segment. In this model, the brush border membrane (BBM) of intestinal epithelial cells stands as the dividing ridge for cholesterol fluxes, making the opposite fluxes competitive and being coordinated by shared BBM-localized transporters, ATP-binding cassette G5/G8 and Niemann-Pick C1-like 1. Furthermore, the idea is applied to address how excess plant sterol/stanol (PS) intake reduces circulating cholesterol level, because the mechanism is still unclear. We propose that unabsorbable PS repeatedly shuttles between the BBM and lumen and promotes concomitant cholesterol efflux. Additionally, PSs, which are chemically analogous to cholesterol, may disturb the trafficking machineries that transport cholesterol to the cell interior.
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Affiliation(s)
- Takanari Nakano
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Saitama 350-0495, Japan.
| | - Ikuo Inoue
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Saitama 350-0495, Japan.
| | - Takayuki Murakoshi
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Saitama 350-0495, Japan.
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Nakano T, Inoue I, Takenaka Y, Ikegami Y, Kotani N, Shimada A, Noda M, Murakoshi T. Luminal plant sterol promotes brush border membrane-to-lumen cholesterol efflux in the small intestine. J Clin Biochem Nutr 2018; 63:102-105. [PMID: 30279620 PMCID: PMC6160726 DOI: 10.3164/jcbn.17-116] [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: 10/28/2017] [Accepted: 12/19/2017] [Indexed: 11/22/2022] Open
Abstract
Plant sterols are used as food additives to reduce intestinal cholesterol absorption. They also increase fecal neutral sterol (FNS) excretion irrespective of the absorption inhibition. Intestine-mediated reverse cholesterol transport, or trans-intestinal cholesterol efflux (TICE), provides the major part of the increase of FNS excretion. However, it is unknown whether plant sterols stimulate TICE or not. We have shown previously that TICE can be evaluated by brush border membrane (BBM)-to-lumen cholesterol efflux. Thus, we examined whether luminal plant sterols stimulate BBM-to-lumen cholesterol efflux in the intestinal tract or not in mice. Cannulated upper jejunum that had been pre-labeled with orally given 3H-cholesterol, was flushed and perfused to collect 3H-cholesterol effluxed back into the lumen from the BBM to estimate the efflux efficiency. Adding 0.5 mg/ml of plant sterols, but not cholesterol, in the perfusion solution doubled the efflux. Plant sterols enter the BBM and are effluxed back to the lumen rapidly, in which process cholesterol transporters in the BBM are involved. We thus speculate that phytosterols alter cholesterol flux in the BBM; thereby, increases BBM-to-lumen cholesterol efflux, resulting in the increased TICE.
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Affiliation(s)
- Takanari Nakano
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
| | - Ikuo Inoue
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
| | - Yasuhiro Takenaka
- Department of Physiology, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Yuichi Ikegami
- Department of Physiology, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Norihiro Kotani
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
| | - Akira Shimada
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
| | - Mitsuhiko Noda
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
| | - Takayuki Murakoshi
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Iruma, Saitama 350-0495, Japan
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Jesch ED, Carr TP. Food Ingredients That Inhibit Cholesterol Absorption. Prev Nutr Food Sci 2017; 22:67-80. [PMID: 28702423 PMCID: PMC5503415 DOI: 10.3746/pnf.2017.22.2.67] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/23/2017] [Indexed: 12/12/2022] Open
Abstract
Cholesterol is a vital component of the human body. It stabilizes cell membranes and is the precursor of bile acids, vitamin D and steroid hormones. However, cholesterol accumulation in the bloodstream (hypercholesterolemia) can cause atherosclerotic plaques within artery walls, leading to heart attacks and strokes. The efficiency of cholesterol absorption in the small intestine is of great interest because human and animal studies have linked cholesterol absorption with plasma concentration of total and low density lipoprotein cholesterol. Cholesterol absorption is highly regulated and influenced by particular compounds in the food supply. Therefore, it is desirable to learn more about natural food components that inhibit cholesterol absorption so that food ingredients and dietary supplements can be developed for consumers who wish to manage their plasma cholesterol levels by non-pharmacological means. Food components thus far identified as inhibitors of cholesterol absorption include phytosterols, soluble fibers, phospholipids, and stearic acid.
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Affiliation(s)
- Elliot D Jesch
- Department of Food, Nutrition and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
| | - Timothy P Carr
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
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15
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Nakano T, Inoue I, Takenaka Y, Ono H, Katayama S, Awata T, Murakoshi T. Ezetimibe Promotes Brush Border Membrane-to-Lumen Cholesterol Efflux in the Small Intestine. PLoS One 2016; 11:e0152207. [PMID: 27023132 PMCID: PMC4811413 DOI: 10.1371/journal.pone.0152207] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 03/10/2016] [Indexed: 11/19/2022] Open
Abstract
Ezetimibe inhibits Niemann-Pick C1-like 1 (NPC1L1), an apical membrane cholesterol transporter of enterocytes, thereby reduces intestinal cholesterol absorption. This treatment also increases extrahepatic reverse cholesterol transport via an undefined mechanism. To explore this, we employed a trans-intestinal cholesterol efflux (TICE) assay, which directly detects circulation-to-intestinal lumen 3H-cholesterol transit in a cannulated jejunal segment, and found an increase of TICE by 45%. To examine whether such increase in efflux occurs at the intestinal brush border membrane(BBM)-level, we performed luminal perfusion assays, similar to TICE but the jejunal wall was labelled with orally-given 3H-cholesterol, and determined elevated BBM-to-lumen cholesterol efflux by 3.5-fold with ezetimibe. Such increased efflux probably promotes circulation-to-lumen cholesterol transit eventually; thus increases TICE. Next, we wondered how inhibition of NPC1L1, an influx transporter, resulted in increased efflux. When we traced orally-given 3H-cholesterol in mice, we found that lumen-to-BBM 3H-cholesterol transit was rapid and less sensitive to ezetimibe treatment. Comparison of the efflux and fractional cholesterol absorption revealed an inverse correlation, indicating the efflux as an opposite-regulatory factor for cholesterol absorption efficiency and counteracting to the naturally-occurring rapid cholesterol influx to the BBM. These suggest that the ezetimibe-stimulated increased efflux is crucial in reducing cholesterol absorption. Ezetimibe-induced increase in cholesterol efflux was approximately 2.5-fold greater in mice having endogenous ATP-binding cassette G5/G8 heterodimer, the major sterol efflux transporter of enterocytes, than the knockout counterparts, suggesting that the heterodimer confers additional rapid BBM-to-lumen cholesterol efflux in response to NPC1L1 inhibition. The observed framework for intestinal cholesterol fluxes may provide ways to modulate the flux to dispose of endogenous cholesterol efficiently for therapeutic purposes.
