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Su F, Koeberle A. Regulation and targeting of SREBP-1 in hepatocellular carcinoma. Cancer Metastasis Rev 2023:10.1007/s10555-023-10156-5. [PMID: 38036934 DOI: 10.1007/s10555-023-10156-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/10/2023] [Indexed: 12/02/2023]
Abstract
Hepatocellular carcinoma (HCC) is an increasing burden on global public health and is associated with enhanced lipogenesis, fatty acid uptake, and lipid metabolic reprogramming. De novo lipogenesis is under the control of the transcription factor sterol regulatory element-binding protein 1 (SREBP-1) and essentially contributes to HCC progression. Here, we summarize the current knowledge on the regulation of SREBP-1 isoforms in HCC based on cellular, animal, and clinical data. Specifically, we (i) address the overarching mechanisms for regulating SREBP-1 transcription, proteolytic processing, nuclear stability, and transactivation and (ii) critically discuss their impact on HCC, taking into account (iii) insights from pharmacological approaches. Emphasis is placed on cross-talk with the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt)-mechanistic target of rapamycin (mTOR) axis, AMP-activated protein kinase (AMPK), protein kinase A (PKA), and other kinases that directly phosphorylate SREBP-1; transcription factors, such as liver X receptor (LXR), peroxisome proliferator-activated receptors (PPARs), proliferator-activated receptor γ co-activator 1 (PGC-1), signal transducers and activators of transcription (STATs), and Myc; epigenetic mechanisms; post-translational modifications of SREBP-1; and SREBP-1-regulatory metabolites such as oxysterols and polyunsaturated fatty acids. By carefully scrutinizing the role of SREBP-1 in HCC development, progression, metastasis, and therapy resistance, we shed light on the potential of SREBP-1-targeting strategies in HCC prevention and treatment.
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Affiliation(s)
- Fengting Su
- Michael Popp Institute and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, 6020, Innsbruck, Austria
| | - Andreas Koeberle
- Michael Popp Institute and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, 6020, Innsbruck, Austria.
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2
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Shao Y, Yao Z, Zhou J, Yu M, Chen S, Yuan Y, Han L, Jiang L, Liu J. A novel small compound TOIDC suppresses lipogenesis via SREBP1-dependent signaling to curb MAFLD. Nutr Metab (Lond) 2022; 19:80. [PMID: 36474251 PMCID: PMC9727880 DOI: 10.1186/s12986-022-00713-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/12/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Inhibition of hepatic lipogenesis is widely regarded as an effective treatment for metabolic-associated fatty liver disease (MAFLD), although numerous related drugs have failed to reach clinical application. The goal of this study is to identify a novel small compound that can effectively treat MAFLD. METHODS Primary hepatocytes were first exposed to palmitic acid and oleic acid, then treated with compounds prior to high through screening for cellular lipid content. The efficacy of these compounds was measured by Nile Red staining and triglyceride analysis. The potential cellular toxicity caused by these compounds was evaluated by CCK8 assay. qPCR and Western blot were used to determine expression of RNAs and proteins, respectively. The compound was intraperitoneally injected into diet-induced obese (DIO) mice to examine its efficacy in vivo. RESULTS We identified the dimethyl 1-methyl-2-thioxoindoline-3,3-dicarboxylate (TOIDC) as a powerful chemical to reduce cellular lipid with minimal cellular toxicity. When injected intraperitoneally, TOIDC effectively ameliorates MAFLD in DIO mice. Mechanically, TOIDC suppresses de novo lipogenesis through inhibiting sterol regulatory element-binding protein 1 (SREBP1). CONCLUSIONS Our findings indicate that TOIDC could be a promising lead compound to develop new drugs to treat MAFLD.
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Affiliation(s)
- Yaodi Shao
- grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233 China
| | - Zhi Yao
- grid.22069.3f0000 0004 0369 6365School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241 China
| | - Junyi Zhou
- grid.22069.3f0000 0004 0369 6365School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241 China
| | - Miao Yu
- grid.22069.3f0000 0004 0369 6365School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241 China
| | - Suzhen Chen
- grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233 China
| | - Yanmei Yuan
- grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233 China
| | - Liu Han
- grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233 China
| | - Liqin Jiang
- grid.22069.3f0000 0004 0369 6365School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241 China
| | - Junli Liu
- grid.16821.3c0000 0004 0368 8293Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233 China
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Hasanvand A. The role of AMPK-dependent pathways in cellular and molecular mechanisms of metformin: a new perspective for treatment and prevention of diseases. Inflammopharmacology 2022; 30:775-788. [PMID: 35419709 PMCID: PMC9007580 DOI: 10.1007/s10787-022-00980-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/20/2022] [Indexed: 02/07/2023]
Abstract
Metformin can suppress gluconeogenesis and reduce blood sugar by activating adenosine monophosphate-activated protein kinase (AMPK) and inducing small heterodimer partner (SHP) expression in the liver cells. The main mechanism of metformin’s action is related to its activation of the AMPK enzyme and regulation of the energy balance. AMPK is a heterothermic serine/threonine kinase made of a catalytic alpha subunit and two subunits of beta and a gamma regulator. This enzyme can measure the intracellular ratio of AMP/ATP. If this ratio is high, the amino acid threonine 172 available in its alpha chain would be activated by the phosphorylated liver kinase B1 (LKB1), leading to AMPK activation. Several studies have indicated that apart from its significant role in the reduction of blood glucose level, metformin activates the AMPK enzyme that in turn has various efficient impacts on the regulation of various processes, including controlling inflammatory conditions, altering the differentiation pathway of immune and non-immune cell pathways, and the amelioration of various cancers, liver diseases, inflammatory bowel disease (IBD), kidney diseases, neurological disorders, etc. Metformin’s activation of AMPK enables it to control inflammatory conditions, improve oxidative status, regulate the differentiation pathways of various cells, change the pathological process in various diseases, and finally have positive therapeutic effects on them. Due to the activation of AMPK and its role in regulating several subcellular signalling pathways, metformin can be effective in altering the cells’ proliferation and differentiation pathways and eventually in the prevention and treatment of certain diseases.
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Affiliation(s)
- Amin Hasanvand
- Department of Physiology and Pharmacology, Faculty of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran.
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4
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A propolis-derived small molecule ameliorates metabolic syndrome in obese mice by targeting the CREB/CRTC2 transcriptional complex. Nat Commun 2022; 13:246. [PMID: 35017472 PMCID: PMC8752738 DOI: 10.1038/s41467-021-27533-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/16/2021] [Indexed: 12/28/2022] Open
Abstract
The molecular targets and mechanisms of propolis ameliorating metabolic syndrome are not fully understood. Here, we report that Brazilian green propolis reduces fasting blood glucose levels in obese mice by disrupting the formation of CREB/CRTC2 transcriptional complex, a key regulator of hepatic gluconeogenesis. Using a mammalian two-hybrid system based on CREB-CRTC2, we identify artepillin C (APC) from propolis as an inhibitor of CREB-CRTC2 interaction. Without apparent toxicity, APC protects mice from high fat diet-induced obesity, decreases fasting glucose levels, enhances insulin sensitivity and reduces lipid levels in the serum and liver by suppressing CREB/CRTC2-mediated both gluconeogenic and SREBP transcriptions. To develop more potential drugs from APC, we designed and found a novel compound, A57 that exhibits higher inhibitory activity on CREB-CRTC2 association and better capability of improving insulin sensitivity in obese animals, as compared with APC. In this work, our results indicate that CREB/CRTC2 is a suitable target for developing anti-metabolic syndrome drugs.
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Associations among perfluorooctanesulfonic/perfluorooctanoic acid levels, nuclear receptor gene polymorphisms, and lipid levels in pregnant women in the Hokkaido study. Sci Rep 2021; 11:9994. [PMID: 33976266 PMCID: PMC8113244 DOI: 10.1038/s41598-021-89285-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 04/19/2021] [Indexed: 12/19/2022] Open
Abstract
The effect of interactions between perfluorooctanesulfonic (PFOS)/perfluorooctanoic acid (PFOA) levels and nuclear receptor genotypes on fatty acid (FA) levels, including those of triglycerides, is not clear understood. Therefore, in the present study, we aimed to analyse the association of PFOS/PFOA levels and single-nucleotide polymorphisms (SNPs) in nuclear receptors with FA levels in pregnant women. We analysed 504 mothers in a birth cohort between 2002 and 2005 in Japan. Serum PFOS/PFOA and FA levels were measured using liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Maternal genotypes in PPARA (rs1800234; rs135561), PPARG (rs3856806), PPARGC1A (rs2970847; rs8192678), PPARD (rs1053049; rs2267668), CAR (rs2307424; rs2501873), LXRA (rs2279238) and LXRB (rs1405655; rs2303044; rs4802703) were analysed. When gene-environment interaction was considered, PFOS exposure (log10 scale) decreased palmitic, palmitoleic, and oleic acid levels (log10 scale), with the observed β in the range of - 0.452 to - 0.244; PPARGC1A (rs8192678) and PPARD (rs1053049; rs2267668) genotypes decreased triglyceride, palmitic, palmitoleic, and oleic acid levels, with the observed β in the range of - 0.266 to - 0.176. Interactions between PFOS exposure and SNPs were significant for palmitic acid (Pint = 0.004 to 0.017). In conclusion, the interactions between maternal PFOS levels and PPARGC1A or PPARD may modify maternal FA levels.
