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

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. 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. 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. 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.