scholarly journals Nordihydroguaiaretic acid improves metabolic dysregulation and aberrant hepatic lipid metabolism in mice by both PPARα-dependent and -independent pathways

2013 ◽  
Vol 304 (1) ◽  
pp. G72-G86 ◽  
Author(s):  
Haiyan Zhang ◽  
Wen-Jun Shen ◽  
Yuan Cortez ◽  
Fredric B. Kraemer ◽  
Salman Azhar
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Nordihydroguaiaretic Acid ◽  
Acid Oxidation ◽  
Hepatic Gene Expression ◽  
Creosote Bush ◽  
Fatty Acid Catabolism

Creosote bush-derived nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, possesses antioxidant properties and functions as a potent antihyperlipidemic agent in rodent models. Here, we examined the effect of chronic NDGA treatment of ob/ob mice on plasma dyslipidemia, hepatic steatosis, and changes in hepatic gene expression. Feeding ob/ ob mice a chow diet supplemented with either low (0.83 g/kg diet) or high-dose (2.5 g/kg diet) NDGA for 16 wk significantly improved plasma triglyceride (TG), inflammatory chemokine levels, hyperinsulinemia, insulin sensitivity, and glucose intolerance. NDGA treatment caused a marked reduction in liver weight and TG content, while enhancing rates of fatty acid oxidation. Microarray analysis of hepatic gene expression demonstrated that NDGA treatment altered genes for lipid metabolism, with genes involved in fatty acid catabolism most significantly increased. NDGA upregulated the mRNA and nuclear protein levels of peroxisome proliferator-activated receptor α (PPARα), and the activated (phosphorylated) form of AMP-activated kinase. NDGA increased PPARα promoter activity in AML12 hepatocytes and also prevented the fatty acid suppression of PPARα expression. In contrast, PPARα siRNA abrogated the stimulatory effect of NDGA on fatty acid catabolism. Likewise, no stimulatory effect of NDGA on hepatic fatty acid oxidation was observed in the livers of PPARα-deficient mice, but the ability of NDGA to reverse fatty liver conditions was unaffected. In conclusion, the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation via PPARα-dependent pathways. However, PPARα-independent pathways also contribute to NDGA's action to ameliorate hepatic steatosis.

scholarly journals Sexually Dimorphic Responses to a High-Refined Carbohydrate Diet in a Nonalcoholic Fatty Liver Disease Mouse Model

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 16-16
Author(s):  
Michael Daniels ◽  
Chun Liu ◽  
Kang-Quan Hu ◽  
Xiang-Dong Wang
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Sexually Dimorphic ◽  
Male Mice ◽  
Carbohydrate Diet ◽  
Nonalcoholic Fatty Liver ◽  
Female Mice

Abstract Objectives Nonalcoholic fatty liver disease (NAFLD) incidence and prevalence have been reported to be higher in men than women, however, the effects of sexual dimorphism on NAFLD risk and progression have not been adequately examined. Our lab has previously shown that a liquid high-refined carbohydrate diet (HRCD) induced more severe hepatic steatosis compared to an isocaloric high fat diet in male mice. Also, HRCD-induced reduction in sirtuin 1 (SIRT1), an NAD-dependent deacetylase protein, has previously been implicated in NAFLD pathogenesis. Therefore, we investigated whether there were sexually dimorphic responses to a liquid high-refined carbohydrate diet (HRCD) in male and female, wildtype and SIRT1-deficient mice. Methods Male and female 10–12-week-old wildtype (SIRT1 +/+: n = 12; M = 6, F = 6) and mice carrying a heterozygous H355Y SIRT1 point mutation (SIRT1 +/y: n = 14; M = 7, F = 7) were both fed a HRCD (Lieber-DeCarli liquid diet supplemented with maltose dextrin; 47% energy from refined carbohydrate, Dyets, #710,260) for 5 weeks and 9 weeks. Hepatic gene expression was examined using qRT-PCR. Plasma ALT (alanine transaminase) and hepatic MDA (malondialdehyde) levels were determined using colorimetric assay kits. Hepatic steatosis scoring was conducted by analyzing Hematoxylin and Eosin (H&E) stains. Results 9 weeks of HRCD induced significantly less hepatic steatosis in female mice irrespective of genotype compared to male mice as determined by grading of H&E stains (P < 0.05). Furthermore, liver expression of several fatty acid oxidation genes (CPT1, ACOX1) was significantly higher in females (P < 0.05), which potentially suggests increased fatty acid oxidation. Additionally, female mice had significantly increased antioxidant gene expression (GPX4, SOD1, SOD2, Catalase) and significantly lower hepatic MDA (P < 0.05), which indicate an increased capacity to mitigate oxidative stress. Lastly, plasma ALT levels were significantly lower in females compared to males after 9 weeks of HRCD (P < 0.05). Conclusions Collectively, these data indicate that female mice are moderately protected against HRCD-induced NAFLD compared to male mice, potentially through increased hepatic fatty acid oxidation and superior mitigation of oxidative stress due to increased antioxidant system gene expression in the liver. Funding Sources HNRCA, USDA/ARS Grants.

