Analytical Characterization of the Role of Phospholipids in Platelet Adhesion and Secretion

Abstract

The cellular phospholipid membrane plays an important role in cell function and cell–cell communication, but its biocomplexity and dynamic nature presents a challenge for examining cellular uptake of phospholipids and the resultant effects on cell function. Platelets, small anuclear circulating cell bodies that influence a wide variety of physiological functions through their dynamic secretory and adhesion behavior, present an ideal platform for exploring the effects of exogenous phospholipids on membrane phospholipid content and cell function. In this work, a broad range of platelet functions are quantitatively assessed by leveraging a variety of analytical chemistry techniques, including ultraperformance liquid chromatography–tandem electrospray ionization mass spectrometry (UPLC–MS/MS), vasculature-mimicking microfluidic analysis, and single cell carbon-fiber microelectrode amperometry (CFMA). The relative enrichments of phosphatidylserine (PS) and phosphatidylethanolamine (PE) were characterized with UPLC–MS/MS, and the effects of the enrichment of these two phospholipids on both platelet secretory behavior and adhesion were examined. Results show that, in fact, both PS and PE influence platelet adhesion and secretion. PS was enriched dramatically and decreased platelet adhesion as well as secretion from δ-, α-, and lysosomal granules. PE enrichment was moderate and increased secretion from platelet lysosomes. These insights illuminate the critical connection between membrane phospholipid character and platelet behavior, and both the methods and results presented herein are likely translatable to other mammalian cell systems.

Shock releases bile acidinducing platelet inhibition and fibrinolysis

“…The proposed mechanism was through membrane deformity. Phospholipid membrane on platelets has been implicated as critical for these cells to aggregate and degranulate [12]. However bile acids also activate a number of cellular calcium related channel receptors [5,13,14].…”

Shear-Mediated Platelet Activation is Accompanied by Unique Alterations of Platelet Lipid Profile

“…Following platelet activation, PS lipids-which are typically sequestered on the interior of the platelet-are externalized and support the binding and assembly of coagulation factors that promote thrombin generation [24,30,[53][54][55]. We previously established that PS externalization in platelets is a marker of shear activation [43].…”

“…In the resting state, platelet plasma membranes maintain bilayer asymmetry with sphingomyelin (SM) and phosphatidylcholine (PC) lipids on the exterior leaflet [22,23]. Upon activation, membrane lipid reorganization occurs, associated with morphological changes and loss of membrane asymmetry leading to externalization of procoagulant lipids, including phosphatidylserine (PS) [23,24]. The overall platelet lipidome is altered upon biochemical activation as lipids are metabolized for energy [25,26], converted to bioactive lipids like thromboxanes involved in coagulation [26,27], and released from internal granules [26][27][28].…”

Analysis of platelets in hypertensive and normotensive individuals using Raman and Fourier transform infrared‐attenuated total reflectance spectroscopies

“…It has been shown that platelet activation induced the cellular distribution of phosphatidylserine, generating a net negative charge that contributes structurally to membrane curvature and fluidity, whereas the electrostatic charge provides a docking site for different proteins . Additionally, phosphatidylserine and phosphatidylethanolamine (PE) are externalized in response to the increase in intracellular Ca + concentrations . The clear increase in the intensity of the band centered at 760 cm −1 could be associated with the N + (CH 3 ) 3 group of PE, and it is possibly related to an activated stage in the hypertensive platelet.…”