Fatty acid synthesis in vitro by liver tissue from control subjects and patients with alcoholic liver disease

1986 ◽  
Vol 71 (6) ◽  
pp. 723-728 ◽  
Author(s):  
S. Venkatesan ◽  
Nancy W. Y. Leung ◽  
Timothy J. Peters

1. Percutaneous liver biopsy specimens were obtained from 11 control subjects, 24 alcoholic patients and six diabetic patients with mild to severe fatty liver and incubated in Krebs–Henseleit buffer containing 3H2O. The incorporation of 3H into fatty acid was measured and the absolute rate of fatty acid synthesis calculated. 2. Fatty acid synthesis rates were significantly lower in alcoholic fatty liver than in controls. 3. Fatty acid synthesis rates were similar in controls and patients with diabetic fatty livers. 4. Addition of 50 mmol/l ethanol did not alter the fatty acid synthesis rates in vitro. It is concluded that enhanced lipogenesis is not the major cause of fatty liver in patients with alcoholic fatty liver.

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6973
Author(s):  
Ting-An Lin ◽  
Bo-Jun Ke ◽  
Shih-Cheng Cheng ◽  
Chun-Lin Lee

Alcohol is metabolized in liver. Chronic alcohol abuse results in alcohol-induced fatty liver and liver injury. Red quinoa (Chenopodium formosanum) was a traditional staple food for Taiwanese aborigines. Red quinoa bran (RQB) included strong anti-oxidative and anti-inflammatory polyphenolic compounds, but it was usually regarded as the agricultural waste. Therefore, this study is to investigate the effect of water and ethanol extraction products of RQB on the prevention of liquid alcoholic diet-induced acute liver injury in mice. The mice were given whole grain powder of red quinoa (RQ-P), RQB ethanol extract (RQB-E), RQB water extract (RQB-W), and rutin orally for 6 weeks, respectively. The results indicated that RQB-E, RQB-W, and rutin decreased alcoholic diet-induced activities of aspartate aminotransferase and alanine aminotransferase, and the levels of serum triglyceride, total cholesterol, and hepatic triglyceride. Hematoxylin and eosin staining of liver tissues showed that RQB-E and RQB-W reduced lipid droplet accumulation and liver injury. However, ethanol extraction process can gain high rutin and antioxidative agents contents from red quinoa, that showed strong effects in preventing alcoholic fatty liver disease and liver injury via increasing superoxide dismutase/catalase antioxidative system and repressing the expressions of fatty acid synthesis enzyme acetyl-CoA carboxylase.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tomohiro Nishino ◽  
Takahiro Horie ◽  
Osamu Baba ◽  
Yasuhide Kuwabara ◽  
Tetsushi Nakao ◽  
...  

Introduction: MicroRNAs (miRs) are small non-protein-coding RNAs that bind to specific mRNAs and inhibit translation or promote degradation. Recent reports, including ours, indicated that miR-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a possible therapeutic target for treating atherosclerosis. Unexpectedly, miR-33 deficient (miR-33 -/- ) mice fed high fat diet (HFD) developed severe fatty liver and the mechanisms were investigated. Methods and Results: The liver weight of miR-33 -/- mice were about 1.5 times heavier than that of miR-33 +/+ mice and histological examination revealed that miR-33 -/- mice developed severe fatty liver under HFD feeding. In order to determine the cause of the fatty liver observed in miR-33 -/- mice fed HFD, we analysed the gene expression profiles using the liver of miR-33 +/+ and miR-33 -/- mice fed normal chow at the age of 16 weeks when they didn’t show fatty liver. As a result, genes involved in fatty acid metabolism were upregulated in miR-33 -/- mice. Among them we found SREBP-1 as a new potential target gene of miR-33 in silico and confirmed that miR-33 targets the 3’UTR of SREBP-1 in vitro . The expression of SREBP-1 and de novo fatty acid production were significantly increased in the liver of miR-33 -/- mice. We further intercrossed miR-33 -/- mice with Srebf1 +/- mice and fed them HFD. Hepatic steatosis was reversed in miR-33 -/- Srebf1 +/- mice compared with miR-33 -/- Srebf1 +/+ mice by histological analysis and measurement of triglyceride levels. The expression levels of genes involved in fatty acid synthesis, including Scd1, Fasn, Acc1 , and Pparg were increased in miR-33 -/- Srebf1 +/+ mice compared with miR-33 +/+ Srebf1 +/+ mice, and those increase were reversed in miR-33 -/- Srebf1 +/- mice. Conclusions: miR-33 regulates lipogenic pathway via regulating SREBP-1 as a novel target in vivo . In sterol-depleted conditions, acetyl-CoA might be preferred as a substrate for cholesterol production and not for fatty acid production by the downregulation of SREBP-1 through the upregulation of miR-33. Conversely, in cholesterol-rich condition, acetyl-CoA might be preferred as a substrate for fatty acid production through the downregulation of miR-33.


