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Wang Z, Li S, Wang R, Guo L, Xu D, Zhang T, Xu Y, Wang W, Wang M, Gan Z, Wang X. The protective effects of the β3 adrenergic receptor agonist BRL37344 against liver steatosis and inflammation in a rat model of high-fat diet-induced nonalcoholic fatty liver disease (NAFLD). Mol Med 2020; 26:54. [PMID: 32503411 PMCID: PMC7275314 DOI: 10.1186/s10020-020-00164-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/30/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Our objective was to investigate the efficacy of the beta-3 adrenergic receptor (β3-AR) agonist BRL37344 for the prevention of liver steatosis and inflammation associated with nonalcoholic fatty liver disease (NAFLD). METHODS Four groups were established: a control group (given a standard diet), a high-fat diet (HFD) group, an HFD + β3-AR agonist (β3-AGO) group, and an HFD + β3-AR antagonist (β3-ANT) group. All rats were fed for 12 weeks. The β3-AR agonist BRL37344 and the antagonist L748337 were administered for the last 4 weeks with Alzet micro-osmotic pumps. The rat body weights (g) were measured at the end of the 4th, 8th, and 12th weeks. At the end of the 12th week, the liver weights were measured. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed with a Hitachi automatic analyzer. The lipid levels of the triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) and the concentrations of free fatty acids (FFAs) were also measured. An oil red O kit was used to detect lipid droplet accumulation in hepatocytes. Steatosis, ballooning degeneration and inflammation were histopathologically determined. The protein and mRNA expression levels of β3-AR, peroxisome proliferator-activated receptor-alpha (PPAR-α), peroxisome proliferator-activated receptor-gamma (PPAR-γ), mitochondrial carnitine palmitoyltransferase-1 (mCPT-1), and fatty acid translocase (FAT)/CD36 were measured by western blot analysis and RT-qPCR, respectively. RESULTS After treatment with the β3-AR agonist BRL37344 for 4 weeks, the levels of ALT, AST, TGs, TC, LDL-C and FFAs were decreased in the NAFLD model group compared with the HFD group. Body and liver weights, liver index values and lipid droplet accumulation were lower in the HFD + β3-AGO group than in the HFD group. Decreased NAFLD activity scores (NASs) also showed that liver steatosis and inflammation were ameliorated after treatment with BRL37344. Moreover, the β3-AR antagonist L748337 reversed these effects. Additionally, the protein and gene expression levels of β3-AR, PPAR-α, and mCPT-1 were increased in the HFD + β3-AGO group, whereas those of PPAR-γ and FAT/CD36 were decreased. CONCLUSION The β3-AR agonist BRL37344 is beneficial for reducing liver fat accumulation and for ameliorating liver steatosis and inflammation in NAFLD. These effects may be associated with PPARs/mCPT-1 and FAT/CD36.
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Affiliation(s)
- Ziwen Wang
- Gastroenterology Department, the First Affiliated Hospital of Harbin Medical University, #23 Postal Street, Harbin, 150001 Heilongjiang China
| | - Shanshan Li
- Gastroenterology Department, the First Affiliated Hospital of Harbin Medical University, #23 Postal Street, Harbin, 150001 Heilongjiang China
| | - Ruifeng Wang
- Gastroenterology Department, the Fourth Affiliated Hospital of Harbin Medical University, #37 Yiyuan Street, Harbin, 150001 Heilongjiang China
| | - Liansheng Guo
- Gastroenterology Department, the First Affiliated Hospital of Harbin Medical University, #23 Postal Street, Harbin, 150001 Heilongjiang China
| | - Dan Xu
- Gastroenterology Department, the First Affiliated Hospital of Harbin Medical University, #23 Postal Street, Harbin, 150001 Heilongjiang China
| | - Tieyuan Zhang
- Harbin Medical University, #157 Baojian Street, Harbin, 150081 Heilongjiang China
| | - Yifan Xu
- Harbin Medical University, #157 Baojian Street, Harbin, 150081 Heilongjiang China
| | - Wenlong Wang
- Harbin Medical University, #157 Baojian Street, Harbin, 150081 Heilongjiang China
