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Effects of Six Weeks of Hypoxia Exposure on Hepatic Fatty Acid Metabolism in ApoE Knockout Mice Fed a High-Fat Diet. LIFE (BASEL, SWITZERLAND) 2022; 12:life12101535. [PMID: 36294970 PMCID: PMC9605121 DOI: 10.3390/life12101535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/08/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease with a characteristic of abnormal lipid metabolism. In the present study, we employed apolipoprotein E knockout (ApoE KO) mice to investigate the effects of hypoxia exposure on hepatic fatty acid metabolism and to test whether a high-fat diet (HFD) would suppress the beneficial effect caused by hypoxia treatment. ApoE KO mice were fed a HFD for 12 weeks, and then were forwarded into a six-week experiment with four groups: HFD + normoxia, normal diet (ND) + normoxia, HFD + hypoxia exposure (HE), and ND + HE. The C57BL/6J wild type (WT) mice were fed a ND for 18 weeks as the baseline control. The hypoxia exposure was performed in daytime with normobaric hypoxia (11.2% oxygen, 1 h per time, three times per week). Body weight, food and energy intake, plasma lipid profiles, hepatic lipid contents, plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and molecular/biochemical makers and regulators of the fatty acid synthesis and oxidation in the liver were measured at the end of interventions. Six weeks of hypoxia exposure decreased plasma triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) contents but did not change hepatic TG and non-esterified fatty acid (NEFA) levels in ApoE KO mice fed a HFD or ND. Furthermore, hypoxia exposure decreased the mRNA expression of Fasn, Scd1, and Srebp-1c significantly in the HFD + HE group compared with those in the HFD + normoxia group; after replacing a HFD with a ND, hypoxia treatment achieved more significant changes in the measured variables. In addition, the protein expression of HIF-1α was increased only in the ND + HE group but not in the HFD + HE group. Even though hypoxia exposure did not affect hepatic TG and NEFA levels, at the genetic level, the intervention had significant effects on hepatic metabolic indices of fatty acid synthesis, especially in the ND + HE group, while HFD suppressed the beneficial effect of hypoxia on hepatic lipid metabolism in male ApoE KO mice. The dietary intervention of shifting HFD to ND could be more effective in reducing hepatic lipid accumulation than hypoxia intervention.
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2
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Simon F, Larena-Avellaneda A, Wipper S. Experimental Atherosclerosis Research on Large and Small Animal Models in Vascular Surgery. J Vasc Res 2022; 59:221-228. [PMID: 35760040 PMCID: PMC9533439 DOI: 10.1159/000524795] [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: 02/04/2022] [Accepted: 04/18/2022] [Indexed: 11/19/2022] Open
Abstract
Animal models have significantly advanced our understanding of the mechanisms of atherosclerosis formation and the evaluation of therapeutic options. The current focus of research is on preventive strategies and includes pharmacologic and biologic interventions directed primarily against smooth-muscle cell proliferation, endovascular devices for recanalization and/or drug delivery, and an integrated approach using both devices and pharmacobiologic agents. The experience over many decades with animal models in vascular research has established that a single, ideal, naturally available model for atherosclerosis does not exist. The spectrum ranges from large animals such as pigs to small animal experiments with genetically modified rodents such as the ApoE-/- mouse with correspondingly differently pronounced changes in their lipid and lipoprotein levels. The development of transgenic variants of currently available models, e.g., an ApoE-deficient rabbit line, has widened our options. Nevertheless, an appreciation of the individual features of natural or stimulated disease in each species is of importance for the proper design and execution of relevant experiments.
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Affiliation(s)
- Florian Simon
- University Hospital Düsseldorf, Clinic for Vascular and Endovascular Surgery, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Axel Larena-Avellaneda
- Department of Vascular and Endovascular Surgery, Asklepios Clinic Altona, Hamburg, Germany
| | - Sabine Wipper
- Department for Vascular Surgery, University Hospital Innsbruck, Innsbruck, Austria
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3
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Kim K, Yu J, Kang JK, Morrow JP, Pajvani UB. Liver-selective γ-secretase inhibition ameliorates diet-induced hepatic steatosis, dyslipidemia and atherosclerosis. Biochem Biophys Res Commun 2020; 527:979-984. [PMID: 32439159 DOI: 10.1016/j.bbrc.2020.04.157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 04/30/2020] [Indexed: 01/05/2023]
Abstract
Hepatic γ-secretase regulates low-density lipoprotein receptor (LDLR) cleavage and degradation, affecting clearance of plasma triglyceride (TG)-rich lipoproteins (TRLs). In this study, we investigated whether γ-secretase inhibition modulates risk of Western (high-fat/sucrose and high-cholesterol)-type diet (WTD)-induced hepatic steatosis, dyslipidemia and atherosclerosis. We evaluated liver and plasma lipids in WTD-fed mice with hepatocyte-specific ablation of the non-redundant γ-secretase-targeting subunit Nicastrin (L-Ncst). In parallel, we investigated the effect of liver-selective Ncst antisense oligonucleotides (ASO) on lipid metabolism and atherosclerosis in wildtype (WT) and ApoE knockout (ApoE-/-) mice fed normal chow or WTD. WTD-fed L-Ncst and Ncst ASO-treated WT mice showed reduced total cholesterol and LDL-cholesterol (LDL-C), as well as reduced hepatic lipid content as compared to Cre- and control ASO-treated WT mice. Treatment of WTD-fed ApoE-/- mice with Ncst ASO markedly lowered total and LDL cholesterol, hepatic TG and attenuated atherosclerotic lesions in the aorta, as compared to control ASO-treated mice. L-Ncst and Ncst ASO similarly showed reduced plasma glucose as compared to control mice. In conclusion, inhibition of hepatic γ-secretase reduces plasma glucose, and attenuates WTD-induced dyslipidemia, hepatic fat accumulation and atherosclerosis, suggesting potential pleiotropic application for diet-induced metabolic dysfunction.
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Affiliation(s)
- KyeongJin Kim
- Department of Medicine, Columbia University, New York, NY, 10032, USA; Department of Biomedical Sciences, College of Medicine, Inha University, Incheon, 22212, South Korea.
| | - Junjie Yu
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Jin Ku Kang
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - John P Morrow
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Utpal B Pajvani
- Department of Medicine, Columbia University, New York, NY, 10032, USA.
