The effects of pre–B-cell colony–enhancing factor on the human fetal membranes by microarray analysis

Objective Our purpose was to show the effects of pre–B-cell colony–enhancing factor on the genes that are expressed by the human fetal membranes. Study design Explants of fetal membranes (amnion, chorion, and decidua) from three term patients were treated with 100 ng/mL recombinant human pre–B-cell colony–enhancing factor for 4 hours. RNAs were hybridized to gene chips that contained >18,000 known genes. One experiment was done in triplicate to assess replication. Data were analyzed to quantitate the signal intensities of each complementary DNA on the array. Confirmation of the results was carried out on tissues from nine other patients by the measurement of the proteins or quantitative real-time reverse transcriptase–polymerase chain reaction. Results Replication gave <92.6% identical results, which showed high method reproducibility. Pre–B-cell colony–enhancing factor treatment caused a significant increase in 103 genes and decrease in 139 genes. Only 8 genes were up-regulated consistently and significantly in all three patients (three key inflammatory cytokines [tumor necrosis factor-α, interleukin-6, and interleukin-1β], four important chemokines [macrophage inflammatory protein-1α, macrophage inflammatory protein-1β, macrophage inflammatory protein-3α, and growth-related oncogene-γ], and prostaglandin-endoperoxide synthase 2). These data were confirmed by the measurement in the media with the use of specific enzyme-linked immunosorbent assays for tumor necrosis factor-α, interleukin-6, and interleukin-1β, macrophage inflammatory protein-1α, macrophage inflammatory protein-1β, and macrophage inflammatory protein-3α and by quantitative real-time reverse transcriptase–polymerase chain reaction for growth-related oncogene-γ and prostaglandin-endoperoxide synthase 2. Conclusion Pre–B-cell colony–enhancing factor appears to be at the proximal end of the pathway to labor initiation and may link sterile distention-induced labor with that of infection-induced labor.