scholarly journals Distinct roles of specific fatty acids in cellular processes: implications for interpreting and reporting experiments

2012 ◽  
Vol 302 (1) ◽  
pp. E1-E3 ◽  
Author(s):  
Matthew J. Watt ◽  
Andrew J. Hoy ◽  
Deborah M. Muoio ◽  
Rosalind A. Coleman

Plasma contains a variety of long-chain fatty acids (FAs), such that about 35% are saturated and 65% are unsaturated. There are countless examples that show how different FAs impart specific and unique effects, or even opposing actions, on cellular function. Despite these differing effects, palmitate (C16:0) is regularly used to represent “FAs” in cell based experiments. Although palmitate can be useful to induce and study stress effects in cultured cells, these effects in isolation are not physiologically relevant to dietary manipulations, obesity, or the consequences of physiological concentrations of FAs. Hence, authors should avoid conclusions that generalize about “FAs” or “saturated FAs” or “high-fat diet” effects if only a single FA was used in the reported experiments.

2011 ◽  
Vol 286 (41) ◽  
pp. 35578-35587 ◽  
Author(s):  
Lena-Solveig Lenz ◽  
Jana Marx ◽  
Walee Chamulitrat ◽  
Iris Kaiser ◽  
Hermann-Josef Gröne ◽  
...  

Fatp4 exhibits acyl-CoA synthetase activity and is thereby able to catalyze the activation of fatty acids for further metabolism. However, its actual function in most tissues remains unresolved, and its role in cellular fatty acid uptake is still controversial. To characterize Fatp4 functions in adipocytes in vivo, we generated a mouse line with adipocyte-specific inactivation of the Fatp4 gene (Fatp4A−/−). Under standard conditions mutant mice showed no phenotypical aberrance. Uptake of radiolabeled palmitic and lignoceric acid into adipose tissue of Fatp4A−/− mice was unchanged. When exposed to a diet enriched in long chain fatty acids, Fatp4A−/− mice gained more body weight compared with control mice, although they were not consuming more food. Pronounced obesity was accompanied by a thicker layer of subcutaneous fat and greater adipocyte circumference, although expression of genes involved in de novo lipogenesis was not changed. However, the increase in total fat mass was contrasted by a significant decrease in various phospholipids, sphingomyelin, and cholesteryl esters in adipocytes. Livers of Fatp4-deficient animals under a high fat diet exhibited a higher degree of fatty degeneration. Nonetheless, no evidence for changes in insulin sensitivity and adipose inflammation was found. In summary, the results of this study confirm that Fatp4 is not crucial for fatty acid uptake into adipocytes. Instead, under the condition of a diet enriched in long chain fatty acids, adipocyte-specific Fatp4 deficiency results in adipose hypertrophy and profound alterations in the metabolism of complex lipids.


2011 ◽  
Vol 22 (4) ◽  
pp. 366-371 ◽  
Author(s):  
Johan De Vogel-van den Bosch ◽  
Sjoerd A.A. van den Berg ◽  
Silvia Bijland ◽  
Peter J. Voshol ◽  
Louis M. Havekes ◽  
...  

2020 ◽  
Author(s):  
Kotaro Hama ◽  
Yuko Fujiwara ◽  
Tamuro Hayama ◽  
Tsuyoshi Ozawa ◽  
Keijiro Nozawa ◽  
...  

Abstract Colorectal cancer (CRC) is a major cancer, and its precise diagnosis is especially important for the development of effective therapeutics. In a series of metabolome analyses, the levels of very long chain fatty acids (VLCFA) was shown to be elevated in CRC tissues, although the endogenous form of VLCFA has not been fully elucidated. In this study we analyzed the amount of non-esterified fatty acids, phospholipids and acyl-CoA species by liquid-chromatography–mass spectrometry and showed that VLCFA is accumulated as the non-esterified form in CRC tissues. We also showed that the expression level of elongation of very long-chain fatty acids 1 (ELOVL1) is increased, whereas fatty acid transport protein 4 (FATP4) is decreased in CRC tissues. Finally, we showed that the amount of non-esterified VLCFA species was significantly up-regulated in cultured cells overexpressing ELOVL1. Our results suggest that the upregulation of ELOVL1 and the down-regulation of FATP4 cooperatively lead to the accumulation of non-esterified VLCFA in CRC tissues.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 682-682 ◽  
Author(s):  
Kayla Dillard ◽  
Morgan Coffin ◽  
Gabriella Hernandez ◽  
Victoria Smith ◽  
Catherine Johnson ◽  
...  

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) represents the major cause of pediatric chronic liver pathology in the United States. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of saturated medium-chain fatty acids (hydrogenated coconut oil), saturated long-chain fatty acids (lard) and unsaturated long-chain fatty acids (olive oil) on endpoints of NAFLD and insulin resistance. Methods Thirty-eight 15-d-old Iberian pigs were fed 1 of 4 diets containing (g/kg body weight × d) 1) control (CON; n = 8): 0 g fructose, 10.5 g fat, and 187 kcal metabolizable energy (ME), 2) lard (LAR; n = 10): 21.6 g fructose, 17.1 g fat (100% lard) and 299 kcal ME, 3) hydrogenated coconut oil (COCO; n = 10): 21.6 g fructose, 16.9 g fat (42.5% lard and 57.5% coconut oil) and 299 kcal ME, and 4) olive oil (OLV, n = 10): 21.6 g fructose, 17.1 g fat (43.5% lard and 56.5% olive oil) and 299 kcal ME, for 9 consecutive weeks. Body weight was recorded every 3 d. Serum markers of liver injury and dyslipidemia were measured on d 60 at 2 h post feeding, with all other serum measures assessed on d 70. Liver tissue was collected on d 70 for histology, triacylglyceride (TG) quantification, and metabolomics analysis. Results Tissue histology indicated the presence of steatosis in LAR, COCO and OLV compared with CON (P ≤ 0.001), with a further increase in in non-alcoholic steatohepatitis (NASH) in OLV and COCO compared with LAR (P ≤ 0.01). Alanine and aspartate aminotransferases were higher in COCO and OLV (P ≤ 0.01) than CON. All treatment groups had lower liver concentrations of methyl donor's choline and betaine versus CON, while bile acids were differentially changed (P ≤ 0.05). COCO had higher levels of TGs with less carbons (Total carbons < 52) than all other groups (P ≤ 0.05). Several long-chain acylcarnitines involved in fat oxidation were higher in OLV versus all other groups (P ≤ 0.05). Conclusions Inclusion of fats enriched in medium-chain saturated and long-chain unsaturated fatty acids in a high-fructose high-fat diet increased liver injury, compared with fats with a long-chain saturated fatty acid profile. Further research is required to investigate the mechanisms causing this difference in physiological response to these dietary fat sources. Funding Sources ARI, AcornSeekers.


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