Abstract:OBJECTIVE: This study aimed to investigate the mechanism of primary cortical neuron injury induced by high concentrations of copper by observing the effect of aceticum culture-medium on apoptosis of rat primary cortical neurons and expression of cleaved caspase-3, caspase-8 and caspase-9. METHODS: Primary cortical neurons were cultured for 72 hrs and then exposed to different concentrations of aceticum culture-medium (20, 40 and 80 μM). The viability of neurons was detected by the MTT method. Apoptosis was observed by Hoechst33258 and flow cytometry Annexin-V/PI. Expression of caspase-3, caspase-8 and caspase-9 was measured by Western blot. RESULTS: Following incubation with aceticum culture-medium, apoptosis of neurons was induced. The viability of neurons was remarkably reduced and the rate of apoptosis was tremendously increased in a concentration-dependent manner. Caspase-8 and caspase-9 were activated in 20 μM of copper aceticum culture-medium 4 hrs after incubation and peaked at 48 hrs in various concentrations of copper aceticum culture-medium, presenting with a time and concentration-dependent manner. The activated caspase-3 was observed in 20 μM of copper aceticum culture-medium 24 hrs after incubation, which was later than the activated caspase-8 and caspase-9. Caspase-3 expression reached a peak 48 hrs in various concentrations of copper aceticum culture-medium, presenting with a time and concentration-dependent manner. CONCLUSIONS: The apoptosis of primary cortical neurons can be induced by copper. Caspase-3, caspase-8 and caspase-9 cascade reaction may involve in the apoptosis of copper-induced rat primary cortical neurons.［Chin J Contemp Pediatr, 2009, 11 (11):917-922］
