Differential gene expresión and immunolocation of proteins of high functional significance throughout the window of implantation

JESSICA H. ZARET; ANAHÍ FRANCHI; SILVINA BOCCA; SERGIO OEHNINGER

Washington DC, USA

Congreso; American Society for Reproductive Medicine 63rd Annual Meeting,; 2007

American Society for Reproductive Medicine

OBJECTIVE: We previously established endometrial gene expression profiles during the early and mid-secretory phases of the menstrual cycle using genomic microarrays.We identified three genes with high potential functional significance based upon the presence of putative estrogen receptor elements and up-regulation between 7?35-fold comparing the pre-receptive and receptive endometrium. Here, we further characterize the temporal expression of these genes and localize their products and ligands. DESIGN: Reverse transcription (RT) and polymerase chain reaction (PCR) analysis of mRNA in human endometrium. Immunohistochemical analysis of human endometrium using frozen sections. MATERIALS AND METHODS: Endometrial tissue was obtained from regularly cycling, ovulatory women at 3, 8 or 11 days after the LH surge. The biopsies corresponded to cycle day 16 (pre-receptive), 20 and 24 (opening and closure of the window of implantation). RT- PCR of secreted phosphoprotein 1 (SPP1 or osteopontin), decay accelerating factor (DAF), and interleukin 15 (IL15) was performed and normalized to expression of the housekeeping gene 18S. The products of these genes and their known ligands were localized with immunohistochemistry. RESULTS: SPP1 expression increased 2?5 fold from cycle day 16 to day 20. It remained at the same level between day 20 and 24. Osteopontin was localized largely to the glands at all time points. avb3 integrin, a ligand of osteopontin, was found in the glands and stroma at all time points. DAF expression increased 25?27 fold between day 16 and 20 with a slight decrease in expression between day 20 and 24. DAF protein was found mainly in the glands at day 16 and 20 with a more diffusely on day 24. Complement component 3, the ligand of DAF, was found in both the glands and stroma at all time points. Little change was seen in expression of IL15 between day 16 and 20 or day 20 and 24. IL-15 and its receptor were identified in both the glands and stroma, with a greater concentration in the glands at day 20 vs. days 16 and 24. CONCLUSIONS: We found differential temporal expression of several genes involved in cell adhesion and immune modulation in the endometrium, with profiles characteristic of the opening, duration and closure of the window of implantation. Localization of the products of these genes to the endometrial glands at the time of implantation supports their involvement in the establishment and maintenance of receptivity.