Platelet ACKR3/CXCR7 Favors Anti-Platelet Lipids over an Atherothrombotic Lipidome and Regulates Thrombo-inflammation

Abstract

Platelet ACKR3/CXCR7 surface expression is enhanced and influences prognosis in coronary artery disease-(CAD) patients, who exhibit a distinct atherothrombotic platelet lipidome. Current investigation validates the potential of ACKR3/CXCR7 in regulating thrombo-inflammatory response, through its impact on the platelet lipidome. CAD patients-(n=230) with enhanced platelet-ACKR3/CXCR7 expression exhibited reduced aggregation. Pharmacological CXCR7-agonist-(VUF11207) significantly reduced pro-thrombotic platelet response in blood from ACS patients-(n=11) ex vivo. CXCR7-agonist administration reduced thrombotic functions and thrombo-inflammatory platelet-leukocyte interactions post myocardial infarction-(MI) and arterial injury in vivo. ACKR3/CXCR7-ligation did not affect surface availability of GPIbα, GPV, GPVI, GPIX, αv-integrin, β3-integrin, coagulation profile-(APTT, PT), bleeding time, plasma-dependent thrombin generation-(thrombinoscopy) or clot formation-(thromboelastography), but counteracted activation-induced phosphatidylserine exposure and procoagulant platelet-assisted thrombin generation. Targeted-(micro-UHPLC-ESI-QTrap-MS/MS) and untargeted-(UHPLC-ESI-QTOF-MS/MS) lipidomics analysis revealed that ACKR3/CXCR7-ligation favored generation of anti-thrombotic lipids-(dihomo-γ-linolenic acid-DGLA, 12-hydroxyeicosatrienoic acid-12-HETrE) over cyclooxygenase-COX-1-(thromboxane-TxA2), or 12-lipoxygenase-LOX-(12-HETE) metabolized pro-thrombotic, and phospholipase derived atherogenic-(lysophosphatidylcholine-LPC) lipids, in healthy subjects and CAD patients, contrary to anti-platelet therapy. Through 12-HETrE, ACKR3/CXCR7-ligation coordinated with Gαs-coupled prostacyclin receptor-(IP) to trigger cAMP-PKA mediated platelet inhibition. ACKR3/CXCR7-ligation reduced generation of lipid agonists-(arachidonic acid-AA,TxA2), lipid signaling intermediates-(lyophosphatidylinositol-LPI, diacylglycerol-DG), which affected calcium mobilization, intracellular signaling, consequently platelet interaction with physiological matrices and thrombo-inflammatory secretion-(IL1β,IFN-γ,TGF-β,IL-8), emphasizing its functional dichotomy from pro-thrombotic CXCR4. Moreover, CXCR7-agonist regulated heparin-induced thrombocytopenia-(HIT)-sera/IgG-induced platelet and neutrophil activation, heparin induced platelet aggregation-(HIPA), generation of COX-1-(TxA2), 12-LOX-(12-HETE) derived thrombo-inflammatory lipids, platelet-neutrophil aggregate formation, and thrombo-inflammatory secretion (sCD40L, IL-1β, IFN-γ, TNF-α, sP-selectin, IL-8, tissue factor-TF) ex vivo. Therefore, ACKR3/CXCR7 may offer a novel therapeutic strategy in acute/chronic thrombo-inflammation exaggerated cardiovascular pathologies, and CAD.