Abstract: OBJECTIVE: To explore effects of PM_2.5 samples from Shenzhen and Taiyuan on oxidative damage and apoptosis in human kidney 2 cells (HK-2 cells). METHODS: A medium-flow sampler was used to collect air samples at a university campus in Taiyuan and at the top of a building of the Shenzhen Center for Disease Control and Prevention. Membranes from the PM_2.5-adsorbed filters were eluted to prepare PM_2.5 suspensions. HK-2 cultures were divided into several groups:negative control,50 μg/mL Shenzhen PM_2.5,50 μg/mL Taiyuan PM_2.5 and positive control groups. Cells were treated for 24 h and levels of malondialdehyde (MDA),superoxide dismutase (SOD),reduced glutathione (GSH),glutathione peroxidase (GSH-PX) and rates of cell apoptosis were measured. RESULTS: Compared with the negative control group, MDA levels in the Shenzhen,Taiyuan and positive control groups were increased by 8.16%,34.51% and 72.23%,respectively; the SOD levels were reduced by 7.49%, 19.67% and 29.55%, respectively; GSH levels were reduced by 10.43%,16.39% and 37.43%,respectively. Among these data,differences between the Taiyuan PM_2.5 and the positive control groups were statistically significant (P < 0.05 or P < 0.01). In similar comparisons among the 4 groups, the GSH-PX levels were reduced by 42.70%, 61.62% and 60.98%, respectively; the differences between the positive control group,and the Shenzhen and Taiyuan groups were statistically significant (P < 0.01). The apoptosis rates were increased by 197.25%, 301.22% and 399.08%, respectively; and the differences were statistically significant (P < 0.05 or P < 0.01). CONCLUSION: Our data indicate that the PM_2.5 from Shenzhen and Taiyuan caused oxidative damage and increased apoptosis rates in HK-2 cells. In addition,the Taiyuan PM_2.5 were more toxic than that from Shenzhen.

Key words: PM_2.5, human kidney 2 cells, oxidative damage, apoptosis