title: Feto-maternal interactions in pregnancies: placental microparticles activate peripheral blood monocytes.
abstract: Normal pregnancy is associated with a systemic maternal inflammatory reaction, including the activation of peripheral blood monocytes. This reaction is exaggerated in pre-eclampsia, a severe placenta-dependent disorder of pregnancy specific to humans. It has been suggested that placental syncytiotrophoblast membrane microparticles (STBM), which are released into the peripheral blood, may contribute to the maternal response. The aim of this study was to investigate the inflammatory properties of STBM generated by four different approaches on primary human monocytes in vitro. Cellular viability, phenotype and functional response were analysed. STBM isolated by mechanical dissection and STBM generated from villous explant cultures incubated in hypoxic conditions had only minor influences on the monocytic phenotype and failed to induce a proinflammatory response. By contrast, STBM washed from the maternal side of a placental cotyledon and STBM shed by explants cultured in air up-regulated cell surface expression of the adhesion molecule CD54 and induced the production of interleukin (IL)-8, IL-6 and IL-1beta. Cytokine production was time- and dose-dependent. Our study, therefore, suggests that monocyte activation in normal pregnancy and pre-eclampsia may be induced by STBM released by the placenta. The higher amounts of STBM circulating in maternal blood in pre-eclampsia might lead to the excessive maternal inflammatory reaction.
authors.affiliation: Department of Biomedicine, University Hospital Basel, Basel, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Messerli
authors.forename: K
authors.initials: K
authors.lastname: May
authors.forename: S R
authors.initials: SR
authors.lastname: Hansson
authors.forename: H
authors.initials: H
authors.lastname: Schneider
authors.forename: W
authors.initials: W
authors.lastname: Holzgreve
authors.forename: S
authors.initials: S
authors.lastname: Hahn
authors.forename: C
authors.initials: C
authors.lastname: Rusterholz
mesh_terms: D040881:CD11a Antigen / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D002450:Cell Communication; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival; D055252:Cell-Derived Microparticles / Q000502:physiology*; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008297:Male; D008431:Maternal-Fetal Exchange; D009000:Monocytes / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology / Q000378:metabolism*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism; D013997:Time Factors; D014327:Trophoblasts / Q000201:enzymology / Q000378:metabolism*
chemical_list: D040881:CD11a Antigen; D016207:Cytokines; D018836:Inflammation Mediators; D018950:Lipopolysaccharide Receptors; D011257:Pregnancy Proteins; D018799:Intercellular Adhesion Molecule-1; D020169:Caspases