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Affiliation(s)
- Takanari Nakano
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
- * E-mail:
| | - Ikuo Inoue
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
| | - Yasuhiro Takenaka
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
| | - Hiraku Ono
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
| | - Shigehiro Katayama
- Department of Diabetes and Endocrinology, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
| | - Takuya Awata
- Department of Diabetes, Endocrinology and Metabolism, International University of Health and Welfare Hospital, Nasushiobara-shi, Tochigi, Japan
| | - Takayuki Murakoshi
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Iruma-gun, Saitama, Japan
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Brautbar A, Leary E, Rasmussen K, Wilson DP, Steiner RD, Virani S. Genetics of familial hypercholesterolemia. Curr Atheroscler Rep 2015; 17:491. [PMID: 25712136 DOI: 10.1007/s11883-015-0491-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol and premature cardiovascular disease, with a prevalence of approximately 1 in 200-500 for heterozygotes in North America and Europe. Monogenic FH is largely attributed to mutations in the LDLR, APOB, and PCSK9 genes. Differential diagnosis is critical to distinguish FH from conditions with phenotypically similar presentations to ensure appropriate therapeutic management and genetic counseling. Accurate diagnosis requires careful phenotyping based on clinical and biochemical presentation, validated by genetic testing. Recent investigations to discover additional genetic loci associated with extreme hypercholesterolemia using known FH families and population studies have met with limited success. Here, we provide a brief overview of the genetic determinants, differential diagnosis, genetic testing, and counseling of FH genetics.
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Affiliation(s)
- Ariel Brautbar
- Division of Genetics, Cook Children's Medical Center, Fort Worth, TX, USA,
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17
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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.
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Xu C, Liu Y, Gong Y, Duan X, Tang X, Zhang M, Pang D, Yu L, Wei H, Ouyang H. Overexpression of NPC1L1 in the livers of transgenic Bama miniature pigs accelerates lipid peroxidation. Genes Genomics 2015. [DOI: 10.1007/s13258-014-0235-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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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.
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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
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20
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Hu M, Yuen YP, Kwok JS, Griffith JF, Tomlinson B. Potential effects of NPC1L1 polymorphisms in protecting against clinical disease in a chinese family with sitosterolaemia. J Atheroscler Thromb 2014; 21:989-95. [PMID: 25056759 DOI: 10.5551/jat.24679] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Sitosterolaemia is caused by mutations in either ABCG5 or ABCG8. Chinese and Japanese individuals usually have mutations in ABCG5. We herein report a known and a novel mutation in ABCG8 and their potential interaction with NPC1L1 polymorphisms in a Chinese family with sitosterolaemia. We sequenced ABCG5 and ABCG8 and measured the levels of plasma plant sterols in a 15-year-old Chinese girl with clinical sitosterolaemia (xanthomas with elevated low-density lipoprotein cholesterol (LDL-C) and plant sterols) and her apparently healthy family members. NPC1L1 was sequenced in the genetically affected sibling and other family members. A known mutation, c.490C>T (p. Arg164(*)), in exon 4 and a novel mutation, c.1949T>G (p.Leu650Arg), in exon 13 of ABCG8 were detected in the proband and her sister, who had elevated sterols but low LDL-C levels and no xanthomas. The genetically affected sister, but not the proband, carried two additional heterozygous changes in NPC1L1 (rs2072183 C>G, rs2301935 A>C), which were inherited from the mother, who also had a low LDL-C level. In this study, we detected a known and a novel mutation in ABCG8 in a Chinese patient with sitosterolaemia. The same mutations were found in her clinically normal sister, suggesting that the contrasting features with the proband may be related to different variants in NPC1L1 and/or some other undetermined lipid-related genetic factors.
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Affiliation(s)
- Miao Hu
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong
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21
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MENG XIANGYU, LI MENG, GUO JUN, TANG WEIQING, WANG SHU, MAN YONG, HUANG XIUQING, LI JIAN. Protein phosphatase 4 promotes hepatic lipogenesis through dephosphorylating acetyl-CoA carboxylase 1 on serine 79. Mol Med Rep 2014; 10:1959-63. [DOI: 10.3892/mmr.2014.2397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 05/09/2014] [Indexed: 11/06/2022] Open
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Escolà-Gil JC, Quesada H, Julve J, Martín-Campos JM, Cedó L, Blanco-Vaca F. Sitosterolemia: Diagnosis, Investigation, and Management. Curr Atheroscler Rep 2014; 16:424. [DOI: 10.1007/s11883-014-0424-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Yu XH, Qian K, Jiang N, Zheng XL, Cayabyab FS, Tang CK. ABCG5/ABCG8 in cholesterol excretion and atherosclerosis. Clin Chim Acta 2014; 428:82-8. [DOI: 10.1016/j.cca.2013.11.010] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/07/2013] [Accepted: 11/09/2013] [Indexed: 12/23/2022]
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Othman RA, Myrie SB, Jones PJH. Non-cholesterol sterols and cholesterol metabolism in sitosterolemia. Atherosclerosis 2013; 231:291-9. [PMID: 24267242 DOI: 10.1016/j.atherosclerosis.2013.09.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 09/05/2013] [Accepted: 09/30/2013] [Indexed: 12/14/2022]
Abstract
Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.
