MMP-9/TIMP-1在脂多糖和N-乙酰半胱氨酸干预体外孵育胎膜中的表达及意义

Expression and significance of MMP-9/TIMP-1 in in vitro cultured amniochorionic membranes stimulated by lipopolysaccharide and N-acetylcysteine

目的探讨感染引发早产的可能机制及N-乙酰半胱氨酸(NAC)预防感染引发早产的可行性。方法取20例正常择期剖宫产孕妇(无妊娠合并症及临产征兆)的胎膜在体外进行孵育,共分成5组:0 h组(取下后未经孵育的胎膜),24 h组,48 h组,72 h细菌内毒素脂多糖组(LPS组),72 h LPS+NAC组(LPS+NAC组)。首先评价体外孵育胎膜的存活力,然后应用逆转录聚合酶链反应(RT-PCR)分别测定5组胎膜的基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制因子-1(TIMP-1)mRNA表达水平的变化,最后比较LPS组和LPS+NAC组MMP-9/TIMP-1比值的变化。结果体外孵育胎膜的存活力达到83%±1.9%,RT-PCR可见0 h组及48 h组的MMP-9表达微弱,24 h组的表达较前两组增强(P<0.05),LPS组的表达最强(与24 h组比较P<0.01),LPS+NAC组的表达低于LPS组(P<0.01),各组TIMP-1的表达无明显区别(P>0.05),LPS+NAC组较LPS组MMP-9/TIMP-1比值明显降低(P<0.01)。结论MMP-9/TIMP-1比值升高可能是感染引发早产的机制之一,NAC有望在预防和治疗早产中发挥作用。

Objective To discuss the mechanism that infection cause preterm labour, and the ability that N-acetylcysteine （NAC） prevent preterm labour causing by infection. Methods Amniochorionic membranes were collected from 20 pregnancy women undergoing elective cesarean delivery at term, without evidence of active labour and complications of pregnancy, then these amniochorionic membranes were cultured in vitro and were divided into 5 groups： 0 h group, 24 h group, 48 h group, 72 h lipopolysaccharide （LPS） group, 72 h LPS ＋ NAC group. The viability of these cultured membranes were assessed, the expression of matrix metalloproteinnase-9 （MMP-9） and tissue inhibitor of metalloproteinase-1 （TIMP-1） were determined in all groups by reverse transcription polymerase chain reaction （RT-PCR）, and the ratio of MMP-9/TIMP-1 in LPS group and LPS ＋ NAC group were compared. Results The viability of cultured amniochorionic membranes was （83±1.9）%. The expression of MMP-9 in 0 h group and 48 h group could hardly be seen by RT - PCR, it was slightly elevated in 24 h group （P 〈 0.05）, and it was strongest in 72 h LPS group （P 〈 0.01 vs 24 h group）. The expression of MMP-9 in 72 h LPS ＋ NAC group was significantly lower than that of 72 h LPS group （P 〈 0.01）. The expression of TIMP-1 had no significant difference in all groups. The ratio of MMP-9/TIMP-1 in 72 h LPS ＋ NAC group was significantly lower than that of 72 h LPS group. Conclusions Increasing of the ratio of MMP-9/TIMP-1 may be one of the mechanisms of preterm labour causing by infection, and NAC can possibly prevent and cure this kind of preterm labour.