Following the historical dietary recommendations, the substitution of polyunsaturated fatty acids (PUFAs) for saturated fatty acids (SFAs) resulted in a dramatic increase of linoleic acid (LA) in the Western diet. While proatherogenic properties of SFAs have been described, the involvement of LA on the inflammatory process remains controversial. Herein, we evaluated the effects of an excessive LA intake on the cytokine-induced expression of endothelial adhesion molecules vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1), through the nuclear factor (NF)-κB pathway, in comparison with a control diet and regarding a "positive" SFA diet.
View Article and Find Full Text PDFPrevious studies on rats and human subjects have established that the linoleic acid (LA) requirement is 2 % of the total energy intake (en%), but is obtained in the absence of α-linolenic acid (ALA) and consequently appear to be overestimated. This raises questions since a recent study including ALA has suggested to divide the historical value by four. However, this recent study has remained inconclusive because the animals used were not totally LA-deficient animals.
View Article and Find Full Text PDFOleic (cis9-18:1), linoleic (cis9,cis12-18:2) and α-linolenic (cis9,cis12,cis15-18:3) acids are well described substrates of the Δ6-desaturase encoded by the mammalian fatty acid desaturase 2 (FADS2) gene. In addition, at least 9 other very structurally different fatty acids have been shown to be Δ6- or even Δ8-desaturated by the FADS2 protein. A better characterization of the substrate specificity of this enzyme is therefore needed.
View Article and Find Full Text PDFObjectives: Do elevated proprotein convertase subtilisin/kexin type 9 (PCSK9) levels constitute an even greater risk for patients who already have reduced low-density lipoprotein receptor (LDLR) levels, such as those with heterozygous familial hypercholesterolemia (HeFH)?
Background: As a circulating inhibitor of LDLR, PCSK9 is an attractive target for lowering LDL-cholesterol (LDL-C) levels.
Methods: Circulating PCSK9 levels were measured by enzyme-linked immunosorbent assay in nontreated patients with HeFH carrying a D206E (n = 237), V408M (n = 117), or D154N (n = 38) LDLR missense mutation and in normolipidemic controls (n = 152). Skin fibroblasts and lymphocytes were isolated from a subset of patients and grown in 0.
Linoleic acid is the most abundant polyunsaturated fatty acid in human nutrition and represents about 14 g per day in the US diet. Following the discovery of its essential functions in animals and humans in the early 1920's, studies are currently questioning the real requirement of linoleic acid. It seems now overestimated and creates controversy: how much linoleic acid should be consumed in a healthy diet? Beyond the necessity to redefine the dietary requirement of linoleic acid, many questions concerning the consequences of its excessive consumption on human health arise.
View Article and Find Full Text PDFPCSK9 proprotein convertase subtilisin/kexin type (PCSK9) is a crucial protein in LDL cholesterol (LDL-C) metabolism by virtue of its pivotal role in the degradation of the LDL receptor. In recent years, both in vitro and in vivo studies have greatly supplemented our understanding of the (patho)physiological role of PCSK9 in human biology. In the current review, we summarize studies published or in print before May 2012 concerning the physiological role of PCSK9 in cholesterol metabolism.
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