Regulation of insulin-like growth factor-binding proteins in the baboon (Papio anubis) uterus during early pregnancy.

The baboon uterus begins to synthesize insulin-like growth factor-binding protein-1 (IGFBP-1) in the deep glands of the late secretory endometrium, and this protein then becomes the major secretory product of the term decidua. We hypothesized that the placenta and/or conceptus may regulate the synthesis and secretion of IGFBP-1 by decidualized stromal cells during pregnancy. To test this hypothesis, tissue was obtained from pregnant baboons on days 18, 25, and 32 postovulation. The uterus was separated into three regions: RI (directly below the implantation site), RII (adjacent to the implantation site), and RIII (opposite the implantation site). Portions of the tissue were fixed in Bouin's solution for immunocytochemistry, and the remainder was subdivided into functionalis, basalis, and myometrium and subjected to organ explant culture. The placenta was fixed or cultured separately. Ligand blot analysis of functionalis medium showed that the major IGFBP had a mol wt (Mr) of 29,000-31,000; however, a doublet of 37,000-43,000 Mr and a band at 24,000 Mr were also present. The functionalis from all regions expressed the majority of the IGFBPs, but basalis from RI tissue also secreted the same array of IGFBPs on days 25 and 32. Ligand blot analysis of placental medium proteins revealed a doublet at Mr 37,000-43,000 on days 25 and 32, but not on day 18. Immunoprecipitation followed by ligand blot analysis of medium proteins using polyclonal antibodies to IGFBP-1 and IGFBP-2 and -3 confirmed that IGFBP-1 and -2 were the predominant products of the endometrium and decidua, while IGFBP-3 was synthesized by the placenta. Immunocytochemistry with a monoclonal antibody to IGFBP-1 demonstrated intense glandular epithelial staining in all regions on days 18, 25, and 32. Stromal staining for IGFBP-1 was first evident on day 25 and was only present in stromal cells in intimate contact with the trophoblastic tissue. By day 32, IGFBP-1 expression was not limited to the endometrial-trophoblastic junction, but extended to the deeper stromal cells and included the perivascular regions. IGFBP-1 staining was most intense in RI, but stromal cells at the luminal surface and those surrounding the spiral arteries also showed some staining in RII and RIII on day 32. These studies suggest that the baboon placenta and/or conceptus regulate IGFBP expression in the uterine endometrium during the initial stages of pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)     

The induction of baboon glycodelin expression by progesterone is not through Sp1

Glycodelin is a major secretory product of the uterine glandular epithelial cells of the human and non-human primate during the late luteal phase of the menstrual cycle and early pregnancy. Since progesterone levels are elevated during these periods we sought to determine how progesterone modulates glycodelin gene expression. Co-transfection of various deletions of the baboon glycodelin promoter with the progesterone receptor (PR) into Ishikawa cells, a human endometrial cell line, revealed that full progesterone responsiveness is retained within the region -119/+48. In COS-1 cells, a kidney cell line, progesterone failed to elevate luciferase levels when various deletion constructs and the PR were co-transfected. Mutation of the Sp1 site in the -67/+48 region lowered basal expression but did not affect the ability of progesterone to increase expression of the luciferase reporter in Ishikawa cells. These findings suggest that Sp1 sites are not involved in the progesterone regulation of the baboon glycodelin gene. We propose that progesterone induces a factor that regulates glycodelin gene expression in the uterus since we failed to obtain a similar response in a non-uterine cell line.     

Heparin-binding EGF-like growth factor modulation by antiprogestin and CG in the baboon (Papio anubis)

The objectives of this study were to determine whether antiprogestin therapy or the infusion of human CG to mimic blastocyst transit in the baboon alters heparin-binding EGF-like growth factor expression during the window of implantation. During the menstrual cycle, heparin-binding EGF-like growth factor protein accumulation in the glandular epithelium was low in the proliferative phase and increased to maximal expression on d 5 and 10 postovulation. Stromal cells accumulated high levels of heparin-binding EGF-like growth factor in the proliferative phase, which decreased by d 5 postovulation. These transitional changes in both cell types were delayed when cycling baboons were treated with the antiprogestin ZK 137.316 during the luteal phase. The treatment with human CG had no effect on expression of heparin-binding EGF-like growth factor when compared with cycling baboons on d 10 postovulation and was comparable with that observed on d 18 and 22 of pregnancy. However, the superimposition of the antiprogestin with the human CG treatment also decreased expression in the epithelial cells. In summary, heparin-binding EGF-like growth factor accumulation in the epithelial glands is under the influence of progesterone and does not seem to be influenced by the paracrine secretion of trophoblast CG.     

