Induction of insulin-like growth factor binding protein-1 expression in baboon endometrial stromal cells by cells of trophoblast origin.
OBJECTIVE
To determine the influence of the conceptus on the induction of decidualization in endometrial stromal cells from the baboon.


METHODS
For in vivo studies, implantation sites from day 22 of pregnancy in the baboon were analyzed for insulin-like growth factor-II (IGF-II) and insulin-like growth factor binding protein-1 (IGFBP-1) mRNAs using in situ hybridization. For in vitro studies, Jeg-3 cells or primary cytotrophoblasts isolated from term placenta were cocultured with a monolayer of stromal cells from the baboon endometrium. Cytotrophoblasts were placed either directly on top of the stromal cell monolayer or in transwell cell culture inserts and cultured for 7 days. No exogenous hormones were added. Stromal cells were analyzed for IGFBP-1 mRNA and protein by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry.


RESULTS
Examination of early implantation sites in the baboon revealed a high expression of IGF-II mRNA in the invading cytotrophoblasts. Conversely, the stromal cells of the endometrium directly adjacent to the cytotrophoblasts expressed IGFBP-1 mRNA. Endometrial stromal cells cocultured with Jeg-3 cells or primary cytotrophoblasts for 7 days expressed IGFBP-1 mRNA and protein. This expression occurred in both the direct coculture system and coculture using the cell culture inserts. Cytotrophoblasts also induced the expression of prolactin in stromal fibroblasts following coculture.


CONCLUSIONS
The conceptus is capable of inducing decidualization of endometrial stromal cells. This is shown in both the in vivo and in vitro systems.
Jasinska
A
A
Department of Obstetrics and Gynecology, University of Illinois at Chicago, Chicago, IL 60612, USA.
Han
V
V
Fazleabas
A T
AT
Kim
J Julie
JJ
D000818:Animals; D004717:Endometrium / Q000166:cytology* / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000096:biosynthesis*; D010215:Papio; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000502:physiology*; D014327:Trophoblasts
D018970:Insulin-Like Growth Factor Binding Protein 1