Comparisons of detergents for purification of platelet membrane lipid rafts: a lipidomics and proteomics analysis focusing on P2XR localization

Introduction: Platelet membrane contains cholesterol and sphingomyelin-rich microdomains also known as lipid rafts (LR). LRs have been considered as pharmacological target of anti-aggregation drugs as they suggested providing a platform for physiological activity of target proteins such as purinergic receptors (P2XR, P2YR) activated by nucleotides (ATP and ADP respectively). Localization of P2XR in these microdomains remains mostly unknown. The aim of this study was to compare the effectivity of different conventional detergents for lipid rafts isolation and investigation on the lipidomics and proteomics features of these microdomains focusing their potentiality of containing P2XR. Obviousl…

Modification of the rat aortic wall during ageing; possible relation with decrease of peptidergic innervation.

Structural changes of the male rat aorta were followed from birth to old age in male and female rats. In males, the vessel media width and area progressively increase concomitantly with a decrease of nuclei density during ageing, suggesting an hypertrophy of the smooth muscle cells. These correlations were however not evidenced in females. TUNEL-positive cells were found in media of 4 and 6 months in both sexes, mainly on the luminal side and in the adventitia. When biochemical markers were investigated with immunohistochemistry, media was uniformly stained by the anti-vimentin and anti-alpha-smooth actin at all stages investigated. On the contrary, the surface of media stained with anti-de…

Impact of high-fat diet on antioxidant status, vascular wall thickening and cardiac function in adult female LDLR<sup>–/–</sup> mice

International audience; Background: Western diet, rich in saturated fatty acids and cholesterol, is associated with increased cardiovascular risk. We thus investigated in female mice the influence of this diet on plasma antioxidant status, vascular wall thickening and cardiac function. Methods and Results: Adult female C57BL/6J wild type (WT) and LDLR–/– mice were fed a normal diet (ND) or a high-fat diet (HFD) for 17 weeks. HFD induced an increase in plasma lipids and vitamin C (Vit C) levels in both groups but at a much higher level in LDLR–/– and a decrease in plasma ascorbyl free radical levels to Vit C ratio (an endogenous oxidative stress index) in LDLR–/–. We only found a slight decr…

24-(S)-hydroxycholesterol is a potent modulator of cholesterol metabolism in rat retinal Müller glia

International audience

General oxidative stress during doxorubicin-induced cardiotoxicity in rats: Absence of cardioprotection and low antioxidant efficiency of alpha-lipoic acid

International audience; To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O₂*⁻ (dihydroethidium fluorescence) content in tissue. After two months, body weight was higher in the DOX-AL group than in DOX (+16%), but this was due to ascites. Histologic…

O32 Le syndrome métabolique induit par un régime enrichi en fructose est promoteur d’un développement néovasculaire et d’altérations fonctionnelles dans la rétine

Role of 24-S-hydroxycholesterol in membrane dynamics during retinal gliosis in glaucoma

International audience; Purpose : Glaucoma is a severe and irreversible ocular disease characterized by progressive optic neuropathy with the loss of retinal ganglion cells (RGC). One of the established causes of RGC apoptosis is Müller Glial Cell (MGC) activation, called “retinal gliosis”. MGC are the most numerous glial cells in the retina and one of their roles is to maintain cholesterol homeostasis. A lack or an excess of cholesterol in neurons can cause neuro-degeneration. Cholesterol 24S-hydroxylase (CYP46A1) is present in RGC where it catalyses the formation of 24S-hydroxycholesterol (24S-OHC), and thereby participates to cholesterol elimination. CYP46A1 is overexpressed during glauc…

Modulation of lipid membrane organization of Müller Glial Cells (MGC) by 24-(S)-hydroxycholesterol (24-S-OHC) in glaucoma

Modulation of lipid membrane organization of Müller Glial Cells (MGC) by 24-(S)-hydroxycholesterol (24-S-OHC) in glaucoma. Session 3: Nutrition and oxysterols biological activities. ENOR Symposium

Identification of functional proteins related to Factor XIII in platelet lipid rafts