| | - Min Wang
- Harbin Medical University, #157 Baojian Street, Harbin, 150081 Heilongjiang China
| | - Zhongwei Gan
- Harbin Medical University, #157 Baojian Street, Harbin, 150081 Heilongjiang China
| | - Xiaobing Wang
- Gastroenterology Department, the First Affiliated Hospital of Harbin Medical University, #23 Postal Street, Harbin, 150001 Heilongjiang China
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Zhao ZH, Xin FZ, Zhou D, Xue YQ, Liu XL, Yang RX, Pan Q, Fan JG. Trimethylamine N-oxide attenuates high-fat high-cholesterol diet-induced steatohepatitis by reducing hepatic cholesterol overload in rats. World J Gastroenterol 2019; 25:2450-2462. [PMID: 31171889 PMCID: PMC6543245 DOI: 10.3748/wjg.v25.i20.2450] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Trimethylamine N-oxide (TMAO) has been shown to be involved in cardiovascular disease (CVD). However, its role in nonalcoholic steatohepatitis (NASH) is unknown. AIM To determine the effect of TMAO on the progression of NASH. METHODS A rat model was induced by 16-wk high-fat high-cholesterol (HFHC) diet feeding and TMAO was administrated by daily oral gavage for 8 wk. RESULTS Oral TMAO intervention attenuated HFHC diet-induced steatohepatitis in rats. Histological evaluation showed that TMAO treatment significantly alleviated lobular inflammation and hepatocyte ballooning in the livers of rats fed a HFHC diet. Serum levels of alanine aminotransferase and aspartate aminotransferase were also decreased by TMAO treatment. Moreover, hepatic endoplasmic reticulum (ER) stress and cell death were mitigated in HFHC diet-fed TMAO-treated rats. Hepatic and serum levels of cholesterol were both decreased by TMAO treatment in rats fed a HFHC diet. Furthermore, the expression levels of intestinal cholesterol transporters were detected. Interestingly, cholesterol influx-related Niemann-Pick C1-like 1 was downregulated and cholesterol efflux-related ABCG5/8 were upregulated by TMAO treatment in the small intestine. Gut microbiota analysis showed that TMAO could alter the gut microbial profile and restore the diversity of gut flora. CONCLUSION These data suggest that TMAO may modulate the gut microbiota, inhibit intestinal cholesterol absorption, and ameliorate hepatic ER stress and cell death under cholesterol overload, thereby attenuating HFHC diet-induced steatohepatitis in rats. Further studies are needed to evaluate the influence on CVD and define the safe does of TMAO treatment.
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Affiliation(s)
- Ze-Hua Zhao
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Feng-Zhi Xin
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Da Zhou
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Ya-Qian Xue
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiao-Lin Liu
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Rui-Xu Yang
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Qin Pan
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Jian-Gao Fan
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
- Shanghai Key Lab of Pediatric Gastroenterology and Nutrition, Shanghai 200092, China
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Zhou D, Fan JG. Microbial metabolites in non-alcoholic fatty liver disease. World J Gastroenterol 2019; 25:2019-2028. [PMID: 31114130 PMCID: PMC6506577 DOI: 10.3748/wjg.v25.i17.2019] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/25/2019] [Accepted: 03/30/2019] [Indexed: 02/06/2023] Open
Abstract
The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising exponentially worldwide. The spectrum of NAFLD includes non-alcoholic fatty liver, non-alcoholic steatohepatitis, liver cirrhosis, and even hepatocellular carcinoma. Evidence shows that microbial metabolites play pivotal roles in the onset and progression of NAFLD. In this review, we discuss how microbe-derived metabolites, such as short-chain fatty acids, endogenous ethanol, bile acids and so forth, contribute to the pathogenesis of NAFLD.