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4
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Briand F, Heymes C, Bonada L, Angles T, Charpentier J, Branchereau M, Brousseau E, Quinsat M, Fazilleau N, Burcelin R, Sulpice T. A 3-week nonalcoholic steatohepatitis mouse model shows elafibranor benefits on hepatic inflammation and cell death. Clin Transl Sci 2020; 13:529-538. [PMID: 31981449 PMCID: PMC7214663 DOI: 10.1111/cts.12735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/12/2019] [Indexed: 12/15/2022] Open
Abstract
The long duration of animal models represents a clear limitation to quickly evaluate the efficacy of drugs targeting nonalcoholic steatohepatitis (NASH). We, therefore, developed a rapid mouse model of liver inflammation (i.e., the mouse fed a high-fat/high-cholesterol diet, where cyclodextrin is co-administered to favor hepatic cholesterol loading, liver inflammation, and NASH within 3 weeks), and evaluated the effects of the dual peroxisome proliferator-activated receptor alpha/delta agonist elafibranor (ELA). C57BL6/J mice were fed a 60% high-fat, 1.25% cholesterol, and 0.5% cholic acid diet with 2% cyclodextrin in drinking water (HFCC/CDX diet) for 3 weeks. After 1 week of the diet, mice were treated orally with vehicle or ELA 20 mg/kg q.d. for 2 weeks. Compared with vehicle, ELA markedly reduced liver lipids and nonalcoholic fatty liver disease activity scoring, through steatosis, inflammation, and fibrosis (all P < 0.01 vs. vehicle). Flow cytometry analysis showed that ELA significantly improved the HFCC/CDX diet-induced liver inflammation by preventing the increase in total number of immune cells (CD45+), Kupffer cells, dendritic cells, and monocytes population, as well as the reduction in natural killer and natural killer T cells, and by blocking conversion of T cells in regulatory T cells. ELA did not alter pyroptosis (Gasdermin D), but significantly reduced necroptosis (cleaved RIP3) and apoptosis (cleaved caspase 3) in the liver. In conclusion, ELA showed strong benefits on NASH, including improvement in hepatic inflammation, necroptosis, and apoptosis in the 3-week NASH mouse. This preclinical model will be useful to rapidly detect the effects of novel drugs targeting NASH.
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Kosakai T, Kato H, Sho C, Kawano K, Iwai KI, Takase Y, Ogawa K, Nishiyama K, Yamasaki M. Dietary fermented products using koji mold and sweet potato- shochu distillery by-product promotes hepatic and serum cholesterol levels and modulates gut microbiota in mice fed a high-cholesterol diet. PeerJ 2019; 7:e7671. [PMID: 31565580 PMCID: PMC6745188 DOI: 10.7717/peerj.7671] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/13/2019] [Indexed: 12/20/2022] Open
Abstract
It has been reported that fermented products (FPs) prepared from sweet potato-shochu distillery by-product suppressed weight gain and decreased serum cholesterol levels in mice under normal dietary conditions. Furthermore, from the information gained from the above data regarding health benefits of the FPs, the aim of this study was evaluating the effects of dietary FPs on lipid accumulation and gut microbiota in mice with or without cholesterol-load in the diet. C57BL/6N mice were fed normal (CO) diet, CO with 10% FPs (CO + FPs) diet, cholesterol loaded (HC) diet, or HC with 10% FPs (HC + FPs) diet for 8 weeks. The mice were then euthanized, and blood samples, tissue samples, and feces were collected. The adipose tissue weight and liver triglyceride levels in the HC + FPs diet groups were significantly reduced compared to that in the HC diet groups. However, FPs significantly increased the serum non-high-density lipoprotein cholesterol (HDL-C) levels, the ratio of non-HDL-C to HDL-C and hepatic total cholesterol levels in mice fed cholesterol-loaded diet compared with that of the HC diet group. Since dietary FPs significantly decreased the protein expression levels of cholesterol 7 alpha-hydroxylase 1 in the HC + FPs diet groups, the cholesterol accumulation in FPs group may be explained by insufficient catabolism from cholesterol to bile acid. In addition, the dietary FPs tended to increase Clostridium cluster IV and XIVa, which are butyrate-producing bacteria. Related to the result, n-butyrate was significantly increased in the CO + FPs and the HC + FPs diet groups compared to their respective control groups. These findings suggested that dietary FPs modulated the lipid pool and gut microbiota.
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Affiliation(s)
- Toshiki Kosakai
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki, Miyazaki, Japan.,Kirishima Shuzo Co., Ltd., Miyakonojo, Miyazaki, Japan
| | - Hirotaka Kato
- Graduate School of Agriculture, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Cho Sho
- Kirishima Shuzo Co., Ltd., Miyakonojo, Miyazaki, Japan
| | | | - Ken-Ichi Iwai
- Kirishima Shuzo Co., Ltd., Miyakonojo, Miyazaki, Japan
| | | | - Kenjiro Ogawa
- Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Kazuo Nishiyama
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki, Miyazaki, Japan.,Graduate School of Agriculture, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Masao Yamasaki
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki, Miyazaki, Japan.,Graduate School of Agriculture, University of Miyazaki, Miyazaki, Miyazaki, Japan
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6
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Li L, Qiao X, Wang X, Liu D, Xue Q, Han L, Dai F, Ma G, Yang Z, Zhang T, Yang S, Cai S, Gao M, Yang J. The association between apolipoprotein E and gallstone disease: an updated meta-analysis. BMC MEDICAL GENETICS 2019; 20:109. [PMID: 31200656 PMCID: PMC6570961 DOI: 10.1186/s12881-019-0843-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/05/2019] [Indexed: 01/28/2023]
Abstract
BACKGROUND Gallstone disease (GSD) is a common biliary tract disease worldwide. Previous studies have investigated the association of apolipoprotein E (APOE) E4 with GSD and reported inconsistent results. METHODS In this paper, we conducted meta-analyses to examine whether APOE E4 is associated with the risk of GSD. A systematic literature search was performed in PubMed, Cochrane Library, EMBASE, and Google Scholar using the following inclusion criteria: 1) Studies on human subjects; 2) subjects in the control group must undergo ultrasound GSD screening, and presence of GSD in the experiment group can be clearly determined, e.g., diagnosis of GSD through ultrasound screening or a previous history of cholecystectomy or cholelithiasis; 3) the studies reported APOE genotype data (APOE E4+ vs. E4-) for subjects with and without GSD. In all the meta-analyses, we used random-effects models to calculate the odds ratios (ORs) as a measure of association as well as the corresponding confidence intervals (CIs). RESULTS Our literature search found 13 publications with 14 studies, including a total of 1632 GSD patients and 5001 controls, that met the eligibility criteria and were included in the meta-analyses. We did not find a significant association between APOE E4 and risk of GSD (OR = 1.23, 95% CI: 0.89-1.68; p = 0.205). No significant associations were observed in subgroup analyses by gender and mean age. We obtained similar insignificant findings if an additive model was used, if subjects who had E2E4 genotype were excluded, or if low-quality studies were excluded. CONCLUSION Our meta-analysis found insufficient evidence for the effect of APOE E4 on GSD risk. Future studies with large sample sizes that control for important confounding/risk factors are needed to validate our findings and to explore other genetic loci that might affect GSD risk.
