title: Epithelial cells are the major source of biologically active granulocyte macrophage colony-stimulating factor in human endometrium.
abstract: Granulocyte macrophage colony-stimulating factor (GM-CSF) has emerged as an important growth factor for trophoblast and other placental cells, leading to improved placental functioning and fetal survival. Recent observations have indicated that GM-CSF is synthesized by epithelial cells in the murine pregnant and non-pregnant uterus. In this study, the production of GM-CSF by cells derived from human endometrium is assessed using a sensitive bioassay and specific neutralization of the cytokine bioactivity with a monoclonal antibody to GM-CSF. Originally, GM-CSF was assayed in the culture supernatants of explant cultures of human endometria. Concentrations of GM-CSF up to 4440 pg/ml were detected. Subsequently, enriched epithelial cell cultures were prepared from glands isolated from human endometrium. The purity of epithelial cultures was demonstrated by the expression of cytokeratin, a weak immunoreactivity for vimentin and a lack of immunoreactivity for leukocyte common antigen, CD68, a macrophage-specific protein and endothelial marker (factor VIII-related antigens). Detected concentrations of GM-CSF were as high as 18,800 pg/ml. Furthermore, pure epithelial cells of a neoplastic endometrial cell line ECC1 secreted GM-CSF, confirming the ability of endometrial epithelial cells to secrete this cytokine. The immunostaining of dated endometria from proliferative and secretory phases showed primarily that epithelial cells, and to a lesser extent stromal cells, exhibited immunoreactivity for GM-CSF. A Western blot analysis, performed to validate the immunohistochemical data, confirmed the presence of an immunoreactive gene product for GM-CSF in human endometrium throughout the menstrual cycle. These findings indicate that human endometrium synthesizes GM-CSF and that epithelial cells are a major contributor to its production.
authors.affiliation: Department of Obstetrics and Gynecology, University of Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Giacomini
authors.forename: S S
authors.initials: SS
authors.lastname: Tabibzadeh
authors.forename: P G
authors.initials: PG
authors.lastname: Satyaswaroop
authors.forename: L
authors.initials: L
authors.lastname: Bonsi
authors.forename: L
authors.initials: L
authors.lastname: Vitale
authors.forename: G P
authors.initials: GP
authors.lastname: Bagnara
authors.forename: P
authors.initials: P
authors.lastname: Strippoli
authors.forename: V M
authors.initials: VM
authors.lastname: Jasonni
mesh_terms: D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D001681:Biological Assay; D015153:Blotting, Western; D017077:Culture Media, Conditioned; D046508:Culture Techniques; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008875:Middle Aged; D009500:Neutralization Tests; D011247:Pregnancy
chemical_list: D000911:Antibodies, Monoclonal; D017077:Culture Media, Conditioned; D016178:Granulocyte-Macrophage Colony-Stimulating Factor