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Abstract
The epidemic of obesity, type 2 diabetes and nonalcoholic liver disease (NAFLD) favors drug consumption, which augments the risk of adverse events including liver injury. For more than 30 years, a series of experimental and clinical investigations reported or suggested that the common pain reliever acetaminophen (APAP) could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data. This discrepancy might come from the extent of obesity and steatosis, accumulation of specific lipid species, mitochondrial dysfunction and diabetes-related parameters such as ketonemia and hyperglycemia. Among these factors, some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI). In contrast, other factors might explain why obesity and NAFLD are not always associated with more frequent or more severe APAP-induced acute hepatotoxicity, such as increased volume of distribution in the body, higher hepatic glucuronidation and reduced CYP3A4 activity. Accordingly, the occurrence and outcome of APAP-induced liver injury in an obese individual with NAFLD would depend on a delicate balance between metabolic factors that augment the generation of NAPQI and others that can mitigate hepatotoxicity.
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Abstract
BACKGROUND Body weight is defended by strong homeostatic forces. Several of the key biological mechanisms that counteract weight loss have been unraveled over the last decades. In contrast, the mechanisms that protect body weight and fat mass from becoming too high remain largely unknown. Understanding this aspect of energy balance regulation holds great promise for curbing the obesity epidemic. Decoding the physiological and molecular pathways that defend against weight gain can be achieved by an intervention referred to as 'experimental overfeeding'. SCOPE OF THE REVIEW In this review, we define experimental overfeeding and summarize the studies that have been conducted on animals. This field of research shows that experimental overfeeding induces a potent and prolonged hypophagic response that seems to be conserved across species and mediated by unidentified endocrine factors. In addition, the literature shows that experimental overfeeding can be used to model the development of non-alcoholic steatohepatitis and that forced intragastric infusion of surplus calories lowers survival from infections. Finally, we highlight studies indicating that experimental overfeeding can be employed to study the transgenerational effects of a positive energy balance and how dietary composition and macronutrient content might impact energy homeostasis and obesity development in animals. MAJOR CONCLUSIONS Experimental overfeeding of animals is a powerful yet underappreciated method to investigate the defense mechanisms against weight gain. This intervention also represents an alternative approach for studying the pathophysiology of metabolic liver diseases and the links between energy balance and infection biology. Future research in this field could help uncover why humans respond differently to an obesogenic environment and reveal novel pathways with therapeutic potential against obesity and cardiometabolic disorders.
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Cheng C, Liu XH, He J, Gao J, Zhou JT, Fan JN, Jin X, Zhang J, Chang L, Xiong Z, Yu J, Li S, Li X. Apolipoprotein A4 Restricts Diet-induced Hepatic Steatosis via SREBF1-mediated Lipogenesis and Enhances IRS-PI3K-Akt Signaling. Mol Nutr Food Res 2022; 66:e2101034. [PMID: 35909347 DOI: 10.1002/mnfr.202101034] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 07/03/2022] [Indexed: 11/12/2022]
Abstract
SCOPE Hepatic steatosis and insulin resistance (IR) are risk factors for many metabolic syndromes such as NAFLD and T2DM. ApoA4 improves glucose hemostasis by increasing glucose-stimulated insulin secretion and glucose uptake via PI3K-Akt activation in adipocytes. However, whether ApoA4 has an effect on hepatic steatosis or IR remains unclear. METHODS AND RESULTS ApoA4-knockout (KO) aggravates diet-induced obesity, hepatic steatosis and IR in mice promoted by increased hepatic lipogenesis gene expression based on RNA-seq data. Conversely, liver-specific overexpression of ApoA4 via AAV-ApoA4 transduction reverses the effect in ApoA4-KO mice, accompanied by suppressed hepatic lipogenesis, increased lipolysis, and fatty acid oxidation. Short-term treatment with recombinant ApoA4 protein improves glucose clearance and liver insulin sensitivity, and reduces hepatic lipogenesis gene expression in the absence of insulin. Moreover, in primary hepatocytes and a hepatic cell line, ApoA4 improves hepatic glucose uptake via IRS-PI3K-Akt signaling and decreases fat deposition and hepatic lipogenesis gene expression by inhibiting SREBF1 activity. CONCLUSION ApoA4 restricts hepatic steatosis by inhibiting SREBF1-mediated lipogenesis and improves insulin sensitivity and glucose uptake via IRS-PI3K-Akt signaling in the liver. These findings indicate that ApoA4 may serve as a therapeutic target for obesity-associated NAFLD. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Cheng Cheng
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Xiao-Huan Liu
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, Precision Medical Institute, Institute of Digestive Diseases. The Second Affiliated Hospital, Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jing He
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jing Gao
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jin-Ting Zhou
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jing-Na Fan
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Xi Jin
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jianbo Zhang
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Liao Chang
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Zijun Xiong
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Jun Yu
- OneHealth Technology Company, Xi'an, 710000, China
| | - Shengbin Li
- Bio-evidence Sciences Academy (BSA), Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China.,Key laboratory of Ministry of Public Health for Forensic Sciences, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
| | - Xiaoming Li
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, Precision Medical Institute, Institute of Digestive Diseases. The Second Affiliated Hospital, Xi'an Jiaotong University, Western China Science & Technology Innovation Harbour, Xi'an, 710100, China
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Huang C, Liu Q, Tang Q, Jing X, Wu T, Zhang J, Zhang G, Zhou J, Zhang Z, Zhao Y, Huang H, Xia Y, Yan J, Xiao J, Li Y, He J. Hepatocyte-specific deletion of Nlrp6 in mice exacerbates the development of non-alcoholic steatohepatitis. Free Radic Biol Med 2021; 169:110-121. [PMID: 33857628 DOI: 10.1016/j.freeradbiomed.2021.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Previous studies have established that deficiency in Nucleotide-binding and oligomerization domain (NOD)-like receptor family pyrin domain containing 6 (Nlrp6) changes the configuration of the gut microbiota, which leads to hepatic steatosis. Here, we aimed to determine the hepatic function of Nlrp6 in lipid metabolism and inflammation and its role in the development of non-alcoholic steatohepatitis (NASH). METHODS Nlrp6Loxp/Loxp and hepatocyte-specific Nlrp6-knockout mice were fed a high-fat diet (HFD) or methionine-choline deficient (MCD) diet to induce fatty liver or steatohepatitis, respectively. Primary hepatocytes were isolated to further explore the underlying mechanisms in vitro. In addition, we used adenovirus to overexpress Nlrp6 in ob/ob mice to demonstrate its role in NASH. RESULTS Hepatic Nlrp6 expression was downregulated in NASH patients and in obese mice. Hepatocyte-specific Nlrp6 deficiency promoted HFD- or MCD diet-induced lipid accumulation and inflammation, whereas Nlrp6 overexpression in ob/ob mice had beneficial effects. In vitro studies demonstrated that knockdown of Nlrp6 aggravated hepatic steatosis and inflammation in hepatocytes, but its overexpression markedly attenuated these abnormalities. Moreover, both in vitro and in vivo study demonstrated that Nlrp6 inhibited Cd36-mediated lipid uptake. Nlrp6 deficiency-enhanced fatty acid uptake was blocked by a Cd36 inhibitor in hepatocytes. Nlrp6 ablation increased the expression of proinflammatory cytokines, likely as a result of increased NF-κB phosphorylation and activation. Mechanistically, Nlrp6 promoted the degradation of transforming growth factor-β-activated kinase 1 (TAK1)-binding protein 2/3 (TAB2/3) via a lysosomal-dependent pathway, which suppressed NF-κB activation. CONCLUSIONS Nlrp6 may play a key role in the pathological process of NASH by inhibiting Cd36 and NF-κB pathways. It may be a potential therapeutic target for NASH.
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Affiliation(s)
- Cuiyuan Huang
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Qinhui Liu
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Qin Tang
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Xiandan Jing
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Tong Wu
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jinhang Zhang
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Guorong Zhang
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jian Zhou
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Zijing Zhang
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Yingnan Zhao
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Hui Huang
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Yan Xia
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jiamin Yan
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jia Xiao
- Clinical Research Institute, First Affiliated Hospital of Jinan University, Guangzhou 510632, China.
| | - Yanping Li
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
| | - Jinhan He
- Department of Pharmacy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Laboratory of Clinical Pharmacy and Adverse Drug Reaction, National Clinical Research Center for Geriatrics,West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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Lavandera JV, Reus V, Saín J, Bernal CA, González MA. Dietary n-9, n-6 and n-3 fatty acids modulate the oxidative stress in brain and liver of mice. Effect of trans fatty acids supplementation. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2021. [DOI: 10.3233/mnm-200508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND: Arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acids interaction affects brain structure and function. Unsaturated fatty acids (UFAs) generate oxygenated lipid-derived eicosanoids which modulate the inflammatory response. The presence of trans fatty acids (TFA) in neuronal membranes can favor to generation of pro-oxidant metabolites. OBJECTIVE: This study evaluated the effect of supplementation with TFA to diets containing different proportions of FA, on the oxidative stress (OS) generation and the inflammatory response in mice brain and liver. METHODS: CF1 mice were fed diets (16 weeks) with olive (O), corn (C) or rapeseed (R) oils. OS parameters and gene expression of some key liver and brain enzymes involved in OS production were evaluated. RESULTS: In brain and liver, lipoperoxidation was increased and catalase activity was decreased in C. In brain, glutathione was diminished by supplementation with TFA in all diets and histological sections showed lymphocytes in O and C. In liver, decreased amount of lipid vacuoles and increased of cyclooxygenase-1 (COX-1) and PPARγ mRNA levels were observed in R and Rt. IL-1b and IL-6 in serum were augmented in O and Ot. CONCLUSIONS: Rapeseed oil could have protective effects on the development of OS and inflammation, while TFA supplementation did not showed marked effects on these parameters.
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Affiliation(s)
- Jimena Verónica Lavandera
- Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Verónica Reus
- Facultad de Ciencias Médicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Juliana Saín
- Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Claudio Adrian Bernal
- Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Santa Fe, Argentina
| | - Marcela Aida González
- Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
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Ronis MJ, Mercer KE, Shankar K, Pulliam C, Pedersen K, Ingelman-Sundberg M, Friso S, Samuelson D, Del Valle L, Taylor C, Welsh DA. Potential role of gut microbiota, the proto-oncogene PIKE (Agap2) and cytochrome P450 CYP2W1 in promotion of liver cancer by alcoholic and nonalcoholic fatty liver disease and protection by dietary soy protein. Chem Biol Interact 2020; 325:109131. [PMID: 32417163 DOI: 10.1016/j.cbi.2020.109131] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 05/06/2020] [Indexed: 12/12/2022]
Abstract
We have previously demonstrated promotion of diethylnitrosamine (DEN) initiated liver tumorigenesis after feeding diets high in fat or ethanol (EtOH) to male mice. This was accompanied by hepatic induction of the proto-oncogene PIKE (Agap2). Switch of dietary protein from casein to soy protein isolate (SPI) significantly reduced tumor formation in these models. We have linked EtOH consumption in mice to microbial dysbiosis. Adoptive transfer studies demonstrate that microbiota from mice fed ethanol can induce hepatic steatosis in the absence of ethanol suggesting that microbiota or the microbial metabolome play key roles in development of fatty liver disease. Feeding SPI significantly changed gut bacteria in mice increasing alpha diversity (P < 0.05) and levels of Clostidiales spp. Feeding soy formula to piglets also resulted in significant changes in microbiota, the pattern of bile acid metabolites and in inhibition of the intestinal-hepatic FXR/FGF19-SHP pathway which has been linked to both steatosis and hepatocyte proliferation. Moreover, feeding SPI also resulted in induction of hepatic PPARα signaling and inhibition of PIKE mRNA expression coincident with inhibition of steatosis and cancer prevention. Feeding studies in the DEN model with differing dietary fats demonstrated tumor promotion specific to the saturated fat, cocoa butter relative to diets containing olive oil or corn oil associated with microbial dysbiosis including dramatic increases in Lachnospiraceae particularly from the genus Coprococcus. Immunohistochemical analysis demonstrated that tumors from EtOH-fed mice and patients with alcohol-associated HCC also expressed high levels of a novel cytochrome P450 enzyme CYP2W1. Additional adoptive transfer experiments and studies in knockout mice are required to determine the exact relationship between soy effects on the microbiota, expression of PIKE, CYP2W1, PPARα activation and prevention of tumorigenesis.
