G. Giacomini et al., EPITHELIAL-CELLS ARE THE MAJOR SOURCE OF BIOLOGICALLY-ACTIVE GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR IN HUMAN ENDOMETRIUM, Human reproduction, 10(12), 1995, pp. 3259-3263
Granulocyte macrophage colony-stimulating factor (GM-CSF) has emerged
as an important growth factor for trophoblast and other placental cell
s, leading to improved placental functioning and fetal survival, Recen
t 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 as
sessed using a sensitive bioassay and specific neutralization of the c
ytokine 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 detec
ted, Subsequently, enriched epithelial cell cultures were prepared fro
m glands isolated from human endometrium, The purity of epithelial cul
tures was demonstrated by the expression of cytokeratin, a weak immuno
reactivity for vimentin and a lack of immunoreactivity for leukocyte c
ommon antigen, CD68, a macrophage-specific protein and endothelial mar
ker (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 ph
ases showed primarily that epithelial cells, and to a lesser extent st
romal cells, exhibited immunoreactivity for GM-CSF, A Western blot ana
lysis, performed to validate the immunohistochemical data, confirmed t
he presence of an immunoreactive gene product for GM-CSF in human endo
metrium throughout the menstrual cycle, These findings indicate that h
uman endometrium synthesizes GM-CSF and that epithelial cells are a ma
jor contributor to its production.