Effect of hyperoxia on A549 cells suppressed with surfactant protein-A suppressed by small RNA interference-mediated gene silencing / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the effect of hyperoxia on A549 cells suppressed with surfactant protein A (SP-A) suppressed by small interference RNA(SiRNA)-mediated gene silencing,and discuss the function of SP-A in hyperoxic lung injury.Methods A549 cells were gained by serial sub cultivation in vitro and randomly divided into 2 groups,silenced of SP-A group and the control group.A549 cells were transfected with synthetic SP-A sequence-specific SiRNA by Lipofectamine 2000,continuously exposed to hyperoxia(950 mL/L 02,50 mL/L CO2).After exposure to hyperoxia for 48 hours,72 hours and 96 hours,total protein and culture supernatant were gained.SP-A protein was detected by Western-blot,the capacity of proliferation was detected by methyl thiazolyl tetrazolium,and thiobarbituric acid colorimetric method was used to detect the malondialdehyde (MDA) in culture supernatant.Results Sequence-specific SiRNA targeted SP-A2 and significantly down-regulated its expression in A549 cells.Compared with the control group in hyperoxia,the expression of SP-A significantly decreased after 48 hours,72 hours in the silenced group (all P ＜ 0.05),and the capacity of proliferation in A549 cells silenced by SP-A were obviously decreased after 48 hours,72 hours and 96 hours(all P ＜0.05).But there was no significant difference in the MDA in culture supernatant between 2 groups(all P ＞ 0.05).Conclusions The capacity of resisting hyperoxia decreased in A549 cells silenced by SP-A,which indicates that SP-A can protect hyperoxic lung injury.