Selective adenosine A2A receptor inhibitor SCH58261 reduces oligodendrocyte loss upon brain injury in young rats

Abstract

Cellular elements of maturing brain are vulnerable to insults, which lead to neurodevelopmental defects. There are no established treatments at present. Here we examined the efficacy of selective adenosine A2A receptor inhibitor SCH58261 to combat brain injury, particularly oligodendrocyte (OL) lineage cells, in young rats. Wistar rats (n = 24, 6.5 days old) were randomly divided into equal groups of four. The sham (SHAM) group received no treatment, the vehicle (VEHICLE) group received 0.1% dimethylsufoxide, the injury (INJ) group was exposed to oxygen-glucose deprivation insult, and the injury+SCH58261 (INJ+SCH58261) group was exposed to the insult and received 1 μM SCH58261. Immunocytochemical experiments revealed that there was a significant reduction in the populations of mature OL (MBP+ OLs) and immature OL precursors (NG2+ OPCs) in the INJ group compared to SHAM group. Furthermore, there was also a significant increase in the percent of apoptotic MBP+ OL and NG2+ OPC populations as evidenced by TUNEL assay. In addition, there was a significant reduction in the proliferation rate among NG2+ OPCs, which was confirmed by BrdU immunostaining. On the other hand, treatment with SCH58261 significantly enhanced survival, evidenced by the reduction in apoptotic indices for both cell types, and it is preserved the NG2+ OPC proliferation. Activation of adenosine A2A receptors may contribute to OL lineage cell loss in association with decreased mitotic behavior of OPCs in neonatal brains upon injury. Future investigations assessing ability of SCH58261 to regenerate myelin will provide insights into its wider clinical relevance.