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Affiliation(s)
- Martin J Ronis
- Louisiana State University Health Sciences Center, New Orleans, USA.
| | | | | | - Casey Pulliam
- Louisiana State University Health Sciences Center, New Orleans, USA
| | - Kim Pedersen
- Louisiana State University Health Sciences Center, New Orleans, USA
| | | | | | | | - Luis Del Valle
- Louisiana State University Health Sciences Center, New Orleans, USA
| | - Chris Taylor
- Louisiana State University Health Sciences Center, New Orleans, USA
| | - David A Welsh
- Louisiana State University Health Sciences Center, New Orleans, USA
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Tanaka Y, Ikeda T, Ogawa H, Kamisako T. Ezetimibe Markedly Reduces Hepatic Triglycerides and Cholesterol in Rats Fed on Fish Oil by Increasing the Expression of Cholesterol Efflux Transporters. J Pharmacol Exp Ther 2020; 374:175-183. [DOI: 10.1124/jpet.120.265660] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/30/2020] [Indexed: 12/13/2022] Open
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Martin GG, Landrock D, McIntosh AL, Milligan S, Landrock KK, Kier AB, Mackie J, Schroeder F. High Glucose and Liver Fatty Acid Binding Protein Gene Ablation Differentially Impact Whole Body and Liver Phenotype in High-Fat Pair-Fed Mice. Lipids 2020; 55:309-327. [PMID: 32314395 DOI: 10.1002/lipd.12238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/12/2020] [Accepted: 03/30/2020] [Indexed: 12/14/2022]
Abstract
Ad libitum-fed diets high in fat and carbohydrate (especially fructose) induce weight gain, obesity, and nonalcoholic fatty liver disease (NAFLD) in humans and animal models. However, interpretation is complicated since ad libitum feeding of such diets induces hyperphagia and upregulates expression of liver fatty acid binding protein (L-FABP)-a protein intimately involved in fatty acid and glucose regulation of lipid metabolism. Wild-type (WT) and L-fabp gene ablated (LKO) mice were pair-fed either high-fat diet (HFD) or high-fat/high-glucose diet (HFGD) wherein total carbohydrate was maintained constant but the proportion of glucose was increased at the expense of fructose. In LKO mice, the pair-fed HFD increased body weight and lean tissue mass (LTM) but had no effect on fat tissue mass (FTM) or hepatic fatty vacuolation as compared to pair-fed WT counterparts. These LKO mice exhibited upregulation of hepatic proteins in fatty acid uptake and cytosolic transport (caveolin and sterol carrier protein-2), but lower hepatic fatty acid oxidation (decreased serum β-hydroxybutyrate). LKO mice pair-fed HFGD also exhibited increased body weight; however, these mice had increased FTM, not LTM, and increased hepatic fatty vacuolation as compared to pair-fed WT counterparts. These LKO mice also exhibited upregulation of hepatic proteins in fatty acid uptake and cytosolic transport (caveolin and acyl-CoA binding protein, but not sterol carrier protein-2), but there was no change in hepatic fatty acid oxidation (serum β-hydroxybutyrate) as compared to pair-fed WT counterparts.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Sherrelle Milligan
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - John Mackie
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843, USA
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Wang P, Lu Z, He M, Shi B, Lei X, Shan A. The Effects of Endoplasmic-Reticulum-Resident Selenoproteins in a Nonalcoholic Fatty Liver Disease Pig Model Induced by a High-Fat Diet. Nutrients 2020; 12:nu12030692. [PMID: 32143527 PMCID: PMC7146353 DOI: 10.3390/nu12030692] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/29/2020] [Accepted: 03/02/2020] [Indexed: 12/20/2022] Open
Abstract
The present study aimed to investigate the intervention of selenium in the oxidative stress and apoptosis of pig livers, which were induced by a high-fat diet, and the effects of four endoplasmic reticulum (ER)-resident selenoproteins in the process. A 2 × 4 design trial was conducted that included two dietary fat levels (BD = basal diet and HFD = high-fat diet) and four dietary Se supplementation levels (0, 0.3, 1.0, and 3.0 mg/kg of the diet, in the form of sodium selenite (Na2SeO3)). Our results indicated that the HFD significantly increased the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, as well as the degree of steatosis, the content of malondialdehyde (MDA), the apoptotic rate, and the level of mRNA caspase-3 in the liver compared to their BD counterparts (p < 0.05). Moreover, these parameters in the HFD groups were more significantly reduced (p < 0.05) for a Se concentration of 1.0 mg/kg than for the other concentrations. Further, for both the BD and HFD, the groups supplemented with 1.0 mg/kg Se showed the highest mRNA level of selenoprotein S. In conclusion, the consumption of an HFD can induce oxidative damage and apoptosis in the liver. This shows that the supplementation of Se at 1.0 mg/kg may be the optimum concentration against damage induced by HFD, and Sels may play a key role in this process.
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Affiliation(s)
- Pengzu Wang
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China; (P.W.); (Z.L.); (M.H.); (B.S.)
| | - Zhuang Lu
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China; (P.W.); (Z.L.); (M.H.); (B.S.)
| | - Meng He
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China; (P.W.); (Z.L.); (M.H.); (B.S.)
| | - Baoming Shi
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China; (P.W.); (Z.L.); (M.H.); (B.S.)
| | - Xingen Lei
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA;
| | - Anshan Shan
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China; (P.W.); (Z.L.); (M.H.); (B.S.)
- Correspondence: ; Tel./Fax: +86-0451-55190685
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10
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Bertasso IM, Pietrobon CB, Lopes BP, Peixoto TC, Soares PN, Oliveira E, Manhães AC, Bonfleur ML, Balbo SL, Cabral SS, Gabriel Kluck GE, Atella GC, Gaspar de Moura E, Lisboa PC. Programming of hepatic lipid metabolism in a rat model of postnatal nicotine exposure - Sex-related differences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 258:113781. [PMID: 31864076 DOI: 10.1016/j.envpol.2019.113781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 12/04/2019] [Accepted: 12/08/2019] [Indexed: 06/10/2023]
Abstract
Maternal nicotine exposure during lactation induces liver damage in adult male rats. However, the mechanism in males is unknown and females have not been tested. Here, we determined the liver lipid composition and lipogenic enzymes in male and female offspring at two ages in a model of postnatal nicotine exposure. Osmotic minipumps were implanted in lactating Wistar rat dams at postnatal day (PND) 2 to release 6 mg/kg/day of nicotine (NIC group) or saline (CON group) for 14 days. Offspring received a standard diet from weaning until euthanasia at PND120 (1 pup/litter/sex) or PND180 (2 pups/litter/sex). At PND120, NIC males showed lower plasma triglycerides (TG), steatosis degree 1, higher hepatic cholesterol (CHOL) ester, free fatty acids, monoacylglycerol content as well as acetyl-coa carboxylase-1 (ACC-1) and fatty acid synthase (FAS) protein expression in the liver compared to CON males. At this age, NIC females had preserved hepatocytes architecture, higher plasma CHOL, higher CHOL ester and lower total CHOL content in the liver compared to CON females. At PND180, NIC males showed steatosis degrees 1 and 2, higher TG, lower free fatty acids and total CHOL content in the liver and an increase in ACC-1 hepatic protein expression. NIC females had higher plasma TG and CHOL levels, no change in hepatic morphology, lower CHOL ester and free fatty acids in the liver, which also showed higher total ACC-1 and FAS protein expression. Maternal nicotine exposure induces long-term liver dysfunction, with an alteration in hepatic cytoarchitecture that was aggravated with age in males. Concerning females, despite unchanged hepatic cytoarchitecture, lipid metabolism was compromised, which deserves further attention.
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Affiliation(s)
- Iala Milene Bertasso
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Carla Bruna Pietrobon
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Bruna Pereira Lopes
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Thamara Cherem Peixoto
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Patrícia Novaes Soares
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Elaine Oliveira
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Alex Christian Manhães
- Laboratory of Neurophysiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Maria Lucia Bonfleur
- Laboratory of Endocrine Physiology and Metabolism, Center of Biological and Health Sciences, Western Paraná State University, Cascavel, PR, Brazil
| | - Sandra Lucinei Balbo
- Laboratory of Endocrine Physiology and Metabolism, Center of Biological and Health Sciences, Western Paraná State University, Cascavel, PR, Brazil
| | - Suellen Silva Cabral
- Laboratory of Lipids and Lipoprotein Biochemistry, Biochemistry Institute of Federal University of Rio de Janeiro, RJ, Brazil
| | - George Eduardo Gabriel Kluck
- Laboratory of Lipids and Lipoprotein Biochemistry, Biochemistry Institute of Federal University of Rio de Janeiro, RJ, Brazil
| | - Georgia Correa Atella
- Laboratory of Lipids and Lipoprotein Biochemistry, Biochemistry Institute of Federal University of Rio de Janeiro, RJ, Brazil
| | - Egberto Gaspar de Moura
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil
| | - Patrícia Cristina Lisboa
- Laboratory of Endocrine Physiology, Biology Institute, State University of Rio de Janeiro, RJ, Brazil.
