NF-kappaB function in the human myometrium during pregnancy and parturition.

Interactions between the nuclear factor kappaB (NF-kappaB) family of proteins (RelA, RelB, c-Rel, p50 and p52) and DNA are vital for cells to function normally; for example, in the human myometrium, NF-kappaB-regulated pro-inflammatory mediators, including TNFalpha, IL-1beta, IL-8 and COX-2 are associated with the onset of labour. NF-kappaB, however, regulates the expression of over 400 genes, although it is unlikely these would all be activated in concert by a single inducer. At present, defining the role of the NF-kappaB RelA:p50 dimer, which governs a number of inflammatory promoters, is at the forefront of the parturition research field. However, to over-look the function of other family members and how they may regulate alternative signalling networks within reproductive tissues, only serves to ensure we will never fully understand the molecular circuitry influenced by this family of transcription factors. Consequently this review highlights other mechanisms by which the NF-kappaB family of regulators have been shown to function in other systems and how they may readily translate to understanding the regulation underpinning human parturition.