scholarly journals In Vitro Fatty Acid Synthesis and Complex Lipid Metabolism in the Cyanobacterium, Anabaena Variabilis

1984 ◽  
Vol 75 (3) ◽  
pp. 700-704 ◽  
Author(s):  
Nora W. Lem ◽  
Paul K. Stumpf
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Anabaena Variabilis ◽  
Complex Lipid ◽  
Cyanobacterium Anabaena

scholarly journals Taurine-Mediated IDOL Contributes to Resolution of Streptococcus uberis Infection

2021 ◽  
Vol 89 (5) ◽  
Author(s):  
Zhixin Wan ◽  
Riguo Lan ◽  
Yilin Zhou ◽  
Yuanyuan Xu ◽  
Zhenglei Wang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Bacterial Load ◽  
Critical Role ◽  
Acid Synthesis ◽  
Content Type ◽  
Streptococcus Uberis

ABSTRACT Metabolic alterations occur in pathogenic infections, but the role of lipid metabolism in the progression of bacterial mastitis is unclear. Cross talk between lipid droplets (LDs) and invading bacteria occurs, and targeting of de novo lipogenesis inhibits pathogen reproduction. In this study, we investigate the role(s) of lipid metabolism in mammary cells during Streptococcus uberis infection. Our results indicate that S. uberis induces the synthesis of fatty acids and production of LDs. Importantly, taurine reduces fatty acid synthesis, the abundance of LDs and the in vitro bacterial load of S. uberis. These changes are mediated, at least partly, by the E3 ubiquitin ligase IDOL, which is associated with the degradation of low-density lipoprotein receptors (LDLRs). We have identified a critical role for IDOL-mediated fatty acid synthesis in bacterial infection, and we suggest that taurine may be an effective prophylactic or therapeutic strategy for preventing S. uberis mastitis.

scholarly journals Glucagon regulates ACC activity in adipocytes through the CAMKKβ/AMPK pathway

2012 ◽  
Vol 302 (12) ◽  
pp. E1560-E1568 ◽  
Author(s):  
I-Chen Peng ◽  
Zhen Chen ◽  
Wei Sun ◽  
Ying-Shiuan Li ◽  
Traci LaNai Marin ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Protein Kinase ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Dependent Protein Kinase ◽  
Ampk Signaling ◽  
Dependent Protein

Glucagon is important for regulating lipid metabolism in part through its inhibition of fatty acid synthesis in adipocytes. Acetyl-CoA carboxylase 1 (ACC1) is the rate-limiting enzyme for fatty acid synthesis. Glucagon has been proposed to activate cAMP-dependent protein kinase A (PKA), which phosphorylates ACC1 to attenuate the lipogenic activity of ACC1. Because AMP-activated protein kinase (AMPK) also inhibits fatty acid synthesis by phosphorylation of ACC1, we examined the involvement of AMPK and its upstream kinase in the glucagon-elicited signaling in adipocytes in vitro and in vivo. LC-MS-MS analysis suggested that ACC1 was phosphorylated only at Ser79, an AMPK-specific site, in glucagon-treated adipocytes. Pharmacological inhibitors and siRNA knockdown of AMPK or PKA in adipocytes demonstrate that glucagon regulates ACC1 and ACC2 activity through AMPK but not PKA. By using Ca2+/calmodulin-dependent protein kinase kinase-β knockout (CaMKKβ−/−) mice and cultured adipocytes, we further show that glucagon activates the CaMKKβ/AMPK/ACC cascade. Additionally, fasting increases the phosphorylation of AMPK and ACC in CaMKKβ+/+ but not CaMKKβ−/− mice. These results indicate that CaMKKβ/AMPK signaling is an important molecular component in regulating lipid metabolism in adipocytes responding to glucagon and could be a therapeutic target for the dysregulation of energy storage.

scholarly journals NUTRITIONAL FACTORS IN FATTY ACID SYNTHESIS BY TISSUE SLICES IN VITRO

1952 ◽  
Vol 197 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Grace. Medes ◽  
Alice. Thomas ◽  
Sidney. Weinhouse
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Tissue Slices ◽  
Nutritional Factors

scholarly journals Effects of Prolactin in Vitro on Fatty Acid Synthesis in Rat Adipose Tissue

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

In vivo and in vitro lipogenesis and aspects of metabolism in ovines: Effect of environmental temperature and dietary lipid supplementation

2000 ◽  
Vol 80 (1) ◽  
pp. 59-67 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Cold Exposure ◽  
Average Daily Gain ◽  
Acid Synthesis ◽  
Dietary Lipid ◽  
Acetate Incorporation ◽  
Lipid Supplementation

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

scholarly journals The regulation of triglyceride synthesis and fatty acid synthesis in rat epididymal adipose tissue. Effects of insulin, adrenaline and some metabolites in vitro

1970 ◽  
Vol 119 (2) ◽  
pp. 193-219 ◽  
Author(s):  
E. D. Saggerson ◽  
A. L. Greenbaum
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fatty Acyl ◽  
Mass Action ◽  
Hexose Monophosphate ◽  
Tissue Concentrations ◽  
Hexose Monophosphate Pathway ◽  
Long Chain

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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