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11
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Jiang T, Zhang Y, Bai M, Li P, Wang W, Chen M, Ma Z, Zeng S, Zhou H, Jiang H. Up-regulation of hepatic fatty acid transporters and inhibition/down-regulation of hepatic OCTN2 contribute to olanzapine-induced liver steatosis. Toxicol Lett 2019; 316:183-193. [DOI: 10.1016/j.toxlet.2019.08.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/07/2019] [Accepted: 08/19/2019] [Indexed: 11/24/2022]
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12
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Martin GG, Seeger DR, McIntosh AL, Milligan S, Chung S, Landrock D, Dangott LJ, Golovko MY, Murphy EJ, Kier AB, Schroeder F. Sterol Carrier Protein-2/Sterol Carrier Protein-x/Fatty Acid Binding Protein-1 Ablation Impacts Response of Brain Endocannabinoid to High-Fat Diet. Lipids 2019; 54:583-601. [PMID: 31487051 DOI: 10.1002/lipd.12192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/16/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
Brain endocannabinoids (EC) such as arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) primarily originate from serum arachidonic acid (ARA), whose level is regulated in part by a cytosolic ARA-binding protein, that is, liver fatty acid binding protein-1 (FABP1), not expressed in the brain. Ablation of the Fabp1 gene (LKO) increases brain AEA and 2-AG by decreasing hepatic uptake of ARA to increase serum ARA, thereby increasing ARA availability for uptake by the brain. The brain also expresses sterol carrier protein-2 (SCP-2), which is also a cytosolic ARA-binding protein. To further resolve the role of SCP-2 independent of FABP1, mice ablated in the Scp-2/Scp-x gene (DKO) were crossed with mice ablated in the Fabp1 gene (LKO) mice to generate triple knock out (TKO) mice. TKO impaired the ability of LKO to increase brain AEA and 2-AG. While a high-fat diet (HFD) alone increased brain AEA, TKO impaired this effect. Overall, these TKO-induced blocks were not attributable to altered expression of brain proteins in ARA uptake, AEA/2-AG synthesis, or AEA/2-AG degrading enzymes. Instead, TKO reduced serum levels of free ARA and/or total ARA and thereby decreased ARA availability for uptake to the brain and downstream synthesis of AEA and 2-AG therein. In summary, Scp-2/Scp-x gene ablation in Fabp1 null (LKO) mice antagonized the impact of LKO and HFD on brain ARA and, subsequently, EC levels. Thus, both FABP1 and SCP-2 participate in regulating the EC system in the brain.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Drew R Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Sherrelle Milligan
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Eric J Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
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13
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Martin GG, Landrock D, Dangott LJ, McIntosh AL, Kier AB, Schroeder F. Human Liver Fatty Acid Binding Protein-1 T94A Variant, Nonalcohol Fatty Liver Disease, and Hepatic Endocannabinoid System. Lipids 2019; 53:27-40. [PMID: 29488637 DOI: 10.1002/lipd.12008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/26/2017] [Accepted: 10/31/2017] [Indexed: 12/16/2022]
Abstract
Hepatic endocannabinoids (EC) and their major binding/"chaperone" protein (i.e., liver fatty acid binding protein-1 [FABP1]) are associated with development of nonalcoholic fatty liver (NAFLD) in animal models and humans. Since expression of the highly prevalent human FABP1 T94A variant induces serum lipid accumulation, it is important to determine its impact on hepatic lipid accumulation and the EC system. This issue was addressed in livers from human subjects expressing only wild-type (WT) FABP1 T94T (TT genotype) or T94A variant (TC or CC genotype). WT FABP1 males had lower total lipids (both neutral cholesteryl esters, triacylglycerols) and phospholipids than females. WT FABP1 males' lower lipids correlated with lower levels of the N-acylethanolamide DHEA and 2-monoacylglycerols (2-MAG) (2-OG, 2-PG). T94A expression in males increased the hepatic total lipids (triacylglycerol, cholesteryl ester), which is consistent with their higher level of CB1-potentiating 2-OG and lower antagonistic EPEA. In contrast, in females, T94A expression did not alter the total lipids, neutral lipids, or phospholipids, which is attributable to the higher cannabinoid receptor-1 (CB1) agonist arachidonoylethanolamide (AEA) and its CB1-potentiator OEA being largely offset by reduced potentiating 2-OG and increased antagonistic EPEA. Taken together, these findings indicate that T94A-induced alterations in the hepatic EC system contribute at least in part to the hepatic accumulation of lipids associated with NAFLD, especially in males.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Lawrence J Dangott
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
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14
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Martin GG, Seeger DR, McIntosh AL, Chung S, Milligan S, Landrock D, Dangott LJ, Golovko MY, Murphy EJ, Kier AB, Schroeder F. Scp-2/Scp-x ablation in Fabp1 null mice differentially impacts hepatic endocannabinoid level depending on dietary fat. Arch Biochem Biophys 2018; 650:93-102. [PMID: 29763591 PMCID: PMC6033332 DOI: 10.1016/j.abb.2018.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/07/2018] [Accepted: 05/11/2018] [Indexed: 12/21/2022]
Abstract
Dysregulation of the hepatic endocannabinoid (EC) system and high fat diet (HFD) are associated with non-alcoholic fatty liver disease. Liver cytosol contains high levels of two novel endocannabinoid binding proteins-liver fatty acid binding protein (FABP1) and sterol carrier protein-2 (SCP-2). While Fabp1 gene ablation significantly increases hepatic levels of arachidonic acid (ARA)-containing EC and sex-dependent response to pair-fed high fat diet (HFD), the presence of SCP-2 complicates interpretation. These issues were addressed by ablating Scp-2/Scp-x in Fabp1 null mice (TKO). In control-fed mice, TKO increased hepatic levels of arachidonoylethanolamide (AEA) in both sexes. HFD impacted hepatic EC levels by decreasing AEA in TKO females and decreasing 2-arachidonoyl glycerol (2-AG) in WT of both sexes. Only TKO males on HFD had increased hepatic 2-AG levels. Hepatic ARA levels were decreased in control-fed TKO of both sexes. Changes in hepatic AEA/2-AG levels were not associated with altered amounts of hepatic proteins involved in AEA/2-AG synthesis or degradation. These findings suggested that ablation of the Scp-2/Scp-x gene in Fabp1 null mice exacerbated hepatic EC accumulation and antagonized the impact of HFD on hepatic EC levels-suggesting both proteins play important roles in regulating the hepatic EC system.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA.
| | - Drew R Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Sherrelle Milligan
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX 77843-2128, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Eric J Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA.
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Jamwal R, de la Monte SM, Ogasawara K, Adusumalli S, Barlock BB, Akhlaghi F. Nonalcoholic Fatty Liver Disease and Diabetes Are Associated with Decreased CYP3A4 Protein Expression and Activity in Human Liver. Mol Pharm 2018; 15:2621-2632. [PMID: 29792708 DOI: 10.1021/acs.molpharmaceut.8b00159] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease in the Western population. We investigated the association of nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus on CYP3A4 activity in human liver tissue from brain dead donors ( n = 74). Histopathologically graded livers were grouped into normal ( n = 24), nonalcoholic fatty liver (NAFL, n = 26), and nonalcoholic steatohepatitis (NASH, n = 24) categories. The rate of conversion of midazolam to its 1-hydroxy metabolite was used to assess in vitro CYP3A4 activity in human liver microsomes (HLM). A proteomics approach was utilized to quantify the protein expression of CYP3A4 and related enzymes. Moreover, a physiologically based pharmacokinetic (PBPK) model was developed to allow prediction of midazolam concentration in NAFL and NASH livers. CYP3A4 activity in NAFL and NASH was 1.9- and 3.1-fold ( p < 0.05) lower than normal donors, respectively. Intrinsic clearance (CLint) was 2.7- ( p < 0.05) and 4.1-fold ( p < 0.01) lower in donors with NAFL and NASH, respectively. CYP3A4 protein expression was significantly lower in NAFL and NASH donors ( p < 0.05) and accounted for significant midazolam hydroxylation variability in a multiple linear regression analysis (β = 0.869, r2 = 0.762, P < 0.01). Diabetes was also associated with decreased CYP3A4 activity and protein expression. Both midazolam CLint and CYP3A4 protein abundance decreased significantly with increase in hepatic fat accumulation. Age and gender did not exhibit any significant association with the observed alterations. Predicted midazolam exposure was 1.7- and 2.3-fold higher for NAFL and NASH, respectively, which may result in a longer period of sedation in these disease-states. Data suggests that NAFLD and diabetes are associated with the decreased hepatic CYP3A4 activity. Thus, further evaluation of clinical consequences of these findings on the efficacy and safety of CYP3A4 substrates is warranted.
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Affiliation(s)
- Rohitash Jamwal
- Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
| | - Suzanne M de la Monte
- Departments of Medicine, Pathology, Neurology, and Neurosurgery , Rhode Island Hospital and the Warren Alpert Medical School of Brown University , Providence , Rhode Island 02903 , United States
| | - Ken Ogasawara
- Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
| | - Sravani Adusumalli
- Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
| | - Benjamin B Barlock
- Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
| | - Fatemeh Akhlaghi
- Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
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16
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McIntosh AL, Martin GG, Huang H, Landrock D, Kier AB, Schroeder F. Δ 9-Tetrahydrocannabinol induces endocannabinoid accumulation in mouse hepatocytes: antagonism by Fabp1 gene ablation. J Lipid Res 2018; 59:646-657. [PMID: 29414765 PMCID: PMC5880504 DOI: 10.1194/jlr.m082644] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/03/2018] [Indexed: 01/06/2023] Open
Abstract
Phytocannabinoids, such as Δ9-tetrahydrocannabinol (THC), bind and activate cannabinoid (CB) receptors, thereby "piggy-backing" on the same pathway's endogenous endocannabinoids (ECs). The recent discovery that liver fatty acid binding protein-1 (FABP1) is the major cytosolic "chaperone" protein with high affinity for both Δ9-THC and ECs suggests that Δ9-THC may alter hepatic EC levels. Therefore, the impact of Δ9-THC or EC treatment on the levels of endogenous ECs, such as N-arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), was examined in cultured primary mouse hepatocytes from WT and Fabp1 gene-ablated (LKO) mice. Δ9-THC alone or 2-AG alone significantly increased AEA and especially 2-AG levels in WT hepatocytes. LKO alone markedly increased AEA and 2-AG levels. However, LKO blocked/diminished the ability of Δ9-THC to further increase both AEA and 2-AG. In contrast, LKO potentiated the ability of exogenous 2-AG to increase the hepatocyte level of AEA and 2-AG. These and other data suggest that Δ9-THC increases hepatocyte EC levels, at least in part, by upregulating endogenous AEA and 2-AG levels. This may arise from Δ9-THC competing with AEA and 2-AG binding to FABP1, thereby decreasing targeting of bound AEA and 2-AG to the degradative enzymes, fatty acid amide hydrolase and monoacylglyceride lipase, to decrease hydrolysis within hepatocytes.
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Affiliation(s)
- Avery L McIntosh
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
| | - Gregory G Martin
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
| | - Huan Huang
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
| | - Danilo Landrock
- Departments of Pathobiology, Texas A&M University, College Station, TX 77843
| | - Ann B Kier
- Departments of Pathobiology, Texas A&M University, College Station, TX 77843
| | - Friedhelm Schroeder
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843.
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17
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Vlaic S, Conrad T, Tokarski-Schnelle C, Gustafsson M, Dahmen U, Guthke R, Schuster S. ModuleDiscoverer: Identification of regulatory modules in protein-protein interaction networks. Sci Rep 2018; 8:433. [PMID: 29323246 PMCID: PMC5764996 DOI: 10.1038/s41598-017-18370-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/06/2017] [Indexed: 02/08/2023] Open
Abstract
The identification of disease-associated modules based on protein-protein interaction networks (PPINs) and gene expression data has provided new insights into the mechanistic nature of diverse diseases. However, their identification is hampered by the detection of protein communities within large-scale, whole-genome PPINs. A presented successful strategy detects a PPIN's community structure based on the maximal clique enumeration problem (MCE), which is a non-deterministic polynomial time-hard problem. This renders the approach computationally challenging for large PPINs implying the need for new strategies. We present ModuleDiscoverer, a novel approach for the identification of regulatory modules from PPINs and gene expression data. Following the MCE-based approach, ModuleDiscoverer uses a randomization heuristic-based approximation of the community structure. Given a PPIN of Rattus norvegicus and public gene expression data, we identify the regulatory module underlying a rodent model of non-alcoholic steatohepatitis (NASH), a severe form of non-alcoholic fatty liver disease (NAFLD). The module is validated using single-nucleotide polymorphism (SNP) data from independent genome-wide association studies and gene enrichment tests. Based on gene enrichment tests, we find that ModuleDiscoverer performs comparably to three existing module-detecting algorithms. However, only our NASH-module is significantly enriched with genes linked to NAFLD-associated SNPs. ModuleDiscoverer is available at http://www.hki-jena.de/index.php/0/2/490 (Others/ModuleDiscoverer).
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Affiliation(s)
- Sebastian Vlaic
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Systems Biology and Bioinformatics, Jena, 07745, Germany.
- Friedrich-Schiller-University, Department of Bioinformatics, Jena, 07743, Germany.
| | - Theresia Conrad
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Systems Biology and Bioinformatics, Jena, 07745, Germany
| | - Christian Tokarski-Schnelle
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Systems Biology and Bioinformatics, Jena, 07745, Germany
- University Hospital Jena, Friedrich-Schiller-University, General, Visceral and Vascular Surgery, Jena, 07749, Germany
| | - Mika Gustafsson
- Linköping University, Bioinformatics, Department of Physics, Chemistry and Biology, Linköping, 581 83, Sweden
| | - Uta Dahmen
- University Hospital Jena, Friedrich-Schiller-University, General, Visceral and Vascular Surgery, Jena, 07749, Germany
| | - Reinhard Guthke
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Systems Biology and Bioinformatics, Jena, 07745, Germany
| | - Stefan Schuster
- Friedrich-Schiller-University, Department of Bioinformatics, Jena, 07743, Germany
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18
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Milligan S, Martin GG, Landrock D, McIntosh AL, Mackie JT, Schroeder F, Kier AB. Ablating both Fabp1 and Scp2/Scpx (TKO) induces hepatic phospholipid and cholesterol accumulation in high fat-fed mice. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:323-338. [PMID: 29307784 DOI: 10.1016/j.bbalip.2017.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/13/2017] [Accepted: 12/31/2017] [Indexed: 01/16/2023]
Abstract
Although singly ablating Fabp1 or Scp2/Scpx genes may exacerbate the impact of high fat diet (HFD) on whole body phenotype and non-alcoholic fatty liver disease (NAFLD), concomitant upregulation of the non-ablated gene, preference for ad libitum fed HFD, and sex differences complicate interpretation. Therefore, these issues were addressed in male and female mice ablated in both genes (Fabp1/Scp2/Scpx null or TKO) and pair-fed HFD. Wild-type (WT) males gained more body weight as fat tissue mass (FTM) and exhibited higher hepatic lipid accumulation than WT females. The greater hepatic lipid accumulation in WT males was associated with higher hepatic expression of enzymes in glyceride synthesis, higher hepatic bile acids, and upregulation of transporters involved in hepatic reuptake of serum bile acids. While TKO had little effect on whole body phenotype and hepatic bile acid accumulation in either sex, TKO increased hepatic accumulation of lipids in both, specifically phospholipid and cholesteryl esters in males and females and free cholesterol in females. TKO-induced increases in glycerides were attributed not only to complete loss of FABP1, SCP2 and SCPx, but also in part to sex-dependent upregulation of hepatic lipogenic enzymes. These data with WT and TKO mice pair-fed HFD indicate that: i) Sex significantly impacted the ability of HFD to increase body weight, induce hepatic lipid accumulation and increase hepatic bile acids; and ii) TKO exacerbated the HFD ability to induce hepatic lipid accumulation, regardless of sex, but did not significantly alter whole body phenotype in either sex.
