In this proposal, the investigator will test the hypothesis that cytokines IL-1b and TNF-a govern COX-2 gene expression via the transcription factor nuclear factor-kB (NF-kB). Using amnion-derived WISH cells as a model system, they will examine whether NF-kB is activated following cytokine challenge. In addition, they will determine whether cytokine treatment leads to phosphorylation and degradation of 1kBa, the inhibitor protein bound to inactive NF-kB, as part of the activation process. Antisense strategies will be employed to determine the effect of ablating NF-kB subunits on COX-2 inducibility by cytokines. The proposal will also use a murine model of PTL induced by endotoxin to explore whether NF-kB activation of the COX-2 gene functions in vivo. Finally, the investigator will test the hypothesis by examining whether nuclear extracts from intrauterine tissues obtained from women in PTL contain activated NF-kB compared with tissues from women of the same gestational age but not in labor.