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Affiliation(s)
- Lizhuo Li
- Emergency Department, Xuanwu Hospital, Capital Medical University, Beijing, China
- Department of Critical Care and Emergency Medicine, The First Affiliated Hospital of Hainan Medical University, Haikou, Hainan, China
| | - Xin Qiao
- Department of Animal Laboratory, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xia Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Di Liu
- Beijing Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, China
| | - Qingmu Xue
- Department of Critical Care and Emergency Medicine, The First Affiliated Hospital of Hainan Medical University, Haikou, Hainan, China
| | - Lu Han
- School of Basic Medicine, Shenyang Medical College, Shenyang, Liaoning, China
| | - Fei Dai
- Division of Gastroenterology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Guomin Ma
- Department of Radiology, Liaoning Provincial People's Hospital, Shenyang, Liaoning, China
| | - Zhipeng Yang
- Emergency Department, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Tao Zhang
- The First Research Institute, Ministry of the Public Security, Beijing, China
| | - Shuo Yang
- Department of Epidemiology and Health Statistics, Shenyang Medical College, Shenyang, Liaoning, China
| | - Shikang Cai
- Hainan Medical University, Haikou, Hainan, China
| | - Mingyue Gao
- Department of Epidemiology and Health Statistics, Shenyang Medical College, Shenyang, Liaoning, China
| | - Jingyun Yang
- Division of Statistics, School of Economics, Shanghai University, Shanghai, China.
- Research Center of Financial Information, Shanghai University, Shanghai, China.
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA.
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7
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Yang H, Wu Z. Genome Editing of Pigs for Agriculture and Biomedicine. Front Genet 2018; 9:360. [PMID: 30233645 PMCID: PMC6131568 DOI: 10.3389/fgene.2018.00360] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/21/2018] [Indexed: 12/26/2022] Open
Abstract
Pigs serve as an important agricultural resource and animal model in biomedical studies. Efficient and precise modification of pig genome by using recently developed gene editing tools has significantly broadened the application of pig models in various research areas. The three types of site-specific nucleases, namely, zinc-finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein, are the main gene editing tools that can efficiently introduce predetermined modifications, including knockouts and knockins, into the pig genome. These modifications can confer desired phenotypes to pigs to improve production traits, such as optimal meat production, enhanced feed digestibility, and disease resistance. Besides, given their genetic, anatomic, and physiologic similarities to humans, pigs can also be modified to model human diseases or to serve as an organ source for xenotransplantation to save human lives. To date, many genetically modified pig models with agricultural or biomedical values have been established by using gene editing tools. These pig models are expected to accelerate research progress in related fields and benefit humans.
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Affiliation(s)
- Huaqiang Yang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhenfang Wu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China
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8
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Inhibition of glycosphingolipid synthesis reverses skin inflammation and hair loss in ApoE-/- mice fed western diet. Sci Rep 2018; 8:11463. [PMID: 30061606 PMCID: PMC6065400 DOI: 10.1038/s41598-018-28663-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/18/2018] [Indexed: 01/19/2023] Open
Abstract
Sphingolipids have been accorded numerous biological functions however, the effects of feeding a western diet (diet rich in cholesterol and fat) on skin phenotypes, and color is not known. Here, we observed that chronic high-fat and high-cholesterol diet intake in a mouse model of atherosclerosis (ApoE-/-) decreases the level of ceramides and glucosylceramide. At the expense of increased levels of lactosylceramide due to an increase in the expression of lactosylceramide synthase (GalT-V). This is accompanied with neutrophil infiltration into dermis, and enrichment of tumor necrosis factor-stimulated gene-6 (TSG-6) protein. This causes skin inflammation, hair discoloration and loss, in ApoE-/- mice. Conversely, inhibition of glycosphingolipid synthesis, by D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), unbound or encapsulated in a biodegradable polymer (BPD) reversed these phenotypes. Thus, inhibition of glycosphingolipid synthesis represents a unique therapeutic approach relevant to human skin and hair Biology.
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9
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Vujic N, Korbelius M, Leopold C, Duta-Mare M, Rainer S, Schlager S, Goeritzer M, Kolb D, Eichmann TO, Diwoky C, Zimmer A, Zimmermann R, Lass A, Radovic B, Kratky D. Monoglyceride lipase deficiency affects hepatic cholesterol metabolism and lipid-dependent gut transit in ApoE-/- mice. Oncotarget 2018; 8:33122-33136. [PMID: 28380440 PMCID: PMC5464855 DOI: 10.18632/oncotarget.16529] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/14/2017] [Indexed: 11/25/2022] Open
Abstract
Monoglyceride lipase (MGL) hydrolyzes monoglycerides (MGs) to glycerol and fatty acids. Among various MG species MGL also degrades 2-arachidonoylglycerol (2-AG), the most abundant endocannabinoid and potent activator of cannabinoid receptors (CBR) 1 and 2. MGL-knockout (-/-) mice exhibit pronounced 2-AG accumulation, but lack central cannabimimetic effects due to CB1R desensitization. We have previously shown that MGL affects plaque stability in apolipoprotein E (ApoE)-/- mice, an established animal model for dyslipidemia and atherosclerosis. In the current study, we investigated functional consequences of MGL deficiency on lipid and energy metabolism in ApoE/MGL double knockout (DKO) mice. MGL deficiency affected hepatic cholesterol metabolism by causing increased cholesterol elimination via the biliary pathway. Moreover, DKO mice exhibit lipid-triggered delay in gastric emptying without major effects on overall triglyceride and cholesterol absorption. The observed phenotype of DKO mice is likely not a consequence of potentiated CB1R signaling but rather dependent on the activation of alternative signaling pathways. We conclude that MGL deficiency causes complex metabolic changes including cholesterol metabolism and regulation of gut transit independent of the endocannabinoid system.