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Chen YQ, Pottanat TG, Zhen EY, Siegel RW, Ehsani M, Qian YW, Konrad RJ. ApoA5 lowers triglyceride levels via suppression of ANGPTL3/8-mediated LPL inhibition. J Lipid Res 2021; 62:100068. [PMID: 33762177 PMCID: PMC8079461 DOI: 10.1016/j.jlr.2021.100068] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/07/2021] [Indexed: 02/06/2023] Open
Abstract
Triglyceride (TG) molecules represent the major storage form of fatty acids, and TG metabolism is essential to human health. However, the mechanistic details surrounding TG metabolism are complex and incompletely elucidated. Although it is known that angiopoietin-like protein 8 (ANGPTL8) increases TGs through an ANGPTL3/8 complex that inhibits LPL, the mechanism governing ApoA5, which lowers TGs, has remained elusive. Current hypotheses for how ApoA5 acts include direct stimulation of LPL, facilitation of TG-containing particle uptake, and regulation of hepatic TG secretion. Using immunoprecipitation-MS and Western blotting, biolayer interferometry, functional LPL enzymatic assays, and kinetic analyses of LPL activity, we show that ApoA5 associates with ANGPTL3/8 in human serum and most likely decreases TG by suppressing ANGPTL3/8-mediated LPL inhibition. We also demonstrate that ApoA5 has no direct effect on LPL, nor does it suppress the LPL-inhibitory activities of ANGPTL3, ANGPTL4, or ANGPTL4/8. Importantly, ApoA5 suppression of ANGPTL3/8-mediated LPL inhibition occurred at a molar ratio consistent with the circulating concentrations of ApoA5 and ANGPTL3/8. Because liver X receptor (LXR) agonists decrease ApoA5 expression and cause hypertriglyceridemia, we investigated the effect of the prototypical LXR agonist T0901317 on human primary hepatocytes. We observed that T0901317 modestly stimulated hepatocyte ApoA5 release, but markedly stimulated ANGPTL3/8 secretion. Interestingly, the addition of insulin to T0901317 attenuated ApoA5 secretion, but further increased ANGPTL3/8 secretion. Together, these results reveal a novel intersection of ApoA5 and ANGPTL3/8 in the regulation of TG metabolism and provide a possible explanation for LXR agonist-induced hypertriglyceridemia.
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Affiliation(s)
- Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Thomas G Pottanat
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA; Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Eugene Y Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Robert W Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Yue-Wei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA.
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7
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Huang Y, Ning K, Li WW, Lin G, Hou CL, Wang MJ, Zhu YC. Hydrogen sulfide accumulates LDL receptor precursor via downregulating PCSK9 in HepG2 cells. Am J Physiol Cell Physiol 2020; 319:C1082-C1096. [DOI: 10.1152/ajpcell.00244.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Endogenous hydrogen sulfide (H2S) affects cholesterol homeostasis and liver X receptor α (LXRα) expression. However, whether low-density lipoprotein (LDL) receptor (LDLR), a key player in cholesterol homeostasis, is regulated by exogenous H2S through LXRα signaling has not been determined. We investigated the effects of sodium hydrosulfide (NaHS, H2S donor) on LDLR expression in the presence or absence of LXR agonists, T0901317 or GW3965 in HepG2 cells. We found that H2S strongly accumulated LDLR precursor in the presence of T0901317. Hence, LDLR transcription and the genes involved in LDLR precursor maturation and degradation were studied. T0901317 increased the LDLR mRNA level, whereas H2S did not affect LDLR transcription. H2S had no significant effect on the expression of LXRα and inducible degrader of LDLR (IDOL). H2S and T0901317 altered mRNA levels of several enzymes for N- and O-glycosylation and endoplasmic reticulum (ER) chaperones assisting LDLR maturation, but did not affect their protein levels. H2S decreased proprotein convertase subtilisin/kexin type 9 (PCSK9) protein levels and its mRNA level elevated by T0901317. T0901317 with PCSK9 siRNA also accumulated LDLR precursor as did T0901317 with H2S. High glucose increased PCSK9 protein levels and attenuated LDLR precursor accumulation induced by T0901317 with H2S. Taken together, H2S accumulates LDLR precursor by downregulating PCSK9 expression but not through the LXRα-IDOL pathway, LDLR transcriptional activation, or dysfunction of glycosylation enzymes and ER chaperones. These results also indicate that PCSK9 plays an important role in LDLR maturation in addition to its well-known effect on the degradation of LDLR mature form.
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Affiliation(s)
- Yong Huang
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Ke Ning
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Wen-Wen Li
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ge Lin
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Cui-Lan Hou
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Ming-Jie Wang
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yi-Chun Zhu
- Shanghai Key Laboratory of Bioactive Small Molecules and Shanghai Key Laboratory of Clinical Geriatric Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
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Su X, Weng S, Peng D. New Insights into Apolipoprotein A5 and the Modulation of Human Adipose-derived Mesenchymal Stem Cells Adipogenesis. Curr Mol Med 2020; 20:144-156. [PMID: 31560287 DOI: 10.2174/1566524019666190927155702] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 11/22/2022]
Abstract
Background:
The hallmark of obesity is the excessive accumulation of
triglyceride (TG) in adipose tissue. Apolipoprotein A5 (ApoA5) has been shown to
influence the prevalence and pathogenesis of obesity. However, the underlying
mechanisms remain to be clarified.
Methods:
Human adipose-derived mesenchymal stem cells (AMSCs) were treated with
600 ng/ml human recombinant ApoA5 protein. The effect of ApoA5 on intracellular TG
content and adipogenic related factors expression were determined. Furthermore, the
effect of ApoA5 on CIDE-C expression was also observed.
Results:
During the process of adipogenesis, ApoA5 treatment reduced the intracellular
accumulation of lipid droplets and the TG levels; meanwhile, ApoA5 down-regulated the
expression levels of adipogenic related factors, including CCAAT enhancer-binding
proteins α/β (C/EBPα/β), fatty acid synthetase (FAS), and fatty acid-binding protein 4
(FABP4). Furthermore, the suppression of adipogenesis by ApoA5 was mediated
through the inhibition of CIDE-C expression, an important factor which promotes the
process of adipogenesis. However, over-expressing intracellular CIDE-C could lead to
the loss-of-function of ApoA5 in inhibiting AMSCs adipogenesis.
Conclusions:
In conclusion, ApoA5 inhibits the adipogenic process of AMSCs through,
at least partly, down-regulating CIDE-C expression. The present study provides novel
mechanisms whereby ApoA5 prevents obesity via AMSCs in humans.
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Affiliation(s)
- Xin Su
- Department of Cardiovascular Medicine, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Shuwei Weng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Daoquan Peng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital of Central South University, Changsha, Hunan, China
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Weiss-Hersh K, Garcia AL, Marosvölgyi T, Szklenár M, Decsi T, Rühl R. Saturated and monounsaturated fatty acids in membranes are determined by the gene expression of their metabolizing enzymes SCD1 and ELOVL6 regulated by the intake of dietary fat. Eur J Nutr 2019; 59:2759-2769. [PMID: 31676951 PMCID: PMC7413877 DOI: 10.1007/s00394-019-02121-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/16/2019] [Indexed: 12/12/2022]
Abstract
PURPOSE We investigated the effect of dietary fats on the incorporation of saturated (SAFAs) and monounsaturated dietary fatty acids (MUFAs) into plasma phospholipids and the regulation of the expression of lipid-metabolizing enzymes in the liver. METHODS Mice were fed different diets containing commonly used dietary fats/oils (coconut fat, margarine, fish oil, sunflower oil, or olive oil) for 4 weeks (n = 6 per diet group). In a second experiment, mice (n = 6 per group) were treated for 7 days with synthetic ligands to activate specific nuclear hormone receptors (NHRs) and the hepatic gene expression of CYP26A1 was investigated. Hepatic gene expression of stearoyl-coenzyme A desaturase 1 (SCD1), elongase 6 (ELOVL6), and CYP26A1 was examined using quantitative real-time PCR (QRT-PCR). Fatty acid composition in mouse plasma phospholipids was analyzed by gas chromatography (GC). RESULTS We found significantly reduced hepatic gene expression of SCD1 and ELOVL6 after the fish oil diet compared with the other diets. This resulted in reduced enzyme-specific fatty acid ratios, e.g., 18:1n9/18:0 for SCD1 and 18:0/16:0 and 18:1n7/16:1n7 for ELOVL6 in plasma phospholipids. Furthermore, CYP26A1 a retinoic acid receptor-specific target was revealed as a new player mediating the suppressive effect of fish oil-supplemented diet on SCD1 and ELOVL6 hepatic gene expression. CONCLUSION Plasma levels of MUFAs and SAFAs strongly reflect an altered hepatic fatty acid-metabolizing enzyme expression after supplementation with different dietary fats/oils.
