[Study of reactive oxygen species on the regulation of platelet apoptosis].

Objective: To study the effect of reactive oxygen species (ROS) on the regulation of platelet apoptosis.
Methods: Washed healthy human platelets were pre-incubated with N-caetyl-Lcysteine (NAC), and then stimulated with dibucaine or thrombin. The production of ROS and depolarization of mitochondrial membrane potential (∆ ψm) were detected by flow cytometry. The activation of caspase-3 and expression of Bcl-xL were analyzed by Western blot.
Results: (1)The average ROS fluorescence value of NAC+dibucaine group was lower than that of dibucaine group(0.66 ± 0.11 vs 1.06 ± 0.08, P<0.01), while that of NAC+thrombin group was also lower than that of thrombin group(0.45 ± 0.05 vs 0.71 ± 0.11, P=0.001). (2)The percentage of platelets with normal ∆ψm in NAC+Dibucaine group was higher than that of dibucaine group[(86.30 ± 9.37)% vs (13.52 ± 3.01)%, P=0.000], while that of NAC+thrombin group was also higher than that of thrombin group[(93.00 ± 3.03)% vs (76.58 ± 5.28)%, P=0.000]. (3)Fragmentation generated by caspase-3 activation in dibucaine group was much more than that in DMSO control group, while the fragmentation in NAC+dibucaine group was significantly decreased. (4)The expression of anti-apoptosis protein Bcl-xL of NAC+dibucaine group was significantly higher than that of the dibucaine group, while that of NAC+thrombin group was also higher than that of thrombin group.
Conclusion: Through the regulation of ROS, NAC could inhibit the platelet apoptosis induced by dibucaine or thrombin.