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Affiliation(s)
- Da Zhou
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai Institute of Liver Disease, Shanghai 200032, China
| | - Jian-Gao Fan
- Center for Fatty Liver, Department of Gastroenterology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Key Lab of Pediatric Gastroenterology and Nutrition, Shanghai 200092, China
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Chow MD, Lee YH, Guo GL. The role of bile acids in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Mol Aspects Med 2017; 56:34-44. [PMID: 28442273 DOI: 10.1016/j.mam.2017.04.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/11/2017] [Accepted: 04/20/2017] [Indexed: 12/14/2022]
Abstract
Nonalcoholic fatty liver disease is growing in prevalence worldwide. It is marked by the presence of macrosteatosis on liver histology but is often clinically asymptomatic. However, it can progress into nonalcoholic steatohepatitis which is a more severe form of liver disease characterized by inflammation and fibrosis. Further progression leads to cirrhosis, which predisposes patients to hepatocellular carcinoma or liver failure. The mechanism by which simple steatosis progresses to steatohepatitis is not entirely clear. However, multiple pathways have been proposed. A common link amongst many of these pathways is disruption of the homeostasis of bile acids. Other than aiding in the absorption of lipids and lipid-soluble vitamins, bile acids act as ligands. For example, they bind to farnesoid X receptor, which is critically involved in many of the pathways responsible for maintaining bile acid, glucose, and lipid homeostasis. Alterations to these pathways can lead to dysregulation of energy balance and increased inflammation and fibrosis. Repeated insults over time may be the key to development of steatohepatitis. For this reason, current drug therapies target aspects of these pathways to try to reduce and halt inflammation and fibrosis. This review will focus on the role of bile acids in these various pathways and how changes in these pathways may result in steatohepatitis. While there is no approved pharmaceutical treatment for either hepatic steatosis or steatohepatitis, this review will also touch upon the multitude of potential therapies.
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Affiliation(s)
- Monica D Chow
- Department of Surgery, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Yi-Horng Lee
- Division of Pediatric Surgery, Department of Surgery, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Grace L Guo
- Department of Pharmacy and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
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Sakai S, Iizuka N, Fujiwara M, Miyoshi M, Aoyama M, Maeshige N, Hamada Y, Usami Y, Usami M. Mild obesity reduces survival and adiponectin sensitivity in endotoxemic rats. J Surg Res 2013; 185:353-63. [PMID: 23838384 DOI: 10.1016/j.jss.2013.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 05/24/2013] [Accepted: 06/04/2013] [Indexed: 12/31/2022]
Abstract
BACKGROUND Recent meta-analyses have reported that critically ill patients with morbid obesity (body mass index >40 kg/m(2)) have poor outcomes, but the effects and mechanisms of action of mild obesity are still unclear. The purpose of this study was to evaluate the effect of mild obesity using a lard-based, high-fat diet (HFD) on pathologic conditions and the mechanisms of adiponectin action in endotoxemic rats. MATERIALS AND METHODS Male Wistar rats underwent HFD feeding for 4 wk and were killed at 0, 1.5, and 6 h after lipopolysaccharide (LPS) injection. Plasma levels of adiponectin, nitric oxide, and interleukin 6; messenger RNA expression of adiponectin receptors (AdipoR1 and AdipoR2) in the liver and the skeletal muscle; blood biochemical test results; and histology of the liver were analyzed. RESULTS HFD-fed rats had a lower survival rate (12.8% versus 85.2%) and lower plasma adiponectin levels after LPS injection (P < 0.01). Messenger RNA expression of adiponectin receptors in the liver, but not the skeletal muscle, also decreased in HFD-fed rats (P < 0.05). Tissue injury and oxidative stress in the liver and plasma inflammatory mediator levels increased, and worsened lipid metabolism abnormalities were noted. The findings indicated that HFD decreased the sensitivity of adiponectin and was associated with an increase in oxidative stress and inflammation, which finally resulted in worsened liver injury and poor survival rate after LPS injection. CONCLUSIONS Short-term, HFD-induced, mild obesity is harmful to the septic host, reduces adiponectin sensitivity, and could be the cause of worsening pathologic conditions.
