Effect of environmental temperature and dietary lipid supplement on activity and protein abundance of acetyl-CoA carboxylase and fatty acid synthase in skeletal muscle, liver and adipose tissues of sheep

2000 ◽  
Vol 80 (1) ◽  
pp. 69-77 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine

To determine the effects of temperature and dietary lipid on the key enzymes regulating fatty acid synthesis, 24 wether lambs were exposed to three temperature treatments (+23 °C warm, 0 °C cold, or coldpairfed) and fed either a control barley-based diet or a lipid supplemented diet for a 5-wk period. After slaughter, tissue samples were collected and frozen for analysis for enzyme activity and enzyme protein abundance. Thermal environment or lipid supplementation did not affect (P > 0.05) acetyl-CoA carboxylase (ACC) activity in longissimus dorsi (LD) muscle. In liver, cold exposure increased (P < 0.05) while lipid supplementation depressed (P < 0.05) ACC activity. In subcutaneous (SC) and mesenteric (MS) adipose tissue ACC activity was not affected (P > 0.05) by cold exposure. Dietary lipid supplementation increased (P < 0.05) ACC activity in both SC and MS but the increase in perirenal (PR) fat was not significant. Western-blot analysis with peroxidase-labelled streptavidin identified two isoforms of ACC (280 and 265 kDa) in LD muscle and the 280 kDa was the more abundant isoform. In liver and adipose tissues only one isoform (265 kDa) was identified but there was a poor relationship between enzyme protein abundance and activity. Neither environment nor diet affected fatty acid synthase (FAS) activity in LD or liver. Cold exposure reduced (P < 0.05) FAS activity in SC tissue of ad libitum fed animals but increased FAS activity in MS tissue of pair-fed sheep and had no effect in PR fat. Dietary lipid supplementation reduced (P < 0.05) FAS activity by 30% in all three fat depots. A single isoform of FAS with MW of 260 kDa was present in all tissues examined with cold exposure increasing FAS protein expression in all tissues. The results indicate that temperature and dietary lipid affect enzyme catalytic activity with differential responses in different tissues. Key words: Environmental temperature, lipid supplement, lipogenic enzymes, enzyme activity, protein abundance, sheep

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


Author(s):  
Ahmed El-Sayed ◽  
Ahmed Ateya ◽  
Mohamed Hamed ◽  
Sherif Shoieb ◽  
Hussam Ibrahim ◽  
...  

Objective: To assess the mRNA level of acetyl CoA carboxylase alpha (ACACA), fatty acid synthase (FASN), and stearoyl-CoA desaturase (SCD) by means of real-time PCR in Barki sheep subjected to complete feed deprivation. Design: Controlled study. Animals: Seven healthy pregnant ewes. Procedures: Ewes were subjected to complete feed deprivation with ad libitum water for five consecutive days. Venous blood samples were collected from each ewe before (zero time) and on the fifth day post-deprivation of feed for measurement of the mRNA level of ACACA, FASN, and SCD and assessment of serum metabolic profile parameters. Results: On the fifth day post-fasting, the gene expression pattern of ACACA, FASN, SCD genes showed a significant (p < 0.05) down regulation in comparison with pre-deprivation of feed. There was a significant (p < 0.05) increase in the serum level of non-esterified fatty acids (NEFA), beta-hydroxyl buteric acid (BHBA), and triglycerides in pregnant ewes in the fifth day post-fasting in comparison with pre-deprivation of feed. On the other hand, there was a significant (p < 0.05) decrease in the level of glucose, cholesterol, and insulin in pregnant ewes in the fifth day post-fasting compared with pre-deprivation of feed. On histopathology, liver showed marked heptic steatosis in midzonal and periportal area, with formation of small fatty cysts in liver lobule. There was a positive correlation between leptin and insulin (r = 0.996; p < 0.01), BHB and leptin (r = 0.951; p < 0.05) and glucose and SCD (r = 1.0, p < 0.01). However, there was a negative correlation between FASN and NEFA (r = - 0.991; p < 0.05), FASN and leptin (r = -0.683; p < 0.05) and FASN and cholesterol (r = - 0.82; p < 0.05). Conclusion and clinical relevance: Pregnant Barki ewes can clinically tolerate complete feed deprivation for five days, with down regulation of ACACA, FASN, SCD genes and presence of marked metabolic changes. Therefore, metabolic monitoring is warranted to predict the early changes associated with feed deprivation under different stressful conditions.


1987 ◽  
Vol 243 (2) ◽  
pp. 437-442 ◽  
Author(s):  
M G Buckley ◽  
E A Rath

1. The effect of nutritional status on fatty acid synthesis in brown adipose tissue was compared with the effect of cold-exposure. Fatty acid synthesis was measured in vivo by 3H2O incorporation into tissue lipids. The activities of acetyl-CoA carboxylase and fatty acid synthetase and the tissue concentrations of malonyl-CoA and citrate were assayed. 2. In brown adipose tissue of control mice, the tissue content of malonyl-CoA was 13 nmol/g wet wt., higher than values reported in other tissues. From the total tissue water content, the minimum possible concentration was estimated to be 30 microM 3. There were parallel changes in fatty acid synthesis, malonyl-CoA content and acetyl-CoA carboxylase activity in response to starvation and re-feeding. 4. There was no correlation between measured rates of fatty acid synthesis and malonyl-CoA content and acetyl-CoA carboxylase activity in acute cold-exposure. The results suggest there is simultaneous fatty acid synthesis and oxidation in brown adipose tissue of cold-exposed mice. This is probably effected not by decreases in the malonyl-CoA content, but by increases in the concentration of free long-chain fatty acyl-CoA or enhanced peroxisomal oxidation, allowing shorter-chain fatty acids to enter the mitochondria independent of carnitine acyltransferase (overt form) activity.


2020 ◽  
Vol 41 (6) ◽  
pp. 778-789 ◽  
Author(s):  
Su-Hyeong Kim ◽  
Eun-Ryeong Hahm ◽  
Krishna B Singh ◽  
Sruti Shiva ◽  
Jacob Stewart-Ornstein ◽  
...  

Abstract Withaferin A (WA) is a promising phytochemical exhibiting in vitro and in vivo anticancer activities against prostate and other cancers, but the mechanism of its action is not fully understood. In this study, we performed RNA-seq analysis using 22Rv1 human prostate cancer cell line to identify mechanistic targets of WA. Kyoto Encyclopedia of Genes and Genomes pathway analysis of the differentially expressed genes showed most significant enrichment of genes associated with metabolism. These results were validated using LNCaP and 22Rv1 human prostate cancer cells and Hi-Myc transgenic mice as models. The intracellular levels of acetyl-CoA, total free fatty acids and neutral lipids were decreased significantly following WA treatment in both cells, which was accompanied by downregulation of mRNA (confirmed by quantitative reverse transcription-polymerase chain reaction) and protein levels of key fatty acid synthesis enzymes, including ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A. Ectopic expression of c-Myc, but not constitutively active Akt, conferred a marked protection against WA-mediated suppression of acetyl-CoA carboxylase 1 and fatty acid synthase protein expression, and clonogenic cell survival. WA was a superior inhibitor of cell proliferation and fatty acid synthesis in comparison with known modulators of fatty acid metabolism including cerulenin and etomoxir. Intraperitoneal WA administration to Hi-Myc transgenic mice (0.1 mg/mouse, three times/week for 5 weeks) also resulted in a significant decrease in circulating levels of total free fatty acids and phospholipids, and expression of ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A proteins in the prostate in vivo.


Sign in / Sign up

Export Citation Format

Share Document