EXPRESSION AND LOCALIZATION OF MESSENGER-RNA FOR TUMOR-NECROSIS-FACTOR RECEPTOR (TNF-R)-I AND TNF-RII IN PREGNANT MOUSE UTERUS AND PLACENTA

The temporal and cell-specific localization of tumor necrosis factor ( TNF) receptor mRNAs in the uterus and placenta during pregnancy in the mouse was investigated. Messenger RNA for TNF and the TNF receptors ( TNF-RI, p55/p60 and TNF-RII, p75/p80) was assessed by northern blot an d in situ hybridization. TNF, TNF-RI and TNF-RII specific transcripts were present on days 7 through 18 of pregnancy. Relative concentration s of TNF mRNA decreased from days 7 to 18 with levels being higher in the uterus than the placenta. In contrast TNF-RI mRNA levels were cons tant throughout gestation and no differences were seen between steady state levels in the uterus and placenta. Two transcripts for TNF-RII ( 3.6 and 4.5 kb) were identified in all tissues. Steady state levels of TNF-RII mRNA increased throughout gestation and levels were higher in the placenta than in the uterus. On day 9 of gestation, TNF-RI and TN F-RII mRNAs were localized to undecidualized endometrium, mesometrial decidual cells, and the developing placenta. In addition, muscle cells contained TNF-RI but not TNF-RII mRNA. By day 15 of gestation, TNF-RI and TNF-RII transcripts were primarily localized to the uterine epith elium and trophoblast giant cells and spongiotrophoblast cells in the placenta. The results of these studies reveal the uterine and placenta l cell-specific expression of TNF receptor mRNAs during pregnancy in t he mouse and provide insight into the cellular targets of TNF action.