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Affiliation(s)
- Kathrin Weiss-Hersh
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Ada L Garcia
- Human Nutrition, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | | | | | - Tamás Decsi
- Department of Paediatrics, University of Pécs, Pécs, Hungary
| | - Ralph Rühl
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.,Paprika Bioanalytics BT, Debrecen, Hungary
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Chang RC, Thomas KN, Bedi YS, Golding MC. Programmed increases in LXRα induced by paternal alcohol use enhance offspring metabolic adaptation to high-fat diet induced obesity. Mol Metab 2019; 30:161-172. [PMID: 31767168 PMCID: PMC6807343 DOI: 10.1016/j.molmet.2019.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/25/2019] [Accepted: 09/29/2019] [Indexed: 12/12/2022] Open
Abstract
Objectives Paternally inherited alterations in epigenetic programming are emerging as relevant factors in numerous disease states, including the growth and metabolic defects observed in fetal alcohol spectrum disorders. In rodents, chronic paternal alcohol use induces fetal growth restriction, as well as sex-specific alterations in insulin signaling and lipid homeostasis in the offspring. Based on previous studies, we hypothesized that the observed metabolic irregularities are the consequence of paternally inherited alterations liver x receptor (LXR) activity. Methods Male offspring of alcohol-exposed sires were challenged with a high-fat diet and the molecular pathways controlling glucose and lipid homeostasis assayed for LXR-induced alterations. Results Similar to findings in studies employing LXR agonists we found that the male offspring of alcohol-exposed sires display resistance to diet-induced obesity and improved glucose homeostasis when challenged with a high-fat diet. This improved metabolic adaptation is mediated by LXRα trans-repression of inflammatory cytokines, releasing IKKβ inhibition of the insulin signaling pathway. Interestingly, paternally programmed increases in LXRα expression are liver-specific and do not manifest in the pancreas or visceral fat. Conclusions These studies identify LXRα as a key mediator of the long-term metabolic alterations induced by preconception paternal alcohol use. Chronic paternal alcohol use induces up-regulation of LXRα in the male offspring. Male offspring of alcohol-exposed fathers are protected from diet-induced obesity. Paternally-inherited up-regulation of LXRα only manifests in the liver. Improved metabolic adaptation is linked to LXRα suppression of cytokine production. Male offspring exhibit the same phenotypes observed in studies of LXR agonists.
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Affiliation(s)
- Richard C Chang
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Kara N Thomas
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Yudhishtar S Bedi
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Michael C Golding
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA.
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Ding P, Chen Z, Chen H, Zhang Z, Liu Z, Yan X, Zhou H, Gu Q, Li C, Xu J. Structurally Selective Mechanism of Liver X Receptor Ligand: In Silico and In Vitro Studies. J Chem Inf Model 2019; 59:3277-3290. [DOI: 10.1021/acs.jcim.9b00292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Peng Ding
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Ziyang Chen
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Hao Chen
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Zizhen Zhang
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Zhihong Liu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Xin Yan
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Huihao Zhou
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Qiong Gu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Chanjuan Li
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, 132 East Circle at University City, Guangzhou 510006, China
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12
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Role of gut microbiota in the development of non-alcoholic fatty liver disease. LIVER RESEARCH 2019. [DOI: 10.1016/j.livres.2019.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Treviño-Villarreal JH, Reynolds JS, Bartelt A, Langston PK, MacArthur MR, Arduini A, Tosti V, Veronese N, Bertozzi B, Brace LE, Mejia P, Trocha K, Kajitani GS, Longchamp A, Harputlugil E, Gathungu R, Bird SS, Bullock AD, Figenshau RS, Andriole GL, Thompson A, Heeren J, Ozaki CK, Kristal BS, Fontana L, Mitchell JR. Dietary protein restriction reduces circulating VLDL triglyceride levels via CREBH-APOA5-dependent and -independent mechanisms. JCI Insight 2018; 3:99470. [PMID: 30385734 DOI: 10.1172/jci.insight.99470] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 09/11/2018] [Indexed: 12/14/2022] Open
Abstract
Hypertriglyceridemia is an independent risk factor for cardiovascular disease. Dietary interventions based on protein restriction (PR) reduce circulating triglycerides (TGs), but underlying mechanisms and clinical relevance remain unclear. Here, we show that 1 week of a protein-free diet without enforced calorie restriction significantly lowered circulating TGs in both lean and diet-induced obese mice. Mechanistically, the TG-lowering effect of PR was due, in part, to changes in very low-density lipoprotein (VLDL) metabolism both in liver and peripheral tissues. In the periphery, PR stimulated VLDL-TG consumption by increasing VLDL-bound APOA5 expression and promoting VLDL-TG hydrolysis and clearance from circulation. The PR-mediated increase in Apoa5 expression was controlled by the transcription factor CREBH, which coordinately regulated hepatic expression of fatty acid oxidation-related genes, including Fgf21 and Ppara. The CREBH-APOA5 axis activation upon PR was intact in mice lacking the GCN2-dependent amino acid-sensing arm of the integrated stress response. However, constitutive hepatic activation of the amino acid-responsive kinase mTORC1 compromised CREBH activation, leading to blunted APOA5 expression and PR-recalcitrant hypertriglyceridemia. PR also contributed to hypotriglyceridemia by reducing the rate of VLDL-TG secretion, independently of activation of the CREBH-APOA5 axis. Finally, a randomized controlled clinical trial revealed that 4-6 weeks of reduced protein intake (7%-9% of calories) decreased VLDL particle number, increased VLDL-bound APOA5 expression, and lowered plasma TGs, consistent with mechanistic conservation of PR-mediated hypotriglyceridemia in humans with translational potential as a nutraceutical intervention for dyslipidemia.
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Affiliation(s)
| | - Justin S Reynolds
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alexander Bartelt
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Sabri Ülker Center for Nutrient, Genetic, and Metabolic Research, Boston, Massachusetts, USA.,Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - P Kent Langston
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Michael R MacArthur
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alessandro Arduini
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Sabri Ülker Center for Nutrient, Genetic, and Metabolic Research, Boston, Massachusetts, USA
| | - Valeria Tosti
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Nicola Veronese
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Beatrice Bertozzi
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Lear E Brace
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Pedro Mejia
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Kaspar Trocha
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Gustavo S Kajitani
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alban Longchamp
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Eylul Harputlugil
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Rose Gathungu
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School (HMS), Boston, Massachusetts, USA
| | - Susan S Bird
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Surgery, HMS, Boston, Massachusetts, USA
| | - Arnold D Bullock
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Robert S Figenshau
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gerald L Andriole
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Andrew Thompson
- Dana Farber Cancer Institute/HMS Rodent Histopathology Core Facility, HMS, Boston, Massachusetts, USA
| | - Jöerg Heeren
- Department for Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Germany
| | - C Keith Ozaki
- Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Bruce S Kristal
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School (HMS), Boston, Massachusetts, USA.,Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Surgery, HMS, Boston, Massachusetts, USA
| | - Luigi Fontana
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,School of Medicine and Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - James R Mitchell
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
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14
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Aibara D, Matsusue K, Takiguchi S, Gonzalez FJ, Yamano S. Fat-specific protein 27 is a novel target gene of liver X receptor α. Mol Cell Endocrinol 2018; 474:48-56. [PMID: 29454584 PMCID: PMC6594021 DOI: 10.1016/j.mce.2018.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/16/2018] [Accepted: 02/12/2018] [Indexed: 12/12/2022]
Abstract
Fat-specific protein 27 (FSP27) is highly expressed in the fatty liver of genetically obese ob/ob mice and promotes hepatic triglyceride (TG) accumulation. The nuclear hormone receptor liver X receptor α (LXRα) also plays a critical role in the control of TG levels in the liver. The present study demonstrated transcriptional regulation of Fsp27a and Fsp27b genes by LXRα. Treatment with the LXR ligand T0901317 markedly increased Fsp27a and Fsp27b mRNAs in wild-type C57BL/6J and ob/ob mouse livers. A reporter assay indicated that two LXR-responsive elements (LXREs) are necessary for LXRα-dependent induction of Fsp27a and Fsp27b promoter activities. Furthermore, the LXRα/retinoid X receptor α complex is capable of directly binding to the two LXREs both in vitro and in vivo. These results suggest that LXRα positively regulates Fsp27a and Fsp27b expression through two functional LXREs. Fsp27a/b are novel LXR target genes in the ob/ob fatty liver.
