OBJECTIVES: The underlying mechanisms of protective immunity of placental 
trophoblast cells against bacterial infection remain largely unknown. NOD1 are 
intracellular pattern recognition receptors that are activated by bacterial 
peptides and mediate innate immunity. This study aimed to investigate the 
expression and function of NOD1 in first trimester trophoblast cells, and 
evaluate the potential role of trophoblast cells in infection-associated 
inflammation.
STUDY DESIGN: Human extravillous trophoblast cell line HTR8 cells were 
stimulated with various concentrations of iE-DAP for various periods of time. 
NOD1 expression was detected by immunofluorescence, and the changes in NOD1 and 
RICK mRNA and protein in H8 cells were determined by real-time polymerase chain 
reaction and Western blot analysis. The concentrations of interleukin (IL)-8 and 
IL-6 secreted by H8 cells were examined by enzyme-linked immunosorbent assay. 
NF-κB transcription activity and P65 expression were detected by electrophoretic 
mobility shift assay and Western blot analysis.
RESULTS: H8 cells expressed NOD1, and the effects of iE-DAP on NOD1 were dose- 
and time-dependent. The concentration of IL-8 increased gradually with 
increasing concentration of iE-DAP, and the levels of IL-8 and IL-6 were 
associated with the duration of exposure to iE-DAP. The dose of iE-DAP was 
significantly associated with expression of RICK and P65, and stimulation of H8 
cells by iE-DAP altered NF-κB transcription activity.
CONCLUSIONS: NOD1 may have a role in mediating infection-associated 
inflammation. Once iE-DAP is recognized by NOD1, the inflammatory response may 
be induced via NOD1-RICK-NF-κB-mediated pathways.