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Affiliation(s)
- Nemanja Vujic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Silvia Rainer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Stefanie Schlager
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madeleine Goeritzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Center for Medical Research, Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Clemens Diwoky
- Institute of Biomedical Engineering, Graz University of Technology, Graz, Austria.,Current address: Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Branislav Radovic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
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Ku CS, Kim B, Pham TX, Yang Y, Wegner CJ, Park YK, Balunas M, Lee JY. Blue-Green Algae Inhibit the Development of Atherosclerotic Lesions in Apolipoprotein E Knockout Mice. J Med Food 2015; 18:1299-306. [PMID: 26566121 DOI: 10.1089/jmf.2015.0025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Hyperlipidemia and inflammation contribute to the development of atherosclerotic lesions. Our objective was to determine antiatherogenic effect of edible blue-green algae (BGA) species, that is, Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP), in apolipoprotein E knockout (ApoE(-/-)) mice, a well-established mouse model of atherosclerosis. Male ApoE(-/-) mice were fed a high-fat/high-cholesterol (HF/HC, 15% fat and 0.2% cholesterol by wt) control diet or a HF/HC diet supplemented with 5% (w/w) of NO or SP powder for 12 weeks. Plasma total cholesterol (TC) and triglycerides (TG) were measured, and livers were analyzed for histology and gene expression. Morphometric analysis for lesions and immunohistochemical analysis for CD68 were conducted in the aorta and the aortic root. NO supplementation significantly decreased plasma TC and TG, and liver TC, compared to control and SP groups. In the livers of NO-fed mice, less lipid droplets were present with a concomitant decrease in fatty acid synthase protein levels than the other groups. There was a significant increase in hepatic low-density lipoprotein receptor protein levels in SP-supplemented mice than in control and NO groups. Quantification of aortic lesions by en face analysis demonstrated that both NO and SP decreased aortic lesion development to a similar degree compared with control. While lesions in the aortic root were not significantly different between groups, the CD68-stained area in the aortic root was significantly lowered in BGA-fed mice than controls. In conclusion, both NO and SP supplementation decreased the development of atherosclerotic lesions, suggesting that they may be used as a natural product for atheroprotection.
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Affiliation(s)
- Chai Siah Ku
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Bohkyung Kim
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Tho X Pham
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Yue Yang
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Casey J Wegner
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Young-Ki Park
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Marcy Balunas
- 2 Department of Pharmaceutical Sciences, University of Connecticut , Storrs, Connecticut, USA
| | - Ji-Young Lee
- 1 Department of Nutritional Sciences, University of Connecticut , Storrs, Connecticut, USA
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11
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Mukhopadhyay R. Mouse models of atherosclerosis: explaining critical roles of lipid metabolism and inflammation. J Appl Genet 2013; 54:185-92. [PMID: 23361320 DOI: 10.1007/s13353-013-0134-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
Abstract
Atherosclerosis is the most common cause of death globally. It is a complex disease involving morphological and cellular changes in vascular walls. Studying molecular mechanism of the disease is hindered by disease complexity and lack of robust noninvasive diagnostics in human. Mouse models are the most popular animal models that allow researchers to study the mechanism of disease progression. In this review we discuss the advantage and development of mouse as a model for atherosclerotic research. Along with commonly used models, this review discusses strains that are used to study the role of two critical processes associated with the disease-lipid metabolism and inflammation.
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Affiliation(s)
- Rupak Mukhopadhyay
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Assam, 784 028, India.
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12
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Di Bartolo BA, Chan J, Bennett MR, Cartland S, Bao S, Tuch BE, Kavurma MM. TNF-related apoptosis-inducing ligand (TRAIL) protects against diabetes and atherosclerosis in Apoe ⁻/⁻ mice. Diabetologia 2011; 54:3157-67. [PMID: 21965021 DOI: 10.1007/s00125-011-2308-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 08/09/2011] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS TNF-related apoptosis-inducing ligand (TRAIL) is implicated in the regulation of diabetes and is reduced in patients with cardiovascular disease. Although TRAIL receptors are widespread, and TRAIL can promote cell proliferation and apoptosis, it is not known how TRAIL might protect against diabetes and atherosclerosis. METHODS We examined the development of atherosclerosis and diabetes in Apoe (-/-), Trail (also known as Tnfsf10)( -/- ) Apoe ( -/- ) and Trail ( -/- ) mice that were fed a high-fat diet. Plasma cholesterol, triacylglycerol, glucose and insulin, as well as changes in various metabolic enzymes and regulators were assessed. Glucose and insulin tolerance tests were performed. Pancreatic islets were examined for insulin and beta cell dysfunction (apoptosis and macrophage infiltration). RESULTS Compared with Apoe ( -/- ) mice, Trail ( -/- ) Apoe ( -/- ) and Trail ( -/- ) mice exhibited several features of diabetes, including increased weight, hyperglycaemia, reduced plasma insulin, impaired glucose tolerance, beta cell dysfunction, reduced islet insulin, macrophage infiltration and increased apoptosis. Trail ( -/- ) Apoe ( -/- ) mice had increased plasma cholesterol, triacylglycerol, and VLDL- and LDL-cholesterol, and increased expression of genes involved in cholesterol synthesis and lipogenesis. Trail ( -/- ) Apoe ( -/- ) mice also had increased atherosclerosis, with several features of plaque instability. CONCLUSIONS/INTERPRETATION We show for the first time that TRAIL deficiency promotes numerous features of diabetes that are typical of human disease, and are associated with reduced insulin and pancreatic inflammation/apoptosis. TRAIL also regulates cholesterol and triacylglycerol homeostasis in Apoe ( -/- ) mice by increasing the expression of genes involved in (1) cholesterol synthesis and absorption, and (2) triacylglycerol production.