scholarly journals Poria cocus Wolf Extract Ameliorates Hepatic Steatosis through Regulation of Lipid Metabolism, Inhibition of ER Stress, and Activation of Autophagy via AMPK Activation

2019 ◽  
Vol 20 (19) ◽  
pp. 4801 ◽  
Author(s):  
Ji-Hyun Kim ◽  
Hyun A Sim ◽  
Dae Young Jung ◽  
Eun Yeong Lim ◽  
Yun Tai Kim ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Er Stress ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Hepg2 Cells ◽  
Acid Oxidation ◽  
Pachymic Acid ◽  
Metabolism Inhibition

Poria cocos Wolf (PCW) is an edible, pharmaceutical mushroom with remarkable biological properties including anti-tumor, anti-inflammation, anti-oxidation, anti-ageing, and anti-diabetic effects. In the current study, we investigated the effects of PCW extract on hepatic steatosis under in vitro and in vivo conditions, and elucidated the underlying mechanisms. In this study, a mixture of HepG2 cells treated with free fatty acid (FFA)—palmitic and oleic acid—and high-fat diet (HFD)-fed obese mice were used; in this background, the triglyceride (TG) levels in HepG2 cells and mice liver were measured, and the expression levels of genes associated with lipogenesis, fatty acid oxidation, endoplasmic reticulum (ER) stress, and autophagy were determined. Treatment of HepG2 cells with FFA enhanced intracellular TG levels in HepG2 cells, but co-treatment with PCW significantly attenuated the TG levels. Notably, PCW significantly enhanced the phosphorylation of AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), and sterol regulatory element-binding protein-1c (SREBP-1c) in FFA-treated HepG2 cells. PCW downregulated the expression of lipogenesis-related genes, but upregulated the expression of genes associated with fatty acid oxidation. Further, PCW inhibited FFA-induced expression of ER stress markers and induced autophagy proteins. However, inhibition of AMPK significantly attenuated the beneficial effects of PCW in HepG2 cells. Moreover, PCW efficiently decreased HFD-induced hepatic TG accumulation in vivo and increased the phosphorylation of hepatic AMPK. Three compounds present in PCW including poricoic acid, pachymic acid, and ergosterol, significantly decreased FFA-induced increase in intracellular TG levels, consistent with increased AMPK phosphorylation, suggesting that poricoic acid, pachymic acid, and ergosterol are responsible for PCW-mediated amelioration of hepatic steatosis. Taken together, these results demonstrated that PCW ameliorates hepatic steatosis through the regulation of lipid metabolism, inhibition of ER stress, and activation of autophagy in an AMPK-dependent manner. This suggested that PCW can be potentially used for the treatment of hepatic steatosis.

scholarly journals Glucagon-induced extracellular cAMP regulates hepatic lipid metabolism

2017 ◽  
Vol 234 (2) ◽  
pp. 73-87 ◽  
Author(s):  
Sihan Lv ◽  
Xinchen Qiu ◽  
Jian Li ◽  
Jinye Liang ◽  
Weida Li ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Lipid Homeostasis ◽  
Acid Oxidation ◽  
Intracellular Camp ◽  
Hepatic Lipid Metabolism ◽  
Hepatic Lipid ◽  
Extracellular Camp

Hormonal signals help to maintain glucose and lipid homeostasis in the liver during the periods of fasting. Glucagon, a pancreas-derived hormone induced by fasting, promotes gluconeogenesis through induction of intracellular cAMP production. Glucagon also stimulates hepatic fatty acid oxidation but the underlying mechanism is poorly characterized. Here we report that following the acute induction of gluconeogenic genes Glucose 6 phosphatase (G6Pase) and Phosphoenolpyruvate carboxykinase (Pepck) expression through cAMP-response element-binding protein (CREB), glucagon triggers a second delayed phase of fatty acid oxidation genes Acyl-coenzyme A oxidase (Aox) and Carnitine palmitoyltransferase 1a (Cpt1a) expression via extracellular cAMP. Increase in extracellular cAMP promotes PPARα activity through direct phosphorylation by AMP-activated protein kinase (AMPK), while inhibition of cAMP efflux greatly attenuates Aox and Cpt1a expression. Importantly, cAMP injection improves lipid homeostasis in fasted mice and obese mice, while inhibition of cAMP efflux deteriorates hepatic steatosis in fasted mice. Collectively, our results demonstrate the vital role of glucagon-stimulated extracellular cAMP in the regulation of hepatic lipid metabolism through AMPK-mediated PPARα activation. Therefore, strategies to improve cAMP efflux could serve as potential new tools to prevent obesity-associated hepatic steatosis.

