Excitatory neurotoxicity of CO-releasing molecules-2 on PC12 cells

  Objective  The effect and mechanism of CO-releasing molecules-2(CORM-2) on glutamate signal pathway in PC12 cells was explored, in order to reveal the possible mechanism of DEACMP caused by acute carbon monoxide poisoning and furthermore improve the treatment of CO poisoning in the future.

  Methods  Highly differentiated PC12 cells were exposed to different concentrations of CO-releasing molecules-2. The cell viability was detected by MTS method, and the appropriate concentration and time of exposure were determined. After the cells were collected, the expression of NMDA receptor major subunit (NR1) and NMDA receptor 2B subunit (NR2B) protein, intracellular calcium concentration and glutamate release were detected by Western blotting, and the apoptosis of cells was detected by flow cytometry.

  Results  With the increase of CO-releasing molecules-2 concentration, the viability of PC12 cells decreased in a dose-dependent manner(P < 0.05). Compared with the control group, the expression of NR1 subunit of NMDA receptor had no significant change (P > 0.05). The relative expression level of NR2B protein, Ca²⁺ concentration and glutamate level in 250 μmol/L and 300 μmol/L CO-releasing molecules-2 treated groups were higher than those in the control and 200 μmol/L CO-releasing molecules-2 treated groups (P < 0.05). With the increase of CO -releasing molecules-2 concentration, the apoptosis rate of PC12 cells also increased in a dose-dependent manner(P < 0.05).

  Conclusions  With the increase of CO-releasing molecules-2 concentration, the viability of PC12 cells decreased in a dose-dependent manner.CO -releasing molecules-2 can activate glutamate signal pathway in PC12 cells and then induce Ca²⁺ influx, finally cause cell apoptosis. These results have important implications for understanding the mechanism of CO poisoning.