[Effects of Nano-SiO 2 combining with cold on cytotoxicity and secretion of inflammatory factors in A549 cells].

To investigate the effects of nano-SiO and cold on the cytotoxicity and secretion of inflammatory factors in human lung adenocarcinoma epithelial cell line A549. A549 was used as experimental subject, a single factor multilevel experiment was designed, A549 cells were exposed to 10, 50, 100, 200 μg/ml nano-SiO particles and/or cultured at 31℃, 33℃, 35℃ for 48 h. After that, cell morphology was observed and relative cell survival rate was detected. According to the results of single factor analysis and based on the selection of nano-SiO dose and temperature that significantly reduced the relative survival rate of A549 cells, the experiment was designed according to 2×2 factor analysis , they were divided into 4 groups: control group(37℃), Nano-SiO exposure group, low temperature exposure group, Nano-SiO and low temperature composite group. After exposure for 48 h, the supernatant of cell culture medium was collected for detecting the LDH activity by colorimetric method and the levels of cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8) were determined by ELISA. The mRNA levels of cellular IL-6 and IL-8 were detected by qRT-PCR. The activities of A549 cells in 100 μg/ml Nano-SiO group and 31℃ low temperature group were decreased significantly. Under the combined conditions, the activity of A549 cells was most inhibited (＜0.01), and the levels of inflammatory factors IL-6 and IL-8 and mRNA were significantly increased (＜0.01). 100 μg/ml Nano-SiO combined with 31℃ cold exposure can synergistically reduce the activity of A549 cells and increase the expression level of inflammatory factors IL-6 and IL-8 .