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Affiliation(s)
- Rgia A Othman
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba, Canada
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Su K, Sabeva NS, Wang Y, Liu X, Lester JD, Liu J, Liang S, Graf GA. Acceleration of biliary cholesterol secretion restores glycemic control and alleviates hypertriglyceridemia in obese db/db mice. Arterioscler Thromb Vasc Biol 2013; 34:26-33. [PMID: 24202306 DOI: 10.1161/atvbaha.113.302355] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Recent studies support a role for cholesterol in the development of obesity and nonalcoholic fatty liver disease. Mice lacking the ABCG5 ABCG8 (G5G8) sterol transporter have reduced biliary cholesterol secretion and are more susceptible to steatosis, hepatic insulin resistance, and loss of glycemic control when challenged with a high-fat diet. We hypothesized that accelerating G5G8-mediated biliary cholesterol secretion would correct these phenotypes in obese mice. APPROACH AND RESULTS Obese (db/db) male and their lean littermates were administered a cocktail of control adenovirus or adenoviral vectors encoding ABCG5 and ABCG8 (AdG5G8). Three days after viral administration, measures of lipid and glucose homeostasis were determined, and tissues were collected for biochemical analyses. AdG5G8 increased biliary cholesterol and fecal sterol elimination. Fasting glucose and triglycerides declined, and glucose tolerance improved in obese mice expressing G5G8 compared with mice receiving control adenovirus. These changes were associated with a reduction in phosphorylated eukaryotic initiation factor 2α and c-Jun N-terminal kinase in liver, suggesting alleviation of endoplasmic reticulum stress. Phosphorylated insulin receptor and protein kinase B were increased, indicating restored hepatic insulin signaling. However, there was no reduction in hepatic triglycerides after the 3-day treatment period. CONCLUSIONS Accelerating biliary cholesterol secretion restores glycemic control and reduces plasma triglycerides in obese db/db mice.
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Affiliation(s)
- Kai Su
- From the Department of Pharmaceutical Sciences, Graduate Center for Nutritional Sciences and Saha Cardiovascular Research Center, University of Kentucky, Lexington (K.S., Y.W., X.L., J.D.L., G.A.G.); Department of Neuroscience, Universidad Central del Caribe, Bayamon, Puerto Rico (N.S.S.); Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas (J.L.); and Department of Clinical Laboratories, Jinshan Branch of the Sixth People's Hospital of Shanghai, Shanghai, China (S.L.)
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The role of the gut in reverse cholesterol transport--focus on the enterocyte. Prog Lipid Res 2013; 52:317-28. [PMID: 23608233 DOI: 10.1016/j.plipres.2013.04.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/01/2013] [Accepted: 04/10/2013] [Indexed: 11/20/2022]
Abstract
In the arterial intima, macrophages become cholesterol-enriched foam cells and atherosclerotic lesions are generated. This atherogenic process can be attenuated, prevented, or even reversed by HDL particles capable of initiating a multistep pathway known as the macrophage-specific reverse cholesterol transport. The macrophage-derived cholesterol released to HDL is taken up by the liver, secreted into the bile, and ultimately excreted in the feces. Importantly, the absorptive epithelial cells lining the lumen of the small intestine, the enterocytes, express several membrane-associated proteins which mediate the influx of luminal cholesterol and its subsequent efflux at their apical and basolateral sides. Moreover, generation of intestinal HDL and systemic effects of the gut microbiota recently revealed a direct link between the gut and the cholesterol cargo of peripheral macrophages. This review summarizes experimental evidence establishing that the reverse cholesterol transport pathway which initiates in macrophages is susceptible to modulation in the small intestine. We also describe four paths which govern cholesterol passage across the enterocyte and define a role for the gut in the regulation of reverse cholesterol transport. Understanding the concerted function of these paths may be useful when designing therapeutic strategies aimed at removing cholesterol from the foam cells which occupy atherosclerotic lesions.
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27
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van der Wulp MYM, Verkade HJ, Groen AK. Regulation of cholesterol homeostasis. Mol Cell Endocrinol 2013; 368:1-16. [PMID: 22721653 DOI: 10.1016/j.mce.2012.06.007] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 05/17/2012] [Accepted: 06/11/2012] [Indexed: 12/28/2022]
Abstract
Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and non-coding RNA's. The last two decades insight into underlying mechanisms has increased vastly but there are still a lot of unknowns, particularly regarding intracellular cholesterol transport. After decades of concentration on the liver, in recent years the intestine has come into focus as an important control point in cholesterol homeostasis. This review will discuss current knowledge of cholesterol physiology, with emphasis on cholesterol absorption, cholesterol synthesis and fecal excretion, and new (possible) therapeutic options for hypercholesterolemia.
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28
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Bonamassa B, Moschetta A. Atherosclerosis: lessons from LXR and the intestine. Trends Endocrinol Metab 2013; 24:120-8. [PMID: 23158108 DOI: 10.1016/j.tem.2012.10.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 10/12/2012] [Accepted: 10/18/2012] [Indexed: 12/17/2022]
Abstract
Modulation of the cholesterol-sensing liver X receptors (LXRs) and their downstream targets has emerged as promising therapeutic avenues in atherosclerosis. The intestine is important for its unique capabilities to act as a gatekeeper for cholesterol absorption and to participate in the process of cholesterol elimination in the feces and reverse cholesterol transport (RCT). Pharmacological and genetic intestine-specific LXR activation have been shown to protect against atherosclerosis. In this review we discuss the LXR-targeted molecular players in the enterocytes as well as the intestine-driven pathways contributing to cholesterol homeostasis with therapeutic potential as targets in the prevention and treatment of atherosclerosis..
