scholarly journals Lack of miR-379/miR-544 Cluster Resists High-Fat Diet-Induced Obesity and Prevents Hepatic Triglyceride Accumulation in Mice

2021 ◽  
Vol 9 ◽  
Author(s):  
Congcong Cao ◽  
Peng Duan ◽  
Wencun Li ◽  
Yang Guo ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Knockout Mice ◽  
High Fat Diet ◽  
Leptin Receptor ◽  
Mirna Cluster ◽  
High Fat ◽  
Gene Expressions ◽  
Alcoholic Fatty Liver ◽  
Triglyceride Accumulation

Non-alcoholic fatty liver disease (NAFLD) affects obesity-associated metabolic syndrome, which exhibits hepatic steatosis, insulin insensitivity and glucose intolerance. Emerging evidence suggests that microRNAs (miRNAs) are essential for the metabolic homeostasis of liver tissues. Many hepatic miRNAs located in the miR-379/miR-544 cluster were significantly increased in leptin-receptor-deficient type 2 mice (db/db), a mouse model of diabetes. However, the function of the miR-379/miR-544 cluster in the process of hepatic steatosis remains unclear. Here, we report that the novel function of miR-379/miR-544 cluster in regulating obesity-mediated metabolic dysfunction. Genetical mutation of miR-379/miR-544 cluster in mice displayed resistance to high-fat diet (HFD)-induced obesity with moderate hepatic steatosis and hypertriglyceridemia. In vitro studies revealed that silencing of miR-379 in human hepatocellular carcinoma (HepG2) cells ameliorated palmitic acid-induced elevation of cellular triglycerides, and overexpression of miR-379 had the opposite effect. Moreover, Igf1r (Insulin-like growth factor 1 receptor) and Dlk1 (Delta-like homolog 1) were directly targeted by miR-379 and miR-329, respectively, and elevated in the livers of the miR-379/miR-544 cluster knockout mice fed on HFD. Further transcriptome analyses revealed that the hepatic gene expressions are dysregulated in miR-379/miR-544 knockout mice fed with HFD. Collectively, our findings identify the miR-379/miR-544 cluster as integral components of a regulatory circuit that functions under conditions of metabolic stress to control hepatic steatosis. Thus, this miRNA cluster provides potential targets for pharmacologic intervention in obesity and NAFLD.

scholarly journals LPIAT1/MBOAT7 depletion increases triglyceride synthesis fueled by high phosphatidylinositol turnover

Gut ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 180-193 ◽  
Author(s):  
Yuki Tanaka ◽  
Yuta Shimanaka ◽  
Andrea Caddeo ◽  
Takuya Kubo ◽  
Yanli Mao ◽  
...  
Keyword(s):  
Knockout Mice ◽  
High Fat Diet ◽  
Acyl Chain ◽  
High Fat ◽  
Triglyceride Synthesis ◽  
Alcoholic Fatty Liver ◽  
Hepatic Cells ◽  
Triglyceride Accumulation ◽  
Lipid Species

ObjectiveNon-alcoholic fatty liver disease (NAFLD) is a common prelude to cirrhosis and hepatocellular carcinoma. The genetic rs641738 C>T variant in the lysophosphatidylinositol acyltransferase 1 (LPIAT1)/membrane bound O-acyltransferase domain-containing 7, which incorporates arachidonic acid into phosphatidylinositol (PI), is associated with the entire spectrum of NAFLD. In this study, we investigated the mechanism underlying this association in mice and cultured human hepatocytes.DesignWe generated the hepatocyte-specific Lpiat1 knockout mice to investigate the function of Lpiat1 in vivo. We also depleted LPIAT1 in cultured human hepatic cells using CRISPR-Cas9 systems or siRNA. The effect of LPIAT1-depletion on liver fibrosis was examined in mice fed high fat diet and in liver spheroids. Lipid species were measured using liquid chromatography-electrospray ionisation mass spectrometry. Lipid metabolism was analysed using radiolabeled glycerol or fatty acids.ResultsThe hepatocyte-specific Lpiat1 knockout mice developed hepatic steatosis spontaneously, and hepatic fibrosis on high fat diet feeding. Depletion of LPIAT1 in cultured hepatic cells and in spheroids caused triglyceride accumulation and collagen deposition. The increase in hepatocyte fat content was due to a higher triglyceride synthesis fueled by a non-canonical pathway. Indeed, reduction in the PI acyl chain remodelling caused a high PI turnover, by stimulating at the same time PI synthesis and breakdown. The degradation of PI was mediated by a phospholipase C, which produces diacylglycerol, a precursor of triglyceride.ConclusionWe found a novel pathway fueling triglyceride synthesis in hepatocytes, by a direct metabolic flow of PI into triglycerides. Our findings provide an insight into the pathogenesis and therapeutics of NAFLD.

