[Effect of Shenfu injection on expression of lipopolysaccharide --induced microRNA-146a in alveolar macrophages].

Objective To study the effects of Shenfu injection(SF)on the expression of lipopolysaccharide (LPS)-induced microRNA-146a(miR-146a)in rat alveolar macrophages(AMs),and to extrapolate its potential anti-inflammatory mechanisms.Methods In vitro cultured rat AMs(NR8383 cells)were randomly divided into control group,LPS stimulation group,and SF stimulation group.The LPS stimulation group was challenged with a final concentration of 1 mg/L LPS,and to the control group an equal volume of phosphate buffer solution(PBS)was added instead.For SF treated group,SF in different concentrations(1 ml/L or 10 ml/L)was used during incubation of AMs for half an hour,and then LPS was added(1 mg/L final concentration).After 6 hours,the cells and culture supematants were collected.MiRNA-146a expression[reverse transcription-polymerase chain reaction(RT-PCR)]in cells and tumor necrosis factor-α(TNF-α)content[enzyme-linked immunosorbent assay(ELISA)]in culture supernatant were determined for each group.Results Both the expression of miR-146a and TNF-α content in LPS stimulation group were significantly elevated compared with control group[miR-146a(expression folds):5.92 ± 1.57 vs.1.04 ±0.38; TNF-α(ng/L):636.93 ± 30.21 vs.20.46 ± 2.81 ; both P＜0.05].Compared with LPS stimulation group,the expression of miR-146a was significantly upregulated in cells in both 1 ml/L and 10 ml/L SF stimulation groups,but TNF-α content was significantly reduced in the supernatant[miR-146a(expression folds):7.02 ± 0.91,8.11 ± 1.07vs.5.92 ±1.57; TNF-α(ng/L):447.24 ±21.29,357.83 ±19.73 vs.636.93 ±30.21,all P＜0.05]in a dose-dependent manner(both P＜0.05).Conclusion SF could up-regulate miR-146a expression in AMs in a dose-dependent manner,and it was speculated that miR-146a might be involved in the anti-inflammatory processes with SF treatment. Key words: Shenfu injection;  MicroRNA-146a;  Tumor necrosis factor-α ;  Alveolar macrophage