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Affiliation(s)
- Daisuke Aibara
- Faculty of Pharmaceutical Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Kimihiko Matsusue
- Faculty of Pharmaceutical Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
| | - Soichi Takiguchi
- Institute for Clinical Research, National Kyushu Cancer Center, 3-1-1 Notame, Minami-ku, Fukuoka 811-1395, Japan
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shigeru Yamano
- Faculty of Pharmaceutical Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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15
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Abstract
Alternative splicing (AS) is a fundamental regulatory process in all higher eukaryotes. However, AS landscapes for a number of animals, including goats, have not been explored to date. Here, we sequenced 60 samples representing 5 tissues from 4 developmental stages in triplicate using RNA-seq to elucidate the goat AS landscape. In total, 14,521 genes underwent AS (AS genes), accounting for 85.53% of intron-containing genes (16,697). Among these AS genes, 6,342 were differentially expressed in different tissues. Of the AS events identified, retained introns were most prevalent (37.04% of total AS events). Functional enrichment analysis of differential and specific AS genes indicated goat AS mainly involved in organ function and development. Particularly, AS genes identified in leg muscle were associated with the “regulation of skeletal muscle tissue development” GO term. Given genes were associated with this term, four of which (NRG4, IP6K3, AMPD1, and DYSF) might play crucial roles in skeletal muscle development. Further investigation indicated these five genes, harbored 13 ASs, spliced exclusively in leg muscle, likely played a role in goat leg muscle development. These results provide novel insights into goat AS landscapes and a valuable resource for investigation of goat transcriptome complexity and gene regulation.
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16
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Su X, Kong Y, Peng DQ. New insights into apolipoprotein A5 in controlling lipoprotein metabolism in obesity and the metabolic syndrome patients. Lipids Health Dis 2018; 17:174. [PMID: 30053818 PMCID: PMC6064078 DOI: 10.1186/s12944-018-0833-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 07/20/2018] [Indexed: 01/01/2023] Open
Abstract
Apolipoprotein A5 (apoA5) has been identified to play an important role in lipid metabolism, specifically in triglyceride (TG) and TG-rich lipoproteins (TRLs) metabolism. Numerous evidence has demonstrated for an association between apoA5 and the increased risk of obesity and metabolic syndrome, but the mechanism remains to be fully elucidated. Recently, several studies verified that apoA5 could significantly reduce plasma TG level by stimulating lipoprotein lipase (LPL) activity, and the intracellular role of apoA5 has also been proved since apoA5 is associated with cytoplasmic lipid droplets (LDs) and affects intrahepatic TG accumulation. Furthermore, since adipocytes provide the largest storage depot for TG and play a crucial role in the development of obesity, we could infer that apoA5 also acts as a novel regulator to modulate TG storage in adipocytes. In this review, we focus on the association of gene and protein of apoA5 with obesity and metabolic syndrome, and provide new insights into the physiological role of apoA5 in humans, giving a potential therapeutic target for obesity and associated disorders.
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Affiliation(s)
- Xin Su
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Yi Kong
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Dao-Quan Peng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.
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17
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Lin MJ, Dai W, Scott MJ, Li R, Zhang YQ, Yang Y, Chen LZ, Huang XS. Metformin improves nonalcoholic fatty liver disease in obese mice via down-regulation of apolipoprotein A5 as part of the AMPK/LXRα signaling pathway. Oncotarget 2017; 8:108802-108809. [PMID: 29312569 PMCID: PMC5752482 DOI: 10.18632/oncotarget.22163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/22/2017] [Indexed: 12/19/2022] Open
Abstract
Apolipoprotein A5 (apoA5) has been implicated in the formation of hepatocyte lipid droplets, a histological hallmark of non-alcoholic fatty liver disease (NAFLD). Recent evidence demonstrated that liver X receptor α (LXRα), a transcription factor involved in down-regulation of APOA5 mRNA, is activated by AMP-activated protein kinase (AMPK) that contributes to metformin-related antihyperglycemic effects. In this study we investigated the role of apoA5 and AMPK/LXRα signaling pathway in metformin-related improvement of NAFLD. Leptin-deficient (ob/ob) obese mice with NAFLD were treated with metformin, and signaling pathways were compared with non-metformin treated mice. Additionally, we determined cellular apoA5 and triglyceride (TG) levels in mouse hepatocytes in vitro and the effects of metformin, with or without an AMPK inhibitor or LXRα siRNA, on these levels. We found that metformin dose-dependently ameliorated hepatosteatosis and liver dysfunction in ob/ob mice, with a significant reduction in hepatic apoA5 expression and TG level. Metformin also dose-dependently increased phosphorylation of hepatic AMPK and LXRα in ob/ob mice. Similarly, metformin decreased apoA5 expression and TG level in mouse hepatocytes, with increased phosphorylation of cellular AMPK and LXRα. Addition of AMPK inhibitor or siRNA knockdown of LXRα significantly attenuated metformin-induced down-regulation of cellular apoA5 expression and TG level. AMPK inhibitor also significantly inhibited metformin-induced LXRα phosphorylation in these hepatocytes. Therefore, our findings indicate that metformin improves obesity-related NAFLD via inhibition of hepatic apoA5 synthesis as part of the AMPK/LXRα signaling pathway.
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Affiliation(s)
- Min-Jie Lin
- Clinical Skills Training Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Wen Dai
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Melanie J Scott
- Department of Surgery Labs, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Rong Li
- Department of Stomatology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Yi-Qi Zhang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Yang Yang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Lu-Zhu Chen
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Xian-Sheng Huang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
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18
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Zhu J, Zhang X, Chen X, Sun Y, Dai Y, Chen C, Zhang T, Yan Z. Studies on the regulation of lipid metabolism and the mechanism of the aqueous and ethanol extracts of Usnea. Biomed Pharmacother 2017; 94:930-936. [DOI: 10.1016/j.biopha.2017.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/24/2017] [Accepted: 08/02/2017] [Indexed: 01/08/2023] Open
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19
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Kick EK, Busch BB, Martin R, Stevens WC, Bollu V, Xie Y, Boren BC, Nyman MC, Nanao MH, Nguyen L, Plonowski A, Schulman IG, Yan G, Zhang H, Hou X, Valente MN, Narayanan R, Behnia K, Rodrigues AD, Brock B, Smalley J, Cantor GH, Lupisella J, Sleph P, Grimm D, Ostrowski J, Wexler RR, Kirchgessner T, Mohan R. Discovery of Highly Potent Liver X Receptor β Agonists. ACS Med Chem Lett 2016; 7:1207-1212. [PMID: 27994765 PMCID: PMC5150697 DOI: 10.1021/acsmedchemlett.6b00234] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/27/2016] [Indexed: 12/13/2022] Open
Abstract
![]()
Introducing a uniquely substituted
phenyl sulfone into a series
of biphenyl imidazole liver X receptor (LXR) agonists afforded a dramatic
potency improvement for induction of ATP binding cassette transporters,
ABCA1 and ABCG1, in human whole blood. The agonist series demonstrated
robust LXRβ activity (>70%) with low partial LXRα agonist
activity (<25%) in cell assays, providing a window between desired
blood cell ABCG1 gene induction in cynomolgus monkeys and modest elevation
of plasma triglycerides for agonist 15. The addition
of polarity to the phenyl sulfone also reduced binding to the plasma
protein, human α-1-acid glycoprotein. Agonist 15 was selected for clinical development based on the favorable combination
of in vitro properties, excellent pharmacokinetic
parameters, and a favorable lipid profile.
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Affiliation(s)
| | - Brett B. Busch
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Richard Martin
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - William C. Stevens
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Venkataiah Bollu
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Yinong Xie
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Brant C. Boren
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Michael C. Nyman
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Max H. Nanao
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Lam Nguyen
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Artur Plonowski
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Ira G. Schulman
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | - Grace Yan
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Raju Mohan
- Exelixis Inc., 210 East Grand
Avenue, South San Francisco, California 94080, United States
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20
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Zhu J, Xu K, Zhang X, Cao J, Jia Z, Yang R, Ma C, Chen C, Zhang T, Yan Z. Studies on the regulation of lipid metabolism and its mechanism of the iridoids rich fraction in Valeriana jatamansi Jones. Biomed Pharmacother 2016; 84:1891-1898. [PMID: 27832992 DOI: 10.1016/j.biopha.2016.10.099] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 10/16/2016] [Accepted: 10/31/2016] [Indexed: 12/27/2022] Open
Abstract
Valeriana jatamansi Jones, a plant with heart-shaped leaves in the Valeriana genus of Valerianaceae, is widely used in Chinese folk medicine. Iridoid is an important constituent of V. jatamansi that contributes to the pharmacological efficacy of the herb. This study aims to investigate the regulation of lipid metabolism and its mechanism of the iridoids rich fraction in V. jatamansi (IRFV). A high fat diet was used to establish the hyperlipidemia rat model, with 2mg/kg/d of simvastatin as a positive control, fed with 7.5, 15, and 30mg/kg/d of IRFV for 20days to investigate the lipid regulation activity and mechanism of IRFV. Body weight, liver index, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in both serum and liver, as well as total bile acid (TBA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in serum were measured. The lipoprotein lipase (LPL) and hepatic lipase (HL) activities and the apoprotein A5 (ApoA5), peroxisome proliferator-activated receptor α (PPAR-α), sterol regulatory element-binding proteins (SREBP-1c), and liver X receptor α (LXR-α) protein expressions were observed. Liver pathology was described through hematoxylin-eosin (HE) staining. Compared with the model group, three different IRFV dosages can slow down the weight gain of rats, reduce the contents of TG, and increase the contents of HDL-C in serum. Low IRFV dosage can significantly reduce the AST and ALT contents in serum, liver index, and the TG contents in liver, enhance LPL activity. Medium IRFV dosage can significantly decrease the TG and LDL-C contents in liver. High IRFV dosage can significantly reduce LDL-C, TBA, AST, and ALT contents in serum, and enhance HL activity. Three different IRFV dosages can significantly increase the ApoA5 and PPAR-α protein expression and decrease the SREBP-1c protein expression. Furthermore, the LXR-α protein expression decreased in low- and high-dose groups. Liver tissue pathological observation showed that IRFV can improve cell degeneration to a certain extent. These results strongly suggest that IRFV play significant roles in regulating lipid metabolism, the mechanism may be related to the increased ApoA5 protein expression.