scholarly journals Deletion of lysophosphatidylcholine acyltransferase3 in myeloid cells worsens hepatic steatosis after a high fat diet

2020 ◽  
pp. jlr.RA120000737
Author(s):  
Thibaut Bourgeois ◽  
Antoine Jalil ◽  
Charles Thomas ◽  
Charlene Magnani ◽  
Naig Le Guern ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Ldl Receptor ◽  
Myeloid Cells ◽  
Lipid Absorption ◽  
High Fat ◽  
Triglyceride Accumulation ◽  
Pufa Composition

Recent studies have highlighted an important role for lysophosphatidylcholine acyltransferase 3 (LPCAT3) in controlling the PUFA composition of cell membranes in the liver and intestine. In these organs, LPCAT3 critically supports cell membrane-associated processes such as lipid absorption or lipoprotein secretion. However, the role of LPCAT3 in macrophages remains controversial. Here, we investigated LPCAT3’s role in macrophages both in vitro and in vivo in mice with atherosclerosis and obesity. To accomplish this, we used the LysMCre strategy to develop a mouse model with conditional Lpcat3 deficiency in myeloid cells (Lpcat3KOMac). We observed that partial Lpcat3 deficiency (approx. 75% reduction) in macrophages alters the PUFA composition of all phospholipid (PL) subclasses, including phosphatidylinositols and phosphatidylserines. A reduced incorporation of C20 PUFAs (mainly arachidonic acid [AA]) into PLs was associated with a redistribution of these FAs toward other cellular lipids such as cholesteryl esters. Lpcat3 deficiency had no obvious impact on macrophage inflammatory response or endoplasmic reticulum (ER) stress; however, Lpcat3KOMac macrophages exhibited a reduction in cholesterol efflux in vitro. In vivo, myeloid Lpcat3 deficiency did not affect atherosclerosis development in LDL receptor deficient mouse (Ldlr-/-) mice. Lpcat3KOMac mice on a high-fat diet displayed a mild increase in hepatic steatosis associated with alterations in several liver metabolic pathways and in liver eicosanoid composition. We conclude that alterations in AA metabolism along with myeloid Lpcat3 deficiency may secondarily affect AA homeostasis in the whole liver, leading to metabolic disorders and triglyceride accumulation.

Cholate inhibits high-fat diet-induced hyperglycemia and obesity with acyl-CoA synthetase mRNA decrease

1997 ◽  
Vol 273 (1) ◽  
pp. E37-E45 ◽  
Author(s):  
S. Ikemoto ◽  
M. Takahashi ◽  
N. Tsunoda ◽  
K. Maruyama ◽  
H. Itakura ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Skeletal Muscles ◽  
Unsaturation Index ◽  
Sodium Cholate ◽  
Fat Absorption ◽  
High Fat ◽  
Cholesterol Accumulation ◽  
Triglyceride Accumulation ◽  
Responsive Element

The effects of sodium cholate on high-fat diet-induced hyperglycemia and obesity were investigated. Insulin resistance was estimated by measuring 2-deoxyglucose uptake in epitrochlearis muscles incubated in vitro. Addition of 0.5% cholate to high-safflower oil diet completely prevented high fat-induced hyperglycemia and obesity in C57BL/6J mice with a slight decrease of energy intake but with no inhibition of fat absorption. Furthermore, the addition of cholate decreased blood insulin levels and prevented high-fat diet-induced decrease of glucose uptake in epitrochlearis. However, there was no change in the unsaturation index of fatty acids in skeletal muscles and in GLUT-4 levels by cholate. In liver, cholate addition resulted in cholesterol accumulation and completely prevented high-fat diet-induced triglyceride accumulation. The changes of triglyceride level in the liver were paralleled to the changes of acyl-CoA synthetase (ACS) mRNA. ACS catalyzes the formation of acyl-CoA from fatty acid, and acyl-CoA is utilized for triglyceride formation in liver. ACS has a sterol-responsive element 1 in its promoter region. These data indicate that the favorable effects of cholate could be partly the result of downregulation of ACS mRNA.