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Affiliation(s)
- Shota Sakai
- Division of Nutrition and Metabolism, Department of Biophysics, Kobe University Graduate School of Health Sciences, Kobe, Japan
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Wang JQ, Zou YH, Huang C, Lu C, Zhang L, Jin Y, Lü XW, Liu LP, Li J. Protective effects of tiopronin against high fat diet-induced non-alcoholic steatohepatitis in rats. Acta Pharmacol Sin 2012; 33:791-7. [PMID: 22543705 DOI: 10.1038/aps.2012.19] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AIM To study the protective effects of tiopronin against high fat diet-induced non-alcoholic steatohepatitis in rats. METHODS Male Sprague-Dawley rats were given a high-fat diet for 10 weeks. The rats were administered tiopronin (20 mg/kg) or a positive control drug ursodeoxycholic acid (UDCA, 15 mg/kg) via gavage daily from week 5 to week 10. After the rats were sacrificed, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C), and liver homogenate FFA, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured using commercial analysis kits. The expression levels of CYP2E1 mRNA and protein were determined using RT-PCR and immunoblot assays, respectively. RESULTS Tiopronin significantly lowered both the serum ALT and AST levels, while only the serum ALT level was lowered by UDCA. Tiopronin significantly decreased the serum and liver levels of TG, TC and FFA as well as the serum LDL-C level, and increased the serum HDL-C level, while UDCA decreased the serum and liver TC levels as well as the serum LDL-C level, but did not change the serum levels of TG, FFA and HDL-C. Tiopronin apparently ameliorated the hepatocyte degeneration and the infiltration of inflammatory cells in the livers, but UDCA did not affect the pathological features of the livers. Both tiopronin and UDCA ameliorated the mitochondrial abnormality in the livers. The benefits of tiopronin were associated with increased SOD and GSH-Px activities, and with decreased MDA activity and CYP2E1 expression in the livers. CONCLUSION Tiopronin exerts protective effects against non-alcoholic steatohepatitis in rats, which may be associated with its antioxidant properties and regulation of lipid metabolism.
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Nunes PM, Jones JG, Rolo AP, Palmeira CMM, Carvalho RA. Ursodeoxycholic acid treatment of hepatic steatosis: a (13)C NMR metabolic study. NMR IN BIOMEDICINE 2011; 24:1145-1158. [PMID: 21538633 DOI: 10.1002/nbm.1672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 12/10/2010] [Accepted: 12/13/2010] [Indexed: 05/30/2023]
Abstract
Ursodeoxycholic acid (UDCA) is commonly used for the treatment of hepatobiliary disorders. In this study, we tested whether a 4-week treatment with this bile acid (12-15 mg/kg/day) could improve hepatic fatty acid oxidation in obese Zucker rats - a model for nonalcoholic fatty liver disease and steatosis. After 24 h of fasting, livers were perfused with physiological concentrations of [U-(13) C]nonesterified fatty acids and [3-(13) C]lactate/[3-(13) C]pyruvate. Steatosis was associated with abundant intracellular glucose, lactate, alanine and methionine, and low concentrations of choline and betaine. Steatotic livers also showed the highest output of glucose and lactate. Glucose and glycolytic products were mostly unlabeled, indicating active glycogenolysis and glycolysis after 24 h of fasting. UDCA treatment resulted in a general amelioration of liver metabolic abnormalities with a decrease in intracellular glucose and lactate, as well as their output. Hepatic betaine and methionine were also normalized after UDCA treatment, suggesting the amelioration of anti-oxidative defenses. Choline levels were not affected by the bile acid, which may indicate a deficient synthesis of very-low-density lipoproteins. The percentage contribution of [U-(13) C]nonesterified fatty acids to acetyl-coenzyme A entering the tricarboxylic acid (TCA) cycle was significantly lower in livers from Zucker obese rats relative to control rats: 23.1 ± 4.9% versus 44.1 ± 2.7% (p < 0.01). UDCA treatment did not alter significantly fatty acid oxidation in control rats, but improved significantly oxidation in Zucker obese rats to 46.0 ± 6.1% (p > 0.05), comparable with control group values. The TCA cycle activity subsequent to fatty acid oxidation was reduced in steatotic livers and improved when UDCA was administered (0.24 ± 0.04 versus 0.37 ± 0.05, p = 0.05). We further suggest that the mechanism of action of UDCA is either related to the activity of the farnesoid receptor, or to the amelioration of the anti-oxidative defenses and cell nicotinamide adenine dinucleotide (NAD(+) /NADH) ratio, favoring TCA cycle activity and β-oxidation.
