PE-22-28 functions as a potent and selective antagonist of TREK-1 (KCNK2) two-pore domain potassium channels[2]. By blocking TREK-1, it depolarizes neurons and enhances excitability, leading to increased firing of serotonergic neurons and elevated monoamine neurotransmission[2]. This mechanism produces rapid antidepressant-like effects in preclinical models—within 4 days, PE-22-28 significantly increases hippocampal neurogenesis and synaptogenesis markers, changes typically requiring weeks with conventional antidepressants[4]. The peptide also activates CaMKII/CREB pathways that promote neuronal survival and plasticity[6]. PE-22-28 represents a shortened, optimized analog of spadin with superior potency (IC50 ~0.12 nM versus 40–60 nM for spadin) and longer duration of action (~23 hours versus ~7 hours)[4]. Notably, research also demonstrates neuroprotective effects in stroke models through biphasic dosing that leverages both TREK-1 activation at ultra-low doses and inhibition at standard doses[5].