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Affiliation(s)
- B A Di Bartolo
- Centre for Vascular Research, University of New South Wales, Sydney, NSW 2052, Australia
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13
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Nikolov IG, Joki N, Nguyen-Khoa T, Ivanovski O, Phan O, Lacour B, Drüeke TB, Massy ZA, Dos Reis LM, Jorgetti V, Lafage-Proust MH. Chronic kidney disease bone and mineral disorder (CKD-MBD) in apolipoprotein E-deficient mice with chronic renal failure. Bone 2010; 47:156-63. [PMID: 20406703 DOI: 10.1016/j.bone.2010.04.600] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 04/11/2010] [Accepted: 04/14/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) is associated with disorders of mineral and bone metabolism (MBD) which include renal osteodystrophy and vascular calcifications. This is of clinical concern because the high risk of cardiovascular (CVD) complications observed in uremic patients may be linked with bone disease. In this context, our aim was to characterize the bone lesions in CKD-apolipoprotein E-deficient mice (apoE(-/-)) and analyze their relationships with the vascular calcifications which these animals develop rapidly in this model. With ApoE being also involved in bone metabolism, we compared the effects of CRF on the bone of apoE(-/-) mice to those observed in wild type mice (WT) of the same genetic background, C57/BL6. METHODS After CRF creation or sham surgery, 10 week-old female apoE(-/-) and WT mice were randomized to 4 groups (n=10-14/group) and fed with standard diet. Eight weeks later, animals were euthanized. Serum, aorta and femur were sampled. Femurs were imaged with 3-dimensional microtomography (microCT) and processed for bone histomorphometry (BHM). Additional quantitative histology was performed on atherosclerotic and calcified lesions in the aortas of apoE(-/-) mice. RESULTS First, apoE(-/-) mice exhibited higher cortical (10%) and trabecular (31%) bone mass than WT. CRF led to a further increase in trabecular BV/TV in WT and in apoE(-/-) mice (10.2% and 77.2%, respectively). We observed a similar increase in osteoid surface and osteoblastic parameters in CRF mice of both genotypes while resorption parameters were less augmented by CRF in apoE(-/-) mice. Finally, based on either BHM or microCT we found positive correlations between the extent of atherosclerotic lesions and bone volume parameters, and between the size of plaque calcification and osteoclast parameters in apoE(-/-) mice. CONCLUSION ApoE deficiency is associated with an increase in bone mass and volumetric mineral density in 20 week-old female mice. Bone mass is further increased, whereas bone mineral density is decreased, in response to CRF in association with histological features of osteitis fibrosa. Finally, our findings of correlations between changes in bone and aortic lesions in apoE(-/-) mice, are compatible with the hypothesis of a link between bone and vascular disease and require further study.
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Greenberg ME, Smith JD, Sehayek E. Moderately decreased cholesterol absorption rates are associated with a large atheroprotective effect. Arterioscler Thromb Vasc Biol 2009; 29:1745-50. [PMID: 19661480 DOI: 10.1161/atvbaha.109.194605] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Human treatment with ezetimibe results in a moderate 50% to 54% decrease in cholesterol absorption and a 15% to 20% decrease in plasma LDL-cholesterol levels; nevertheless, the efficacy of ezetimibe therapy has been recently challenged by the ENHANCE trial. We examined the efficacy of a moderate decrease in cholesterol absorption in preventing atherosclerosis formation in the mouse. METHODS AND RESULTS Congenic 14DKK animals, consisting of a castaneus (CASA/Rk) chromosome 14 interval introgressed onto the C57BL/6J background, displayed a moderate decrease in cholesterol absorption rates. The effect of moderately decreased absorption on atherosclerosis formation was determined in 14DKK apolipoprotein E knockouts (14DKK-apoEKO). When compared to chow diet-fed control apoEKO mice, congenic 14DKK-apoEKO displayed a moderate 41% decrease in cholesterol absorption rates, 30% to 37% decrease in plasma cholesterol levels, and a 70% decrease in atherosclerosis formation. Studies on cholesterol efflux and reverse cholesterol transport (RCT) from 14DKK bone marrow-derived macrophages rejected a 14DKK interval-dependent atheroprotective effects that operate in macrophages. In contrast, 14DKK-apoEKO congenics were characterized by a 60% increase in RCT from peripheral tissue macrophages. CONCLUSIONS These studies strongly suggest that moderately decreased cholesterol absorption rates result in a large atheroprotective effect attributable to a decrease in plasma cholesterol levels and an increase in RCT from peripheral tissue macrophages.
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Chlamydial and periodontal pathogens induce hepatic inflammation and fatty acid imbalance in apolipoprotein E-deficient mice. Infect Immun 2009; 77:3442-9. [PMID: 19451238 DOI: 10.1128/iai.00389-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Periodontitis and Chlamydia pneumoniae infection are independent risk factors for cardiovascular diseases. The aim of this study was to investigate the effect of C. pneumoniae and Aggregatibacter actinomycetemcomitans infection on hepatic inflammation and lipid homeostasis of apolipoprotein E-deficient mice. Mice were infected with viable C. pneumoniae intranasally three times for chronic infection or once for acute infection. Viable A. actinomycetemcomitans was administered 10 times intravenously alone or in concert with C. pneumoniae. Hepatic alterations were assessed by histochemistry, lipid quantification, and fatty acid profile analysis. The RNA expression levels and the presence of pathogens in the livers and lungs were detected by quantitative real-time PCR. Both pathogens were detected in the livers of the infected animals. Chronic C. pneumoniae infection induced marked changes in hepatic lipid homeostasis. A. actinomycetemcomitans infection resulted in inflammatory cell infiltration into the liver, accompanied by elevated hepatic RNA expression levels of inflammation-related genes and higher serum amyloid A and lipopolysaccharide concentrations. Our results indicate that proatherogenic pathogens infect the liver, causing proinflammatory alterations and lipid disturbances. This infection may maintain chronic systemic inflammation attributable to atherogenesis.