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Affiliation(s)
- Jiali Zhu
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Keke Xu
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Xuemei Zhang
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Jiahong Cao
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Zhanrong Jia
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Ruocong Yang
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Chaoying Ma
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
| | - Chang Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China
| | - Tiane Zhang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine,Chengdu 611137, PR China.
| | - Zhiyong Yan
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China.
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21
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Kirchgessner TG, Sleph P, Ostrowski J, Lupisella J, Ryan CS, Liu X, Fernando G, Grimm D, Shipkova P, Zhang R, Garcia R, Zhu J, He A, Malone H, Martin R, Behnia K, Wang Z, Barrett YC, Garmise RJ, Yuan L, Zhang J, Gandhi MD, Wastall P, Li T, Du S, Salvador L, Mohan R, Cantor GH, Kick E, Lee J, Frost RJA. Beneficial and Adverse Effects of an LXR Agonist on Human Lipid and Lipoprotein Metabolism and Circulating Neutrophils. Cell Metab 2016; 24:223-33. [PMID: 27508871 DOI: 10.1016/j.cmet.2016.07.016] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/21/2016] [Accepted: 07/21/2016] [Indexed: 01/20/2023]
Abstract
The development of LXR agonists for the treatment of coronary artery disease has been challenged by undesirable properties in animal models. Here we show the effects of an LXR agonist on lipid and lipoprotein metabolism and neutrophils in human subjects. BMS-852927, a novel LXRβ-selective compound, had favorable profiles in animal models with a wide therapeutic index in cynomolgus monkeys and mice. In healthy subjects and hypercholesterolemic patients, reverse cholesterol transport pathways were induced similarly to that in animal models. However, increased plasma and hepatic TG, plasma LDL-C, apoB, apoE, and CETP and decreased circulating neutrophils were also evident. Furthermore, similar increases in LDL-C were observed in normocholesterolemic subjects and statin-treated patients. The primate model markedly underestimated human lipogenic responses and did not predict human neutrophil effects. These studies demonstrate both beneficial and adverse LXR agonist clinical responses and emphasize the importance of further translational research in this area.
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Affiliation(s)
| | - Paul Sleph
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Jacek Ostrowski
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - John Lupisella
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Carol S Ryan
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Xiaoqin Liu
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Gayani Fernando
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Denise Grimm
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Petia Shipkova
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Rongan Zhang
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Ricardo Garcia
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Jun Zhu
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Aiqing He
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Harold Malone
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | | | - Kamelia Behnia
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Zhaoqing Wang
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Yu Chen Barrett
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Robert J Garmise
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Long Yuan
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Jane Zhang
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Mohit D Gandhi
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Philip Wastall
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Tong Li
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Shuyan Du
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Lisa Salvador
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Raju Mohan
- Exelixis, Inc., South San Francisco, CA 94080, USA
| | - Glenn H Cantor
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Ellen Kick
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - John Lee
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
| | - Robert J A Frost
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, USA
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22
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Abstract
Apolipoprotein A5 (apoA5) is a potent regulator of triglyceride (TG) metabolism and therefore may contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD), a disease characterised by excessive TG-rich lipid droplets in hepatocytes. To test this hypothesis, we examined the mRNA expression of apoA5 in paediatric NAFLD livers in comparison to healthy controls. According to microarray and quantitative real-time PCR, human NAFLD livers exhibited elevated apoA5 expression compared to healthy controls. The apoA5 expression levels were positively correlated with hepatic TG storage and a marker for lipid droplets (perilipin), but were not correlated with plasma TG levels. These observations were confirmed with a NAFLD rat model. Interestingly, apoA5 expression was not altered in cultured fat-laden HepG2 cells, demonstrating that fat storage does not induce apoA5 in NAFLD livers. Therefore, the correlation between apoA5 and intracellular fat storage is likely explained by the potent effect of apoA5 in promoting intracellular fat storage. Our NAFLD patients and rats had elevated insulin resistance, which may have a role in elevating apoA5 expression in NAFLD livers. Our data support the hypothesis that apoA5 promotes hepatic TG storage and therefore contributes to the pathogenesis of NAFLD, and may represent a potential target for therapeutic intervention.
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Wang M, Zhao S, Tan M. Is neuregulin 4 a potential regulator of apolipoprotein A-V gene expression. Int J Cardiol 2015; 184:314. [DOI: 10.1016/j.ijcard.2015.02.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
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Kirchgessner TG, Martin R, Sleph P, Grimm D, Liu X, Lupisella J, Smalley J, Narayanan R, Xie Y, Ostrowski J, Cantor GH, Mohan R, Kick E. Pharmacological characterization of a novel liver X receptor agonist with partial LXRα activity and a favorable window in nonhuman primates. J Pharmacol Exp Ther 2014; 352:305-14. [PMID: 25467132 DOI: 10.1124/jpet.114.219923] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Liver X Receptors (LXRs) α and β are nuclear hormone receptors that regulate multiple genes involved in reverse cholesterol transport (RCT) and are potential drug targets for atherosclerosis. However, full pan agonists also activate lipogenic genes, resulting in elevated plasma and hepatic lipids. We report the pharmacology of BMS-779788 [2-(2-(1-(2-chlorophenyl)-1-methylethyl)-1-(3'-(methylsulfonyl)-4-biphenylyl)-1H-imidazol-4-yl)-2-propanol], a potent partial LXR agonist with LXRβ selectivity, which has an improved therapeutic window in the cynomolgus monkey compared with a full pan agonist. BMS-779788 induced LXR target genes in blood in vivo with an EC50 = 610 nM, a value similar to its in vitro blood gene induction potency. BMS-779788 was 29- and 12-fold less potent than the full agonist T0901317 in elevating plasma triglyceride and LDL cholesterol, respectively, with similar results for plasma cholesteryl ester transfer protein and apolipoprotein B. However, ABCA1 and ABCG1 mRNA inductions in blood, which are critical for RCT, were comparable. Increased liver triglyceride was observed after 7-day treatment with BMS-779788 at the highest dose tested and was nearly identical to the dose response for plasma triglyceride, consistent with the central role of liver LXR in these lipogenic effects. Dose-dependent increases in biliary cholesterol and decreases in phospholipid and bile acid occurred in BMS-779788-treated animals, similar to LXR agonist effects reported in mouse. In summary, BMS-779788, a partial LXRβ selective agonist, has decreased lipogenic potential compared with a full pan agonist in cynomolgus monkeys, with similar potency in the induction of genes known to stimulate RCT. This provides support in nonhuman primates for improving LXR agonist therapeutic windows by limiting LXRα activity.
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Affiliation(s)
- Todd G Kirchgessner
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Richard Martin
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Paul Sleph
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Denise Grimm
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Xiaoqin Liu
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - John Lupisella
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - James Smalley
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Rangaraj Narayanan
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Yinong Xie
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Jacek Ostrowski
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Glenn H Cantor
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Raju Mohan
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
| | - Ellen Kick
- Bristol-Myers Squibb Research and Development, Bristol-Myers Squibb, Inc., Princeton, New Jersey (T.G.K., P.S., D.G., X.L., J.L., J.S., R.N., J.O., G.H.C., E.K.); and Exelixis, Inc., South San Francisco, California (R.Ma., Y.X., R.Mo.)
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Guardiola M, Oliva I, Guillaumet A, Martín-Trujillo Á, Rosales R, Vallvé JC, Sabench F, Del Castillo D, Zaina S, Monk D, Ribalta J. Tissue-specific DNA methylation profiles regulate liver-specific expression of the APOA1/C3/A4/A5 cluster and can be manipulated with demethylating agents on intestinal cells. Atherosclerosis 2014; 237:528-35. [PMID: 25463085 DOI: 10.1016/j.atherosclerosis.2014.10.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/17/2014] [Accepted: 10/19/2014] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The tissue-specific expression profiles of genes within the APOA1/C3/A4/A5 cluster play an important role in lipid metabolism regulation. We hypothesize that the tissue-specific expression of the APOA1/C3/A4/A5 gene cluster will show an inverse pattern with DNA methylation, and that repression in non- or low-expressing tissue, such as the intestine, can be reversed using epigenetic drugs. METHODS AND RESULTS We analyzed DNA samples from different human adult tissues (liver, intestine, leukocytes, brain, kidney, pancreas, muscle and sperm) using the Infinium HumanMethyation450 BeadChip array. DNA methylation profiles in APOA1/C3/A4/A5 gene cluster were confirmed by bisulfite PCR and pyrosequencing. To determine whether the observed tissue-specific methylation was associated with the expression profile we exposed intestinal TC7/Caco-2 cells to the demethylating agent 5-Aza-2'-deoxycytidine and monitored intestinal APOA1/C3/A4/A5 transcript re-expression by RT-qPCR. The promoters of APOA1, APOC3 and APOA5 genes were less methylated in liver compared to other tissues, and APOA4 gene was highly methylated in most tissues and partially methylated in liver and intestine. In TC7/Caco-2 cells, 5-Aza-2'-deoxycytidine treatment induced a decrease between 37 and 24% in the methylation levels of APOA1/C3/A4/A5 genes and a concomitant re-expression mainly in APOA1, APOA4 and APOA5 genes ranging from 22 to 600%. CONCLUSIONS We have determined the methylation patterns of the APOA1/C3/A4/A5 cluster that may be directly involved in the transcriptional regulation of this cluster. DNA demethylation of intestinal cells increases the RNA levels especially of APOA1, APOA4 and APOA5 genes.
