Adenosine A2A receptor blockade promotes oligodendrocyte differentiation and myelination: Highlighting the potency of an edaravone-conjugated A2A receptor antagonist

Many neurodegenerative diseases, including demyelinating pathologies, are characterized by complex pathological processes mediated by multiple damage mechanisms. While current drugs predominantly target oxidative stress pathways, understanding multi-target modulation could clarify mechanisms underlying demyelination. This study aimed to explore the pharmacological effects of different selective adenosine A_2A receptor antagonists, alone or conjugated with antioxidant edaravone, on oligodendrogliogenesis and myelination processes in purified rat cultured oligodendrocyte precursor cells (OPCs) or co-cultured with rat dorsal root ganglion neuron, respectively. We hypothesize that simultaneously targeting adenosine A_2A receptor signalling and oxidative stress pathways may enhance oligodendrocyte differentiation and promote myelination. To this purpose, we used patch-clamp recordings, antioxidant assay, quantitative real-time PCR and the OPC/dorsal root ganglion neuron co-culture. Selective A_2A receptor activation inhibited voltage-dependent K⁺ currents in cultured OPCs, an effect strictly correlated with their differentiation and prevented by the thiazolopyrimidine adenosine A_2A receptor antagonists. The block of these receptors promoted OPC differentiation, as determined by measuring total myelin basic protein (MBP) expression, and counteracted the increase in reactive oxygen species levels induced by oxidative stress in purified cultured OPCs. Among all compounds tested, only the edaravone hybrid derivative P686 enhanced myelination in OPC/dorsal root ganglion neuron co-cultures, quantified by the Mander's coefficient which reflects the overlap between MBP⁺-pixels and the neuronal marker βIII-tubulin⁺-pixels. These results provide mechanistic insight into how multitarget modulation of A_2A receptor signalling and oxidative stress regulates oligodendrocyte differentiation and myelination, highlighting avenues for future studies rather than therapeutic application in support demyelinating diseases.