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Guillén N, Navarro MA, Arnal C, Noone E, Arbonés-Mainar JM, Acín S, Surra JC, Muniesa P, Roche HM, Osada J. Microarray analysis of hepatic gene expression identifies new genes involved in steatotic liver. Physiol Genomics 2009; 37:187-98. [PMID: 19258494 PMCID: PMC2685506 DOI: 10.1152/physiolgenomics.90339.2008] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Trans-10, cis-12-conjugated linoleic acid (CLA)-enriched diets promote fatty liver in mice, while cis-9, trans-11-CLA ameliorates this effect, suggesting regulation of multiple genes. To test this hypothesis, apoE-deficient mice were fed a Western-type diet enriched with linoleic acid isomers, and their hepatic gene expression was analyzed with DNA microarrays. To provide an initial screening of candidate genes, only 12 with remarkably modified expression between both CLA isomers were considered and confirmed by quantitative RT-PCR. Additionally mRNA expression of 15 genes involved in lipid metabolism was also studied. Ten genes (Fsp27, Aqp4, Cd36, Ly6d, Scd1, Hsd3b5, Syt1, Cyp7b1, and Tff3) showed significant associations among their expressions and the degree of hepatic steatosis. Their involvement was also analyzed in other models of steatosis. In hyperhomocysteinemic mice lacking Cbs gene, only Fsp27, Cd36, Scd1, Syt1, and Hsd3b5 hepatic expressions were associated with steatosis. In apoE-deficient mice consuming olive-enriched diet displaying reduction of the fatty liver, only Fsp27 and Syt1 expressions were found associated. Using this strategy, we have shown that expression of these genes is highly associated with hepatic steatosis in a genetic disease such as Cbs deficiency and in two common situations such as Western diets containing CLA isomers or a Mediterranean-type diet. Conclusion: The results highlight new processes involved in lipid handling in liver and will help to understand the complex human pathology providing new proteins and new strategies to cope with hepatic steatosis.
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Affiliation(s)
- Natalia Guillén
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto Aragonés de Ciencias de la Salud (Universidad de Zaragoza-Salud del Gobierno de Aragón), Spain
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17
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18
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Velez-Carrasco W, Merkel M, Twiss CO, Smith JD. Dietary methionine effects on plasma homocysteine and HDL metabolism in mice. J Nutr Biochem 2007; 19:362-70. [PMID: 17707632 PMCID: PMC2430472 DOI: 10.1016/j.jnutbio.2007.05.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 05/17/2007] [Indexed: 01/07/2023]
Abstract
The effects of dietary manipulation of folate and methionine on plasma homocysteine (Hcy) and high-density lipoprotein cholesterol (HDL-C) levels in wild-type and apolipoprotein-E-deficient mice were determined. A low-folate diet with or without folate and/or methionine supplementation in drinking water was administered for 7 weeks. Fasted Hcy rose to 23 microM on a low-folate/high-methionine diet, but high folate ameliorated the effect of high methionine on fasted plasma Hcy to approximately 10 microM. Determination of nonfasted plasma Hcy levels at 6-h intervals revealed a large diurnal variation in Hcy consistent with a nocturnal lifestyle. The daily average of nonfasted Hcy levels was higher than fasted values for high-methionine diets but lower than fasted values for low-methionine diets. An acute methionine load by gavage of fasted mice increased plasma Hcy 2.5 h later, but mice that had been on high-methionine diets had a lower fold induction. Mice fed high-methionine diets weighed less than mice fed low-methionine diets. Based on these results, two solid-food diets were developed: one containing 2% added methionine and the other containing 2% added glycine. The methionine diet led to fasted plasma Hcy levels of >60 microM, higher than those with methionine supplementation in drinking water. Mice on methionine diets had >20% decreased body weights and decreased HDL-C levels. An HDL turnover study demonstrated that the HDL-C production rate was significantly reduced in mice fed the methionine diet.
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Affiliation(s)
- Wanda Velez-Carrasco
- Department of Biochemical Genetics and Metabolism, Rockefeller University, New York, NY 10021, USA
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Moreno JA, López-Miranda J, Pérez-Jiménez F. Influencia de los factores genéticos y ambientales en el metabolismo lipídico y riesgo cardiovascular asociado al gen apoE. Med Clin (Barc) 2006; 127:343-51. [PMID: 16987455 DOI: 10.1157/13092316] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The apolipoprotein E (ApoE) plays an important role in lipid metabolism. This apoprotein presents three major isoforms (apoE2, apoE3 and apoE4) that modulate lipid levels. Carriers of the apoE4 allele have higher total and LDL-cholesterol plasma concentration and a greater coronary risk, particularly for myocardial infarction. Nevertheless, not all the people with this allele develop the disease, which suggests that other genetic or environmental factors are necessary for its total expression. In this review, we will analyze the importance of several polymorphisms in the apoE gene promoter region, as well as various environmental factors, including diet, in the association of this gene with lipid metabolism and cardiovascular risk.
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Affiliation(s)
- Juan Antonio Moreno
- Unidad de Lípidos y Aterosclerosis, Hospital Universitario Reina Sofía, Córdoba, España
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20
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Acín S, Navarro MA, Carnicer R, Arbonés-Mainar JM, Guzmán MA, Arnal C, Beltrán G, Uceda M, Maeda N, Osada J. Dietary cholesterol suppresses the ability of olive oil to delay the development of atherosclerotic lesions in apolipoprotein E knockout mice. Atherosclerosis 2005; 182:17-28. [PMID: 16115471 DOI: 10.1016/j.atherosclerosis.2005.01.050] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 01/21/2005] [Accepted: 01/27/2005] [Indexed: 11/30/2022]
Abstract
To test the hypothesis that cholesterol might suppress the beneficial effect of olive oil in atherosclerosis, we fed apoE KO mice diets containing extra virgin olive oil, either with or without cholesterol, for 10 weeks and assessed the development of atherosclerosis. Within each sex, mice were assigned randomly to one of the following four experimental groups: (1) a standard chow diet, (2) a chow diet supplemented with 0.1% cholesterol (w/w) cholesterol, (3) a chow diet enriched with 20% (w/w) extra virgin olive oil and (4) a chow diet containing 0.1% cholesterol and 20% extra virgin olive oil. On the standard chow diet, average plasma cholesterol levels were higher in males than in females. Olive oil- and cholesterol-enriched diets, separately or in combination, induced hypercholesterolemia in both sexes, and abolished the difference between the sexes in plasma cholesterol levels. The addition of cholesterol to chow or olive oil diets decreased apolipoprotein A-I significantly in females and serum paraoxonase activities in males. The latter activity was higher in females than in males. In both sexes, the size of aortic atherosclerotic lesions was similar in olive oil- and chow-fed animals and smaller than in cholesterol-supplemented groups. Size of aortic lesions were positively correlated with circulating paraoxonase activity, particularly in males, and the relationship remained after adjusting for apolipoprotein A-I and HDL cholesterol levels. Our results demonstrate that the nutritional regulation of paraoxonase is an important determinant of atherosclerotic lesions dependent on sex. They also suggest that the mere inclusion of olive oil in Western diets is insufficient and the adoption of Mediterranean diet would be more effective in retarding the development of atherosclerotic lesions.