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Affiliation(s)
- Patrícia M Nunes
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, Portugal
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Haddad Y, Vallerand D, Brault A, Spénard J, Haddad PS. NCX 1000 Alone or in Combination with Vitamin E Reverses Experimental Nonalcoholic Steatohepatitis in the Rat Similarly to UDCA. Int J Hepatol 2011; 2011:136816. [PMID: 22013536 PMCID: PMC3195504 DOI: 10.4061/2011/136816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 06/20/2011] [Indexed: 12/21/2022] Open
Abstract
We explored the therapeutic effect of NCX 1000, a derivative of ursodeoxycholic acid (UDCA) with nitric oxide (NO) donating properties, alone or in combination with vitamin E, in an experimental model of NASH in the rat. Methods. A control group was fed a standard liquid diet (Control), and the NASH groups were fed a high-fat liquid diet for 12 weeks without (NASH) or with simultaneous daily gavage with either NCX 1000 at 15 or 30 mg/kg (N15 and N30, resp.), or N15 plus vitamin E 100 mg/kg (N15 + VitE) for the last 6 weeks; UDCA 17.2 mg/kg was used as a reference. Results. NASH rats developed all key features of the disease. Treatments with N30 improved liver histology, decreased lipid peroxidation, and completely suppressed increases in LDH release, plasma insulin, and TNF-α. It also decreased O(2) (∙-) release and returned liver weight and glutathione back to normal. All effects were similar to the reference treatment, UDCA. The N15 treatment was less efficient than the N30 group, but became comparable to the latter when combined to vitamin E. Conclusion. Our study demonstrates that NCX 1000 has potent cytoprotective, antioxidant, and hypoinsulinemic properties that can be enhanced by combination with vitamin E.
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Affiliation(s)
- Yara Haddad
- Natural Health Products and Metabolic Diseases Laboratory, Department of Pharmacology Université de Montréal and Montreal Diabetes Research Center, Montreal, QC, Canada H3C 3J7,Institute of Nutraceutical and Functional Foods, Laval University, Sillery, QC, Canada GIV 0A6
| | - Diane Vallerand
- Natural Health Products and Metabolic Diseases Laboratory, Department of Pharmacology Université de Montréal and Montreal Diabetes Research Center, Montreal, QC, Canada H3C 3J7,Institute of Nutraceutical and Functional Foods, Laval University, Sillery, QC, Canada GIV 0A6
| | - Antoine Brault
- Natural Health Products and Metabolic Diseases Laboratory, Department of Pharmacology Université de Montréal and Montreal Diabetes Research Center, Montreal, QC, Canada H3C 3J7,Institute of Nutraceutical and Functional Foods, Laval University, Sillery, QC, Canada GIV 0A6
| | - Jean Spénard
- Department of Pharmacology, Université de Montréal, Montreal, QC, Canada H3C 3J7,R & D Axcan Pharma Inc, Mont-St-Hilaire, QC, Canada J3H 6C4
| | - Pierre S. Haddad
- Natural Health Products and Metabolic Diseases Laboratory, Department of Pharmacology Université de Montréal and Montreal Diabetes Research Center, Montreal, QC, Canada H3C 3J7,Institute of Nutraceutical and Functional Foods, Laval University, Sillery, QC, Canada GIV 0A6,*Pierre S. Haddad:
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Niu N, Yu YH, Wang Y, Wang LJ, Li Q, Guo LM. Combined effects of niacin and chromium treatment on vascular endothelial dysfunction in hyperlipidemic rats. Mol Biol Rep 2008; 36:1275-81. [PMID: 18622720 DOI: 10.1007/s11033-008-9309-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 06/27/2008] [Indexed: 01/30/2023]
Abstract
Combined treatment with niacin and chromium has been found to have a protective effect against oxidative damage to different tissues of hyperlipidemic rats. But its effects on vascular endothelial dysfunction are less clear. This study was performed to investigate the effect of combined treatment with niacin and chromium on vascular endothelial dysfunction, with the aim of gaining insight to the mechanisms by detecting the expression levels of ox-LDL and LOX-1. Twenty-four male, 4-week-old Wistar rats were randomly divided into three groups: control group (CG; n = 8), high-fat group (HF; n = 8), and drug control group (DG; n = 8). In CG group, rats were fed with pellet chow. In HF group, rats were fed with high-fat diet for 12 weeks. In DG group, rats were fed with the same high-fat diet and treated with CrCl(3) x 6 H(2)O (250 microg/kg days) and niacin (100 mg/kg days) by gavage technique for 12 weeks. At the end of the 12th week, samples from aorta and blood were collected. In HF group, the serum levels of total cholesterol (TC), low-density lipoprotein (LDL), oxidized low-density lipoprotein (ox-LDL) and endothelin (ET) were higher, whereas the levels of high-density lipoprotein (HDL), serum NO were lower than those in CG group. The levels of serum TC, LDL, ox-LDL and ET decreased and HDL, NO levels increased in DG group when compared with HF group. The levels of LOX-1, ICAM-1 were also observed in abdominal artery. In HF group, the protein and mRNA expression of LOX-1, ICAM-1 were elevated comparing with CG group. In DG group, the protein and mRNA expression of LOX-1, ICAM-1 were decreased obviously, but still differed significantly from those in CG group. ox-LDL was related positively to TC, LDL, ET, ICAM-1 and LOX-1, but related negatively to NO and HDL. These findings indicated that combined treatment with niacin and chromium has potential therapeutic protection of endothelial function by down-regulating ox-LDL/LOX-1 signaling pathway.