scholarly journals Effects of a Low Dose of Caffeine Alone or as Part of a Green Coffee Extract, in a Rat Dietary Model of Lean Non-Alcoholic Fatty Liver Disease without Inflammation

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3240
Author(s):  
Ana Magdalena Velázquez ◽  
Núria Roglans ◽  
Roger Bentanachs ◽  
Maria Gené ◽  
Aleix Sala-Vila ◽  
...  
Keyword(s):  
Liver Disease ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Fatty Liver Disease ◽  
Low Dose ◽  
Female Rats ◽  
Green Coffee ◽  
High Fat ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is a highly prevalent condition without specific pharmacological treatment, characterized in the initial stages by hepatic steatosis. It was suggested that lipid infiltration in the liver might be reduced by caffeine through anti-inflammatory, antioxidative, and fatty acid metabolism-related mechanisms. We investigated the effects of caffeine (CAF) and green coffee extract (GCE) on hepatic lipids in lean female rats with steatosis. For three months, female Sprague-Dawley rats were fed a standard diet or a cocoa butter-based high-fat diet plus 10% liquid fructose. In the last month, the high-fat diet was supplemented or not with CAF or a GCE, providing 5 mg/kg of CAF. Plasma lipid levels and the hepatic expression of molecules involved in lipid metabolism were determined. Lipidomic analysis was performed in liver samples. The diet caused hepatic steatosis without obesity, inflammation, endoplasmic reticulum stress, or hepatic insulin resistance. Neither CAF nor GCE alleviated hepatic steatosis, but GCE-treated rats showed lower hepatic triglyceride levels compared to the CAF group. The GCE effects could be related to reductions of hepatic (i) mTOR phosphorylation, leading to higher nuclear lipin-1 levels and limiting lipogenic gene expression; (ii) diacylglycerol levels; (iii) hexosylceramide/ceramide ratios; and (iv) very-low-density lipoprotein receptor expression. In conclusion, a low dose of CAF did not reduce hepatic steatosis in lean female rats, but the same dose provided as a green coffee extract led to lower liver triglyceride levels.

scholarly journals Fisetin Protects Against Hepatic Steatosis Through Regulation of the Sirt1/AMPK and Fatty Acid β-Oxidation Signaling Pathway in High-Fat Diet-Induced Obese Mice

2018 ◽  
Vol 49 (5) ◽  
pp. 1870-1884 ◽  
Author(s):  
Chian-Jiun Liou ◽  
Ciao-Han Wei ◽  
Ya-Ling Chen ◽  
Ching-Yi Cheng ◽  
Chia-Ling Wang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Fatty Acid Synthase ◽  
Epididymal Adipose Tissue ◽  
Obese Mice ◽  
High Fat

Background/Aims: Fisetin is a naturally abundant flavonoid isolated from various fruits and vegetables that was recently identified to have potential biological functions in improving allergic airway inflammation, as well as anti-oxidative and anti-tumor properties. Fisetin has also been demonstrated to have anti-obesity properties in mice. However, the effect of fisetin on nonalcoholic fatty liver disease (NAFLD) is still elusive. Thus, the present study evaluated whether fisetin improves hepatic steatosis in high-fat diet (HFD)-induced obese mice and regulates lipid metabolism of FL83B hepatocytes in vitro. Methods: NAFLD was induced by HFD in male C57BL/6 mice. The mice were then injected intraperitoneally with fisetin for 10 weeks. In another experiment, FL83B cells were challenged with oleic acid to induce lipid accumulation and treated with various concentrations of fisetin. Results: NAFLD mice treated with fisetin had decreased body weight and epididymal adipose tissue weight compared to NAFLD mice. Fisetin treatment also reduced liver lipid droplet and hepatocyte steatosis, alleviated serum free fatty acid, and leptin concentrations, significantly decreased fatty acid synthase, and significantly increased phosphorylation of AMPKα and the production of sirt-1 and carnitine palmitoyltransferase I in the liver tissue. In vitro, fisetin decreased lipid accumulation and increased lipolysis and β-oxidation in hepatocytes. Conclusion: This study suggests that fisetin is a potential novel treatment for alleviating hepatic lipid metabolism and improving NAFLD in mice via activation of the sirt1/AMPK and β-oxidation pathway.

