INTERLEUKIN-1-BETA STIMULATES COLONY-STIMULATING FACTOR-I PRODUCTION IN HUMAN TERM PLACENTA

The human placenta produces hematopoietic growth factors including colony stimulating factor-1 (CSF-1). We have previously demonstrated Interleukin-1beta (IL-1beta) production by decidualized endometrium during pregnancy. Since IL-1beta stimulates CSF- 1 production in a variety of mesenchymal cell types including second trimester villous core mesenchymal cells, the present study was designed to determine if IL-1beta could also regulate CSF-1 production in term placental explants in vitro. Placental villous explants from normal term placentas (n = 5) were cultured with or without recombinant human IL-1beta. A dose response relationship between increased added IL-1beta and increased CSF-I production as measured by enzyme-linked immunosorbent assay was observed with 1 ng/mL IL-1beta being the lowest dose to significantly increase CSF-I production (P < 0.01). In time course experiments, 10 ng/mL maximally induced CSF-I messenger RNA expression 2.7 fold (P < 0.005) compared to controls at 8 h of culture as determined by dot blot analysis. Production rates of CSF-1 were linear up to 24 h at which time IL-1beta (10 ng/mL)-treated samples had 1.7-fold higher levels of CSF-I in the media than nontreated controls (8.38 ng/gm tissue vs. 4.94 ng/gm tissue, P < 0.01). These results demonstrate that IL-1beta can regulate placental CSF-I production in vitro and suggest that maternal decidual IL-1beta may regulate placental CSF-1 production in vivo.