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Affiliation(s)
- N Niu
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, 250021, China
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Steatohepatitis und Leberzirrhose: Erstmanifestation 23 Jahre nach ejunoilealem Bypass. Wien Klin Wochenschr 2007; 119:733-8. [DOI: 10.1007/s00508-007-0850-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 07/12/2007] [Indexed: 01/16/2023]
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Riley P, O'Donohue J, Crook M. A growing burden: the pathogenesis, investigation and management of non-alcoholic fatty liver disease. J Clin Pathol 2007; 60:1384-91. [PMID: 17483247 PMCID: PMC2095560 DOI: 10.1136/jcp.2006.044891] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder in western countries, and its incidence is increasing. This review outlines the significant health burden posed by NAFLD and discusses what is presently known about its pathogenesis, including the roles of the metabolic syndrome, obesity, insulin resistance, hepatic steatosis, reactive oxygen species, inflammatory cytokines and adipocytokines. The way in which NAFLD is clinically diagnosed is described, and areas of uncertainty surrounding its investigation are identified, before discussing the relative merits of the limited treatment options available and looking ahead to potential therapeutic strategies for the future.
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Affiliation(s)
- P Riley
- Department of Gastroenterology, University Hospital Lewisham, London, UK.
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Romestaing C, Piquet MA, Bedu E, Rouleau V, Dautresme M, Hourmand-Ollivier I, Filippi C, Duchamp C, Sibille B. Long term highly saturated fat diet does not induce NASH in Wistar rats. Nutr Metab (Lond) 2007; 4:4. [PMID: 17313679 PMCID: PMC1805500 DOI: 10.1186/1743-7075-4-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Accepted: 02/21/2007] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Understanding of nonalcoholic steatohepatitis (NASH) is hampered by the lack of a suitable model. Our aim was to investigate whether long term high saturated-fat feeding would induce NASH in rats. METHODS 21 day-old rats fed high fat diets for 14 weeks, with either coconut oil or butter, and were compared with rats feeding a standard diet or a methionine choline-deficient (MCD) diet, a non physiological model of NASH. RESULTS MCDD fed rats rapidly lost weight and showed NASH features. Rats fed coconut (86% of saturated fatty acid) or butter (51% of saturated fatty acid) had an increased caloric intake (+143% and +30%). At the end of the study period, total lipid ingestion in term of percentage of energy intake was higher in both coconut (45%) and butter (42%) groups than in the standard (7%) diet group. No change in body mass was observed as compared with standard rats at the end of the experiment. However, high fat fed rats were fattier with enlarged white and brown adipose tissue (BAT) depots, but they showed no liver steatosis and no difference in triglyceride content in hepatocytes, as compared with standard rats. Absence of hepatic lipid accumulation with high fat diets was not related to a higher lipid oxidation by isolated hepatocytes (unchanged ketogenesis and oxygen consumption) or hepatic mitochondrial respiration but was rather associated with a rise in BAT uncoupling protein UCP1 (+25-28% vs standard). CONCLUSION Long term high saturated fat feeding led to increased "peripheral" fat storage and BAT thermogenesis but did not induce hepatic steatosis and NASH.
