Protection of taurine and granulocyte colony-stimulating factor against excitotoxicity induced by glutamate in primary cortical neurons

BACKGROUND: Both taurine, an inhibitory neurotransmitter and granulocyte colony-stimulating factor (G-CSF), a growth factor, possess neuroprotective and neurotrophic properties in vitro. However, the mechanisms of their underlying neuroprotective effects are not fully understood. METHODS: In the present study, we investigated the potential protective benefits of taurine, G-CSF and the combination of taurine and G-CSF against excitotoxicity induced by glutamate in primary cortical neuronal cultures. RESULTS: 25 mM taurine, 25 ng/ml G-CSF and the combination of 25 mM taurine and 25 ng/ml G-CSF showed a protective effect reaching 75%, 75% and 88%, respectively. Furthermore, taurine exerted its protective effect through down-regulation of expression of GRP 78, CHOP, Bim and caspase 12. CONCLUSION: The results showed that all of these treatments, taurine, G-CSF and the combination of taurine and G-CSF, protected primary cortical neurons against excitotoxicity induced by glutamate. ER stress is suppressed by taurine after glutamate toxicity.