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Affiliation(s)
- Barbara Bonamassa
- Laboratory of Lipid Metabolism and Cancer, Department of Translational Pharmacology, Consorzio Mario Negri Sud, Via Nazionale 8/A, 66030 Santa Maria Imbaro (CH), Italy
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Nguyen TM, Sawyer JK, Kelley KL, Davis MA, Kent CR, Rudel LL. ACAT2 and ABCG5/G8 are both required for efficient cholesterol absorption in mice: evidence from thoracic lymph duct cannulation. J Lipid Res 2012; 53:1598-609. [PMID: 22669916 PMCID: PMC3540850 DOI: 10.1194/jlr.m026823] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 05/24/2012] [Indexed: 11/20/2022] Open
Abstract
The metabolic fate of newly absorbed cholesterol and phytosterol is orchestrated through adenosine triphosphate-binding cassette transporter G5 and G8 heterodimer (G5G8), and acyl CoA:cholesterol acyltransferase 2 (ACAT2). We hypothesized that intestinal G5G8 limits sterol absorption by reducing substrate availability for ACAT2 esterification and have attempted to define the roles of these two factors using gene deletion studies in mice. Male ACAT2(-/-), G5G8(-/-), ACAT2(-/-)G5G8(-/-) (DKO), and wild-type (WT) control mice were fed a diet with 20% of energy as palm oil and 0.2% (w/w) cholesterol. Sterol absorption efficiency was directly measured by monitoring the appearance of [(3)H]sitosterol and [(14)C]cholesterol tracers in lymph after thoracic lymph duct cannulation. The average percentage (± SEM) absorption of [(14)C]cholesterol after 8 h of lymph collection was 40.55 ± 0.76%, 19.41 ± 1.52%, 32.13 ± 1.60%, and 21.27 ± 1.35% for WT, ACAT2(-/-), G5G8(-/-), and DKO mice, respectively. [(3)H]sitosterol absorption was <2% in WT and ACAT2(-/-) mice, whereas it was up to 6.8% in G5G8(-/-) and DKO mice. G5G8(-/-) mice also produced chylomicrons with ∼70% less cholesterol ester mass than WT mice. In contrast to expectations, the data demonstrated that the absence of G5G8 led to decreased intestinal cholesterol esterification and reduced cholesterol transport efficiency. Intestinal G5G8 appeared to limit the absorption of phytosterols; ACAT2 more efficiently esterified cholesterol than phytosterols. The data indicate that handling of sterols by the intestine involves both G5G8 and ACAT2 but that an additional factor (possibly Niemann-Pick C1-like 1) may be key in determining absorption efficiency.
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Affiliation(s)
- Tam M. Nguyen
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Janet K. Sawyer
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Kathryn L. Kelley
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Matthew A. Davis
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Carol R. Kent
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Lawrence L. Rudel
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157
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Davis HR, Tershakovec AM, Tomassini JE, Musliner T. Intestinal sterol transporters and cholesterol absorption inhibition. Curr Opin Lipidol 2011; 22:467-78. [PMID: 22101558 DOI: 10.1097/mol.0b013e32834c7c28] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Statin therapy is the mainstay of lipid-lowering therapy; however, many patients, particularly those at high risk, do not achieve sufficient LDL-cholesterol (LDL-C) lowering. Thus, there remains an unmet medical need for more effective and well tolerated lipid-lowering agents. Guidelines recommend combining additional lipid-lowering agents with a complementary mode of action for these patients. One approach to complementing statin therapy is combination with inhibitors that block the intestinal absorption of dietary and biliary cholesterol. This review summarizes what is currently known about intestinal sterol transporters and cholesterol absorption inhibitors (CAIs). RECENT FINDINGS The only lipid-lowering agent currently available that specifically targets an intestinal sterol transporter (Niemann-Pick C1-like 1) is the CAI, ezetimibe. It is effective in lowering LDL-C, both when given alone and when combined with a statin. Clinical outcome data with ezetimibe combined with simvastatin have recently become available, and definitive evidence that the incremental LDL-C lowering attributable to the ezetimibe component reduces cardiovascular events beyond simvastatin alone is currently under study. Other novel CAIs have been evaluated based upon the structure and properties of ezetimibe, but none remain in development. SUMMARY Additional lipid-lowering agents are needed to fulfill an unmet medical need for those patients who do not achieve optimal LDL-C goals on statin monotherapy. The inhibition of cholesterol absorption is an important therapeutic strategy to reduce cholesterol levels. Based upon the demonstrated lipid-altering efficacy and safety of ezetimibe, several CAIs have been identified; all to date have been discontinued due to limited efficacy.
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Affiliation(s)
- Harry R Davis
- Merck Research Laboratories, Merck Sharp & Dohme Corp./Merck & Co., Inc., Whitehouse Station, New Jersey, USA.
