Abstract
In view of the accumulating evidence for paracrine mechanisms regulating trophoblast function, we tested the hypothesis that placental macrophages affect trophoblast activity in a paracrine fashion. Trophoblast was isolated from 17 term placentas (–IP). One aliquot of cells was further immunopurified (+IP) using an HLA class I antibody. This increased the proportion of trophoblast (+IP >97%; –IP ∼70%) as identified by rigorous immunocytochemistry. Most (∼70%) non-trophoblast cells in –IP were macrophages. The cells were cultured for 5 days with a daily medium change. In addition, +IP cells from seven placentas were cultured with lipopolysaccharide (LPS)-stimulated or -unstimulated macrophage-conditioned media. The concentrations of lactate, trophoblast-specific hormones, human chorionic gonadotropin-β (hCG-β) and human placental lactogen (hPL), of several prostanoids and of endothelin-1 and angiotensin II were determined in the culture media. The accumulated amounts of substances released into the culture media, corrected for the greater proportion of trophoblast in +IP cultures, were on average two- to threefold higher (hCG-β: 18-fold) in +IP than in –IP, with the exception of endothelin-1,2 (no change), angiotensin II (–70%) and 6-keto-prostaglandin-F1α (–40%). [3H]leucine incorporation into the trichloroacetic acid (TCA)-precipitable pool measured on day 5 was twofold higher in +IP than in –IP. Addition of conditioned media reverted these changes. The data demonstrate that placental macrophages in culture affect trophoblast biosynthetic activity in a paracrine fashion. We conclude that macrophages are important regulators of trophoblast activity.
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Received: 10 August 1998 / Accepted: 18 September 1998
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Cervar, M., Blaschitz, A., Dohr, G. et al. Paracrine regulation of distinct trophoblast functions in vitro by placental macrophages. Cell Tissue Res 295, 297–305 (1999). https://doi.org/10.1007/s004410051236
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DOI: https://doi.org/10.1007/s004410051236