1952 ◽  
Vol 197 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Grace. Medes ◽  
Alice. Thomas ◽  
Sidney. Weinhouse

1959 ◽  
Vol 234 (12) ◽  
pp. 3111-3114 ◽  
Author(s):  
Albert I. Winegrad ◽  
Walter N. Shaw ◽  
Francis D.W. Lukens ◽  
William C. Stadie

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruiwen Wang ◽  
Zhecheng Wang ◽  
Ruimin Sun ◽  
Rong Fu ◽  
Yu Sun ◽  
...  

Fatty acid β-oxidation is an essential pathogenic mechanism in nonalcoholic fatty liver disease (NAFLD), and TATA-box binding protein associated factor 9 (TAF9) has been reported to be involved in the regulation of fatty acid β-oxidation. However, the function of TAF9 in NAFLD, as well as the mechanism by which TAF9 is regulated, remains unclear. In this study, we aimed to investigate the signaling mechanism underlying the involvement of TAF9 in NAFLD and the protective effect of the natural phenolic compound Danshensu (DSS) against NAFLD via the HDAC1/TAF9 pathway. An in vivo model of high-fat diet (HFD)-induced NAFLD and a palmitic acid (PA)-treated AML-12 cell model were developed. Pharmacological treatment with DSS significantly increased fatty acid β-oxidation and reduced lipid droplet (LD) accumulation in NAFLD. TAF9 overexpression had the same effects on these processes both in vivo and in vitro. Interestingly, the protective effect of DSS was markedly blocked by TAF9 knockdown. Mechanistically, TAF9 was shown to be deacetylated by HDAC1, which regulates the capacity of TAF9 to mediate fatty acid β-oxidation and LD accumulation during NAFLD. In conclusion, TAF9 is a key regulator in the treatment of NAFLD that acts by increasing fatty acid β-oxidation and reducing LD accumulation, and DSS confers protection against NAFLD through the HDAC1/TAF9 pathway.


2000 ◽  
Vol 80 (1) ◽  
pp. 59-67 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine

