Abstract: Objective To investigate the relationship between the expressions of nucleotide-binding oligomerization domain-containing 2 (NOD2), matrix metalloproteinase -9 (MMP-9) and activated Caspase-3 in the fetal membranes and TNF-α level in amniotic fluid from women with premature rupture of the membranes (PROM)． Methods Thirty pregnant women with term premature rupture of the membranes (tPROM), 30 cases of preterm premature rupture of the membranes (pPROM) and 30 cases of healthy term pregnancy (control group) were enrolled in the experiment. Immunohistochemistry was used to detect the location of NOD2, MMP-9 and activated Caspase-3 in the fetal membranes. Western blot assay was performed to analyze the expression levels of the three proteins. ELISA was used to detect the level of TNF-α in amniotic fluid. The relationship between the levels of the four proteins was also analyzed. Results The expression levels of NOD2, MMP-9 and activated Caspase-3 in fetal membranes and the level of TNF-α in amniotic fluid were significantly higher in PROM groups than those in control group (P＜0.05). The levels of NOD2 and TNF-α were significantly higher in pPROM group than those in tPROM group (P＜0.05). There were no significant difference in the levels of MMP-9 and activated Caspase-3 between tPROM group and pPROM group. Furthermore, the level of NOD2 was positively correlated with the levels of TNF-α, MMP-9 and activated Caspase-3 (P＜0.01). Conclusion The elevated expression levels of NOD2, TNF- α, MMP-9 and activated Caspase-3 play an important role in PROM. NOD2, TNF-α, MMP-9 and activated Caspase-3 may play associative roles in the process of PROM.

Key words: fetal membranes, premature rupture, Nod2 signaling adaptor protein, tumor necrosis factor-alpha, matrix metalloproteinase 9, Caspase 3