In this study, we examined in detail the pattern of expression of G-CSFR mRNA and protein in placental chorionic villi and maternal decidua throughout gestation. We have shown that 1) expression of human placental mRNA and protein corresponding to membrane-bound G-CSFR is down-regulated in the chorionic villi during the second trimester; 2) interstitial cytotrophoblast in the first and second trimester of pregnancy expresses G-CSFR; and 3) expression of placental G-CSFR does not appear to be modulated by PGE1, oxytocin, or mifepristone. buy ventolin inhalers
We detected by RPA one form of G-CSFR throughout pregnancy, corresponding to the Class I receptor. The G-CSFR mRNA levels were relatively high in the first trimester of pregnancy, decreased early in the second, and increased in the third. Although it has previously been shown by reverse transcription-polymerase chain reaction that both class I and class III G-CSFR exist in placental tissue, the mRNA corresponding to the class III receptor, a membrane-bound G-CSFR containing a 27-amino acid insertion in the cytoplasmic domain, was not detected by RPA. The class III receptor may be expressed at low levels in placental tissue and therefore be undetectable in the assays we used in this study. Both G-CSFR mRNAs are derived from the same gene by differential splicing. This raises the possibility that the regulation of alternative splicing may be tissue type-specific, with the class III receptor specifically expressed in nonhemopoietic tissues such as the placenta.