Mechanism of Neuroprotective Function of Taurine
Taurine has potent protective function against glutamate-induced neuronal injury presumably through its function in regulation of intracellular free calcium level, [Ca2+]i. In this communication, we report that taurine exerts its protective function through one or more of the following mechanisms: 1. Inhibition of glutamate-induced calcium influx through L-, N- and P/Q-type voltage-gated calcium channels and NMDA receptor calcium channel; 2. Attenuation of glutamate-induced membrane depolarization; 3. Prevention of glutamate-induced apoptosis via preventing glutamate-mediated down-regulation of Bcl-2; 4. Prevention of cleavage of Bcl-2 by calpain. This action of taurine is due to its inhibition on glutamate induced calpain activation. Based on these observations, we propose that taurine protects neurons against glutamate-induced neurotoxicity in part, by preventing glutamate-induced membrane depolarization, elevation of [Ca2+]i, activation of calpain, reduction of Bcl-2 and apoptosis.
KeywordsNMDA Receptor Neuroprotective Function Primary Neuronal Cell Culture Intracellular Free Calcium Level Intracellular Calcium Accumulation
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- El Idrissi A (2006) Taurine increases mitochondrial buffering of calcium: role in neuroprotection. Amino Acids [Epub ahead of print]Google Scholar
- Schaffer S, Azuma J, Takahashi K, Mozaffari M (2003) Why is taurine cytoprotective? In: Lombardini JB, Schaffer S W and Azuma J (eds) Taurine 5, Kluwer Academic/Plenum Publishers, pp 307–321Google Scholar
- Tang XW, Deupree DL, Sun Y, Wu JY (1996) Biphasic effect of taurine on excitatory amino acid-induced neurotoxicity. In: Huxtable RJ, Azuma J, Nakagawa M, Kuriyama K, Bala A (eds) Taurine: Basic and Clinical Aspects, Plenum Publishing Co, pp 499–506Google Scholar