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Calandra S, Tarugi P, Speedy HE, Dean AF, Bertolini S, Shoulders CC. Mechanisms and genetic determinants regulating sterol absorption, circulating LDL levels, and sterol elimination: implications for classification and disease risk. J Lipid Res 2011; 52:1885-926. [PMID: 21862702 DOI: 10.1194/jlr.r017855] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review integrates historical biochemical and modern genetic findings that underpin our understanding of the low-density lipoprotein (LDL) dyslipidemias that bear on human disease. These range from life-threatening conditions of infancy through severe coronary heart disease of young adulthood, to indolent disorders of middle- and old-age. We particularly focus on the biological aspects of those gene mutations and variants that impact on sterol absorption and hepatobiliary excretion via specific membrane transporter systems (NPC1L1, ABCG5/8); the incorporation of dietary sterols (MTP) and of de novo synthesized lipids (HMGCR, TRIB1) into apoB-containing lipoproteins (APOB) and their release into the circulation (ANGPTL3, SARA2, SORT1); and receptor-mediated uptake of LDL and of intestinal and hepatic-derived lipoprotein remnants (LDLR, APOB, APOE, LDLRAP1, PCSK9, IDOL). The insights gained from integrating the wealth of genetic data with biological processes have important implications for the classification of clinical and presymptomatic diagnoses of traditional LDL dyslipidemias, sitosterolemia, and newly emerging phenotypes, as well as their management through both nutritional and pharmaceutical means.
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Affiliation(s)
- Sebastiano Calandra
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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Jia L, Betters JL, Yu L. Niemann-pick C1-like 1 (NPC1L1) protein in intestinal and hepatic cholesterol transport. Annu Rev Physiol 2011; 73:239-59. [PMID: 20809793 DOI: 10.1146/annurev-physiol-012110-142233] [Citation(s) in RCA: 234] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increased blood cholesterol is an independent risk factor for atherosclerotic cardiovascular disease. Cholesterol homeostasis in the body is controlled mainly by endogenous synthesis, intestinal absorption, and hepatic excretion. Niemann-Pick C1-Like 1 (NPC1L1) is a polytopic transmembrane protein localized at the apical membrane of enterocytes and the canalicular membrane of hepatocytes. It functions as a sterol transporter to mediate intestinal cholesterol absorption and counter-balances hepatobiliary cholesterol excretion. NPC1L1 is the molecular target of ezetimibe, a potent cholesterol absorption inhibitor that is widely used in treating hypercholesterolemia. Recent findings suggest that NPC1L1 deficiency or ezetimibe treatment also prevents diet-induced hepatic steatosis and obesity in addition to reducing blood cholesterol. Future studies should focus on molecular mechanisms underlying NPC1L1-dependent cholesterol transport and elucidation of how a cholesterol transporter modulates the pathogenesis of metabolic diseases.
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Affiliation(s)
- Lin Jia
- Section on Lipid Sciences, Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1040, USA
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33
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Brufau G, Groen AK, Kuipers F. Reverse cholesterol transport revisited: contribution of biliary versus intestinal cholesterol excretion. Arterioscler Thromb Vasc Biol 2011; 31:1726-33. [PMID: 21571685 DOI: 10.1161/atvbaha.108.181206] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Reverse cholesterol transport (RCT) is usually defined as high-density lipoprotein-mediated transport of excess cholesterol from peripheral tissues, including cholesterol-laden macrophages in vessel walls, to the liver. From the liver, cholesterol can then be removed from the body via secretion into the bile for eventual disposal via the feces. According to this paradigm, high plasma high-density lipoprotein levels accelerate RCT and hence are atheroprotective. New insights in individual steps of the RCT pathway, in part derived from innovative mouse models, indicate that the classical concept of RCT may require modification.
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Affiliation(s)
- Gemma Brufau
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, The Netherlands
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Jia L, Ma Y, Rong S, Betters JL, Xie P, Chung S, Wang N, Tang W, Yu L. Niemann-Pick C1-Like 1 deletion in mice prevents high-fat diet-induced fatty liver by reducing lipogenesis. J Lipid Res 2010; 51:3135-44. [PMID: 20699423 DOI: 10.1194/jlr.m006353] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Niemann-Pick C1-Like 1 (NPC1L1) mediates intestinal absorption of dietary and biliary cholesterol. Ezetimibe, by inhibiting NPC1L1 function, is widely used to treat hypercholesterolemia in humans. Interestingly, ezetimibe treatment appears to attenuate hepatic steatosis in rodents and humans without a defined mechanism. Over-consumption of a high-fat diet (HFD) represents a major cause of metabolic disorders including fatty liver. To determine whether and how NPC1L1 deficiency prevents HFD-induced hepatic steatosis, in this study, we fed NPC1L1 knockout (L1-KO) mice and their wild-type (WT) controls an HFD, and found that 24 weeks of HFD feeding causes no fatty liver in L1-KO mice. Hepatic fatty acid synthesis and levels of mRNAs for lipogenic genes are substantially reduced but hepatic lipoprotein-triglyceride production, fatty acid oxidation, and triglyceride hydrolysis remain unaltered in L1-KO versus WT mice. Strikingly, L1-KO mice are completely protected against HFD-induced hyperinsulinemia under both fed and fasted states and during glucose challenge. Despite similar glucose tolerance, L1-KO relative WT mice are more insulin sensitive and in the overnight-fasted state display significantly lower plasma glucose concentrations. In conclusion, NPC1L1 deficiency in mice prevents HFD-induced fatty liver by reducing hepatic lipogenesis, at least in part, through attenuating HFD-induced insulin resistance, a state known to drive hepatic lipogenesis through elevated circulating insulin levels.
