Acyl derivatives of coenzyme A inhibit platelet function via antagonism at P2Y₁and P2Y₁₂receptors: A new finding that may influence the design of anti-thrombotic agents

Abstract

We have performed a detailed investigation of the effects on platelet function of coenzyme A (CoA) and several acyl-CoAs. Platelet aggregation was measured by turbidimetry and by platelet counting; platelet shape change was measured using light scattering; P-selectin, Ca2+ mobilization and vasodilator-stimulated phosphoprotein (VASP) phosphorylation were measured by flow cytometry. The compounds investigated inhibited ADP-induced platelet aggregation; those with saturated acyl groups containing 16-18 carbons were most effective. The effects of palmitoyl-CoA (16:0) were studied in depth. It inhibited platelet shape change and Ca2+ mobilization brought about by ADP (but not other agonists) indicating antagonism at P2Y(1) receptors, and also inhibited ADP-induced P-selectin expression. Effects of palmitoyl-CoA on the platelet aggregation and Ca2+ mobilization induced by several different agonists and agonist combinations were compared with those of MRS 2179 (a P2Y(1) antagonist) and AR-C69931 (a P2Y(12) antagonist), and were consistent with palmitoyl-CoA acting mainly at P2Y(1) but also with partial antagonism at P2Y(12) receptors. Antagonism at P2Y(12) receptors was confirmed in studies of VASP-phosphorylation. Palmitoyl-CoA did not act as an antagonist at P2X(1) receptors. The results are discussed in relation to the possibility that acyl-CoAs may contribute as endogenous modulators of platelet function and might serve as lead compounds for the design of novel antithrombotics.

Agonist and antagonist effects of diadenosine tetraphosphate, a platelet dense granule constituent, on platelet P2Y1, P2Y12 and P2X1 receptors

“…Taken together, these results indicate that Ap 4 A is an antagonist for both P2Y 1 and P2Y 12 receptors. Such dual specificity on platelet P2Y 1 and P2Y 12 receptors has been recently reported for other compounds[29,30]. …”

Calcium-Channel Blockers Reduce the Antiplatelet Effect of Clopidogrel

“…We performed the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and platelet aggregometry. The VASP assay is a fairly new platelet function assay (11)(12)(13). It is specific for clopidogrel and other P2Y12 antagonists in the absence of cilostazol (14,15), and it can be used to quantify platelet inhibition by clopidogrel (16).…”

Signalling functions of coenzyme A and its derivatives in mammalian cells

“…In contrast, a handful of papers have been published to date on extracellular signalling by CoA/acyl-CoA implicated mainly in the regulation of platelet aggregation and vasoconstriction [20][21][22][23].…”

“…Manolopoulos et al [23] hypothesized that CoA/acyl-CoAs may have an antagonistic role in regulating GPCR activation in the process of platelet activation. The authors performed a detailed investigation of the effects of CoA and several acyl-CoAs on platelet function by measuring platelet shape change using light scattering and Ca 2 + mobilization and VASP (vasodilator-stimulated phosphoprotein) phosphorylation by flow cytometry.…”