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…

Comparative lipidomics and proteomics analysis of platelet lipid rafts using different detergents

Lipid rafts play a pivotal role in physiological functions of platelets. Their isolation using nonionic mild detergents is considered as the gold standard method, but there is no consensual detergent for lipid raft studies. We aimed to investigate which detergent is the most suitable for lipid raft isolation from platelet membrane, based on lipidomics and proteomics analysis. Platelets were obtained from healthy donors. Twelve sucrose fractions were extracted by three different detergents, namely Brij 35, Lubrol WX, and Triton X100, at 0.05% and 1%. After lipidomics analysis and determination of fractions enriched in cholesterol (Ch) and sphingomyelin (SM), proteomics analysis was performed…

Impact of ticagrelor on P2Y1 and P2Y12 localization and on cholesterol levels in platelet plasma membrane

Ticagrelor is an antiplatelet agent that inhibits platelet activation via P2Y12 antagonism. There are several studies showing that P2Y12 needs lipid rafts to be activated, but there are few data about how ticagrelor impacts lipid raft organization. Therefore, we aimed to investigate how ticagrelor could impact the distribution of cholesterol and consequently alter the organization of lipid rafts on platelet plasma membranes. We identified cholesterol-enriched raft fractions in platelet membranes by quantification of their cholesterol levels. Modifications in cholesterol and protein profiles (Flotillin 1, Flotillin 2, CD36, P2Y1, and P2Y12) were studied in platelets stimulated by ADP, treate…

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