scholarly journals Prebiotic Xylo-Oligosaccharides Ameliorate High-Fat-Diet-Induced Hepatic Steatosis in Rats

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3225
Author(s):  
Sanna Lensu ◽  
Raghunath Pariyani ◽  
Elina Mäkinen ◽  
Baoru Yang ◽  
Wisam Saleem ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Alcoholic Fatty Liver ◽  
Branched Chain Fatty Acids ◽  
Hepatic Fat ◽  
Branched Chain ◽  
Underlying Mechanisms ◽  
A Minor ◽  
Alcoholic Fatty Liver Disease

Understanding the importance of the gut microbiota (GM) in non-alcoholic fatty liver disease (NAFLD) has raised the hope for therapeutic microbes. We have shown that high hepatic fat content associated with low abundance of Faecalibacterium prausnitzii in humans and, further, the administration of F. prausnitzii prevented NAFLD in mice. Here, we aimed at targeting F. prausnitzii by prebiotic xylo-oligosaccharides (XOS) to treat NAFLD. First, the effect of XOS on F. prausnitzii growth was assessed in vitro. Then, XOS was supplemented or not with high (HFD, 60% of energy from fat) or low (LFD) fat diet for 12 weeks in Wistar rats (n = 10/group). XOS increased F. prausnitzii growth, having only a minor impact on the GM composition. When supplemented with HFD, XOS ameliorated hepatic steatosis. The underlying mechanisms involved enhanced hepatic β-oxidation and mitochondrial respiration. Nuclear magnetic resonance (1H-NMR) analysis of cecal metabolites showed that, compared to the HFD, the LFD group had a healthier cecal short-chain fatty acid profile and on the HFD, XOS reduced cecal isovalerate and tyrosine, metabolites previously linked to NAFLD. Cecal branched-chain fatty acids associated positively and butyrate negatively with hepatic triglycerides. In conclusion, XOS supplementation can ameliorate NAFLD by improving hepatic oxidative metabolism and affecting GM.

scholarly journals Anti-adipogenic and anti-obesity activities of purpurin in 3T3-L1 preadipocyte cells and in mice fed a high-fat diet

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Woo Nam ◽  
Seok Hyun Nam ◽  
Sung Phil Kim ◽  
Carol Levin ◽  
Mendel Friedman
Keyword(s):  
Weight Gain ◽  
High Fat Diet ◽  
Biological Activities ◽  
The Body ◽  
High Fat ◽  
In Vivo Models ◽  
Triglyceride Accumulation ◽  
In Cells

Abstract Background The body responds to overnutrition by converting stem cells to adipocytes. In vitro and in vivo studies have shown polyphenols and other natural compounds to be anti-adipogenic, presumably due in part to their antioxidant properties. Purpurin is a highly antioxidative anthraquinone and previous studies on anthraquinones have reported numerous biological activities in cells and animals. Anthraquinones have also been used to stimulate osteoblast differentiation, an inversely-related process to that of adipocyte differentiation. We propose that due to its high antioxidative properties, purpurin administration might attenuate adipogenesis in cells and in mice. Methods Our study will test the effect purpurin has on adipogenesis using both in vitro and in vivo models. The in vitro model consists of tracking with various biomarkers, the differentiation of pre-adipocyte to adipocytes in cell culture. The compound will then be tested in mice fed a high-fat diet. Murine 3T3-L1 preadipocyte cells were stimulated to differentiate in the presence or absence of purpurin. The following cellular parameters were measured: intracellular reactive oxygen species (ROS), membrane potential of the mitochondria, ATP production, activation of AMPK (adenosine 5′-monophosphate-activated protein kinase), insulin-induced lipid accumulation, triglyceride accumulation, and expression of PPARγ (peroxisome proliferator activated receptor-γ) and C/EBPα (CCAAT enhancer binding protein α). In vivo, mice were fed high fat diets supplemented with various levels of purpurin. Data collected from the animals included anthropometric data, glucose tolerance test results, and postmortem plasma glucose, lipid levels, and organ examinations. Results The administration of purpurin at 50 and 100 μM in 3T3-L1 cells, and at 40 and 80 mg/kg in mice proved to be a sensitive range: the lower concentrations affected several measured parameters, whereas at the higher doses purpurin consistently mitigated biomarkers associated with adipogenesis, and weight gain in mice. Purpurin appears to be an effective antiadipogenic compound. Conclusion The anthraquinone purpurin has potent in vitro anti-adipogenic effects in cells and in vivo anti-obesity effects in mice consuming a high-fat diet. Differentiation of 3T3-L1 cells was dose-dependently inhibited by purpurin, apparently by AMPK activation. Mice on a high-fat diet experienced a dose-dependent reduction in induced weight gain of up to 55%.

