CaMKIIα overactivity and epileptogenesis in temporal lobe epilepsy : proposing novel inhibitors

Abstract

Ca²⁺/Calmodulin Dependent Kinase II (CaMKIIα), a serine/threonine kinase abundantly expressed in neurons throughout the brain, plays a crucial role in regulating synaptic plasticity. This dodecameric complex presents a regulatory domain (T-site residues 274–314) and a Ca²⁺/calmodulin-binding site (S-site residues 301–314) in each subunit which together form a contiguous groove mediating the enzyme’s synergistic activation. CaMKIIα is critical for long-term potentiation (LTP) and long-term depression (LTD). The balance between these opposite forms of plasticity and the degree of enzymatic activity depends on the frequency of excitatory synapse activation and the specific site of CaMKIIα autophosphorylation. Temporal Lobe Epilepsy (TLE), the most common yet typically treatment-resistant focal epilepsy, is characterised by recurrent unprovoked seizures and dyscognitive symptoms greatly affecting patients’ quality of life. Synaptic plasticity is central to its pathogenesis, with key players being CaMKII isoforms and glial fibrillary acidic protein, as evidenced by their increased expression in affected tissue. Evidence proposes increased CaMKII signalling as a contributor to maladaptive synaptic remodelling and epileptogenesis, although the causal relationship between this overactivity and TLE remains unclear. Consequently, this data highlights CaMKIIα inhibitors (e.g., AIP, Evans Blue) as promising novel focus for antiepileptic therapy studies.