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Affiliation(s)
- Sherrelle Milligan
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Gregory G Martin
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Avery L McIntosh
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - John T Mackie
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA.
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19
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Martin GG, Landrock D, Chung S, Dangott LJ, McIntosh AL, Mackie JT, Kier AB, Schroeder F. Loss of fatty acid binding protein-1 alters the hepatic endocannabinoid system response to a high-fat diet. J Lipid Res 2017; 58:2114-2126. [PMID: 28972119 DOI: 10.1194/jlr.m077891] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 09/08/2017] [Indexed: 12/31/2022] Open
Abstract
Upregulation of the hepatic endocannabinoid (EC) receptor [cannabinoid receptor-1 (CB1)] and arachidonoylethanolamide (AEA) is associated with nonalcoholic fatty liver disease (NAFLD). Male mice fed high-fat diet (HFD) ad libitum also exhibit NAFLD, increased hepatic AEA, and obesity. But, preference for HFD complicates interpretation and almost nothing is known about these effects in females. These issues were addressed by pair-feeding HFD. Similarly to ad libitum-fed HFD, pair-fed HFD also increased WT male and female mouse fat tissue mass (FTM), but preferentially at the expense of lean tissue mass. In contrast, pair-fed HFD did not elicit NAFLD in WT mice regardless of sex. Concomitantly, pair-fed HFD oppositely impacted hepatic AEA, 2-arachidonoyl glycerol, and/or CB1 in WT males versus females. In pair-fed HFD mice, liver FA binding protein-1 (Fabp1) gene ablation (LKO): i) exacerbated FTM in both sexes; ii) did not elicit liver neutral lipid accumulation in males and only slightly in females; iii) increased liver AEA in males, but decreased it in females; and iv) decreased CB1 only in males. Thus, pair-fed HFD selectively impacted hepatic ECs more in females, but did not elicit NAFLD in either sex. These effects were modified by LKO consistent with FABP1's ability to impact EC and FA metabolism.
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Affiliation(s)
- Gregory G Martin
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
| | - Danilo Landrock
- Pathobiology, Texas A&M University, College Station, TX 77843
| | - Sarah Chung
- Pathobiology, Texas A&M University, College Station, TX 77843
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX 77843
| | - Avery L McIntosh
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
| | - John T Mackie
- Pathobiology, Texas A&M University, College Station, TX 77843
| | - Ann B Kier
- Pathobiology, Texas A&M University, College Station, TX 77843
| | - Friedhelm Schroeder
- Departments of Physiology and Pharmacology Texas A&M University, College Station, TX 77843
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20
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Martin GG, Huang H, McIntosh AL, Kier AB, Schroeder F. Endocannabinoid Interaction with Human FABP1: Impact of the T94A Variant. Biochemistry 2017; 56:5147-5159. [DOI: 10.1021/acs.biochem.7b00647] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843-4466, United States
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843-4466, United States
| | - Avery L. McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843-4466, United States
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, Texas 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843-4466, United States
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Ronis M, Mercer K, Engi B, Pulliam C, Zimniak P, Hennings L, Shearn C, Badger T, Petersen D. Global Deletion of Glutathione S-Transferase A4 Exacerbates Developmental Nonalcoholic Steatohepatitis. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:418-430. [PMID: 27998724 PMCID: PMC5389362 DOI: 10.1016/j.ajpath.2016.10.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/16/2016] [Accepted: 10/17/2016] [Indexed: 01/27/2023]
Abstract
We established a mouse model of developmental nonalcoholic steatohepatitis (NASH) by feeding a high polyunsaturated fat liquid diet to female glutathione-S-transferase 4-4 (Gsta4-/-)/peroxisome proliferator activated receptor α (Ppara-/-) double knockout 129/SvJ mice for 12 weeks from weaning. We used it to probe the importance of lipid peroxidation in progression of NASH beyond simple steatosis. Feeding Gsta4-/-/Ppara-/- double-knockout (dKO) mice liquid diets containing corn oil resulted in a percentage fat-dependent increase in steatosis and necroinflammatory injury (P < 0.05). Increasing fat to 70% from 35% resulted in increases in formation of 4-hydroxynonenal protein adducts accompanied by evidence of stellate cell activation, matrix remodeling, and fibrosis (P < 0.05). Comparison of dKO mice with wild-type (Wt) and single knockout mice revealed additive effects of Gsta4-/- and Ppara-/- silencing on steatosis, 4-hydroxynonenal adduct formation, oxidative stress, serum alanine amino transferase, expression of tumor necrosis factor alpha, Il6, interferon mRNA, and liver pathology (P < 0.05). Induction of Cyp2e1 protein by high-fat diet was suppressed in Gsta4-/- and dKO groups (P < 0.05). The dKO mice had similar levels of markers of stellate cell activation and matrix remodeling as Ppara-/- single KO mice. These data suggest that lipid peroxidation products play a role in progression of liver injury to steatohepatitis in NASH produced by high-fat feeding during development but appear less important in development of fibrosis.
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Affiliation(s)
- Martin Ronis
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center-New Orleans, New Orleans, Louisiana.
| | - Kelly Mercer
- Arkansas Children's Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
| | - Bridgette Engi
- Department of Laboratory Animal Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Casey Pulliam
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center-New Orleans, New Orleans, Louisiana
| | - Piotr Zimniak
- Department of Pharmacology and Toxicology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Leah Hennings
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Colin Shearn
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Thomas Badger
- Arkansas Children's Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Dennis Petersen
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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Mercer KE, Pulliam CF, Pedersen KB, Hennings L, Ronis MJ. Soy protein isolate inhibits hepatic tumor promotion in mice fed a high-fat liquid diet. Exp Biol Med (Maywood) 2017; 242:635-644. [PMID: 28056552 DOI: 10.1177/1535370216685436] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alcoholic and nonalcoholic fatty liver diseases are risk factors for development of hepatocellular carcinoma, but the underlying mechanisms are poorly understood. On the other hand, ingestion of soy-containing diets may oppose the development of certain cancers. We previously reported that replacing casein with a soy protein isolate reduced tumor promotion in the livers of mice with alcoholic liver disease after feeding a high fat ethanol liquid diet following initiation with diethylnitrosamine. Feeding soy protein isolate inhibited processes that may contribute to tumor promotion including inflammation, sphingolipid signaling, and Wnt/β-catenin signaling. We have extended these studies to characterize liver tumor promotion in a model of nonalcoholic fatty liver disease produced by chronic feeding of high-fat liquid diets in the absence of ethanol. Mice treated with diethylnitrosamine on postnatal day 14 were fed a high-fat liquid diet made with casein or SPI as the sole protein source for 16 weeks in adulthood. Relative to mice fed normal chow, a high fat/casein diet led to increased tumor promotion, hepatocyte proliferation, steatosis, and inflammation. Replacing casein with soy protein isolate counteracted these effects. The high fat diets also resulted in a general increase in transcripts for Wnt/β-catenin pathway components, which may be an important mechanism, whereby hepatic tumorigenesis is promoted. However, soy protein isolate did not block Wnt signaling in this nonalcoholic fatty liver disease model. We conclude that replacing casein with soy protein isolate blocks development of steatosis, inflammation, and tumor promotion in diethylnitrosamine-treated mice fed high fat diets. Impact statement The impact of dietary components on cancer is a topic of great interest for both the general public and the scientific community. Liver cancer is currently the second leading form of cancer deaths worldwide. Our study has addressed the effect of the protein source on hepatic tumor promotion in a mouse model reflecting aspects of non-alcoholic fatty liver disease (NAFLD). A high-fat liquid diet with casein as the protein source promotes hepatic injury and tumor promotion in diethylnitrosamine-treated mice. Replacing casein with a soy protein isolate led to a pronounced diminishment of tumor promotion and associated hepatic injury and inflammation. The study thus demonstrates that a dietary protein source can have beneficial, preventative effects on hepatic tumor promotion.
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Affiliation(s)
- Kelly E Mercer
- 1 Department of Pediatrics at the University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.,2 Arkansas Children's Nutrition Center, Little Rock, AR 72202, USA
| | - Casey F Pulliam
- 3 Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Kim B Pedersen
- 3 Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Leah Hennings
- 4 Department of Pathology at the University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Martin Jj Ronis
- 3 Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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23
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Martin GG, Landrock D, Chung S, Dangott LJ, Seeger DR, Murphy EJ, Golovko MY, Kier AB, Schroeder F. Fabp1 gene ablation inhibits high-fat diet-induced increase in brain endocannabinoids. J Neurochem 2017; 140:294-306. [PMID: 27861894 PMCID: PMC5225076 DOI: 10.1111/jnc.13890] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 10/28/2016] [Accepted: 11/03/2016] [Indexed: 01/03/2023]
Abstract
The endocannabinoid system shifts energy balance toward storage and fat accumulation, especially in the context of diet-induced obesity. Relatively little is known about factors outside the central nervous system that may mediate the effect of high-fat diet (HFD) on brain endocannabinoid levels. One candidate is the liver fatty acid binding protein (FABP1), a cytosolic protein highly prevalent in liver, but not detected in brain, which facilitates hepatic clearance of fatty acids. The impact of Fabp1 gene ablation (LKO) on the effect of high-fat diet (HFD) on brain and plasma endocannabinoid levels was examined and data expressed for each parameter as the ratio of high-fat diet/control diet. In male wild-type mice, HFD markedly increased brain N-acylethanolamides, but not 2-monoacylglycerols. LKO blocked these effects of HFD in male mice. In female wild-type mice, HFD slightly decreased or did not alter these endocannabinoids as compared with male wild type. LKO did not block the HFD effects in female mice. The HFD-induced increase in brain arachidonic acid-derived arachidonoylethanolamide in males correlated with increased brain-free and total arachidonic acid. The ability of LKO to block the HFD-induced increase in brain arachidonoylethanolamide correlated with reduced ability of HFD to increase brain-free and total arachidonic acid in males. In females, brain-free and total arachidonic acid levels were much less affected by either HFD or LKO in the context of HFD. These data showed that LKO markedly diminished the impact of HFD on brain endocannabinoid levels, especially in male mice.
