[Ibudilast prevents oxygen-glucose deprivation-induced oligodendroglial injury]

Abstract

Previously we have demonstrated that ibudilast, which is used clinically for treating patients with asthma and cerebrovascular diseases, prevents excitotoxicity of oligodendroglial lineage mediated by Ca2+ influx via non-N-methyl-D-aspartate (NMDA) glutamate receptor (GluR) channels. We here present a finding that ibudilast prevents oxygen-glucose deprivation (OGD)-induced oligodendroglial injury. The oligodendrocyte-like cells (OLC), differentiated from the CG-4 cell line established from rat oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells, were exposed to hypoxia in the absence of glucose for 12 h and subsequent reoxygenation for 2 h. Cell damage was evaluated by measuring activity of lactate dehydrogenase (LDH) released into the culture medium. OGD for 12 h induced 30 to 50% LDH release into the medium. OLC damage induced by deprivation of oxygen and glucose was prevented by ibudilast at concentrations of > or = 50 microM. The protection given by ibudilast against OGD-induced injury was enhanced by prostacyclin (PGI2). OGD-induced OLC injury was prevented by 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX), an inhibitor of non-NMDA GluR or deprivation of Ca2+ from culture medium. While ibudilast increased intracellular cAMP at concentrations of > or = 10 microM, at least 100 microM concentrations were needed to increase intracellular cGMP. Therefore, we concluded that ibudilast prevented OGD-induced oligodendroglial injury possibly by increasing intracellular cAMP which modulates Ca2+ influx via non-NMDA GluR channels.