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Affiliation(s)
- Montse Guardiola
- Unitat de Recerca en Lípids i Arteriosclerosi, Universitat Rovira i Virgili, IISPV, CIBERDEM, Spain.
| | - Iris Oliva
- Unitat de Recerca en Lípids i Arteriosclerosi, Universitat Rovira i Virgili, IISPV, CIBERDEM, Spain.
| | - Amy Guillaumet
- Imprinting and Cancer Group, Epigenetics and Cancer Biology Program (PEBC), Bellvitge Institute for Biomedical Research (IDIBELL), Barcelona, Spain.
| | - Álex Martín-Trujillo
- Imprinting and Cancer Group, Epigenetics and Cancer Biology Program (PEBC), Bellvitge Institute for Biomedical Research (IDIBELL), Barcelona, Spain.
| | - Roser Rosales
- Unitat de Recerca en Lípids i Arteriosclerosi, Universitat Rovira i Virgili, IISPV, CIBERDEM, Spain.
| | - Joan Carles Vallvé
- Unitat de Recerca en Lípids i Arteriosclerosi, Universitat Rovira i Virgili, IISPV, CIBERDEM, Spain.
| | - Fàtima Sabench
- Unitat de Recerca en Cirurgia, Universitat Rovira i Virgili, IISPV, Spain.
| | | | - Silvio Zaina
- Cancer Epigenetics Group, Epigenetics and Cancer Biology Program (PEBC), Bellvitge Institute for Biomedical Research (IDIBELL), Barcelona, Spain; Department of Medical Sciences, Division of Health Sciences, León Campus, University of Guanajuato, Mexico.
| | - David Monk
- Imprinting and Cancer Group, Epigenetics and Cancer Biology Program (PEBC), Bellvitge Institute for Biomedical Research (IDIBELL), Barcelona, Spain.
| | - Josep Ribalta
- Unitat de Recerca en Lípids i Arteriosclerosi, Universitat Rovira i Virgili, IISPV, CIBERDEM, Spain.
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Parikh M, Patel K, Soni S, Gandhi T. Liver X Receptor: A Cardinal Target for Atherosclerosis and Beyond. J Atheroscler Thromb 2014. [DOI: 10.5551/jat.19778] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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27
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Apolipoprotein A5 T-1131C variant and risk for metabolic syndrome in obese adolescents. Gene 2014; 534:44-7. [DOI: 10.1016/j.gene.2013.10.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/12/2013] [Accepted: 10/14/2013] [Indexed: 11/19/2022]
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Serviddio G, Blonda M, Bellanti F, Villani R, Iuliano L, Vendemiale G. Oxysterols and redox signaling in the pathogenesis of non-alcoholic fatty liver disease. Free Radic Res 2013; 47:881-93. [PMID: 24000796 DOI: 10.3109/10715762.2013.835048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Oxysterols are oxidized species of cholesterol coming from exogenous (e.g. dietary) and endogenous (in vivo) sources. They play critical roles in normal physiologic functions such as regulation of cellular cholesterol homeostasis. Most of biological effects are mediated by interaction with nuclear receptor LXRα, highly expressed in the liver as well as in many other tissues. Such interaction participates in the regulation of whole-body cholesterol metabolism, by acting as "lipid sensors". Moreover, it seems that oxysterols are also suspected to play key roles in several pathologies, including cardiovascular and inflammatory disease, cancer, and neurodegeneration. Growing evidence suggests that oxysterols may contribute to liver injury in non-alcoholic fatty liver disease. The present review focuses on the current status of knowledge on oxysterols' biological role, with an emphasis on LXR signaling and oxysterols' physiopathological relevance in NAFLD, suggesting new pharmacological development that needs to be addressed in the near future.
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Affiliation(s)
- G Serviddio
- C.U.R.E. Centre for Liver Diseases Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia , Italy
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Identification and characterization of cyclic AMP response element-binding protein H response element in the human apolipoprotein A5 gene promoter. BIOMED RESEARCH INTERNATIONAL 2013; 2013:892491. [PMID: 23957007 PMCID: PMC3730137 DOI: 10.1155/2013/892491] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/03/2013] [Accepted: 06/27/2013] [Indexed: 12/14/2022]
Abstract
The cyclic AMP response element-binding protein H (CREBH) plays important roles in hepatic lipogenesis, fatty acid oxidation, and lipolysis under metabolic stress. Here, we report CREBH as a novel regulator of human APOA5. Knockdown of endogenous CREBH expression via small interfering RNA resulted in the downregulation of human APOA5 mRNA expression in human hepatoma cells, HepG2. Sequence analysis suggested that putative CREBH response element (CREBHRE) is located in the human APOA5 promoter region and is highly conserved in both human and rodent. To clarify whether the human APOA5 promoter is regulated by CREBH, we analyzed the human APOA5 promoter region using a transient transfection assay and determined that transfection of CREBH induced human APOA5 promoter activity. Moreover, it was shown that CREBH directly regulated human APOA5 gene expression by binding to a unique CREBHRE located in the proximal human APOA5 promoter region, using 5′-deletion and mutagenesis of human APOA5 promoter analysis and chromatin immunoprecipitation assay. Taken together, our results demonstrated that human APOA5 is directly regulated by CREBH via CREBHRE and provided a new insight into the role of this liver-specific bZIP transcription factor in lipoprotein metabolism and triglyceride homeostasis.
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30
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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: 47] [Impact Index Per Article: 4.3] [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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31
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Zheng XY, Zhao SP, Yan H. The role of apolipoprotein A5 in obesity and the metabolic syndrome. Biol Rev Camb Philos Soc 2012; 88:490-8. [PMID: 23279260 DOI: 10.1111/brv.12005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 11/10/2012] [Accepted: 11/20/2012] [Indexed: 12/17/2022]
Affiliation(s)
- Xiao-Yan Zheng
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
| | - Shui-Ping Zhao
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
| | - Hu Yan
- Institute of Mental Health; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
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Abstract
Emerging experimental and human evidence has linked altered hepatic cholesterol homeostasis and free cholesterol (FC) accumulation to the pathogenesis of non-alcoholic steatohepatits (NASH). This review focuses on cellular mechanisms of cholesterol toxicity involved in liver injury and on alterations in cholesterol homeostasis promoting hepatic cholesterol overload in NASH. FC accumulation injures hepatocytes directly, by disrupting mitochondrial and endoplasmic reticulum (ER) membrane integrity, triggering mitochondrial oxidative injury and ER stress, and by promoting generation of toxic oxysterols, and indirectly, by inducing adipose tissue dysfunction. Accumulation of oxidized LDL particles may also activate Kupffer and hepatic stellate cells, promoting liver inflammation and fibrogenesis. Hepatic cholesterol accumulation is driven by a deeply deranged cellular cholesterol homeostasis, characterized by elevated cholesterol synthesis and uptake from circulating lipoproteins and by a reduced cholesterol excretion. Extensive dysregulation of cellular cholesterol homeostasis by nuclear transcription factors sterol regulatory binding protein (SREBP)-2, liver X-receptor (LXR)-α and farnesoid X receptor (FXR) plays a key role in hepatic cholesterol accumulation in NASH. The therapeutic implications and opportunities for normalizing cellular cholesterol homeostasis in these patients are also discussed.
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Nuclear receptors in nonalcoholic Fatty liver disease. J Lipids 2012; 2012:139875. [PMID: 22187655 PMCID: PMC3236492 DOI: 10.1155/2012/139875] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 09/14/2011] [Indexed: 01/03/2023] Open
Abstract
Nuclear receptors comprise a superfamily of ligand-activated transcription factors that are involved in important aspects of hepatic physiology and pathophysiology. There are about 48 nuclear receptors in the human. These nuclear receptors are regulators of many hepatic processes including hepatic lipid and glucose metabolism, bile acid homeostasis, drug detoxification, inflammation, regeneration, fibrosis, and tumor formation. Some of these receptors are sensitive to the levels of molecules that control lipid metabolism including fatty acids, oxysterols, and lipophilic molecules. These receptors direct such molecules to the transcriptional networks and may play roles in the pathogenesis and treatment of nonalcoholic fatty liver disease. Understanding the mechanisms underlying the involvement of nuclear receptors in the pathogenesis of nonalcoholic fatty liver disease may offer targets for the development of new treatments for this liver disease.
