ABSTRACT
Objective:To investigate the effect of intercellular adhesion molecule-1 (ICAM1) targeted miR-133a-5p on lipopolysaccharide (LPS)-induced alveolar epithelial A549 cell injury.Methods:Dual lucife-rase reporter assay was used to verify the ICAM1 targeted effect of miR-133a-5p.A549 cells were induced by LPS in vitro and divided into the control group, LPS group, LPS+ negative control(miR-NC) group, LPS+ miR-133a-5p group, LPS+ small interfering RNA(si)-NC group, and LPS+ si-ICAM1 group.The expression levels of miR-133a-5p and ICAM1 mRNA were detected by real-time fluorescent quantitative PCR.Apoptosis was detected by flow cytometry.The expression levels of ICAM1, Bcl-2, Bax and cleaved caspase-3 protein that could activate cysteine were detected by Western blot.The expression levels of interleukin-6 (IL-6) and tumor necrosis factor α(TNF-α) were detected by enzyme linked immunosorbent assay kit. Results:Compared with the control group, the LPS group had a decreased expression level of miR-133a-5p (0.39±0.04 vs.1.00±0.09) in A549 cells, increased expression of ICAM1 (0.86±0.08 vs.0.39±0.03), an increased apoptotic rate [(27.65±2.47)% vs.(8.13±0.89)%], and increased secretion of IL-6 [(624.59 ± 51.42) ng/L vs.(194.25±18.43) ng/L] and TNF-α [(548.35±51.42) ng/L vs.(174.26±19.43) ng/L]. The differences were significant (all P<0.05). Compared with the LPS+ miR-NC group, the apoptosis rate of A549 cells [(13.46±1.38)% vs.(28.71±2.54)%] in LPS+ miR-133a-5p group were significantly decreased, and the secretion of IL-6 [(296.43±23.51) ng/L vs.(635.86±55.41) ng/L] and TNF-α [(321.14±30.56) ng/L vs.(563.24±49.52) ng/L] was significantly decreased (all P<0.05). Compared with LPS+ si-NC group, the apoptosis rate of A549 cells [(13.65±1.64)% vs.(23.51±2.33)%] in LPS+ si-ICAM1 group was significantly decreased, and the secretion of IL-6 [(324.15±29.41) ng/L vs.(625.39±52.59) ng/L] and TNF-α [(334.65±20.46) ng/L vs.(534.97±51.42) ng/L] were significantly decreased (all P<0.05). Conclusions:miR-133a-5p can alleviate LPS-induced alveolar epithelial cell injury, and the mechanism may be related to down-regulation of ICAM1 expression.