Syndrome métabolique et diabète chez l'Homme. Composition lipidique et oxydation des lipoprotéines de basse densité (LDL) plasmatiques en relation avec l'activation des plaquettes sanguines.

Abstract : Type-2 diabetes and metabolic syndrome are associated with increased oxidative stress and cardiovascular risk. Platelet hyperactivation and dyslipoproteinemia are two major factors favoring atherothrombosis. We have shown that low-density lipoproteins (LDL) from type-2 diabetic patients activate platelets from healthy volunteers. The primary objective of our study was to establish the lipid and lipid peroxide profile of LDL isolated from plasma of volunteers with a metabolic syndrome (SM), of type-1 (DT-1) or type-2 (DT-2) diabetic patients compared to LDL from healthy volunteers (V). The second objective was to explore their role in platelet activation. Only LDL from MS and DT-2 groups have lipid abnormalities (increased triacylglycerols and decreased cholesteryl esters, decreased linoleic acid). LDL from SM, DT-1 and DT-2 groups show oxidative stress as assessed by increased lipid peroxide derivatives (hydroxylated fatty acids, malondialdehyde) and decreased plasmalogens. Compared to platelets incubated with LDL from the V group, platelets incubated with LDL from other groups are activated as shown by the enhancement of the arachidonic acid signalling cascade (p38 MAPK, cytosolic phospholipase A2, thromboxane B2). Thus, in a pre-diabetic state and in type-2 diabetes, LDL undergo lipid and oxidative modifications and activate platelets. Our results show that lipid peroxides in LDL could be the common denominator underlying platelet hyperactivation.
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Biochimie [q-bio.BM]. INSA de Lyon, 2010. Français


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Romain Colas. Syndrome métabolique et diabète chez l'Homme. Composition lipidique et oxydation des lipoprotéines de basse densité (LDL) plasmatiques en relation avec l'activation des plaquettes sanguines.. Biochimie [q-bio.BM]. INSA de Lyon, 2010. Français. <tel-00587355>

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