Abstract: Objective To investigate the expressions of Pellino 1, zinc finger protein A20 (A20) and NF-κB P65 in fetal membranes of patients with premature rupture of the membranes (PROM), analyze their relationship with the level of IL- 6 in amniotic fluid, and provide a new way for further understanding the mechanism of the occurrence and development of PROM. Methods Sixty pregnant women with PROM (including 30 with term premature rupture of the fetal membranes, tPROM and 30 with preterm premature rupture of the fetal membranes，pPROM) and 30 women with healthy term pregnancy (control group) were enrolled in the experiment. Immunohistochemistry and Western blot assay were performed to evaluate the expressions of Pellino 1, A20 and NF -κB P65 in fetal membranes. ELISA was used to measure the level of IL-6 in amniotic fluid. The relationship between the expressions of Pellino 1, A20 and NF - κB P65 and the level of IL-6 was analyzed. Results The expression levels of Pellino 1, NF-κB P65 and IL-6 were significantly higher in PROM group than those in control group (P＜0.05). On the contrary, the expression of A20 was significantly lower in PROM group than that in control group (P＜0.05). The expression levels of Pellino 1, NF-κB P65 and IL-6 were significantly higher in pPROM group than those in tPROM group (P＜0.05). And the expression of A20 was significantly lower in pPROM group than that in tPROM group (P＜0.05). Furthermore, the expressions of Pellino 1 and NF-κB P65 were positively correlated with the level of IL-6 (P＜0.01). However, the expression of A20 was negatively correlated with the level of IL-6 (P＜0.01). Conclusion The over-expressions of Pellino 1, NF-κB P65 and IL-6 and the down-expression of A20 play an important role in PROM.

Key words: fetal membranes, premature rupture, tumor necrosis factor alpha-induced protein 3, NF-kappa B, interleukin-6, Pellino 1, Zinc finger protein A20