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Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Sarah Chung
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Lawrence J. Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX 77843-2128
| | - Drew R. Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Eric J. Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Mikhail Y. Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
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Application of an In Vivo Hepatic Triacylglycerol Production Method in the Setting of a High-Fat Diet in Mice. Nutrients 2016; 9:nu9010016. [PMID: 28036028 PMCID: PMC5295060 DOI: 10.3390/nu9010016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/02/2016] [Accepted: 12/21/2016] [Indexed: 12/21/2022] Open
Abstract
High-fat (HF) diets typically promote diet-induced obesity (DIO) and metabolic dysfunction (i.e., insulin resistance, hypertriglyceridemia, and hepatic steatosis). Dysfunction of triacylglycerol (TAG) metabolism may contribute to the development of hepatic steatosis, via increased de novo lipogenesis or repackaging of circulating nonesterified fatty acids (NEFAs). Hepatic TAG production (HTP) rate can be assessed through injecting mice with nonionic detergents that inhibit tissue lipoprotein lipase. Potential confounding effects of detergent-based HTP tests (HTPTs) used in longitudinal studies—including the impact on food intake, energy balance, and weight gain—have not been reported. To examine this, male C57BL/6J mice were fed a 10% or 60% kcal diet. After 4 weeks, the mice underwent an HTPT via poloxamer 407 intraperitoneal injections (1000 mg/kg). Weight gain, energy intake, and postabsorptive TAG levels normalized 7–10 days post-HTPT. The post-HTPT recovery of body weight and energy intake suggest that, in metabolic phenotyping studies, any additional sample collection should occur at least 7–10 days after the HTPT to reduce confounding effects. Diet-specific effects on HTP were also observed: HF-fed mice had reduced HTP, plasma TAG, and NEFA levels compared to controls. In conclusion, the current study highlights the procedural and physiological complexities associated with studying lipid metabolism using a HTPT in the DIO mouse model.
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25
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Martin GG, Chung S, Landrock D, Landrock KK, Dangott LJ, Peng X, Kaczocha M, Murphy EJ, Kier AB, Schroeder F. Female Mice are Resistant to Fabp1 Gene Ablation-Induced Alterations in Brain Endocannabinoid Levels. Lipids 2016; 51:1007-20. [PMID: 27450559 PMCID: PMC5418128 DOI: 10.1007/s11745-016-4175-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
Abstract
Although liver fatty acid binding protein (FABP1, L-FABP) is not detectable in the brain, Fabp1 gene ablation (LKO) markedly increases endocannabinoids (EC) in brains of male mice. Since the brain EC system of females differs significantly from that of males, it was important to determine if LKO differently impacted the brain EC system. LKO did not alter brain levels of arachidonic acid (ARA)-containing EC, i.e. arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), but decreased non-ARA-containing N-acylethanolamides (OEA, PEA) and 2-oleoylglycerol (2-OG) that potentiate the actions of AEA and 2-AG. These changes in brain potentiating EC levels were not associated with: (1) a net decrease in levels of brain membrane proteins associated with fatty acid uptake and EC synthesis; (2) a net increase in brain protein levels of cytosolic EC chaperones and enzymes in EC degradation; or (3) increased brain protein levels of EC receptors (CB1, TRVP1). Instead, the reduced or opposite responsiveness of female brain EC levels to loss of FABP1 (LKO) correlated with intrinsically lower FABP1 level in livers of WT females than males. These data show that female mouse brain endocannabinoid levels were unchanged (AEA, 2-AG) or decreased (OEA, PEA, 2-OG) by complete loss of FABP1 (LKO).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Xiaoxue Peng
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Eric J Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA.
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26
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Martin GG, Chung S, Landrock D, Landrock KK, Huang H, Dangott LJ, Peng X, Kaczocha M, Seeger DR, Murphy EJ, Golovko MY, Kier AB, Schroeder F. FABP-1 gene ablation impacts brain endocannabinoid system in male mice. J Neurochem 2016; 138:407-22. [PMID: 27167970 PMCID: PMC4961623 DOI: 10.1111/jnc.13664] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/14/2016] [Accepted: 04/26/2016] [Indexed: 12/15/2022]
Abstract
Liver fatty acid-binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid-binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as oleoyl ethanolamide (OEA), PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* as a result of compensatory up-regulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid-binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids. Fatty acid-binding protein-1 (FABP-1) is not detectable in brain but instead is highly expressed in liver. The possibility that FABP1 outside the central nervous system may regulate brain endocannabinoids arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG) was examined in wild-type (WT) and FABP-1 null (LKO) male mice. LKO increased brain levels of arachidonic acid-containing endocannabinoids (AEA, 2-AG), correlating with increased free and total arachidonic acid in brain and serum. Read the Editorial Highlight for this article on page 371.
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Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Sarah Chung
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Kerstin K. Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Lawrence J. Dangott
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128
| | - Xiaoxue Peng
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794
| | - Drew R. Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Eric J. Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Mikhail Y. Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
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27
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Schroeder F, McIntosh AL, Martin GG, Huang H, Landrock D, Chung S, Landrock KK, Dangott LJ, Li S, Kaczocha M, Murphy EJ, Atshaves BP, Kier AB. Fatty Acid Binding Protein-1 (FABP1) and the Human FABP1 T94A Variant: Roles in the Endocannabinoid System and Dyslipidemias. Lipids 2016; 51:655-76. [PMID: 27117865 PMCID: PMC5408584 DOI: 10.1007/s11745-016-4155-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/11/2016] [Indexed: 01/01/2023]
Abstract
The first discovered member of the mammalian FABP family, liver fatty acid binding protein (FABP1, L-FABP), occurs at high cytosolic concentration in liver, intestine, and in the case of humans also in kidney. While the rat FABP1 is well studied, the extent these findings translate to human FABP1 is not clear-especially in view of recent studies showing that endocannabinoids and cannabinoids represent novel rat FABP1 ligands and FABP1 gene ablation impacts the hepatic endocannabinoid system, known to be involved in non-alcoholic fatty liver (NAFLD) development. Although not detectable in brain, FABP1 ablation nevertheless also impacts brain endocannabinoids. Despite overall tertiary structure similarity, human FABP1 differs significantly from rat FABP1 in secondary structure, much larger ligand binding cavity, and affinities/specificities for some ligands. Moreover, while both mouse and human FABP1 mediate ligand induction of peroxisome proliferator activated receptor-α (PPARα), they differ markedly in pattern of genes induced. This is critically important because a highly prevalent human single nucleotide polymorphism (SNP) (26-38 % minor allele frequency and 8.3 ± 1.9 % homozygous) results in a FABP1 T94A substitution that further accentuates these species differences. The human FABP1 T94A variant is associated with altered body mass index (BMI), clinical dyslipidemias (elevated plasma triglycerides and LDL cholesterol), atherothrombotic cerebral infarction, and non-alcoholic fatty liver disease (NAFLD). Resolving human FABP1 and the T94A variant's impact on the endocannabinoid and cannabinoid system is an exciting challenge due to the importance of this system in hepatic lipid accumulation as well as behavior, pain, inflammation, and satiety.
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Affiliation(s)
- Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA.
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Lawrence J Dangott
- Department of Biochemistry and Biophysics, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
| | - Shengrong Li
- Avanti Polar Lipids, 700 Industrial Park Dr., Alabaster, AL, 35007-9105, USA
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Eric J Murphy
- Department of Pharmacology, Physiology, and Therapeutics and Chemistry, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX, 77843-4466, USA
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Cheah IK, Tang R, Ye P, Yew TSZ, Lim KHS, Halliwell B. Liver ergothioneine accumulation in a guinea pig model of non-alcoholic fatty liver disease. A possible mechanism of defence? Free Radic Res 2015; 50:14-25. [PMID: 26634964 DOI: 10.3109/10715762.2015.1099642] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
L-ergothioneine (ET), a putative antioxidant compound acquired by animals through dietary sources, has been suggested to accumulate in certain cells and tissues in the body that are predisposed to high oxidative stress. In the present study, we identified an elevation of ET in the liver of a guinea pig model of non-alcoholic fatty liver disease (NAFLD), elucidated a possible mechanism for the increased uptake and investigated the possible role for this accumulation. This increase in liver ET levels correlated with cholesterol accumulation and disease severity. We identified an increase in the transcriptional factor, RUNX1, which has been shown to upregulate the expression of the ET-specific transporter OCTN1, and could consequently lead to the observable elevation in ET. An increase was also seen in heat shock protein 70 (HSP70) which seemingly corresponds to ET elevation. No significant increase was observed in oxidative damage markers, F2-isoprostanes, and protein carbonyls, which could possibly be attributed to the increase in liver ET through direct antioxidant action, induction of HSP70, or by chelation of Fe(2+), preventing redox chemistry. The data suggest a novel mechanism by which the guinea pig fatty liver accumulates ET via upregulation of its transporter, as a possible stress response by the damaged liver to further suppress oxidative damage and delay tissue injury. Similar events may happen in other animal models of disease, and researchers should be aware of the possibility.
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Affiliation(s)
- Irwin K Cheah
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Richard Tang
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Peng Ye
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Terry S Z Yew
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Keith H S Lim
- b Department of Radiation Oncology , National University Cancer Institute Singapore, National University Health System , Singapore
| | - Barry Halliwell
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
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29
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Zheng X, Dai W, Chen X, Wang K, Zhang W, Liu L, Hou J. Caffeine reduces hepatic lipid accumulation through regulation of lipogenesis and ER stress in zebrafish larvae. J Biomed Sci 2015; 22:105. [PMID: 26572131 PMCID: PMC4647812 DOI: 10.1186/s12929-015-0206-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 10/16/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Caffeine, the main component of coffee, has showed its protective effect on non-alcoholic fatty liver disease (NAFLD) in many studies. However, the hepatoprotection of caffeine and its mechanisms in zebrafish were unexplored. Thus, this study's intentions are to establish a NAFLD model of zebrafish larvae and to examine the role of caffeine on fatty liver with the model. RESULTS Growth and the incidence of fatty liver of zebrafish larvae increased with the increased amount of feeding in a dose-dependent manner. The degree of hepatic steatosis of larvae also gradually aggravated with the increased quantity and duration of feeding. Triglyceride contents of zebrafish fed for 20 days significantly increased in model group (180 mg/d) compared with control group (30 mg/d) (P < 0.001). Significant decreases in body weight and hepatic steatosis rate were observed in 2.5, 5, 8 % caffeine treatment group compared with model group (P < 0.05). Hepatic lipid accumulation was also significantly reduced in caffeine treatment larvae. Moreover, caffeine treatment was associated with upregulation of lipid β-oxidation gene ACO and downregulation of lipogenesis-associated genes (SREBP1, ACC1, CD36 and UCP2), ER stress-associated genes (PERK, IRE1, ATF6 and BIP), the inflammatory cytokine genes (IL-1beta and TNF-alpha) and autophagy associated genes (ATG12 and Beclin-1). Protein expression of CHOP, BIP and IL-1beta remarkably reduced in caffeine treatment group compared with model group. CONCLUSIONS We induced hepatoteatosis in zebrafish by overfeeding regimen and demonstrated caffeine have a role in suppression of hepatosteatosis by downregulation of genes associated with lipogenesis, ER stress, inflammatory response and enhancement of lipid oxidation, indicating zebrafish model may be used to identify putative pharmacological targets and to test novel drugs for human NAFLD treatment.
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Affiliation(s)
- Xinchun Zheng
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Wencong Dai
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Xiaohui Chen
- Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Cell Biology, Southern Medical University, Guangzhou, 510515, China.
| | - Kunyuan Wang
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Wenqing Zhang
- Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Cell Biology, Southern Medical University, Guangzhou, 510515, China.
| | - Li Liu
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Jinlin Hou
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
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Pierce AA, Duwaerts CC, Soon RK, Siao K, Grenert JP, Fitch M, Hellerstein MK, Beysen C, Turner SM, Maher JJ. Isocaloric manipulation of macronutrients within a high-carbohydrate/moderate-fat diet induces unique effects on hepatic lipogenesis, steatosis and liver injury. J Nutr Biochem 2015; 29:12-20. [PMID: 26895660 DOI: 10.1016/j.jnutbio.2015.10.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 10/05/2015] [Accepted: 10/30/2015] [Indexed: 12/19/2022]
Abstract
Diets containing excess carbohydrate and fat promote hepatic steatosis and steatohepatitis in mice. Little is known, however, about the impact of specific carbohydrate/fat combinations on liver outcome. This study was designed to determine whether high-energy diets with identical caloric density but different carbohydrate and fat composition have unique effects on the liver. Four experimental diets were formulated with 60%kcal carbohydrate and 20%kcal fat, each in nearly pure form from a single source: starch-oleate, starch-palmitate, sucrose-oleate and sucrose-palmitate. The diets were fed to mice for 3 or 12 weeks for analysis of lipid metabolism and liver injury. All mice developed hepatic steatosis over 12 weeks, but mice fed the sucrose-palmitate diet accumulated more hepatic lipid than those in the other three experimental groups. The exaggerated lipid accumulation in sucrose-palmitate-fed mice was attributable to a disproportionate rise in hepatic de novo lipogenesis. These mice accrued more hepatic palmitate and exhibited more evidence of liver injury than any of the other experimental groups. Interestingly, lipogenic gene expression in mice fed the custom diets did not correlate with actual de novo lipogenesis. In addition, de novo lipogenesis rose in all mice between 3 and 12 weeks, without feedback inhibition from hepatic steatosis. The pairing of simple sugar (sucrose) and saturated fat (palmitate) in a high-carbohydrate/moderate-fat diet induces more de novo lipogenesis and liver injury than other carbohydrate/fat combinations. Diet-induced liver injury correlates positively with hepatic de novo lipogenesis and is not predictable by isolated analysis of lipogenic gene expression.