scholarly journals Muscular G9a regulates muscle-liver-fat axis by musclin under overnutrition in female mice

2020 ◽  
Author(s):  
Ada Admin ◽  
Wenquan Zhang ◽  
Dong Yang ◽  
Yangmian Yuan ◽  
Chong Liu ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Critical Role ◽  
Liver Fat ◽  
High Fat ◽  
Core Domain ◽  
Female Mice ◽  
Methylase Activity

Crosstalk among different tissues and organs is a hotspot in metabolic research. Recent studies have revealed the regulatory roles of a number of myokines in metabolism. Here, we report that female mice muscle-specific lacking histone methylase G9a (<i>Ehmt2</i><sup>Ckmm </sup>KO<i> </i>or <i>Ehmt2</i><sup>HSA</sup> KO) are resistant to high-fat-diet (HFD) induced obesity and hepatic steatosis. Furthermore, we identified significantly upregulated circulating level of musclin, a myokine, in HFD-fed <i>Ehmt2</i><sup>Ckmm </sup>KO or <i>Ehmt2</i><sup>HSA</sup> KO female mice. Similarly, upregulated musclin was observed in mice injected with two structurally different inhibitors for G9a methylase activity, BIX01294 and A366. Moreover, injection of recombinant full-length musclin or its functional core domain, inhibited the HFD-induced obesity and hepatic steatosis in wildtype female and male mice. Mechanistically, G9a methylase activity-dependently regulated muscular musclin level by binding to its promoter, also by regulating p-Foxo1/Foxo1 level <i>in vivo</i> and <i>in vitro</i>. Collectively, these data suggested a critical role for G9a in the ‘muscle-liver-fat’ metabolic axis, at least for female mice. Musclin may serve as a potential therapeutic candidate for obesity and associated diseases.

The antianginal ranolazine does not confer beneficial actions against hepatic steatosis in male mice subjected to high-fat diet and streptozotocin induced type 2 diabetes

2021 ◽  
Author(s):  
Christina T Saed ◽  
Amanda A Greenwell ◽  
Seyed Amirhossein Tabatabaei Dakhili ◽  
Keshav Gopal ◽  
Farah Eaton ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
High Fat ◽  
Alcoholic Fatty Liver ◽  
Low Fat Diet ◽  
Insulin Tolerance ◽  
Triacylglycerol Content ◽  
Hepatic Triacylglycerol

Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of excess fat in the liver in the absence of alcohol and increases one’s risk for both diabetes and cardiovascular disease (e.g. angina). We have shown that the second-line anti-anginal therapy, ranolazine, mitigates obesity-induced NAFLD, and our aim was to determine whether these actions of ranolazine also extend to NAFLD associated with type 2 diabetes (T2D). 8-week-old male C57BL/6J mice were fed either a low-fat diet or a high-fat diet for 15-weeks, with a single dose of streptozotocin (STZ; 75 mg/kg) administered in the high-fat diet fed mice at 4-weeks to induce experimental T2D. Mice were treated with either vehicle control or ranolazine during the final 7-weeks (50 mg/kg once daily). We assessed glycemia via monitoring glucose tolerance, insulin tolerance, and pyruvate tolerance, whereas hepatic steatosis was assessed via quantifying triacylglycerol content. We observed that ranolazine did not improve glycemia in mice with experimental T2D, while also having no impact on hepatic triacylglycerol content. Therefore, the salutary actions of ranolazine against NAFLD may be limited to obese individuals but not those who are obese with T2D.

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