Effects of Mycobacterium tuberculosis heat-resistant antigen on secretion of SP-B and apoptosis in A549 cells / 安徽医科大学学报

ABSTRACT

Objective To investigate secreting pulmonary surfactant-associated protein B (SP-B) and apoptosis in human lung adenocarcinoma cell line (A549) cells,treated with heat-resistant antigen of Mycobacterium tuberculosis (Mtb-HAg).Methods Different concentrations of Mtb-HAg were used to culture A549 cells for 24 h and 48 h respectively,and the blank control groups(control group 1 and control group 2) and positive control groups [lipopolysaccharide (LPS) group and curcumin group] were set up.SP-B in the culture supernatant,was assessed by ELISA in control group 1,LPS group and experimental group 1 (A549 cells were respectively induced by 2 μg/ml,3 μg/ml Mtb-HAg to culture for 24 h and 48 h).For control group 1,LPS group and experimental group 1,the relative expression of SFTPB gene was quantified with quantitative real-time fluorescence quantitative PCR (qRT-PCR).The apoptosis rate of control group 2,curcumin group and experimental group 2(A549 cells were respectively induced by 2 μg/ml,3 μg/ml Mtb-HAg to culture for 24 h) in A549 cells were detected by flow cytometry.Results SP-B expression in the experimental group 1 was significantly lower than the control group 1,the difference was statistically significant (P ＜ 0.05).The difference of SP-B expression in the experimental group 1 was not obvious with the prolongation of the same concentration.At the same incubation time,the expression of SFTPB in the experimental group 1 decreased obviously with the increasing concentration of Mtb-HAg,the difference was statistically significant (P ＜ 0.05).The change with time was not significant.The apoptosis rate of curcumin group and experimental group 2 were significantly higher than that in control group 2 in A549 cells (P ＜ 0.05).Conclusion Mtb-HAg inhibited the expression of SP-B in A549 cells significantly,and induced apoptosis of A549 cells.