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Affiliation(s)
- Andrew A Pierce
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143-0410, USA
| | - Caroline C Duwaerts
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143-0410, USA
| | - Russell K Soon
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143-0410, USA
| | - Kevin Siao
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143-0410, USA
| | - James P Grenert
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94143-0410, USA
| | - Mark Fitch
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA 94720, USA; KineMed, Inc., Emeryville, CA 94608, USA
| | - Marc K Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California Berkeley, Berkeley, CA 94720, USA; KineMed, Inc., Emeryville, CA 94608, USA
| | | | | | - Jacquelyn J Maher
- Liver Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143-0410, USA.
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CHO JINKYUNG, KIM SHINUK, LEE SHINHO, KANG HYUNSIK. Effect of Training Intensity on Nonalcoholic Fatty Liver Disease. Med Sci Sports Exerc 2015; 47:1624-34. [DOI: 10.1249/mss.0000000000000595] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Martin GG, Atshaves BP, Landrock KK, Landrock D, Schroeder F, Kier AB. Loss of L-FABP, SCP-2/SCP-x, or both induces hepatic lipid accumulation in female mice. Arch Biochem Biophys 2015; 580:41-9. [PMID: 26116377 DOI: 10.1016/j.abb.2015.06.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 06/08/2015] [Accepted: 06/17/2015] [Indexed: 02/06/2023]
Abstract
Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals-suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States.
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Borengasser SJ, Faske J, Kang P, Blackburn ML, Badger TM, Shankar K. In utero exposure to prepregnancy maternal obesity and postweaning high-fat diet impair regulators of mitochondrial dynamics in rat placenta and offspring. Physiol Genomics 2014; 46:841-50. [PMID: 25336449 DOI: 10.1152/physiolgenomics.00059.2014] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The proportion of pregnant women who are obese at conception continues to rise. Compelling evidence suggests the intrauterine environment is an important determinant of offspring health. Maternal obesity and unhealthy diets are shown to promote metabolic programming in the offspring. Mitochondria are maternally inherited, and we have previously shown impaired mitochondrial function in rat offspring exposed to maternal obesity in utero. Mitochondrial health is maintained by mitochondrial dynamics, or the processes of fusion and fission, which serve to repair damaged mitochondria, remove irreparable mitochondria, and maintain mitochondrial morphology. An imbalance between fusion and fission has been associated with obesity, insulin resistance, and reproduction complications. In the present study, we examined the influence of maternal obesity and postweaning high-fat diet (HFD) on key regulators of mitochondrial fusion and fission in rat offspring at important developmental milestones which included postnatal day (PND)35 (2 wk HFD) and PND130 (∼16 wk HFD). Our results indicate HFD-fed offspring had reduced mRNA expression of presenilin-associated rhomboid-like (PARL), optic atrophy (OPA)1, mitofusin (Mfn)1, Mfn2, fission (Fis)1, and nuclear respiratory factor (Nrf)1 at PND35, while OPA1 and Mfn2 remained decreased at PND130. Putative transcriptional regulators of mitochondrial dynamics were reduced in rat placenta and offspring liver and skeletal muscle [peroxisome proliferator-activated receptor gamma coactivator (PGC1)α, PGC1β, and estrogen-related receptor (ERR)α], consistent with indirect calorimetry findings revealing reduced energy expenditure and impaired fat utilization. Overall, maternal obesity detrimentally alters mitochondrial targets that may contribute to impaired mitochondrial health and increased obesity susceptibility in later life.
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Affiliation(s)
- Sarah J Borengasser
- Arkansas Children's Nutrition Center, Little Rock, Arkansas; and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Jennifer Faske
- Arkansas Children's Nutrition Center, Little Rock, Arkansas; and
| | - Ping Kang
- Arkansas Children's Nutrition Center, Little Rock, Arkansas; and
| | | | - Thomas M Badger
- Arkansas Children's Nutrition Center, Little Rock, Arkansas; and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Kartik Shankar
- Arkansas Children's Nutrition Center, Little Rock, Arkansas; and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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Li X, Li Y, Yang W, Xiao C, Fu S, Deng Q, Ding H, Wang Z, Liu G, Li X. SREBP-1c overexpression induces triglycerides accumulation through increasing lipid synthesis and decreasing lipid oxidation and VLDL assembly in bovine hepatocytes. J Steroid Biochem Mol Biol 2014; 143:174-82. [PMID: 24565561 DOI: 10.1016/j.jsbmb.2014.02.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/20/2014] [Accepted: 02/14/2014] [Indexed: 02/06/2023]
Abstract
The natural incidence of fatty liver in ruminants is significantly higher than in monogastric animals. Fatty liver is associated with sterol regulatory element-binding protein 1c (SREBP-1c). The aim of this study was to investigate the regulatory network effects of SREBP-1c on the lipid metabolic genes involved in fatty acid uptake, activation, oxidation, synthesis, and very low-density lipoprotein (VLDL) assembly in bovine hepatocytes. In vitro, bovine hepatocytes were transfected with an adenovirus-mediated SREBP-1c overexpression vector. SREBP-1c overexpression significantly up-regulated the expression and activity of the fatty acid uptake, activation, and synthesis enzymes: liver fatty acid binding protein, fatty acid translocase, acyl-CoA synthetase long-chain 1, acetyl-CoA carboxylase 1, and fatty acid synthase, increasing triglyceride (TG) synthesis and accumulation. SREBP-1c overexpression down-regulated the expression and activity of the lipid oxidation enzymes: carnitine palmitoyltransferase 1 and carnitine palmitoyltransferase 2. Furthermore, the apolipoprotein B100 expression and microsomal triglyceride transfer protein activity were significantly decreased. SREBP-1c overexpression reduced lipid oxidation and VLDL synthesis, thereby decreasing TG disposal and export. Therefore, large amounts of TG accumulated in the bovine hepatocytes. Taken together, these results indicate that SREBP-1c overexpression increases lipid synthesis and decreases lipid oxidation and VLDL export, thereby inducing TG accumulation in bovine hepatocytes.
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Affiliation(s)
- Xinwei Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Yu Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Wentao Yang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Chong Xiao
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Shixin Fu
- Institute of Animal Science and Technology, Heilongjiang Bayi Agriculture University, Daqing 163319, Heilongjiang, China
| | - Qinghua Deng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Hongyan Ding
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Zhe Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China
| | - Guowen Liu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China.
| | - Xiaobing Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, Jilin, China.
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Kucera O, Cervinkova Z. Experimental models of non-alcoholic fatty liver disease in rats. World J Gastroenterol 2014; 20:8364-8376. [PMID: 25024595 PMCID: PMC4093690 DOI: 10.3748/wjg.v20.i26.8364] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/15/2014] [Accepted: 02/20/2014] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world, and it persists at a high prevalence. NAFLD is characterised by the accumulation of triglycerides in the liver and includes a spectrum of histopathological findings, ranging from simple fatty liver through non-alcoholic steatohepatitis (NASH) to fibrosis and ultimately cirrhosis, which may progress to hepatocellular carcinoma. The pathogenesis of NAFLD is closely related to the metabolic syndrome and insulin resistance. Understanding the pathophysiology and treatment of NAFLD in humans has currently been limited by the lack of satisfactory animal models. The ideal animal model for NAFLD should reflect all aspects of the intricate etiopathogenesis of human NAFLD and the typical histological findings of its different stages. Within the past several years, great emphasis has been placed on the development of an appropriate model for human NASH. This paper reviews the widely used experimental models of NAFLD in rats. We discuss nutritional, genetic and combined models of NAFLD and their pros and cons. The choice of a suitable animal model for this disease while respecting its limitations may help to improve the understanding of its complex pathogenesis and to discover appropriate therapeutic strategies. Considering the legislative, ethical, economical and health factors of NAFLD, animal models are essential tools for the research of this disease.
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Handa P, Maliken BD, Nelson JE, Morgan-Stevenson V, Messner DJ, Dhillon BK, Klintworth HM, Beauchamp M, Yeh MM, Elfers CT, Roth CL, Kowdley KV. Reduced adiponectin signaling due to weight gain results in nonalcoholic steatohepatitis through impaired mitochondrial biogenesis. Hepatology 2014; 60:133-45. [PMID: 24464605 PMCID: PMC5993561 DOI: 10.1002/hep.26946] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 12/19/2022]
Abstract
UNLABELLED Obesity and adiponectin depletion have been associated with the occurrence of nonalcoholic fatty liver disease (NAFLD). The goal of this study was to identify the relationship between weight gain, adiponectin signaling, and development of nonalcoholic steatohepatitis (NASH) in an obese, diabetic mouse model. Leptin-receptor deficient (Lepr(db/db) ) and C57BL/6 mice were administered a diet high in unsaturated fat (HF) (61%) or normal chow for 5 or 10 weeks. Liver histology was evaluated using steatosis, inflammation, and ballooning scores. Serum, adipose tissue, and liver were analyzed for changes in metabolic parameters, messenger RNA (mRNA), and protein levels. Lepr(db/db) HF mice developed marked obesity, hepatic steatosis, and more than 50% progressed to NASH at each timepoint. Serum adiponectin level demonstrated a strong inverse relationship with body mass (r = -0.82; P < 0.0001) and adiponectin level was an independent predictor of NASH (13.6 μg/mL; P < 0.05; area under the receiver operating curve (AUROC) = 0.84). White adipose tissue of NASH mice was characterized by increased expression of genes linked to oxidative stress, macrophage infiltration, reduced adiponectin, and impaired lipid metabolism. HF lepr (db/db) NASH mice exhibited diminished hepatic adiponectin signaling evidenced by reduced levels of adiponectin receptor-2, inactivation of adenosine monophosphate activated protein kinase (AMPK), and decreased expression of genes involved in mitochondrial biogenesis and β-oxidation (Cox4, Nrf1, Pgc1α, Pgc1β and Tfam). In contrast, recombinant adiponectin administration up-regulated the expression of mitochondrial genes in AML-12 hepatocytes, with or without lipid-loading. CONCLUSION Lepr(db/db) mice fed a diet high in unsaturated fat develop weight gain and NASH through adiponectin depletion, which is associated with adipose tissue inflammation and hepatic mitochondrial dysfunction. We propose that this murine model of NASH may provide novel insights into the mechanism for development of human NASH.
