Effect of resveratrol on expression of lipopolysaccharide-induced microRNA-146a in alveolar macrophages

Objective To observe the effect of resveratrol on expression of lipopolysaccharide (LPS) -induced microRNA-146a (miR-146a) in alveolar macrophages.Methods Rat alveolar macrophages (NR8383) were seeded at 2 × 106cell/pore in 6 well plates in vitro and incubated for 90 min.NR8383 were randomly divided into four groups:control group,NR8383 stimulated with phosphate buffer solution (PBS) ; LPS-stimulated group,NR8383 stimulated with 1 μg/mL of LPS ; resveratrol-treated group,NR8383 treated with different concentrations of resveratrol (1 μg/mL or 10 μg/mL) for 30 min,then stimulated with 1 μg/ mL of LPS.After incubation for 6 h,the cells were harvested and the supernatant of cell culture medium was collected.The expression of miR-146a of cells was detected by using fluoroilluminance real-time quantitative PCR device,and the levels of TNF-α protein in the supernatant were assayed by using enzyme-linked immunosorbent assay (ELISA).Results Compared with control group,the expression of miR-146a and the level of TNF-oα were significantly increased in LPS stimulated group (miR-146a' s expression folds:5.92 ±l.57vs 1.03±0.58,P＜0.01; TNF-α:644.2±36.82 pg/mL vs.26.15 ±13.43 pg/mL,P＜0.01).Compared with LPS-stimulated group,the expressions of miR-146a were significantly increased in resveratrol-treated groups (1 μg/mL and 10 μg/mL) (miR-146a' s expression folds:8.67 ± 1.18,11.17± 1.40 vs.5.92 ± 1.57,both P ＜ 0.01),but the level of TNF-oα in the supernatant was significantly reduced (TNF-α:447.7 ± 41.48 pg/mL,345.0 ± 42.54 pg/mL vs.644.2 ± 36.82 pg/mL,both P ＜ 0.01).Compared with the low concentration of group (1 μg/mL),the expression of miR-146a were significantly increased and the production of TNF-α in the supernatant of cells was significantly reduced in high concentration of resveratrol group (10 μg/mL) (P ＜ 0.01).Conclusions Resveratrol could upregulate the expression of miR-146a in alveolar macrophage inflammatory response,suggesting miR-146a involved in the anti-inflammtory processes with resveratrol treatment. Key words: Resveratrol;  MicroRNA-146a;  Alveolar macrophages;  Tumor necrosis factor-α