P2X7R/NLRP3 signaling pathway-mediated pyroptosis and neuroinflammation contributed to cognitive impairment in a mouse model of migraine.

Migraine is the second most common form of headache disorder and the second leading cause of disability worldwide. Cognitive symptoms ranked second resulting in migraine-related disability, after pain. P2X7 receptor (P2X7R) was recently shown to be involved in hyperalgesia in migraine. However, the role of P2X7R in migraine-related cognitive impairment is still ill-defined. The aim of this study was to explore the molecular mechanisms underlying migraine-related cognitive impairment and the role of P2X7R in it. Here we used a well-established mouse model of migraine that triggered migraine attacks by application of inflammatory soup (IS) to the dura. Our results showed that repeated dural IS stimulation triggered upregulation of P2X7R, activation of NLRP3 inflammasome, release of proinflammatory cytokines (IL-1β and IL-18) and activation of pyroptotic cell death pathway. Gliosis (microgliosis and astrogliosis), neuronal loss and cognitive impairment also occurred in the IS-induced migraine model. No significant apoptosis or whiter matter damage was observed following IS-induced migraine attacks. These pathological changes occurred mainly in the cerebral cortex and to a less extent in the hippocampus, all of which can be prevented by pretreatment with a specific P2X7R antagonist Brilliant Blue G (BBG). Moreover, BBG can alleviate cognitive impairment following dural IS stimulation. These results identified P2X7R as a key contributor to migraine-related cognitive impairment and may represent a potential therapeutic target for mitigating cognitive impairment in migraine.