Objective: To investigate the role of transcription factor Ets-1 involved in premature rupture of membranes(PROM)by detecting its expression and location in human fetal membranes.
Methods: Between Feb. and Nov. 2007, 100 pregnant women who delivered in the First Affiliated Hospital, Chongqing Medical University were enrolled in this study. According to gestational weeks, rupture of amniochorionic membranes and delivery mode, those women were classified into preterm labor group, preterm premature rupture of membranes (PPROM) group, term labor group and term premature rupture of membranes (TPROM) group, matched with elective term cesarean sections women as control group. There were 20 pregnant women in every group. The expression and distribution of Ets-1 protein in fetal membranes were detected by immunohistochemical streptravidin-biotin peroxidase (SP) method and histoscore. In the mean time, 6 cases were chosen from each group randomly and reverse transcription-PCR was used to measure the Ets-1 mRNA expression.
Results: (1) The expression of Ets-1 mRNA in fetal membranes were 0.342 ± 0.016 in preterm labor group, 0.603 ± 0.027 in PPROM group, 0.325 ± 0.013 in term labor group, 0.582 ± 0.075 in TPROM group, 0.139 ± 0.012 in control group, respectively. When compared with that in control group, Ets-1 mRNA expression were significantly increased in both PPROM and TPROM group (P < 0.05). However, it did not show remarkably difference between preterm group and term labor group, as well as between PPROM and TPROM group (P > 0.05). (2) Ets-1 was in stromal layers of amniochorionic membranes and in both cytoplasm and nuclei of trophoblast, which were shown with diffuse intracellular positive granularities (brown-yellow) clearly. No expression of Ets-1 was observed in amniotic epithelial cells. (3) The expression of Ets-1 protein was 0.552 ± 0.018 in preterm labor group, 2.853 ± 0.174 in PPROM group, 0.538 ± 0.042 in term labor group, 2.731 ± 0.090 in TPROM group and 0.214 ± 0.013 in control group, respectively. Ets-1 protein was significantly increased in the stroma of both PPROM and TPROM group than that in control group (P < 0.05). However, no remarkable different expression of Ets-1 was observed between preterm and term labor group, so was that between PPROM and TPROM group (P > 0.05).
Conclusion: Transcription factor Ets-1 is expressed in human amniochorionic membranes and it could be up-regulated in PROM.