CDP-choline prevents glutamate-mediated cell death in cerebellar granule neurons

Cytidine 5'-diphosphocholine (CDP-choline) has been shown to reduce neuronal degeneration induced in central nervous system (CNS) injury. However, the precise mechanism underlying the neuroprotective properties of this molecule is still unknown. Excitotoxicity causes cell death in CNS injury (trauma or ischemia) and has also been involved in neurodegenerative diseases. We have examined whether CDP-choline prevents glutamate-mediated cell death, determined by trypan blue exclusion and lactate dehydrogenase activity assays. Pretreatment of rat cerebellar granule cells (CGCs) with CDP-choline causes a dose- and time-dependent reduction of glutamate-induced excitotoxicity. Cell death is prevented >50% when 100 microM CDP-choline is added 6 d before the glutamate excitotoxic insult but less than 20% when added concomitantly with glutamate. Pretreatment of CGCs with CDP-choline reduces almost completely (>80%) the number of apoptotic cells analyzed by flow cytometry, suggesting that CDP-choline exerts a neuroprotective effect by inhibiting the apoptotic pathway induced by glutamate.