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Affiliation(s)
- Priya Handa
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | - Bryan D. Maliken
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | - James E. Nelson
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | - Vicki Morgan-Stevenson
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | | | - Barjinderjit K. Dhillon
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | - Heather M. Klintworth
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA
| | - Mary Beauchamp
- Benaroya Research Institute at Virginia Mason Medical Center, Seattle, WA
| | | | - Clinton T. Elfers
- Department of Pediatrics, Division of Endocrinology & Diabetes, Center for Integrative Brain Research, Seattle Children’s Research Institute, University of Washington, Seattle, WA
| | - Christian L. Roth
- Department of Pediatrics, Division of Endocrinology & Diabetes, Center for Integrative Brain Research, Seattle Children’s Research Institute, University of Washington, Seattle, WA
| | - Kris V. Kowdley
- Liver Center of Excellence, Digestive Disease Institute, and Benaroya Research Institute, Virginia Mason Medical Center, Seattle, WA,Benaroya Research Institute at Virginia Mason Medical Center, Seattle, WA
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Enhanced amelioration of high-fat diet-induced fatty liver by docosahexaenoic acid and lysine supplementations. BIOMED RESEARCH INTERNATIONAL 2014; 2014:310981. [PMID: 24967351 PMCID: PMC4055637 DOI: 10.1155/2014/310981] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 04/15/2014] [Accepted: 04/29/2014] [Indexed: 01/21/2023]
Abstract
Fatty liver disease is the most common pathological condition in the liver. Here, we generated high-fat diet-(HFD-) induced nonalcoholic fatty liver disease (NAFLD) in mice and tested the effects of docosahexaenoic acid (DHA) and lysine during a four-week regular chow (RC)feeding. Our results showed that 1% lysine and the combination of 1% lysine + 1% DHA reduced body weight. Moreover, serum triglyceride levels were reduced by 1% DHA and 1% lysine, whereas serum alanine transaminase activity was reduced by 1% DHA and 1% DHA + 0.5% lysine. Switching to RC reduced hepatic lipid droplet accumulation, which was further reduced by the addition of DHA or lysine. Furthermore, the mRNA expressions of hepatic proinflammatory cytokines were suppressed by DHA and combinations of DHA + lysine, whereas the mRNA for the lipogenic gene, acetyl-CoA carboxylase 1 (ACC1), was suppressed by DHA. In the gonadal adipose tissues, combinations of DHA and lysine inhibited mRNA expression of lipid metabolism-associated genes, including ACC1, fatty acid synthase, lipoprotein lipase, and perilipin. In conclusion, the present study demonstrated that, in conjunction with RC-induced benefits, supplementation with DHA or lysine further ameliorated the high-fat diet-induced NAFLD and provided an alternative strategy to treat, and potentially prevent, NAFLD.
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Huang H, McIntosh AL, Martin GG, Landrock KK, Landrock D, Gupta S, Atshaves BP, Kier AB, Schroeder F. Structural and functional interaction of fatty acids with human liver fatty acid-binding protein (L-FABP) T94A variant. FEBS J 2014; 281:2266-83. [PMID: 24628888 DOI: 10.1111/febs.12780] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/17/2014] [Accepted: 03/11/2014] [Indexed: 12/13/2022]
Abstract
The human liver fatty acid-binding protein (L-FABP) T94A variant, the most common in the FABP family, has been associated with elevated liver triglyceride levels. How this amino acid substitution elicits these effects is not known. This issue was addressed using human recombinant wild-type (WT) and T94A variant L-FABP proteins as well as cultured primary human hepatocytes expressing the respective proteins (genotyped as TT, TC and CC). The T94A substitution did not alter or only slightly altered L-FABP binding affinities for saturated, monounsaturated or polyunsaturated long chain fatty acids, nor did it change the affinity for intermediates of triglyceride synthesis. Nevertheless, the T94A substitution markedly altered the secondary structural response of L-FABP induced by binding long chain fatty acids or intermediates of triglyceride synthesis. Finally, the T94A substitution markedly decreased the levels of induction of peroxisome proliferator-activated receptor α-regulated proteins such as L-FABP, fatty acid transport protein 5 and peroxisome proliferator-activated receptor α itself meditated by the polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid in cultured primary human hepatocytes. Thus, although the T94A substitution did not alter the affinity of human L-FABP for long chain fatty acids, it significantly altered human L-FABP structure and stability, as well as the conformational and functional response to these ligands.
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Affiliation(s)
- Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX, USA
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Radwan MM, Radwan BM, Nandipati KC, Hunter WJ, Agrawal DK. Immunological and molecular basis of nonalcoholic steatohepatitis and nonalcoholic fatty liver disease. Expert Rev Clin Immunol 2014; 9:727-38. [PMID: 23971751 DOI: 10.1586/1744666x.2013.816484] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is rising worldwide with the increasing incidence of obesity, Type 2 diabetes mellitus and metabolic syndrome. NASH is currently one of the most common indications of liver transplantation in the United States. The immune system plays a major role in the pathogenesis of NAFLD/NASH. The metabolic changes, associated with obesity and metabolic syndrome, induce immunological responses resulting in NAFLD and further aggravation of the metabolic derangement in a feed-forward loop. Genetic and endocrine factors modulate the immunological and metabolic responses and determine the pathophysiological features of NAFLD. Histologically, NAFLD is a spectrum that ranges from simple hepatic steatosis to severe steatohepatitis, liver cirrhosis and/or hepatocellular carcinoma. Liver cirrhosis and hepatocellular carcinoma are responsible for the morbidity and mortality of the disease. This article is a critical evaluation of our current knowledge of the immunological and molecular basis of the disease.
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Affiliation(s)
- Mohamed M Radwan
- Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, NE 68178, USA
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40
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Influence of fat/carbohydrate ratio on progression of fatty liver disease and on development of osteopenia in male rats fed alcohol via total enteral nutrition (TEN). Alcohol 2014; 48:133-44. [PMID: 24581955 DOI: 10.1016/j.alcohol.2013.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 12/04/2013] [Accepted: 12/16/2013] [Indexed: 12/12/2022]
Abstract
Alcohol abuse is associated with the development of fatty liver disease and also with significant osteopenia in both genders. In this study, we examined ethanol-induced pathology in response to diets with differing fat/carbohydrate ratios. Male Sprague-Dawley rats were fed intragastrically with isocaloric liquid diets. Dietary fat content was either 5% (high carbohydrate, HC) or 45% (high fat, HF), with or without ethanol (12-13 g/kg/day). After 14, 28, or 65 days, livers were harvested and analyzed. In addition, bone morphology was analyzed after 65 days. HC rats gained more weight and had larger fat pads than HF rats with or without ethanol. Steatosis developed in HC + ethanol (HC + EtOH) compared to HF + ethanol (HF + EtOH) rats, accompanied by increased fatty acid (FA) synthesis and increased nuclear carbohydrate response element binding protein (ChREBP) (p < 0.05), but in the absence of effects on hepatic silent mating type information regulation 2 homolog (SIRT-1) or nuclear sterol regulatory binding element protein (SREBP-1c). Ethanol reduced serum leptin (p < 0.05) but not adiponectin. Over time, HC rats developed fatty liver independent of ethanol. FA degradation was significantly elevated by ethanol in both HC and HF groups (p < 0.05). HF + EtOH rats had increased oxidative stress from 28 days, increased necrosis compared to HF controls and higher expression of cytochromes P450, CYP2E1, and CYP4A1 compared to HC + EtOH rats (p < 0.05). In contrast, HC + EtOH rats had no significant increase in oxidative stress until day 65 with no observed increase in necrosis. Unlike liver pathology, no dietary differences were observed on ethanol-induced osteopenia in HC compared to HF groups. These data demonstrate that interactions between diet composition and alcohol are complex, dependent on the length of exposure, and are an important influence in development of fatty liver injury. Importantly, it appears that diet composition does not affect alcohol-associated skeletal toxicity.
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Abstract
Non-alcoholic steatohepatitis (NASH) is a disorder marked by alterations in hepatic lipid homeostasis as well as liver injury in the form of cell death, inflammation and fibrosis. Research into the pathophysiology of NASH is dynamic. New concepts from the fields of cell biology, microbiology, immunology and genetics are being tested for their applicability to NASH; discoveries in each of these areas are enriching our understanding of this complex disease. This review summarizes how recent developments from the bench and bedside are merging with more traditional concepts to reshape our view of NASH pathogenesis. Highlights include human studies that emphasize the role of de novo lipogenesis in NASH and experimental work uncovering a role for the inflammasome in NASH. Genetic predispositions to NASH are being clarified, and intestinal microbiome is emerging as a determinant of fatty liver. These unique ideas are now taking their place within an integrated picture of NASH pathogenesis.
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Affiliation(s)
- Caroline C Duwaerts
- Liver Center and Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Jacquelyn J Maher
- Liver Center and Department of Medicine, University of California, San Francisco, San Francisco, CA
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Borengasser SJ, Kang P, Faske J, Gomez-Acevedo H, Blackburn ML, Badger TM, Shankar K. High fat diet and in utero exposure to maternal obesity disrupts circadian rhythm and leads to metabolic programming of liver in rat offspring. PLoS One 2014; 9:e84209. [PMID: 24416203 PMCID: PMC3886966 DOI: 10.1371/journal.pone.0084209] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 11/21/2013] [Indexed: 01/21/2023] Open
Abstract
The risk of obesity in adulthood is subject to programming beginning at conception. In animal models, exposure to maternal obesity and high fat diets influences the risk of obesity in the offspring. Among other long-term changes, offspring from obese rats develop hyperinsulinemia, hepatic steatosis, and lipogenic gene expression in the liver at weaning. However, the precise underlying mechanisms leading to metabolic dysregulation in the offspring remains unclear. Using a rat model of overfeeding-induced obesity, we previously demonstrated that exposure to maternal obesity from pre-conception to birth, is sufficient to program increased obesity risk in the offspring. Offspring of obese rat dams gain greater body weight and fat mass when fed high fat diet (HFD) as compared to lean dam. Since, disruptions of diurnal circadian rhythm are known to detrimentally impact metabolically active tissues such as liver, we examined the hypothesis that maternal obesity leads to perturbations of core clock components and thus energy metabolism in offspring liver. Offspring from lean and obese dams were examined at post-natal day 35, following a short (2 wk) HFD challenge. Hepatic mRNA expression of circadian (CLOCK, BMAL1, REV-ERBα, CRY, PER) and metabolic (PPARα, SIRT1) genes were strongly suppressed in offspring exposed to both maternal obesity and HFD. Using a mathematical model, we identified two distinct biological mechanisms that modulate PPARα mRNA expression: i) decreased mRNA synthesis rates; and ii) increased non-specific mRNA degradation rate. Moreover, our findings demonstrate that changes in PPARα transcription were associated with epigenomic alterations in H3K4me3 and H3K27me3 histone marks near the PPARα transcription start site. Our findings indicated that offspring from obese rat dams have detrimental alternations to circadian machinery that may contribute to impaired liver metabolism in response to HFD, specifically via reduced PPARα expression prior to obesity development.
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Affiliation(s)
- Sarah J. Borengasser
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Ping Kang
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
| | - Jennifer Faske
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
| | - Horacio Gomez-Acevedo
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Michael L. Blackburn
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
| | - Thomas M. Badger
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Kartik Shankar
- Arkansas Children's Nutrition Center, Little Rock, Arkansas, United States of America
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
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High-fat-cholesterol diet mainly induced necrosis in fibrotic steatohepatitis rat by suppressing caspase activity. Life Sci 2013; 93:673-80. [DOI: 10.1016/j.lfs.2013.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 08/22/2013] [Accepted: 09/10/2013] [Indexed: 12/30/2022]
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Hsu HC, Dozen M, Matsuno N, Obara H, Tanaka R, Enosawa S. Experimental Nonalcoholic Steatohepatitis Induced by Neonatal Streptozotocin Injection and a High-Fat Diet in Rats. CELL MEDICINE 2013; 6:57-62. [PMID: 26858881 DOI: 10.3727/215517913x674252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nonalcoholic steatohepatitis (NASH) has become a major concern in clinical hepatology. To elucidate the disease mechanisms and to develop a treatment, the advent of an appropriate experimental model is crucial. Pregnant Sprague-Dawley rats were fed a high-fat diet from gestational day 16. Two days after birth, the neonates were injected subcutaneously with streptozotocin (STZ) (180, 200, or 256 mg/kg). The mothers were fed a high-fat diet during the nursing period. After being weaned (4 weeks of age), the juvenile rats were fed the same high-fat diet. The survival rates at the time of weaning were 25.6% (180 mg/kg STZ), 22.8% (200 mg/kg STZ), and 19.4% (256 mg/kg STZ). The mean body weight of NASH rats was approximately 20% less than that of normal rats. Serum levels of glucose, alanine aminotransferase, and hyaluronic acid increased in NASH rats. Histologically, typical features of steatohepatitis such as ballooning, inflammatory cell infiltration, and perivenular and pericellular fibrosis were observed. In an indocyanine green loading test, the blood half-life was significantly longer in NASH rats (5.04 ± 2.14 vs. 2.72 ± 0.72 min; p < 0.05), which was suggestive of an impaired hepatobiliary transportation function. Concomitantly, biliary ICG concentrations in NASH rats stabilized in a delayed fashion compared with normal rats. In addition, the amount of bile excreted in NASH rats was significantly lower than that in normal rats (4.32 ± 0.83 vs. 7.66 ± 1.05 mg/min; p < 0.01). The rat NASH model presented here mimics the clinical features of the disease and will be a helpful tool for medical and bioscience research.
