Differential effects of single fatty acids and fatty acid mixtures on the phosphoinositide 3-kinase/Akt/eNOS pathway in endothelial cells

Jackson, K. G. ORCID: https://orcid.org/0000-0002-0070-3203, Newens, K. J., Fry, M. J., Thompson, A. K. and Williams, C. M. (2022) Differential effects of single fatty acids and fatty acid mixtures on the phosphoinositide 3-kinase/Akt/eNOS pathway in endothelial cells. European Journal of Nutrition, 61. pp. 2463-2473. ISSN 1436-6215 doi: 10.1007/s00394-022-02821-2

Abstract/Summary

Scope: Dietary fat composition is an important modulator of vascular function. Non-esterified fatty acids (NEFA) enriched in saturated fatty acids (SFA) are thought to reduce vascular reactivity by attenuating insulin signalling via vasodilator pathways (phosphoinositide 3-kinase (PI3K)/Akt/endothelial nitric oxide synthase (eNOS)) and enhancing signalling via pro-inflammatory pathways. Methods: To examine the effects of fatty acids on these pathways, human aortic endothelial cells were incubated with single fatty acids, and mixtures of these fatty acids to mimic typical NEFA composition and concentrations achieved in our previous human study. RNA was extracted to determine gene expression using real-time RT-PCR and cell lysates prepared to assess protein phosphorylation by Western blotting. Results: Oleic acid (OA, 100 µM) was shown to down-regulate expression of the insulin receptor, PTEN and a PI3K catalytic (p110β) and regulatory (p85α) subunit compared with palmitic, linoleic and stearic acids (P<0.04), and promote greater eNOS phosphorylation at Ser1177. Both concentration and composition of the SFA and SFA plus n-3 polyunsaturated fatty acids (PUFA) mixtures had significant effects on genes involved in the PI3K/Akt pathway. Greater up-regulation was found with 800 than 400 µM concentration (respective of concentrations in insulin resistant and normal individuals), whereas greater down-regulation was evident with SFA plus n-3 PUFA than SFA mixture alone. Conclusion: Our findings provide novel insights into the modulation of the PI3K/Akt/eNOS pathway by single fatty acids and fatty acid mixtures. In particular, OA appears to promote signalling via this pathway, with further work required to determine the primary molecular site(s) of action.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/102922
Item Type	Article
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Institute for Cardiovascular and Metabolic Research (ICMR) Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Human Nutrition Research Group
Publisher	Springer
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