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Apolipoprotein A-V; a potent triglyceride reducer. Atherosclerosis 2011; 219:15-21. [DOI: 10.1016/j.atherosclerosis.2011.07.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 07/03/2011] [Accepted: 07/04/2011] [Indexed: 11/21/2022]
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Weiss K, Mihály J, Liebisch G, Marosvölgyi T, Schmitz G, Decsi T, Rühl R. Effect of synthetic ligands of PPAR α, β/δ, γ, RAR, RXR and LXR on the fatty acid composition of phospholipids in mice. Lipids 2011; 46:1013-20. [PMID: 21792736 DOI: 10.1007/s11745-011-3593-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 06/01/2011] [Indexed: 01/14/2023]
Abstract
Nuclear hormone receptors are transcription factors that can be activated by nutrition-derived ligands and alter the expression of various specific target genes. Stearoyl-Coenzyme A desaturase (SCD1) converts palmitic acid (16:0) to palmitoleic acid (16:1n-7) as well as stearic acid (18:0) to oleic acid (18:1n-9). At the same time, elongase 6 (ELOVL6) elongates 16:1n-7 and 18:1n-9 to vaccenic acid (18:1n-7) and eicosenoic acid (20:1n-9). We examined how synthetic selective ligands of nuclear hormone receptors alter the gene expression of hepatic enzymes in mice. In addition, we examined how the regulation of these two enzymes influences fatty acid composition of phospholipids in liver and plasma. Mice were gavaged daily for 1 week with synthetic ligands of peroxisome proliferator-activated receptor (PPAR) α, β/δ, γ, liver X receptor (LXR), retinoic acid receptor (RAR) and retinoid-X receptor (RXR) for 1 week. Phospholipids from liver and plasma were analysed using ESI-MS/MS and GC after saponification. Hepatic gene expression of SCD1 and ELOVL6 was measured using QRT-PCR. SCD1 and ELOVL6 expression increased after the gavage of LXR and RXR ligands. The analysis of fatty acid composition of total phospholipids in plasma and liver showed increased percentage contributions of the SCD1 and ELOVL6 products 18:1n-9, 18:1n-7 and 20:1n-9 after LXR and RXR ligand application. Analysis of total phospholipids from plasma and liver revealed a significant increase in monounsaturated fatty acids bound in phosphatidylcholine (PtdCho) and lysophosphatidylcholine (PtdEtn) after LXR and RXR ligand administration. Increased hepatic gene expression of SCD1 and ELOVL6 after gavage of selective RXR or LXR ligands to mice resulted in increased concentrations of their metabolic products in phospholipids of liver and plasma.
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Affiliation(s)
- Kathrin Weiss
- Laboratory of Nutritional Bioactivation and Bioanalysis, Department of Biochemistry and Molecular Biology, University of Debrecen, Medical and Health Center, Nagyerdei Krt. 98, 4032, Debrecen, Hungary
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Patel MB, Oza NA, Anand IS, Deshpande SS, Patel CN. Liver x receptor: a novel therapeutic target. Indian J Pharm Sci 2011; 70:135-44. [PMID: 20046702 PMCID: PMC2792482 DOI: 10.4103/0250-474x.41445] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2007] [Revised: 02/14/2008] [Accepted: 02/20/2008] [Indexed: 01/04/2023] Open
Abstract
The liver X receptors α and β are orphan nuclear receptors that are key regulators in maintaining cholesterol homeostasis. Originally they were found to play an important role in reverse cholesterol transport, a pathway for the removal of excess cellular cholesterol. However several groups have now shown that the liver X receptors also functions in lipid and carbohydrate metabolism, cellular differentiation, apoptosis and many immune responses. Tissue distribution of the two paralogues differs with liver X receptor β ubiquitously expressed, while liver X receptor α is confined to the liver, kidney, intestine, spleen, adipose tissue, macrophages and skeletal muscle. The endogenous ligands for the liver X receptors are certain oxidized derivatives of cholesterol, the oxysterols. Upon activation by oxysterols, the receptors form obligate heterodimers with retinoid X receptors α, β and γ; and become competent to activate the transcription of target genes.
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Affiliation(s)
- M B Patel
- Department of Pharmacology, Shri Sarvajanik Pharmacy College, Near Arvind Baug, Mehsana - 384 001, India
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37
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Abstract
The burden of atherothrombotic cardiovascular disease remains high despite currently available optimum medical therapy. To address this substantial residual risk, the development of novel therapies that attempt to harness the atheroprotective functions of HDL is a major goal. These functions include the critical role of HDL in reverse cholesterol transport, and its anti-inflammatory, antithrombotic, and antioxidant activities. Discoveries in the past decade have shed light on the complex metabolic and antiatherosclerotic pathways of HDL. These insights have fueled the development of HDL-targeted drugs, which can be classified among four different therapeutic approaches: directly augmenting apolipoprotein A-I (apo A-I) levels, such as with apo A-I infusions and upregulators of endogenous apo A-I production; indirectly augmenting apo A-I and HDL-cholesterol levels, such as through inhibition of cholesteryl ester transfer protein or endothelial lipase, or through activation of the high-affinity niacin receptor GPR109A; mimicking the functionality of apo A-I with apo A-I mimetic peptides; and enhancing steps in the reverse cholesterol transport pathway, such as via activation of the liver X receptor or of lecithin-cholesterol acyltransferase.
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Affiliation(s)
- Emil M Degoma
- Division of Cardiovascular Medicine, University of Pennsylvania, Penn Tower, 6th Floor, 3400 Spruce Street, Philadelphia, PA 19104, USA.
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Vacca M, Degirolamo C, Mariani-Costantini R, Palasciano G, Moschetta A. Lipid-sensing nuclear receptors in the pathophysiology and treatment of the metabolic syndrome. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2011; 3:562-87. [PMID: 21755605 DOI: 10.1002/wsbm.137] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metabolic syndrome (MS) is a cluster of different diseases, namely central obesity, hypertension, hyperglycemia, and dyslipidemia, together with a pro-thrombotic and pro-inflammatory state. These metabolic abnormalities are often associated with an increased risk for cardiovascular disease (CVD) and cancer. Dietary and lifestyle modifications are currently believed more effective than pharmacological therapies in the management of MS patients. Nevertheless, the relatively low grade of compliance of patients to these recommendations, as well as the failure of current therapies, highlights the need for the discovery of new pharmacological and nutraceutic approaches. A deeper knowledge of the patho-physiological events that initiate and support the MS is mandatory. Lipid-sensing nuclear receptors (NRs) are the master transcriptional regulators of lipid and carbohydrate metabolism and inflammatory responses, thus standing as suitable targets. This review focuses on the physiological relevance of the NRs (peroxisome proliferator-activated receptors, liver X receptors, and farnesoid X receptor) in the control of whole-body homeostasis, with a special emphasis on lipid and glucose metabolism, and on the relationships between metabolic unbalances, systemic inflammation, and the onset of CVD. Future perspectives and possible clinical applications are also presented.
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Affiliation(s)
- Michele Vacca
- Clinica Medica Augusto Murri, Aldo Moro University of Bari, and Department of Translational Pharmacology, Consorzio Mario Negri Sud, Santa Maria Imbaro (CH), Italy
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Blade AM, Fabritius MA, Hou L, Weinberg RB, Shelness GS. Biogenesis of apolipoprotein A-V and its impact on VLDL triglyceride secretion. J Lipid Res 2011; 52:237-44. [PMID: 21115968 PMCID: PMC3023543 DOI: 10.1194/jlr.m010793] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 11/09/2010] [Indexed: 12/12/2022] Open
Abstract
Apolipoprotein A-V (apoA-V) is a potent regulator of intravascular triglyceride (TG) metabolism, yet its plasma concentration is very low compared with that of other apolipoproteins. To examine the basis for its low plasma concentration, the secretion efficiency of apoA-V was measured in stably transfected McA-RH7777 rat hepatoma cells. Pulse-chase experiments revealed that only ∼20% of newly synthesized apoA-V is secreted into culture medium within 3 h postsynthesis and that ∼65% undergoes presecretory turnover; similar results were obtained with transfected nonhepatic Chinese hamster ovary cells. ApoA-V secreted by McA-RH7777 cells was not associated with cell surface heparin-competable binding sites. When stably transfected McA-RH7777 cells were treated with oleic acid, the resulting increase in TG synthesis caused a reduction in apoA-V secretion, a reciprocal increase in cell-associated apoA-V, and movement of apoA-V onto cytosolic lipid droplets. In a stably transfected doxycycline-inducible McA-RH7777 cell line, apoA-V expression inhibited TG secretion by ∼50%, increased cellular TG, and reduced Z-average VLDL(1) particle diameter from 81 to 67 nm; however, no impact on apoB secretion was observed. These data demonstrate that apoA-V inefficiently traffics within the secretory pathway, that its intracellular itinerary can be regulated by changes in cellular TG accumulation, and that apoA-V synthesis can modulate VLDL TG mobilization and secretion.