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Affiliation(s)
- Huai-Che Hsu
- Clinical Research Center, National Center for Child Health and Development, Tokyo, Japan; †Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Masaharu Dozen
- Clinical Research Center, National Center for Child Health and Development , Tokyo , Japan
| | - Naoto Matsuno
- Clinical Research Center, National Center for Child Health and Development , Tokyo , Japan
| | - Hiromichi Obara
- ‡ Department of Mechanical Engineering, Graduate School of Science and Engineering, Tokyo Metropolitan University , Tokyo , Japan
| | - Ryou Tanaka
- † Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology , Tokyo , Japan
| | - Shin Enosawa
- Clinical Research Center, National Center for Child Health and Development , Tokyo , Japan
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Ronis MJJ, Baumgardner JN, Sharma N, Vantrease J, Ferguson M, Tong Y, Wu X, Cleves MA, Badger TM. Medium chain triglycerides dose-dependently prevent liver pathology in a rat model of non-alcoholic fatty liver disease. Exp Biol Med (Maywood) 2013; 238:151-62. [PMID: 23576797 DOI: 10.1258/ebm.2012.012303] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Metabolic syndrome is often accompanied by development of hepatic steatosis and less frequently by non-alcoholic fatty liver disease (NAFLD) leading to non-alcoholic steatohepatitis (NASH). Replacement of corn oil with medium chain triacylglycerols (MCT) in the diets of alcohol-fed rats has been shown to protect against steatosis and alcoholic liver injury. The current study was designed to determine if a similar beneficial effect of MCT occurs in a rat model of NAFLD. Groups of male rats were isocalorically overfed diets containing 10%, 35% or 70% total energy as corn oil or a 70% fat diet in which corn oil was replaced with increasing concentrations of saturated fat (18:82, beef tallow:MCT oil) from 20% to 65% for 21 days using total enteral nutrition (TEN). As dietary content of corn oil increased, hepatic steatosis and serum alanine amino transferases were elevated (P < 0.05). This was accompanied by greater expression of cytochrome P450 enzyme CYP2E1 (P < 0.05) and higher concentrations of polyunsaturated 18:2 and 20:4 fatty acids (FA) in the hepatic lipid fractions (P < 0.05). Keeping the total dietary fat at 70%, but increasing the proportion of MCT-enriched saturated fat resulted in a dose-dependent reduction in steatosis and necrosis without affecting CYP2E1 induction. There was no incorporation of C8-C10 FAs into liver lipids, but increasing the ratio of MCT to corn oil: reduced liver lipid 18:2 and 20:4 concentrations; reduced membrane susceptibility to radical attack; stimulated FA β- and ω-oxidation as a result of activation of peroxisomal proliferator activated receptor (PPAR)α, and appeared to increase mitochondrial respiration through complex III. These data suggest that replacing unsaturated fats like corn oil with MCT oil in the diet could be utilized as a potential treatment for NAFLD.
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Affiliation(s)
- Martin J J Ronis
- Arkansas Children's Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, AR 72202, USA.
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Li DY, Yang M, Edwards S, Ye SQ. Nonalcoholic fatty liver disease: for better or worse, blame the gut microbiota? JPEN J Parenter Enteral Nutr 2013; 37:787-93. [PMID: 23538296 DOI: 10.1177/0148607113481623] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major clinical consequence for people with obesity and metabolic syndrome and is also associated with enteral and parenteral nutrition. Early studies suggested that altered gut microbiota might contribute to obesity by affecting energy harvest from the diet and energy storage in the host. Recent evidence in humans as well as in animal models has linked gut microbiota to the development of NAFLD through the gut-liver axis. With bacterial overgrowth and increased intestinal permeability observed in patients with NAFLD and in animal models, gut-derived bacterial products such as endotoxin (lipopolysaccharide) and bacterial DNA are being delivered to the liver through the portal vein and then activate Toll-like receptors (TLRs), mainly TLR4 and TLR9, and their downstream cytokines and chemokines, leading to the development and progression of NAFLD. Given the limited data in humans, the role of gut microbiota in the pathogenesis of NAFLD is still open to discussion. Prebiotics and probiotics have been attempted to modify the microbiota as preventive or therapeutic strategies on this pathological condition. Their beneficial effects on NALFD have been demonstrated in animal models and limited human studies. However, prospective, appropriately powered, randomized, controlled clinical trials are needed to determine whether prebiotics and probiotics and other integrated strategies to modify intestinal microbiota are efficacious therapeutic modalities to treat NALFD.
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Affiliation(s)
- Ding-You Li
- Division of Gastroenterology, Children's Mercy Hospital, University of Missouri School of Medicine, Kansas City, Missouri
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Wu R, Zhang W, Liu B, Gao J, Xiao XQ, Zhang F, Zhou HM, Wu XL, Zhang X. Probucol ameliorates the development of nonalcoholic steatohepatitis in rats fed high-fat diets. Dig Dis Sci 2013; 58:163-71. [PMID: 22878918 DOI: 10.1007/s10620-012-2335-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Accepted: 07/19/2012] [Indexed: 12/17/2022]
Abstract
AIMS We sought to evaluate the effects of probucol on steatohepatitis and associated molecular mechanisms in a rat model of nonalcoholic steatohepatitis (NASH) induced by high-fat diet (HFD). METHODS Forty male rats weighing 100-120 g were randomly assigned to the following treatments (n = 10 for each treatment): standard diet + normal saline (NC group), standard diet + 500 mg/kg/day probucol (NP group), HFD + normal saline (HD group), and HFD + 500 mg/kg/day probucol (HP group). All animals received the above treatments for 15 weeks. Lipid metabolism and steatohepatitis were assessed. Systemic insulin resistance, oxidative stress status, serum tumor necrosis factor-alpha (TNF-α) and adiponectin levels, and gene expression were examined. RESULTS High-fat feeding resulted in macrovesicular steatosis, lobular inflammation, and hepatocellular ballooning degeneration in the liver, coupled with increased concentrations of serum aspartate aminotransferase and alanine aminotransferase. Probucol exposure attenuated the biochemical and histological changes comparable with NASH. Moreover, probucol treatment significantly prevented the elevations of serum total cholesterol, low-density lipoprotein, and high-density lipoprotein and the increase in the expression of numerous lipid metabolism-related genes in HFD-fed rats. There were increased insulin sensitivity and serum adiponectin levels and enhanced hepatic AMP-activated protein kinase phosphorylation in the HP group. Probucol lessened the HFD-induced elevation of serum TNF-α and hepatic malondialdehyde and reduced antioxidant enzymatic activities. CONCLUSIONS Probucol shows beneficial effects on HFD-induced steatohepatitis by improving insulin resistance and attenuating oxidative stress and systemic inflammation.
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Affiliation(s)
- Rong Wu
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
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Dey A. Cytochrome P450 2E1: its clinical aspects and a brief perspective on the current research scenario. Subcell Biochem 2013; 67:1-104. [PMID: 23400917 DOI: 10.1007/978-94-007-5881-0_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Research on Cytochrome P450 2E1 (CYP2E1), a key enzyme in alcohol metabolism has been very well documented in literature. Besides the involvement of CYP2E1 in alcohol metabolism as illustrated through the studies discussed in the chapter, recent studies have thrown light on several other aspects of CYP2E1 i.e. its extrahepatic expression, its involvement in several diseases and pathophysiological conditions; and CYP2E1 mediated carcinogenesis and modulation of drug efficacy. Studies involving these interesting facets of CYP2E1 have been discussed in the chapter focusing on the recent observations or ongoing studies illustrating the crucial role of CYP2E1 in disease development and drug metabolism.
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Affiliation(s)
- Aparajita Dey
- AU-KBC Research Centre, Anna University, MIT Campus, Chromepet, Chennai, Tamil Nadu, 600044, India,
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Ronis MJJ, Baumgardner JN, Marecki JC, Hennings L, Wu X, Shankar K, Cleves MA, Gomez-Acevedo H, Badger TM. Dietary fat source alters hepatic gene expression profile and determines the type of liver pathology in rats overfed via total enteral nutrition. Physiol Genomics 2012; 44:1073-89. [PMID: 22991207 DOI: 10.1152/physiolgenomics.00069.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
To determine if dietary fat composition affects the progression of nonalcoholic fatty liver disease (NAFLD), we overfed male Sprague-Dawley rats low (5%) or high (70%) fat diets with different fat sources: olive oil (OO), corn oil (CO), or echium oil (EO), with total enteral nutrition (TEN) for 21 days. Overfeeding of the 5% CO or 5% EO diets resulted in less steatosis than 5% OO (P < 0.05). Affymetrix array analysis revealed significant differences in hepatic gene expression signatures associated with greater fatty acid synthesis, ChREBP, and SREBP-1c signaling and increased fatty acid transport (P < 0.05) in the 5% OO compared with 5% CO group. The OO groups had macrosteatosis, but no evidence of oxidative stress or necrosis. The 70% CO and 70% EO groups had a mixture of micro- and macrosteatosis or only microsteatosis, respectively; increased oxidative stress; and increased necrotic injury relative to their respective 5% groups (P < 0.05). Oxidative stress and necrosis correlated with increasing peroxidizability of the accumulated triglycerides. Affymetrix array analysis comparing the 70% OO and 70% CO groups revealed increased antioxidant pathways and lower expression of genes linked to inflammation and fibrosis in the 70% OO group. A second study in which 70% OO diet was overfed for 50 days produced no evidence of progression of injury beyond simple steatosis. These data suggest that dietary fat type strongly influences the progression of NAFLD and that a Mediterranean diet high in olive oil may reduce the risk of NAFLD progressing to nonalcoholic steatohepatitis.
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Affiliation(s)
- M J J Ronis
- Arkansas Children's Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72202, USA.
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50
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Yao HT, Luo MN, Hung LB, Chiang MT, Lin JH, Lii CK, Huang CY. Effects of chitosan oligosaccharides on drug-metabolizing enzymes in rat liver and kidneys. Food Chem Toxicol 2012; 50:1171-7. [PMID: 22386817 DOI: 10.1016/j.fct.2012.02.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 01/25/2012] [Accepted: 02/13/2012] [Indexed: 01/10/2023]
Abstract
To investigate the effect of chitosan oligosaccharides (COS) on drug-metabolizing enzymes in rat liver and kidneys, male Spraque-Dawley rats were fed a diet containing 1% or 3% COS for 5 weeks. The activities of cytochrome P450 (CYP) enzymes, UDP-glucurosyltransferase (UGT) and glutathione S-transferase (GST) in the liver and kidneys were determined. Significant decreases in microsomal CYP3A-catalyzed testosterone 6β-hydroxylation, CYP2C-catalyzed diclofenac 4-hydroxylation, and CYP4A-catalyzed lauric acid 12-hydroxylation in the liver of rats fed the COS diets were observed compared with those rats fed the control diet. Immunoblot analyses of CYP proteins showed the same trend as with enzyme activities. Increased glutathione content in liver was found in rats fed the 1% COS diet. Increased hepatic NADPH: quinone oxidoreductase 1 (NQO1) activity was found in rats fed the COS diets. In kidneys, COS had little or no effect on CYP enzyme activities. However, increased GST activity was observed in rats fed the COS diets. Moreover, a higher UGT activity was found in rats fed the 1% COS diet. Our results indicate that COS may suppress hepatic CYP enzymes and induce phase II detoxifying reactions in the liver and kidneys of rats.
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Affiliation(s)
- Hsien-Tsung Yao
- Department of Nutrition, China Medical University, 91 Hsueh-Shih Road, Taichung 404, Taiwan, ROC.
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