Immunological characterization and immunocytochemical localization of oviduct-specific glycoproteins in the baboon (Papio anubis)

Oviducts obtained from estradiol-treated ovariectomized baboons synthesize and release a family of high mol wt (100,000-130,000) glycoproteins during short term explant culture. The objective of this study was to make a polyclonal antibody to these glycoproteins and then use the antibody to determine the presence of the glycoproteins in oviduct flushings, tissue culture media, and tissues obtained from cycling and steroid-treated baboons. Oviduct culture medium proteins from estradiol-treated baboons were separated on one-dimensional polyacrylamide gels and transferred to nitrocellulose membranes. The region containing the glycoproteins was cut out, solubilized in dimethylsulfoxide, mixed with Freund's adjuvant, and injected at 2-week intervals into a male rabbit. The anti-serum used in this study was obtained 6 weeks after the initial injection and cross-reacted with antigens on Western blots of oviduct flushings and oviduct culture media obtained from follicular stage and estradiol-treated baboons. The antigens were absent in oviduct flushings obtained from luteal stage, ovariectomized and estradiol-primed baboons treated with estradiol and progesterone or progesterone alone. The antigens were not detected on Western blots of other reproductive and nonreproductive tract culture media or in serum obtained from follicular stage or estradiol-treated baboons. Immunoperoxidase staining was limited to discrete granules in the apical cytoplasm of secretory cells in oviducts obtained from follicular stage and estradiol-treated baboons. Thus, the secretory cells of the baboon oviduct synthesize and secrete a family of estradiol-dependent oviduct-specific glycoproteins that may have potential functional significance during fertilization and embryo development.     

Endometrial stromal cells and immune cell populations within lymph nodes in a nonhuman primate model of endometriosis

Mounting evidence suggests that immunological responses may be altered in endometriosis. The baboon (Papio anubis) is generally considered the best model of endometriosis pathogenesis. The objective of the current study was to investigate for the first time immunological changes within uterine and peritoneal draining lymph nodes in a nonhuman primate baboon model of endometriosis. Paraffin-embedded femoral lymph nodes were obtained from 22 normally cycling female baboons (induced endometriosis n = 11; control n = 11). Immunohistochemical staining was performed with antibodies for endometrial stromal cells, T cells, immature and mature dendritic cells, and B cells. Lymph nodes were evaluated using an automated cellular imaging system. Endometrial stromal cells were significantly increased in lymph nodes from animals with induced endometriosis, compared to control animals (P = .033). In animals with induced endometriosis, some lymph node immune cell populations including T cells, dendritic cells and B cells were increased, suggesting an efficient early response or peritoneal drainage.     

Altered expression of HOXA10 in endometriosis: potential role in decidualization

Endometriosis is a poorly understood gynaecologic disorder thatis associated with infertility. In this study, we examined theexpression of HOXA10 in the eutopic endometrium of baboons withinduced endometriosis. A decrease in HOXA10 mRNA was observedafter 3, 6, 12 and 16 months of disease, which reached statisticalsignificance at 12 and 16 months. HOXA10 protein levels weredecreased in both the epithelial and stromal cells of the endometrium.Furthermore, expression of ß3 integrin (ITGB3), whichis upregulated by HOXA10, was decreased, whereas EMX2, a genethat is inhibited by HOXA10, was increased. Next, methylationpatterns of the HOXA10 gene were analysed in the diseased andcontrol animals. The F1 region on the promoter was found tobe the most significantly methylated in the endometriosis animalsand this may account for the decrease in HOXA10 expression.Finally, we demonstrate that stromal cells from the eutopicendometrium of baboons with endometriosis expressed significantlyhigher levels of insulin-like growth factor binding protein-1(IGFBP1) mRNA than disease-free animals in response to estradiol,medroxyprogesterone acetate and dibutyryl cAMP (H + dbcAMP).The functional role of HOXA10 in IGFBP1 expression was furtherexplored using human endometrial stromal cells (HSC). Overexpressionof HOXA10 in HSC resulted in a decrease of IGFBP1 mRNA, whereassilencing HOXA10 caused an increase of IGFBP1 mRNA, even inthe presence of H + dbcAMP. These data demonstrate that HOXA10negatively influences IGFBP1 expression in decidualizing cells.Thus, the decrease in HOXA10 levels may in part be involvedwith the altered uterine environment associated with endometriosis.