Pravastatin inhibits microRNA-155 expression and improves functions of lipopolysaccharide-treated human extravillous trophoblast cells / 中华围产医学杂志

ABSTRACT

Objective To investigate the effects ofpravastatin on the expression ofmicroRNA-155 (miR-155) and the functions of lipopolysaccharide (LPS)-treated extravillous trophoblast cells.Methods In vitro cultured HTR-8/SVneo cells were divided into the following groupscontrol group,enhanced plasmid with green fluoscent protein (pEGFP)-miR-155 group (transfected with green fluorescent protein-tagged miR-155),LPS group (treated with 100 ng/mL of LPS),miR-155 inhibitor+LPS group,pravastatin+LPS group (treated with 100 ng/mL of LPS following pretreatment with 12.50,25.00,50.00 and 100.00 μ g/ml of pravastatin),and pravastatin+pEGFP-miR-155 group (transfected with pEGFP-miR-155 following pretreatment with 50 μ g/ml of pravastatin).Levels of miR-155 in HTR-8/SVneo cells treated with different strategies were measured by real-time polymerase chain reaction.Expression of phosphorylated JunB (p-JunB) and p-FosB proteins was analyzed by Western blotting.Migration,invasion and apoptosis of HTR-8/SVneo cells were also analyzed.All data were analyzed with t test.Results (1) Compared with the control group,HTR-8/SVneo cells in the pEGFP-miR-155 group were characterized by shorter migration distance [(274.70± 18.82) vs (181.00±8.62) μ m],less transmembrane cells [(123.00±4.36) vs (63.00±6.08)] and enhanced apoptosis [(5.40± 0.68)％ vs (9.27±0.68)％] (all P＜0.05).(2) Compared with the LPS group,the miR-155 inhibitor+LPS group showed longer migration distance of HTR-8/SVneo cells [(166.30±5.07) vs (242.00±18.07) μm,P＜0.05],more transmembrane cells [(71.67±6.12) vs (109.00±7.81),P＜0.05] and decreased cell apoptosis [(14.40±1.69)％ vs (6.23± 0.44)％,P＜0.05].(3) Expression of miR-155 at mRNA level in the LPS group was increased as compared with that of the control group (1.65 0.07 vs 0.79±0.12,P＜0.05).Compared with the LPS group,pretreatment with 12.50,25.00,50.00 and 100.00 μ g/ml of pravastatin decreased the expression of miR-155 at mRNA level [(1.14±0.10),(1.02±0.10),(0.74±0.15) and (1.140.02)],especially at the concentration of 50 μμ g/ml (all P＜0.05).(4) Expression ofp-JunB and p-FosB proteins in the control,LPS and pravastatin (50 μ g/ml)+LPS groups were (0.33 ±0.06) vs (0.37±0.07),(1.22±0.20) vs (0.80±-0.13),and (0.31 ±0.02) vs (0.21 ±0.05),respectively,showing higher expression level in both p-JunB and p-FosB proteins in the LPS group compared with that of the other two groups (all P＜0.05).(5) Compared with the LPS group,the pravastatin (50 μμ g/ml)+LPS group showed increased migration distance [(166.30±5.07) vs (246.80± 13.42) μ m,P＜0.05],increased numbers of transmembrane cells [(71.67 ± 6.12) vs (95.33 ± 2.73),P＜0.05] and decreased cell apoptosis [(14.40± 1.69) vs (6.05 ± 0.35)％,P＜0.05].(6) Compared with the pEGFP-miR-155 group,the pravastatin (50.00.00 μμ g/mL)+pEGFP-miR-155 group showed longer migration distance [(197.50± 13.86) vs (275.80± 13.63) μ m,P＜0.05],more transmembrane cells [(52.67±5.49) vs (125.00±6.66),P＜0.05] and lower rate of cell apoptosis [(8.90± 1.00) vs (5.05±0.35)％,P＜0.05].Conclusions Pretreatment of extravillous trophoblast cells with pravastatin can protect them from apoptosis and loss of migratory and invasive abilities through inhibiting the activation of AP-1 and down-regulating the expression of miR-155,which may be a mechanism that inhibits the development of preeclampsia.