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Affiliation(s)
- Lin Jia
- Department of Pathology Section on Lipid Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1040, USA
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Jakulj L, Vissers MN, van Roomen CP, van der Veen JN, Vrins CLJ, Kunne C, Stellaard F, Kastelein JJP, Groen AK. Ezetimibe stimulates faecal neutral sterol excretion depending on abcg8 function in mice. FEBS Lett 2010; 584:3625-8. [PMID: 20659465 DOI: 10.1016/j.febslet.2010.07.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 07/20/2010] [Indexed: 11/19/2022]
Abstract
Ezetimibe stimulates faecal neutral sterol (FNS) excretion in mice, which cannot be explained by cholesterol absorption inhibition alone. We investigated whether these effects are mediated via the sterol exporter ATP binding cassette transporter G8 (abcg8). Ezetimibe increased FNS excretion 2.7-fold in WT mice and 1.5-fold in abcg8(-/-) mice, without affecting biliary cholesterol secretion. Daily FNS excretion exceeded the sum of dietary cholesterol intake and biliary secretion by about 60%. Ezetimibe enhanced this 'extra' FNS excretion by 3.5-fold and 1.5-fold in wildtype (WT) and abcg8(-/-) mice, respectively. Ezetimibe stimulates fecal sterol excretion of non-biliary and non-dietary origin, probably through stimulation of trans-intestinal cholesterol excretion. We show that this effect depends on intact abcg8 function.
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Affiliation(s)
- Lily Jakulj
- Department of Vascular Medicine, University of Amsterdam, Amsterdam, The Netherlands.
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36
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Jia L, Ma Y, Liu G, Yu L. Dietary cholesterol reverses resistance to diet-induced weight gain in mice lacking Niemann-Pick C1-Like 1. J Lipid Res 2010; 51:3024-33. [PMID: 20601625 DOI: 10.1194/jlr.m008599] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Niemann-Pick C1-Like 1 (NPC1L1) mediates intestinal cholesterol absorption. NPC1L1 knockout (L1-KO) mice were recently shown to be resistant to high-fat diet (HFD)-induced obesity in one study, which was contrary to several other studies. Careful comparison of dietary compositions in these studies implies a potential role of dietary cholesterol in regulating weight gain. To examine this potential, wild-type (WT) and L1-KO mice were fed one of three sets of diets for various durations: (1) a HFD without added cholesterol for 5 weeks; (2) a high-carbohydrate diet with or without added cholesterol for 5 weeks; or (3) a synthetic HFD with or without added cholesterol for 18 weeks. We found that L1-KO mice were protected against diet-induced weight gain only on a diet without added cholesterol but not on a diet containing 0.16% or 0.2% (w/w) cholesterol, an amount similar to a typical Western diet, regardless of the major energy source of the diet. Food intake and intestinal fat absorption were similar between the two genotypes. Intestinal cholesterol absorption was blocked, and fecal cholesterol excretion increased in L1-KO mice. Under all diets, L1-KO mice were protected from hepatosteatosis. In conclusion, increasing dietary cholesterol restores diet-induced weight gain in mice deficient in NPC1L1-dependent cholesterol absorption.
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Affiliation(s)
- Lin Jia
- Department of Pathology and Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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37
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Betters JL, Yu L. NPC1L1 and cholesterol transport. FEBS Lett 2010; 584:2740-7. [PMID: 20307540 PMCID: PMC2909875 DOI: 10.1016/j.febslet.2010.03.030] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 12/18/2022]
Abstract
The polytopic transmembrane protein, Niemann-Pick C1-Like 1 (NPC1L1), is enriched in the apical membrane of small intestine absorptive enterocytes where it mediates extracellular sterol transport across the brush border membrane. It is essential for intestinal sterol absorption and is the molecular target of ezetimibe, a potent cholesterol absorption inhibitor that lowers blood cholesterol in humans. NPC1L1 is also highly expressed in human liver. The hepatic function of NPC1L1 may be to limit excessive biliary cholesterol loss. NPC1L1-dependent sterol uptake seems to be a clathrin-mediated endocytic process and is regulated by cellular cholesterol content. Recently, NPC1L1 inhibition has been shown to have beneficial effects on components of the metabolic syndrome, such as obesity, insulin resistance, and fatty liver, in addition to atherosclerosis.
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Affiliation(s)
- Jenna L. Betters
- Department of Pathology Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Liqing Yu
- Department of Pathology Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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38
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Abstract
PURPOSE OF REVIEW Regulation of cholesterol homeostasis is a complex interplay of a multitude of metabolic pathways situated in different organs. The liver plays a central role and has received most attention of the research community. In this review, we discuss recent progress in the understanding of the emerging role of the intestine in cholesterol transport. RECENT FINDINGS In recent years, insight in the transport systems that mediate intestinal cholesterol excretion has deepened considerably. Evidence is emerging that the proximal part of the small intestine is able to secrete cholesterol actively, a pathway called transintestinal cholesterol efflux (TICE). In mice, TICE accounts for up to 70% of fecal neutral sterol excretion. SUMMARY The small intestine plays a significant role in the regulation of body cholesterol homeostasis. Active processes control both absorption and excretion of the sterol and the pathways involved are being elucidated. TICE might provide an attractive target for therapy aiming at reduction of atherosclerosis.
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Costet P. Molecular pathways and agents for lowering LDL-cholesterol in addition to statins. Pharmacol Ther 2010; 126:263-78. [PMID: 20227438 DOI: 10.1016/j.pharmthera.2010.02.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/09/2010] [Indexed: 01/07/2023]
Abstract
Recent guidelines in North America and Europe recommend lowering low density lipoprotein associated cholesterol (LDLC) to achieve optimal coronary heart disease risk reduction. Statins have been the therapy of choice and proven successful and relatively safe. However, we are now facing new challenges and it appears that additional or alternative drugs are urgently needed. This boosts research in the field, reopening old cases like other inhibitors of cholesterol synthesis or making attractive tools from the latest technologies like gene silencing by anti-sense oligonucleotides. LDLs are cholesterol-enriched lipoproteins stabilized by the hepatic apolipoprotein B100, and derived from TG rich very low density lipoprotein. This review focuses on the molecular pathways involved in plasma LDLC production and elimination, in particular cholesterol absorption and the hepatobiliary route, apoB100 and VLDL production, and LDL clearance via the LDL receptor. We will identify important or rate-limiting proteins (including Niemann-Pick C1-like 1 (NPC1L1), microsomal TG transfer protein (MTP), acyl-coenzyme A/cholesterol acyltransferase (ACAT), Acyl-CoA:diacylglycerol acyltransferases 2 (DGAT2), proprotein convertase subtilisin kexin type 9 (PCSK9)), and nuclear receptors (farnesoid X receptor (FXR), thyroid hormone receptor (TR)) that constitute interesting therapeutic targets. Numerous compounds already in use modulate these pathways, such as phytosterols, ezetimibe, bile acids sequestrants, niacin, and fibrates. Many pathways can be considered to lower LDLC, but the road has been paved with disappointments and difficulties. With new targets identified and diversification of the drugs, a new era for better LDLC management is plausible.