scholarly journals Gomisin N Alleviates Ethanol-Induced Liver Injury through Ameliorating Lipid Metabolism and Oxidative Stress

2018 ◽  
Vol 19 (9) ◽  
pp. 2601 ◽  
Author(s):  
Arulkumar Nagappan ◽  
Dae Jung ◽  
Ji-Hyun Kim ◽  
Hoyoung Lee ◽  
Myeong Jung
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Fatty Acid ◽  
Liver Injury ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Antioxidant Genes ◽  
Gomisin N

Gomisin N (GN), a lignan derived from Schisandra chinensis, has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. In the present study, we investigated the protective effect of GN against ethanol-induced liver injury using in vivo and in vitro experiments. Histopathological examination revealed that GN administration to chronic-binge ethanol exposure mice significantly reduced ethanol-induced hepatic steatosis through reducing lipogenesis gene expression and increasing fatty acid oxidation gene expression, and prevented liver injury by lowering the serum levels of aspartate transaminase and alanine transaminase. Further, it significantly inhibited cytochrome P450 2E1 (CYP2E1) gene expression and enzyme activity, and enhanced antioxidant genes and glutathione level in hepatic tissues, which led to decreased hepatic malondialdehyde levels. It also lowered inflammation gene expression. Finally, GN administration promoted hepatic sirtuin1 (SIRT1)-AMP-activated protein kinase (AMPK) signaling in ethanol-fed mice. Consistent with in vivo data, treatment with GN decreased lipogenesis gene expression and increased fatty acid oxidation gene expression in ethanol-treated HepG2 cells, thereby preventing ethanol-induced triglyceride accumulation. Furthermore, it inhibited reactive oxygen species generation by downregulating CYP2E1 and upregulating antioxidant gene expression, and suppressed inflammatory gene expression. Moreover, GN prevented ethanol-mediated reduction in SIRT1 and phosphorylated AMPK. These findings indicate that GN has therapeutic potential against alcoholic liver disease through inhibiting hepatic steatosis, oxidative stress and inflammation.

scholarly journals Ahnak deficiency attenuates high-fat diet-induced fatty liver in mice through FGF21 induction

2021 ◽  
Author(s):  
Yo Na Kim ◽  
Jae Hoon Shin ◽  
Dong Soo Kyeong ◽  
Soo Young Cho ◽  
Mi-Young Kim ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Fibroblast Growth Factor 21 ◽  
Acid Oxidation ◽  
Chow Diet ◽  
High Fat

AbstractThe AHNAK nucleoprotein has been determined to exert an anti-obesity effect in adipose tissue and further inhibit adipogenic differentiation. In this study, we examined the role of AHNAK in regulating hepatic lipid metabolism to prevent diet-induced fatty liver. Ahnak KO mice have reportedly exhibited reduced fat accumulation in the liver and decreased serum triglyceride (TG) levels when provided with either a normal chow diet or a high-fat diet (HFD). Gene expression profiling was used to identify novel factors that could be modulated by genetic manipulation of the Ahnak gene. The results revealed that fibroblast growth factor 21 (FGF21) was markedly increased in the livers of Ahnak KO mice compared with WT mice fed a HFD. Ahnak knockdown in hepatocytes reportedly prevented excessive lipid accumulation induced by palmitate treatment and was associated with increased secretion of FGF21 and the expression of genes involved in fatty acid oxidation, which are primarily downstream of PPARα. These results indicate that pronounced obesity and hepatic steatosis are attenuated in HFD-fed Ahnak KO mice. This may be attributed, in part, to the induction of FGF21 and regulation of lipid metabolism, which are considered to be involved in increased fatty acid oxidation and reduced lipogenesis in the liver. These findings suggest that targeting AHNAK may have beneficial implications in preventing or treating hepatic steatosis.

scholarly journals PPARα-Deficient ob/ob Obese Mice Become More Obese and Manifest Severe Hepatic Steatosis Due to Decreased Fatty Acid Oxidation

2015 ◽  
Vol 185 (5) ◽  
pp. 1396-1408 ◽  
Author(s):  
Qian Gao ◽  
Yuzhi Jia ◽  
Gongshe Yang ◽  
Xiaohong Zhang ◽  
Prajwal C. Boddu ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Obese Mice

scholarly journals Tang-Nai-Kang Alleviates Pre-diabetes and Metabolic Disorders and Induces a Gene Expression Switch toward Fatty Acid Oxidation in SHR.Cg-Leprcp/NDmcr Rats

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0122024 ◽  
Author(s):  
Linyi Li ◽  
Hisae Yoshitomi ◽  
Ying Wei ◽  
Lingling Qin ◽  
Jingxin Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Metabolic Disorders ◽  
Acid Oxidation
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