TNFα concentrations and mRNA expression are increased in preeclamptic placentas

Abstract

Tumor necrosis factor-α (TNFα), a cytokine produced mainly by macrophages, is involved in immunoregulation, the modulation of cell growth and differentiation, as well as in the induction of oxygen free radicals. In preeclamptic placentas, lipid peroxides are increased as compared to normal placentas. If TNFα was abnormally increased in preeclamptic placentas, it might contribute to the increased oxidative stress and the formation of lipid peroxides. We hypothesized that TNFα levels would be higher in preeclamptic than in normal placentas. We determined: (1) the levels of TNFα protein in whole placental tissue; (2) the concentrations of TNFα protein and lipid peroxides in the medium after 48 h of incubation of whole placental villi; (3) mRNA expression of TNFα. Placental TNFα protein levels were measured by ELISA, lipid peroxides by a spectrophotometric method specific for peroxides, and TNFα mRNA expression by RT-PCR. Results: (1) TNFα tissue levels were significantly higher in preeclamptic than in normal placentas, P < 0.05. (2) Concentrations of both TNFα and lipid peroxides were higher in the incubation medium of preeclamptic than normal placentas, P < 0.05. (3) TNFα concentrations in the incubation medium were positively correlated with lipid peroxide concentrations, r = 0.608. (4) TNFα mRNA was expressed in preeclamptic placentas, but not in normal placentas. Conclusions: TNFα protein concentrations and mRNA expression are higher in preeclamptic than normal placentas and this is associated with increased lipid peroxidation.