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Diab KJ, Adamowicz JJ, Kamocki K, Rush NI, Garrison J, Gu Y, Schweitzer KS, Skobeleva A, Rajashekhar G, Hubbard WC, Berdyshev EV, Petrache I. Stimulation of sphingosine 1-phosphate signaling as an alveolar cell survival strategy in emphysema. Am J Respir Crit Care Med 2010; 181:344-52. [PMID: 19965812 PMCID: PMC5455841 DOI: 10.1164/rccm.200906-0826oc] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 11/20/2009] [Indexed: 01/05/2023] Open
Abstract
RATIONALE Vascular endothelial growth factor receptor (VEGFR) inhibition increases ceramides in lung structural cells of the alveolus, initiating apoptosis and alveolar destruction morphologically resembling emphysema. The effects of increased endogenous ceramides could be offset by sphingosine 1-phosphate (S1P), a prosurvival by-product of ceramide metabolism. OBJECTIVES The aims of our work were to investigate the sphingosine-S1P-S1P receptor axis in the VEGFR inhibition model of emphysema and to determine whether stimulation of S1P signaling is sufficient to functionally antagonize alveolar space enlargement. METHODS Concurrent to VEGFR blockade in mice, S1P signaling augmentation was achieved via treatment with the S1P precursor sphingosine, S1P agonist FTY720, or S1P receptor-1 (S1PR1) agonist SEW2871. Outcomes included sphingosine kinase-1 RNA expression and activity, sphingolipid measurements by combined liquid chromatography-tandem mass spectrometry, immunoblotting for prosurvival signaling pathways, caspase-3 activity and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assays, and airspace morphometry. MEASUREMENTS AND MAIN RESULTS Consistent with previously reported de novo activation of ceramide synthesis, VEGFR inhibition triggered increases in lung ceramides, dihydroceramides, and dihydrosphingosine, but did not alter sphingosine kinase activity or S1P levels. Administration of sphingosine decreased the ceramide-to-S1P ratio in the lung and inhibited alveolar space enlargement, along with activation of prosurvival signaling pathways and decreased lung parenchyma cell apoptosis. Sphingosine significantly opposed ceramide-induced apoptosis in cultured lung endothelial cells, but not epithelial cells. FTY720 or SEW2871 recapitulated the protective effects of sphingosine on airspace enlargement concomitant with attenuation of VEGFR inhibitor-induced lung apoptosis. CONCLUSIONS Strategies aimed at augmenting the S1P-S1PR1 signaling may be effective in ameliorating the apoptotic mechanisms of emphysema development.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/physiology
- Blotting, Western
- Cells, Cultured
- Ceramides/biosynthesis
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Fingolimod Hydrochloride
- Indoles/pharmacology
- Lysophospholipids/biosynthesis
- Lysophospholipids/pharmacology
- Mice
- Mice, Inbred C57BL
- Phosphotransferases (Alcohol Group Acceptor)/metabolism
- Polymerase Chain Reaction
- Propylene Glycols/pharmacology
- Pulmonary Alveoli/drug effects
- Pulmonary Alveoli/physiopathology
- Pulmonary Emphysema/drug therapy
- Pulmonary Emphysema/physiopathology
- Pyrroles/pharmacology
- Receptors, Lysosphingolipid/drug effects
- Receptors, Lysosphingolipid/physiology
- Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors
- Receptors, Vascular Endothelial Growth Factor/drug effects
- Receptors, Vascular Endothelial Growth Factor/physiology
- Signal Transduction/drug effects
- Sphingosine/analogs & derivatives
- Sphingosine/biosynthesis
- Sphingosine/pharmacology
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Abstract
Dysregulation of cholesterol balance contributes significantly to atherosclerotic cardiovascular disease (ASCVD), the leading cause of death in the United States. The intestine has the unique capability to act as a gatekeeper for entry of cholesterol into the body, and inhibition of intestinal cholesterol absorption is now widely regarded as an attractive non-statin therapeutic strategy for ASCVD prevention. In this chapter we discuss the current state of knowledge regarding sterol transport across the intestinal brush border membrane. The purpose of this work is to summarize substantial progress made in the last decade in regards to protein-mediated sterol trafficking, and to discuss this in the context of human disease.
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Affiliation(s)
| | - Liqing Yu
- Address correspondence to: Liqing Yu, M.D., Ph.D., Department of Pathology Section on Lipid Sciences, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1040, Tel: 336-716-0920, Fax: 336-716-6279,
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Sabeva NS, Liu J, Graf GA. The ABCG5 ABCG8 sterol transporter and phytosterols: implications for cardiometabolic disease. Curr Opin Endocrinol Diabetes Obes 2009; 16:172-7. [PMID: 19306529 PMCID: PMC4097028 DOI: 10.1097/med.0b013e3283292312] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review summarizes recent developments in the activity, regulation, and physiology of the ABCG5 ABCG8 (G5G8) transporter and the use of its xenobiotic substrates, phytosterols, as cholesterol lowering agents in the treatment of cardiovascular disease. Recent progress has significant implications for the role of G5G8 and its substrates in complications associated with features of the metabolic syndrome. RECENT FINDINGS Recent reports expand the clinical presentation of sitosterolemia to include platelet and adrenal dysfunction. The G5G8 sterol transporter is critical to hepatobiliary excretion of cholesterol under nonpathological conditions and has been linked to the cholesterol gallstone susceptibility. Finally, the cardiovascular benefits of cholesterol lowering through the use of phytosterol supplements were offset by vascular dysfunction, suggesting that alternative strategies to reduced cholesterol absorption offer greater benefit. SUMMARY Insulin resistance elevates G5G8 and increases susceptibility to cholesterol gallstones. However, this transporter is critical for the exclusion of phytosterols from the absorptive pathways in the intestine. Challenging the limits of this protective mechanism through phytosterol supplementation diminishes the cardioprotective benefits of cholesterol lowering in mouse models of cardiovascular disease.
