Effect of antiplatelet therapy in clinical practice and ex vivo CXCR7 agonist treatment on the platelet lipidome of CAD patients. Data are derived from untargeted lipidomics analysis of platelets. The asymmetric beanplot in (A) is derived from data on the basal platelet lipidome of CAD (n = 107, Table 3) patients. It represents the distribution of the concentration levels of individual lipid species within each of the lipid classes DG, LPC, and LPI among CAD patients treated with antiplatelet therapy (APT) (n = 46) and those without APT (n = 61). Smaller lines indicate concentration levels of individual lipid species within a group; the larger lines mark the average concentration of all detected lipid species within each class and group. (Bi-Diii) Lipidomics analysis of platelets from n = 15 CAD patients (Table 2) in their resting status and after thrombin (0.1 U/mL)-induced activation for 15 minutes at room temperature in presence/absence of ex vivo pretreatment with CXCR7 agonist (100 µg/mL) or vehicle control (1% DMSO) for 30 minutes at room temperature. Lipid concentrations were scaled for each donor by a z-score calculation. The 3D representation of a PLS-DA model in panel Bi shows clear clustering of platelet samples in accordance with their resting status, thrombin-induced activation, and thrombin plus CXCR7 agonist treatment conditions (six components with R²X(cum) = 0.566, R²Y(cum) = 0.971, and Q2(cum) = 0.780). The heat map in panel Bii is based on lipids with a variable importance in projection (VIP) score (which is a measure of a variable’s importance in the PLS-DA model) >1.5 in the PLS-DA model further illustrates alterations in the lipidome, especially in thrombin-activated platelets. (C) Asymmetric beanplots indicate changes in the platelet lipidome for the different lipid classes phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), LPC, lysophosphatidylethanolamine (LPE), LPI, DG, triacylglycerol (TG), ceramides (Cer), sphingomyelin (SM), and fatty acids (FA), either comparing (Ci) resting vs thrombin-activated platelets or (Cii) thrombin-activated vs thrombin plus CXCR7 agonist–treated platelets (small lines denote individual lipid species and larger markings denote average concentration per lipid class and group). (Di-Dii) Boxplots depict changing concentration levels of significantly altered lipids in thrombin vs thrombin plus CXCR7 agonist–treated platelets (nonparametric paired Wilcoxon signed rank test with FDR correction, significance level: q-value < 0.05), which belong to the DG and LPC lipid classes. (Diii) The boxplots of 4 LPI species (showing a trend of reduced generation in the presence of CXCR7 agonist as compared with thrombin alone, without reaching statistical significance). All lipid concentrations were determined by relative quantification using class-specific isotope labeled internal standard (ILIS) related to 100 µL lipid extract from 3 × 10⁸ platelets. DMSO, dimethyl sulfoxide; PLS-DA, partial least square-discriminant analysis.