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Affiliation(s)
- Sergio Acín
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain
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Jolodar A, Hourihane S, Moghadasian MH. Dietary phytosterols alter gene expression in the intestine of apolipoprotein E knockout mice. Nutr Res 2005. [DOI: 10.1016/j.nutres.2005.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Tous M, Ferré N, Camps J, Riu F, Joven J. Feeding apolipoprotein E-knockout mice with cholesterol and fat enriched diets may be a model of non-alcoholic steatohepatitis. Mol Cell Biochem 2005; 268:53-8. [PMID: 15724437 DOI: 10.1007/s11010-005-2997-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study was aimed (1) to investigate the effect of cholesterol and fat enriched diets on the development of steatohepatitis in apolipoprotein E-knockout mice, and (2) to study the chronological relationships between the development of hepatic alterations, hypercholesterolemia and atherosclerotic lesions in this experimental model. The study consisted of two protocols. Protocol 1 was used in 90 mice subdivided in groups of 18. For 10 weeks, each group was given a diet with different fat and cholesterol contents. Protocol 2 was used in 42 mice, subdivided in four groups. Each group was given a diet enriched with cholesterol and palm oil and they were sacrificed at 8, 13, 18 and 24 weeks of age. Results were as following. (1) Mice given high fat/high cholesterol diets developed an impairment of liver histology consisting of fat accumulation, macrophage proliferation, and inflammation. (2) These effects were modulated by the type of fat: olive oil was mainly associated with macrovesicular steatosis and cholesterol plus palm oil with severe steatohepatitis. (3) There was a chronological and quantitative relationship between liver impairment and the formation of atheromatous lesions. We conclude that apolipoprotein E-knockout mice may be a useful model for investigating the mechanisms of diet-induced steatohepatitis.
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Affiliation(s)
- Mònica Tous
- Centre de Recerca Biomèdica, Institut de Recerca en Ciències de la Salut, Hospital Universitari de Sant Joan, 43201-Reus, Catalunya, Spain
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Calpe-Berdiel L, Escolà-Gil JC, Ribas V, Navarro-Sastre A, Garcés-Garcés J, Blanco-Vaca F. Changes in intestinal and liver global gene expression in response to a phytosterol-enriched diet. Atherosclerosis 2005; 181:75-85. [PMID: 15939057 DOI: 10.1016/j.atherosclerosis.2004.11.025] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Revised: 10/27/2004] [Accepted: 11/05/2004] [Indexed: 11/28/2022]
Abstract
BACKGROUND Dietary phytosterols are a recommended therapeutic option for decreasing plasma cholesterol. The increased activity of ATP-binding cassette (ABC) transporters ABCA1, ABCG5 and ABCG8, or, alternatively, a decrease in Niemann-Pick C1 Like 1 (NPC1L1) could mediate the reduction in intestinal cholesterol absorption caused by phytosterols. Other biological properties such as a direct immune modulatory activity have recently been ascribed to these plant compounds. METHODS To gain insight into the molecular effects of phytosterols, global genome-wide gene profiling and real-time RT-PCR studies were conducted in small intestines and livers of phytosterol-treated apolipoprotein E-deficient (apoE(-/-)) mice. Re-testing of the main results was performed in C57BL/6J and LDL receptor-deficient (LDLR(-/-)) mice. RESULTS Intestinal cholesterol absorption was decreased in all mouse models but plasma cholesterol was only decreased in apoE(-/-) and LDLR(-/-) mice. ABCA1, ABCG5, ABCG8 and NPC1L1 mRNA levels were slightly reduced in the intestine of phytosterol-treated apoE(-/-) and LDLR(-/-) mice, but increased in C57BL/6J-treated mice. Phytosterols changed genes involved in immune regulation in apoE(-/-) mice. However, these changes were less extensive in LDLR(-/-) mice and were not found in C57BL/6J mice. CONCLUSIONS Inhibition of intestinal cholesterol absorption by phytosterols is not mediated via transcriptional changes in ABCA1, ABCG5, ABCG8 or NPC1L1. Changes suggestive of immunomodulation are associated with the hypocholesterolemic effect of phytosterols and with apoE deficiency.
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Affiliation(s)
- Laura Calpe-Berdiel
- Servei de Bioquímica, Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
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Wang DQH, Afdhal NH. Genetic analysis of cholesterol gallstone formation: searching for Lith (gallstone) genes. Curr Gastroenterol Rep 2004; 6:140-50. [PMID: 15191694 DOI: 10.1007/s11894-004-0042-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The genetics of cholesterol cholelithiasis is complex because a number of interacting genes regulate biliary cholesterol homeostasis. Quantitative trait locus (QTL) analysis is a powerful method for identifying primary rate-limiting genetic defects and discriminating them from secondary downstream lithogenic effects caused by mutations of the primary genes. The subsequent positional cloning of such genes responsible for QTLs may lead to the discovery of pathophysiologic functions of Lith (gallstone) genes. In this review, we present a map of candidate genes for Lith genes that may determine gallstone susceptibility in mice. The physical-chemical, pathophysiologic, and genetic studies of Lith genes in bile, liver, gallbladder, and intestine will be crucial for elucidating the genetic mechanisms of cholesterol gallstone disease in mice and in humans. Because exceptionally close homology exists between mouse and human genomes, the orthologous human LITH genes can often be recognized after mouse genes are identified.