Twenty-four wether lambs were randomly allocated to six treatments to investigate the effect of temperature and dietary lipid supplements on fatty acid synthesis and metabolic activity in sheep. The treatments consisted of four groups exposed to either cold (0 °C) or warm temperature (+23 °C) and given ad libitum access to either a control barley-based diet or with lipid supplementation. Two other groups were placed on the dietary regimen at 0 °C, but pair-fed to intake of animals in the +23 °C environment. At 5 wk, fatty acid synthesis was measured by [1-14C]acetate incorporation into tissue lipids. Cold exposure and dietary lipid supplementation had no effect (P > 0.05) on in vivo fatty acid synthesis rates in either longissimus dorsi or the liver. In both subcutaneous and mesenteric adipose tissue depots, the rate of acetate incorporation into tissue lipid was not significantly affected by cold exposure. In the perirenal fat depot, cold exposure increased (P < 0.05) the rate of fatty acid synthesis, while lipid supplementation decreased (P < 0.05) the rate in all tissue adipose depots. In vitro, mesenteric and perirenal adipose tissues from cold pair-fed animals had higher (P < 0.05) rates of fatty acid synthesis compared to tissues from animals in the warm environment. However, there was no effect of dietary lipid supplementation in these two fat depots. Metabolic heat production, and energy and nitrogen excretion by animals were increased (P < 0.05) by cold exposure while lipid supplementation had the opposite effect (P < 0.05). The relationship between average daily gain and feed intake was linear at both warm and cold environments, but with higher (P < 0.05) average daily gain at all levels of intake in the cold compared to the warm environment. Results indicate that both environment and diet regulate metabolic activity in sheep. However, there were differences in lipogenic response by tissues to the treatments. Key words: Environmental temperature, dietary lipid, fatty acid synthesis, metabolic rate, sheep


1970 ◽  
Vol 119 (2) ◽  
pp. 193-219 ◽  
Author(s):  
E. D. Saggerson ◽  
A. L. Greenbaum

1. Adipose tissues from rats fed a balanced diet were incubated in the presence of glucose (20mm) with the following additions: insulin, anti-insulin serum, insulin+acetate, insulin+pyruvate, insulin+lactate, insulin+phenazine methosulphate, insulin+oleate+albumin, insulin+adrenaline+albumin, insulin+6-N-2′-O-dibutyryl 3′:5′-cyclic AMP+albumin. 2. Measurements were made of the whole tissue concentrations of adenine nucleotides, hexose phosphates, triose phosphates, glycerol 1-phosphate, 3 phosphoglycerate, 6-phosphogluconate, long-chain fatty acyl-CoA, acid-soluble CoA, citrate, isocitrate, malate and 2-oxoglutarate, and of the release into the incubation medium of lactate, pyruvate and glycerol after 1h of incubation. 3. Fluxes of [14C]glucose carbon through the major pathways of glucose metabolism were calculated from the yields of 14C in various products after 2h of incubation. Fluxes of [14C]acetate, [14C]pyruvate or [14C]lactate carbon in the presence of glucose were also determined. 4. Measurements were also made of the whole-tissue concentrations of metabolites in tissues taken directly from Nembutal-anaesthetized rats. 5. Whole tissue mass-action ratios for phosphofructokinase, phosphoglucose isomerase and the combined (aldolase×triose phosphate isomerase) reaction were similar in vivo and in vitro. The reactants of phosphofructokinase appeared to be far from mass-action equilibrium. In vitro, the reactants of hexokinase also appeared to be far from mass-action equilibrium. 6. Correlation of observed changes in glycolytic flux with changes in fructose 6-phosphate concentration suggested that phosphofructokinase may show regulatory behaviour. The enzyme appeared to be activated in the presence of oleate or adrenaline and to be inhibited in the presence of lactate or pyruvate. 7. Evidence is presented that the reactants of lactate dehydrogenase and glycerol 1-phosphate dehydrogenase may be near to mass-action equilibrium in the cytoplasm. 8. No satisfactory correlations could be drawn between the whole-tissue concentrations of long-chain fatty acyl-CoA, citrate and glycerol 1-phosphate and the observed rates of triglyceride and fatty acid synthesis. Under the conditions employed, the concentration of glycerol 1-phosphate appeared to depend mainly on the cytoplasmic [NAD+]/[NADH] ratios. 9. Calculated hexose monophosphate pathway flux rates roughly correlated with fatty acid synthesis rates and with whole tissue [6-phosphogluconate]/[glucose 6-phosphate] ratios. The relative rates of production of NADPH for fatty acid synthesis by the hexose monophosphate pathway and by the `malic enzyme' are discussed. It is suggested that all NADH produced in the cytoplasm may be used in that compartment for reductive synthesis of fatty acids, lactate or glycerol 1-phosphate.


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