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Affiliation(s)
- Anna M. Blade
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Melissa A. Fabritius
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Li Hou
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Richard B. Weinberg
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
- Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Gregory S. Shelness
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
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Song KH. Orphan nuclear receptor Nur77 participates in human apolipoprotein A5 gene expression. Biochem Biophys Res Commun 2010; 392:63-6. [DOI: 10.1016/j.bbrc.2009.12.168] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Accepted: 12/28/2009] [Indexed: 11/25/2022]
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Fiévet C, Staels B. Liver X receptor modulators: Effects on lipid metabolism and potential use in the treatment of atherosclerosis. Biochem Pharmacol 2009; 77:1316-27. [DOI: 10.1016/j.bcp.2008.11.026] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 11/24/2008] [Accepted: 11/25/2008] [Indexed: 10/21/2022]
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Del Bas JM, Ricketts ML, Baiges I, Quesada H, Ardevol A, Salvadó MJ, Pujadas G, Blay M, Arola L, Bladé C, Moore DD, Fernandez-Larrea J. Dietary procyanidins lower triglyceride levels signaling through the nuclear receptor small heterodimer partner. Mol Nutr Food Res 2009; 52:1172-81. [PMID: 18720348 DOI: 10.1002/mnfr.200800054] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hypertriglyceridemia is an independent risk factor in the development of cardiovascular diseases, and we have previously reported that oral administration of a grape seed procyanidin extract (GSPE) drastically decreases plasma levels of triglycerides (TG) and apolipoprotein B (ApoB) in normolipidemic rats, with a concomitant induction in the hepatic expression of the nuclear receptor small heterodimer partner (NR0B2/SHP). Our objective in this study was to elucidate whether SHP is the mediator of the reduction of TG-rich ApoB-containing lipoproteins triggered by GSPE. We show that GSPE inhibited TG and ApoB secretion in human hepatocarcinoma HepG2 cells and had and hypotriglyceridemic effect in wild-type mouse. The TG-lowering action of GSPE was abolished in HepG2 cells transfected with a SHP-specific siRNA and in a SHP-null mouse. Moreover, in mouse liver, GSPE downregulated several lipogenic genes, including steroid response element binding protein 1c (SREBP-1c), and upregulated carnitine palmitoyltransferase-1A (CPT-1A) and apolipoprotein A5 (ApoA5), in a SHP-dependent manner. In HepG2 cells GSPE also inhibited ApoB secretion, but in a SHP-independent manner. In conclusion, SHP is a key mediator of the hypotriglyceridemic response triggered by GSPE. This novel signaling pathway of procyanidins through SHP may be relevant to explain the health effects ascribed to the regular consumption of dietary flavonoids.
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Affiliation(s)
- Josep Maria Del Bas
- Departament de Bioquímica i Biotecnología, Universitat Rovira i Virgili, Campus Sescelades, Tarragona, Spain
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Hahne P, Krempler F, Schaap FG, Soyal SM, Höffinger H, Miller K, Oberkofler H, Strobl W, Patsch W. Determinants of plasma apolipoprotein A-V and APOA5 gene transcripts in humans. J Intern Med 2008; 264:452-62. [PMID: 18537870 PMCID: PMC3533125 DOI: 10.1111/j.1365-2796.2008.01987.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Apolipoprotein A-V (apoAV) contributes to the regulation of triglyceride metabolism, which plays a role in the pathogenesis of atherosclerotic diseases. We therefore ascertained determinants of hepatic APOA5 transcript and apoAV plasma levels in humans. DESIGN We determined influences of anthropometric variables, biochemical factors related to lipid and glucose metabolism, hepatic mRNA levels transcribed from the APOA1/C3/A4/A5 cluster and transcription factor genes implicated in the regulation of APOA5 as well as common single nucleotide polymorphisms (SNPs) at the APOA5 locus on APOA5 expression in 89 obese patients and 22 non-obese controls. RESULTS Mean, age and sex adjusted, hepatic APOA5 mRNA or apoAV plasma levels did not differ by obesity status, homoeostasis model assessment insulin resistance or inflammatory markers. In multivariate regression models, the c56C > G SNP, plasma apoCIII, plasma nonesterified fatty acids, hepatic APOA5 transcripts, sex and a weak association with obesity status explained 61% of the variance in apoAV plasma levels. Hepatic transcript levels of carnitine palmitoyltransferase 1 (CPT1A1) and peroxisome proliferator-activated receptor alpha (PPARA), plasma nonesterified fatty acids and the c56C > G SNP explained 48% of the variance in hepatic APOA5 transcript levels. CONCLUSION Apolipoprotein A-V plasma levels are independently associated with plasma free fatty acid and hepatic APOA5 mRNA levels. Associations of APOA5 transcripts with PPARA and CPT1A1 transcripts suggest that APOA5 expression is intimately linked to hepatic lipid metabolism.
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Affiliation(s)
- P Hahne
- Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
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Berriel Diaz M, Krones-Herzig A, Metzger D, Ziegler A, Vegiopoulos A, Klingenspor M, Müller-Decker K, Herzig S. Nuclear receptor cofactor receptor interacting protein 140 controls hepatic triglyceride metabolism during wasting in mice. Hepatology 2008; 48:782-91. [PMID: 18712775 DOI: 10.1002/hep.22383] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED In mammals, triglycerides (TG) represent the most concentrated form of energy. Aberrant TG storage and availability are intimately linked to the negative energy balance under severe clinical conditions, such as starvation, sepsis, or cancer cachexia. Despite its crucial role for energy homeostasis, molecular key determinants of TG metabolism remain enigmatic. Here we show that the expression of nuclear receptor cofactor receptor interacting protein (RIP) 140 was induced in livers of starved, septic, and tumor-bearing mice. Liver-specific knockdown of RIP140 led to increased hepatic TG release and alleviated hepatic steatosis in tumor-bearing, cachectic animals. Indeed, hepatic RIP140 was found to control the expression of lipid-metabolizing genes in liver. CONCLUSION By preventing the mobilization of hepatic TG stores, the induction of RIP140 in liver provides a molecular rationale for hepatic steatosis in starvation, sepsis, or cancer cachexia. Inhibition of hepatic RIP140 transcriptional activity might, thereby, provide an attractive adjunct scheme in the treatment of these conditions.
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Affiliation(s)
- Mauricio Berriel Diaz
- Emmy Noether and Marie Curie Research Group, Molecular Metabolic Control, German Cancer Research Center Heidelberg, Heidelberg, Germany
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Prieur X, Huby T, Rodríguez JC, Couvert P, Chapman MJ. Apolipoprotein AV: gene expression, physiological role in lipid metabolism and clinical relevance. ACTA ACUST UNITED AC 2008. [DOI: 10.2217/17460875.3.4.371] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Glucose Regulates the Expression of the Apolipoprotein A5 Gene. J Mol Biol 2008; 380:789-98. [DOI: 10.1016/j.jmb.2008.04.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 04/22/2008] [Accepted: 04/23/2008] [Indexed: 11/23/2022]
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Liver X receptor agonist downregulates hepatic apoM expression in vivo and in vitro. Biochem Biophys Res Commun 2008; 371:114-7. [PMID: 18413148 DOI: 10.1016/j.bbrc.2008.04.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 04/02/2008] [Indexed: 01/10/2023]
Abstract
It has been demonstrated that apolipoprotein M (apoM), a recently discovered HDL apolipoprotein, has antiatherosclerotic properties, which may be mediated by the enhancement of reversed cholesterol transportation and/or hepatic cholesterol catabolism. The detailed mechanisms are unknown yet. Liver X receptor (LXR) belongs to the nuclear receptor superfamily and is a ligand-activated transcription factor involved in the regulation of lipid metabolism and inflammation. Activation of LXR in the cell cultures results in an enhancement of cholesterol efflux to apoAI. In the present study, we investigated effects of the LXR agonist, T0901317 on hepatic apoM expression in vivo and in vitro. Serum apoM levels in mice given T0901317 at 10 mg or 100 mg/kg for 7 days were reduced by 12-17% (P<0.05). In HepG2 cell cultures, apoM mRNA levels were significantly lower in presence of 25 microM T0901317 (37.1%) than in control cells (P<0.001). A similar reduction was found by the addition of 9-cis retinoic acid (RA). Twenty-five micromolar T0901317 together with 100 nM RA decreased apoM mRNA expression by 65% (P<0.001). Thus, the LXR agonist T0901317 significantly downregulates apoM mRNA expression in vivo and in vitro, which indicates that apoM is another novel target gene regulated by the LXR. The combination of RA and T0901317 showed additive effects, which suggests that apoM expression can be modulated by LXR/RXR pathway.
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Apolipoprotein A5 gene C56G variant confers risk for the development of large-vessel associated ischemic stroke. J Neurol 2008; 255:649-54. [DOI: 10.1007/s00415-008-0768-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 09/18/2007] [Accepted: 10/05/2007] [Indexed: 10/22/2022]
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50
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Upregulating APOAV expression by statins via PPAR-α activated pathway possibly contributes to their triglyceride-lowering effect. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.bihy.2008.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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