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Affiliation(s)
- David Q-H Wang
- Liver Center, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, DA 601, Boston, MA 02215, USA
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Abstract
Atherosclerosis and its major clinical manifestation, coronary heart disease, is and will remain the main cause of mortality. Reviews on this subject dealt with factors that enhance development of atherosclerosis. This review deals with a new facet, that some individuals are less prone to develop atherosclerosis: (1) despite high cholesterol intake or (2) despite hypercholesterolemia with elevated low-density lipoprotein cholesterol (LDL-C) levels. The variability of response of plasma cholesterol to dietary intake was shown to be regulated by liver x receptor (LXR) that determines the rate of intestinal cholesterol absorption through the ATP-binding cassette (ABC) gene family. Other gene products, such as apolipoprotein-E (apo-E), scavenger receptor-B1 (SR-B1) and acyl coenzyme: cholesterol acyltransferase-2 (ACAT-2) affect cholesterol absorption also. The role of a genetic background for relative resistance to atherosclerosis is highlighted by subjects with familial hypercholesterolemia in whom high plasma cholesterol levels has not curtailed their expected life span. Studies in animals have shown that resistance to atherosclerosis in spite of hypercholesterolemia is affected by factors such as high-density lipoprotein (HDL) phospholipids that enhance reverse cholesterol transport, non-responsiveness to induction or lack of monocyte chemotactic protein-1 (MCP-1), C-C chemokine receptor 2 (CCR2), macrophage colony stimulating factor (MCSF), or vascular cell adhesion molecule-1 (VCAM-1). Since macrophages have been regarded as pro- or anti-atherogenic, evidence was collated that the high activity of scavenger receptors may contribute towards resistance to atherosclerosis if accompanied by adequate amounts of apo-E for cholesterol removal.
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MESH Headings
- Animals
- Apolipoproteins E/genetics
- Arteriosclerosis/complications
- Arteriosclerosis/genetics
- CD36 Antigens/genetics
- Carrier Proteins/genetics
- Chemokine CCL2/genetics
- Cholesterol/blood
- Cholesterol/genetics
- Cholesterol, Dietary
- Coronary Disease/complications
- Coronary Disease/genetics
- DNA-Binding Proteins
- Gene Expression Regulation/genetics
- Genetic Markers/genetics
- Genetic Predisposition to Disease/genetics
- Humans
- Hypercholesterolemia/complications
- Hypercholesterolemia/genetics
- Liver X Receptors
- Macrophage Colony-Stimulating Factor/genetics
- Membrane Proteins
- Orphan Nuclear Receptors
- Receptors, CCR2
- Receptors, Chemokine/genetics
- Receptors, Cytoplasmic and Nuclear
- Receptors, Immunologic
- Receptors, Lipoprotein
- Receptors, Retinoic Acid/genetics
- Receptors, Scavenger
- Receptors, Thyroid Hormone/genetics
- Scavenger Receptors, Class B
- Sterol O-Acyltransferase/genetics
- Vascular Cell Adhesion Molecule-1/genetics
- Vascular Resistance/genetics
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Affiliation(s)
- Olga Stein
- Department of Experimental Medicine and Cancer Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Merkel M, Velez-Carrasco W, Hudgins LC, Breslow JL. Compared with saturated fatty acids, dietary monounsaturated fatty acids and carbohydrates increase atherosclerosis and VLDL cholesterol levels in LDL receptor-deficient, but not apolipoprotein E-deficient, mice. Proc Natl Acad Sci U S A 2001; 98:13294-9. [PMID: 11606787 PMCID: PMC60864 DOI: 10.1073/pnas.231490498] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heart-healthy dietary recommendations include decreasing the intake of saturated fatty acids (SFA). However, the relative benefit of replacing SFA with monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), or carbohydrates (CARB) is still being debated. We have used two mouse models of atherosclerosis, low density lipoprotein receptor-deficient (LDLRKO) and apolipoprotein E-deficient (apoEKO) mice to measure the effects of four isocaloric diets enriched with either SFA, MUFA, PUFA, or CARB on atherosclerotic lesion area and lipoprotein levels. In LDLRKO mice, compared with the SFA diet, the MUFA and CARB diets significantly increased atherosclerosis in both sexes, but the PUFA diet had no effect. The MUFA and CARB diets also increased very low density lipoprotein-cholesterol (VLDL-C) and LDL-cholesterol (LDL-C) in males and VLDL-C levels in females. Analysis of data from LDLRKO mice on all diets showed that atherosclerotic lesion area correlated positively with VLDL-C levels (males: r = 0.47, P < 0.005; females: r = 0.52, P < 0.001). In contrast, in apoEKO mice there were no significant dietary effects on atherosclerosis in either sex. Compared with the SFA diet, the CARB diet significantly decreased VLDL-C in males and the MUFA, PUFA, and CARB diets decreased VLDL-C and the CARB diet decreased LDL-C in females. In summary, in LDLRKO mice the replacement of dietary SFA by either MUFA or CARB causes a proportionate increase in both atherosclerotic lesion area and VLDL-C. There were no significant dietary effects on atherosclerotic lesion area in apoEKO mice. These results are surprising and suggest that, depending on the underlying genotype, dietary MUFA and CARB can actually increase atherosclerosis susceptibility, probably by raising VLDL-C levels through a non-LDL receptor, apoE-dependent pathway.
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Affiliation(s)
- M Merkel
- Laboratory of Biochemical Geneticsand Metabolism, The Rockefeller University, New York, NY 10021, USA
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27
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Abstract
Absorption of dietary cholesterol from the intestine is an important part of cholesterol homeostasis and represents the first step that allows dietary cholesterol to exert its metabolic effects. Although the role of bile salts in the initial absorption of dietary cholesterol, by the formation of emulsions, is readily appreciated, the recognition that other molecular mechanisms might govern this process is only recently gaining momentum. Not only does the intestine regulate the amount of dietary cholesterol that enters the body; it is very selective with regard to the sterols that are allowed in. The human intestine is responsible for absorbing a significant amount of cholesterol each day. In addition to approximately 0.5 g d(-1) of dietary cholesterol, many other sterols are also present in almost equal abundance in the normal diet. Approximately 0.4 g of plant sterols, such as sitosterol, brassicasterol and avanesterol, are also present. However, the human body seems to allow only cholesterol to enter and remain in the body, with almost negligible amounts of plant sterols being retained. That specific molecular mechanisms are responsible for this behavior is supported by the identification of the genetic defect(s) in a rare disorder, beta-sitosterolemia (MIM 210250), where this process is disrupted. Such studies are now beginning to throw light on sterol absorption and excretion and elucidate the molecular mechanisms that govern these processes.
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Affiliation(s)
- K Lu
- Division of Endocrinology, Diabetes and Medical Genetics, Medical University of South Carolina, STR 541, 114 Doughty Street, Charleston, SC 29403, USA
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