Selenium Modulates 1-O-Alkyl-2-Acetyl-sn-Glycero-3-Phosphocholine (PAF) Biosynthesis in Bovine Aortic Endothelial Cells

Abstract

Selenium (Se) deficiency has been reported to increase platelet-activating factor (PAF) production in human endothelial cells; however, the mechanism is unclear. This study demonstrated that tumor necrosis factor-alpha (TNF-alpha) stimulated Se-deficient bovine aortic endothelial cells (BAEC) produced significantly more PAF than Se-supplemented cells. Moreover, the increase in the level of PAF was associated with enhanced activity of two anabolic enzymes in the remodeling pathway: phospholipase A2 and Lyso-PAF:acetyl-coenzyme A acetyltransferase (Lyso-PAF-AcT). In contrast, the activity of the PAF catabolic enzyme, PAF-acetylhydrolase, was not affected by Se status. Interestingly, prostacyclin, a potent vasodilator and inhibitor of platelet aggregation, inhibited the activity of Lyso-PAF-AcT and reduced the PAF production in TNF-alpha-stimulated BAEC. Therefore, we conclude that Se deficiency alters PAF production in TNF-alpha-stimulated BAEC by altering the activity of anabolic enzymes involved in the remodeling pathway partially through the inhibition of prostacyclin production.

Selenium-Dependent Regulation of Oxidative Stress and Immunity in Periparturient Dairy Cattle

“…Se nutritional status can directly influence vascular endothelial cell functions in several ways. Bovine mammary and aortic endothelial cells grown in Se-deficient culture media exhibited increased platelet activating factor (PAF) biosynthesis [63, 64], and increased PAF expression is associated with increased vascular disorders during oxidative stress [65]. Se status also can modify the biosynthesis of other vasoactive lipid mediators such as the eicosanoids.…”

Metabolic factors affecting the inflammatory response of periparturient dairy cows

“…These data suggest that 15LOX1 may facilitate the development of inflammation-based diseases, at least in part, by enhancing the pro-inflammatory phenotype of endothelial cells. Recent studies showed that 15-HPETE induces expression of ICAM-1, inhibits PGI 2 function, alters platelet activating factor production and induces apoptosis in bovine endothelial cells (Cao et al, 2001;Weaver et al, 2001;Sordillo et al, 2005Sordillo et al, , 2008Corl et al, 2008). Aitken et al (2009) also demonstrated for the first time that 15LOX1 gene expression increases markedly in mammary tissue during early lactation, but its impact on bovine health is unknown.…”

Proteomics of inflammatory and oxidative stress response in cows with subclinical and clinical mastitis

“…phagocytosis, bacterial killing and oxidative metabolism of neutrophils [24][25][26]. Additionally, antioxidants can decrease the synthesis of platelet activating factor (PAF) [27] which is an inflammatory mediator promoting chemotaxis of leukocytes, their adhesion to the endothelium and granule secretion, platelet activation, vascular permeability and oxygen radical production from leukocytes [28][29][30]. The limitation of PAF bioactivity and its catabolism is regulated by the platelet-activating factor acetylhydrolase (PAF-AH).…”