title: Microglia is a key player in the reduction of stroke damage promoted by the new antithrombotic agent ticagrelor.
abstract: The ADP-responsive P2Y12 receptor is expressed on both platelets and microglia. Clinical data show that ticagrelor, a direct-acting, reversibly binding P2Y12-receptor antagonist, reduces total cardiovascular events, including stroke. In our present study, we investigated the expression of P2Y12 receptors and the effects of ticagrelor on brain injury in Sprague-Dawley rats subjected to a permanent middle cerebral artery occlusion (MCAo). Rats were treated per os with ticagrelor 3 mg/kg or vehicle at 10 minutes, 22, and 36 hours after MCAo and killed after 48 hours. Immunofluorescence analysis showed an ischemia-related modulation of the P2Y12 receptor, which is constitutively expressed in Iba1(+) resting microglia. After MCAo, activated microglia was mainly concentrated around the lesion, with fewer cells present inside the ischemic core. Ticagrelor significantly attenuated the evolution of ischemic damage-evaluated by magnetic resonance imaging (MRI) at 2, 24, and 48 hours after MCAo-, the number of infiltrating cells expressing the microglia/monocyte marker ED-1, the cerebral expression of proinflammatory mediators (interleukin 1 (IL-1), monocyte chemoattractant protein 1 (MCP-1), nitric oxide synthase (iNOS)) and the associated neurologic impairment. In transgenic fluorescent reporter CX3CR1-green fluorescent protein (GFP) mice, 72 hours after MCAo, ticagrelor markedly reduced GFP(+) microglia and both early and late infiltrating blood-borne cells. Finally, in primary cultured microglia, ticagrelor fully inhibited ADP-induced chemotaxis (P<0.01). Our results show that ticagrelor is protective against ischemia-induced cerebral injury and this effect is mediated, at least partly, by inhibition of P2Y12-mediated microglia activation and chemotaxis.
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gelosa
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lecca
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Fumagalli
authors.affiliation: 1] Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy [2] Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Wypych
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Pignieri
authors.affiliation: Department of Biomolecular Sciences, University of Urbino, Urbino, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Cimino
authors.affiliation: Institute of Neuroscience, CNR, Milan and IRCCS Humanitas, Rozzano, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Verderio
authors.affiliation: AstraZeneca R&D Mölndal, Mölndal, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Enerbäck
authors.affiliation: AstraZeneca R&D Mölndal, Mölndal, Sweden.
authors.forename: Elham
authors.initials: E
authors.lastname: Nikookhesal
authors.affiliation: 1] Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy [2] Centro Cardiologico Monzino IRCCS, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Tremoli
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Abbracchio
authors.affiliation: 1] Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy [2] Centro Cardiologico Monzino IRCCS, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Sironi
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D018932:Chemokine CCL2 / Q000096:biosynthesis; D053331:Ectodysplasins / Q000096:biosynthesis; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D007375:Interleukin-1 / Q000096:biosynthesis; D051379:Mice; D008822:Mice, Transgenic; D017628:Microglia / Q000378:metabolism* / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000235:genetics; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D000077486:Ticagrelor; D013997:Time Factors
chemical_list: C491768:Ccl2 protein, mouse; C491766:Ccl2 protein, rat; D018932:Chemokine CCL2; D053331:Ectodysplasins; C506019:Eda protein, mouse; D005343:Fibrinolytic Agents; D007375:Interleukin-1; D009419:Nerve Tissue Proteins; D058921:Purinergic P2Y Receptor Antagonists; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D000077486:Ticagrelor; D000241:Adenosine