Microglial P2Y12 deficiency/inhibition protects against brain ischemia

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Microglia are key immune responders to ischemic brain injury.
• The purinergic G protein-coupled receptor P2Y12 on microglia is activated by extracellular nucleotides released from injured cells.
• P2Y12 is also the target of the antiplatelet drug clopidogrel.

Purpose of the Study:

• To investigate the role of microglial P2Y12 in neurotoxicity and inflammation after ischemic injury.
• To determine if inhibiting P2Y12 can mitigate microglial-mediated neurotoxicity and offer neuroprotection.

Main Methods:

• Cerebral ischemia was induced using oxygen-glucose deprivation (OGD) in vitro and bilateral common carotid artery occlusion (BCCAO) in vivo.
• P2Y12 function was manipulated using genetic knockdown (siRNA), P2Y12 knockout mice, or clopidogrel treatment.
• Assessed outcomes included neuron death, microglial activation, and microglial migration.

Main Results:

• Microglial P2Y12 deficiency significantly reduced OGD-induced neurotoxicity and microglial clustering around neurons.
• P2Y12 knockout microglia exhibited reduced migration towards OGD-conditioned neuronal supernatant.
• Mice lacking P2Y12 or treated with clopidogrel showed reduced neuronal injury, decreased microglial activation, and lower NFkB levels after ischemia.

Conclusions:

• P2Y12 plays a critical role in ischemia-induced inflammation by driving microglial migration and enhancing neurotoxicity.
• These findings highlight a potential anti-inflammatory and neuroprotective effect of clopidogrel beyond its antiplatelet action.