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Affiliation(s)
- Nadezhda S Sabeva
- University of Kentucky, College of Pharmacy, Pharmaceutical Sciences, Lexington, KY 40536-0082, USA
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44
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Brown JM, Yu L. Opposing Gatekeepers of Apical Sterol Transport: Niemann-Pick C1-Like 1 (NPC1L1) and ATP-Binding Cassette Transporters G5 and G8 (ABCG5/ABCG8). IMMUNOLOGY, ENDOCRINE & METABOLIC AGENTS IN MEDICINAL CHEMISTRY 2009; 9:18-29. [PMID: 20174593 PMCID: PMC2824437 DOI: 10.2174/187152209788009797] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cholesterol is essential for the growth and function of all mammalian cells, but abnormally elevated levels of circulating low-density lipoprotein cholesterol (LDL-C) are a major risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). For many years, statin drugs have been used to effectively lower LDL-C, but ASCVD still persists in most of the world. Hence, additional LDL-C lowering is now recommended, and the search for therapeutic strategies that work in synergy with statins has now begun. Intestinal absorption and biliary excretion of cholesterol represent two major pathways and continue to show promise as druggable processes. Importantly, both of these complex physiological pathways are tightly regulated by key proteins located at the apical surface of the small intestine and the liver. One of these proteins, the target of ezetimibe Niemann-Pick C1-Like 1 (NPC1L1), was recently identified to be essential for intestinal cholesterol absorption and protect against excessive biliary sterol loss. In direct opposition of NPC1L1, the heterodimer of ATP-binding cassette transporters G5 and G8 (ABCG5/ABCG8) has been shown to be critical for promoting biliary cholesterol secretion in the liver, and has also been proposed to play a direct role in intestinal disposal of sterols. The purpose of this review is to summarize the current state of knowledge regarding the function of these opposing apical cholesterol transporters, and provide a framework for future studies examining these proteins.
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Affiliation(s)
- J. Mark Brown
- Department of Pathology-Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Liqing Yu
- Department of Pathology-Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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45
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Davis HR, Altmann SW. Niemann-Pick C1 Like 1 (NPC1L1) an intestinal sterol transporter. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:679-83. [PMID: 19272334 DOI: 10.1016/j.bbalip.2009.01.002] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/06/2009] [Accepted: 01/06/2009] [Indexed: 01/02/2023]
Abstract
Niemann-Pick C1 Like 1 (NPC1L1) has been identified and characterized as an essential protein in the intestinal cholesterol absorption process. NPC1L1 localizes to the brush border membrane of absorptive enterocytes in the small intestine. Intestinal expression of NPC1L1 is down regulated by diets containing high levels of cholesterol. While otherwise phenotypically normal, Npc1l1 null mice exhibit a significant reduction in the intestinal uptake and absorption of cholesterol and phytosterols. Characterization of the NPC1L1 pathway revealed that cholesterol absorption inhibitor ezetimibe specifically binds to an extracellular loop of NPC1L1 and inhibits its sterol transport function. Npc1l1 null mice are resistant to diet-induced hypercholesterolemia, and when crossed with apo E null mice, are completely resistant to the development of atherosclerosis. Intestinal gene expression studies in Npc1l1 null mice indicated that no exogenous cholesterol was entering enterocytes lacking NPC1L1, which resulted in an upregulation of intestinal and hepatic LDL receptor and cholesterol biosynthetic gene expression. Polymorphisms in the human NPC1L1 gene have been found to influence cholesterol absorption and plasma low density lipoprotein levels. Therefore, NPC1L1 is a critical intestinal sterol uptake transporter which influences whole body cholesterol homeostasis.
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Affiliation(s)
- Harry R Davis
- Department of Cardiovascular/Metabolic Disease, Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA.
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Abstract
Mammalian cells have developed various responses to minimize accumulation of unesterified cholesterol, as the latter can result in cell toxicity and death [reviewed in this edition by Björkhem (Björkhem, I. 2009. Are side-chain oxidized oxysterols regulators also in vivo? J. Lipid Res. In press)]. These responses include esterification to sequester excess sterol in intracellular lipid droplets, repression of both cholesterol synthesis and LDL receptor expression (thus reducing endocytosis of LDL), and induction of a panoply of genes that promote sterol efflux and affect lipid metabolism. The nuclear receptor liver-X-receptor (LXR) functions as a cellular "sterol sensor" and plays a critical role in these latter transcriptional changes [reviewed in this edition by Glass (Shibata, N., and Glass C, K. 2009. Regulation of macrophage function in inflammation and atherosclerosis. J. Lipid Res. In press)]. Activation of LXR by either endogenous oxysterols or synthetic agonists induces the expression of many genes, including those encoding ATP-binding cassette (ABC) transporters ABCA1, ABCG1, ABCG5, and ABCG8. As discussed below, these four proteins function to promote sterol efflux from cells.
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Affiliation(s)
- Angel Baldán
- Department of Biological Chemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
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