Experimental Approach
Human neurons were differentiated from two induced pluripotent stem cell
(hiPSC) lines. P2X7R function on neurons was assessed via P2X7R agonist
BzATP-evoked calcium transients. Acute or chronic in vitro models
of epileptiform-like events were generated by exposure of hiPSC cultures
to the GABAA receptor antagonist picrotoxin or a
cocktail of picrotoxin and neuroinflammatory agents with or without the
presence of P2X7R antagonists. Epileptiform-like activity was measured
via single cell patch-clamp recordings.
Key Results
BzATP application (300 µM) resulted in increased calcium influx in
hiPSC-derived neurons which was blocked by the P2X7R antagonists
JNJ-47965567 (100 nM) and AFC-5128 (30 nM). Single-cell patch-clamp
recordings showed that, while treatment with AFC -5128 did not
reduce epileptiform-like activity triggered by picrotoxin alone,AFC -5128 reduced the severity of epileptiform-like activity
under inflammatory conditions. Notably, epileptiform-like events in the
inflammation-primed picrotoxin model were refractory to the anti-seizure
medication carbamazepine alone but were reduced by the co-application of
carbamazepine with AFC -5128.