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Affiliation(s)
- Caroline Romestaing
- Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS, Université Lyon 1, F-69622 France
| | - Marie-Astrid Piquet
- Imagerie Fonctionnelle et Métabolique en Oncologie, EA 3916, Département de Nutrition et d'hépatogastroentérologie, CHU Côte de nacre, Caen, F-14033 France
| | - Elodie Bedu
- Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS, Université Lyon 1, F-69622 France
| | - Vincent Rouleau
- Imagerie Fonctionnelle et Métabolique en Oncologie, EA 3916, Département de Nutrition et d'hépatogastroentérologie, CHU Côte de nacre, Caen, F-14033 France
| | - Marianne Dautresme
- Imagerie Fonctionnelle et Métabolique en Oncologie, EA 3916, Département de Nutrition et d'hépatogastroentérologie, CHU Côte de nacre, Caen, F-14033 France
| | - Isabelle Hourmand-Ollivier
- Imagerie Fonctionnelle et Métabolique en Oncologie, EA 3916, Département de Nutrition et d'hépatogastroentérologie, CHU Côte de nacre, Caen, F-14033 France
| | - Céline Filippi
- Department of Hepatology, Chancellor's Building, 49 Little France Crescent, Edinburgh, UK
| | - Claude Duchamp
- Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS, Université Lyon 1, F-69622 France
| | - Brigitte Sibille
- Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS, Université Lyon 1, F-69622 France
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Abstract
There is no proven medical treatment of non-alcoholic steatohepatitis (NASH). Most prior therapeutic trials have had methodologic limitations. Insulin sensitizers are the more promising therapeutic candidates among categories that include antioxidants, lipid-lowering agents, and antiobesity drugs. The future will see the evaluation of novel agents and a comprehensive treatment strategy that addresses the risk factors for the metabolic syndrome. This article reviews the current status of medical management options for NASH.
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Affiliation(s)
- Abdurrahman Kadayifci
- Division of Gastroenterology, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143-0538, USA.
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Begriche K, Igoudjil A, Pessayre D, Fromenty B. Mitochondrial dysfunction in NASH: causes, consequences and possible means to prevent it. Mitochondrion 2006; 6:1-28. [PMID: 16406828 DOI: 10.1016/j.mito.2005.10.004] [Citation(s) in RCA: 532] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Accepted: 10/13/2005] [Indexed: 02/07/2023]
Abstract
Calorie-enriched diet and lack of exercise are causing a worldwide surge of obesity, insulin resistance and lipid accretion in liver (i.e. hepatic steatosis), which can lead to steatohepatitis. Steatosis and nonalcoholic steatohepatitis (NASH) can also be induced by drugs such as amiodarone, tamoxifen and some antiretroviral drugs, including stavudine and zidovudine. There is accumulating evidence that mitochondrial dysfunction (more particularly respiratory chain deficiency) plays a key role in the physiopathology of NASH whatever its initial cause. In contrast, the mitochondrial beta-oxidation of fatty acids can be either increased (as in insulin resistance-associated NASH) or decreased (as in drug-induced NASH). However, in both circumstances, generation of reactive oxygen species (ROS) by the damaged respiratory chain can be augmented. ROS generation in an environment enriched in lipids in turn induces lipid peroxidation which releases highly reactive aldehydic derivatives (e.g. malondialdehyde) that have diverse detrimental effects on hepatocytes and other hepatic cells. In hepatocytes, ROS, reactive nitrogen species and lipid peroxidation products further impair the respiratory chain, either directly or indirectly through oxidative damage to the mitochondrial genome. This consequently leads to the generation of more ROS and a vicious cycle occurs. Mitochondrial dysfunction can also lead to apoptosis or necrosis depending on the energy status of the cell. ROS and lipid peroxidation products also increase the generation of several cytokines (TNF-alpha, TGF-beta, Fas ligand) playing a key role in cell death, inflammation and fibrosis. Recent investigations have shown that some genetic polymorphisms can significantly increase the risk of steatohepatitis and that several drugs can prevent or even reverse NASH. Interestingly, most of these drugs could exert their beneficial effects by improving directly or indirectly mitochondrial function in liver. Finding a drug, which could fully prevent oxidative stress and mitochondrial dysfunction in NASH is a major challenge for the next decade.
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Affiliation(s)
- Karima Begriche
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 481, Faculté de Médecine Xavier Bichat, 16 rue Henri Huchard, 750118 Paris, France
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