P2Y12 receptor blockers are anti-inflammatory drugs inhibiting both circulating monocytes and macrophages including THP-1 cells

Abstract

P2Y12 blockade improves patient outcomes after myocardial infarction. As well as antithrombotic effects, anti-inflammatory effects may contribute to this beneficial clinical outcome. Here we aimed to identify potential anti-inflammatory effects of P2Y12 receptor blockers on monocytes and macrophages. Using flow cytometry, migration assays, flow chambers and RNA microarrays, we investigated the effects of adenosine diphosphate (ADP) and P2Y12 receptor blockers on blood monocytes, THP-1 monocytes and THP-1 monocytes after differentiation to macrophages. P2Y12 -expressing platelets can form aggregates with monocytes in circulating blood. Mediated by platelets, ADP results in activation of the integrin receptor Mac-1 on blood monocytes, as detected by the conformation-specific single-chain antibody MAN-1. Via the same association with platelets, THP-1 monocyte adhesion to the endothelial intercellular adhesion molecule 1 (ICAM-1) is induced by ADP. P2Y12 receptor blockers prevent these ADP effects on monocytes. Interestingly, in contrast to THP-1 monocytes, THP-1 monocytes, after differentiation to macrophages, directly expressed the P2Y12 receptor and consequently ADP was found to be a potent chemoattractant. Again, P2Y12 receptor blockers antagonised this effect. Accordingly, stimulation of THP-1 macrophages with ADP caused a substantial change in gene expression pattern and upregulation of several genes associated with inflammation and atherogenesis. These data establish novel anti-inflammatory effects of P2Y12 receptor blockers on monocytes and macrophages, which are expected to contribute to cardiovascular risk reduction.

Combined Antiplatelet Therapy Reduces the Proinflammatory Properties of Activated Platelets

“…One possible chemoattractant is adenosine diphosphate (ADP), released from dense granules by activated platelets, and was shown to attract monocytes and macrophages through the action of the P2Y 12 receptor in recent studies. [50][51][52] Although our results indicated that CCL5 was mainly responsible for the chemotactic effect of platelet supernatants, an involvement of ADP appears feasible since remnant levels of cangrelor in the platelet supernatants might be sufficient to reduce chemotaxis. In addition, cangrelor inhibited the release of serotonin, which is likewise stored in dense granules, and this could explain why a strong inhibition of monocyte chemotaxis toward supernatants of cangrelor þ ASA-treated platelets was observed, while CCL5 secretion was poorly affected by this combined treatment.…”

“…A possible explanation for this observation might be that the combination of ASA and cangrelor can inhibit the release of several chemoattractants from platelets, other than CCL5. One possible chemoattractant is ADP, released from dense granules by activated platelets, and was shown to attract monocytes and macrophages through the action of the P2Y 12 receptor in recent studies [50][51][52]. Although our results indicated that CCL5 was mainly responsible for the chemotactic effect of platelet supernatants, an involvement of ADP appears feasible since remnant levels of cangrelor in the platelet supernatants might be sufficient to reduce chemotaxis.…”

“…[43][44][45][46] Furthermore, clopidogrel reduced CCL5 plasma levels both in animals and in patients. [47][48][49] All P2Y 12 antagonists appear to interfere with the interaction of platelets with monocytes and with neutrophils, 43,45,50 although all may have plateletindependent effects, as stated above. We have observed that treatment of platelets with cangrelor showed a similar effect as with ASA.…”

P2Y12 Inhibition in Murine Myocarditis Results in Reduced Platelet Infiltration and Preserved Ejection Fraction

“…The P2Y 12 receptor is mainly expressed on platelets, but also on vascular smooth muscle cells and immune cells including mast cells, monocytes, macrophages, and lymphocytes [ 31 ]. Inhibiting these immune cells via P2Y 12 inhibitors may exert anti-inflammatory effects beyond the well-known anti-platelet effects of these inhibitors [ 32 ]. Myocardial necrosis was reduced and ejection fraction was preserved in ischemia reperfusion injury in P2Y 12 knockout mice in a previous study by our group [ 23 ].…”

P2Y12 Antagonists in Cardiovascular Disease—Finding the Best Balance Between Preventing Ischemic Events and Causing Bleeding

“…It may also relate to ticagrelor’s preferential effects in increasing extracellular adenosine concentrations. These have been recognized as potential benefits of P2Y 12 receptor antagonists ( 10 ).…”