PARENT SESSION
PLATFORM SESSION 20: FEMALE REPRODUCTIVE TRACT 2
Chair: Brenner, Robert¹, ¹
Co-chair: Bowen-Shauver, Jennifer¹, ¹
Harborside B
2:00 PM-4:00 PM

(444) COULD ACROGRANIN (GRANULINS / EPITHELINS PRECURSOR) BE A NOVEL IMPLANTATION MARKER?

Perez, Christian¹, Diaz, Laura¹, Jun, Jin¹, Vandervoort, Dustin¹, Gerton, George¹, ¹ Center for Research on Reproduction and Women's Health., Philadelphia., PA.

ABSTRACT- Successful implantation of blastocysts into receptive uteri is associated with a cascade of events such as apposition, attachment, stromal decidualization, intrusion and, finally, invasion. Several cytokines and growth factors have been demonstrated to be important during the pre- and peri-implantation periods. We show here that the epithelial growth factor, acrogranin, could be a marker of implantation. Many tissues express acrogranin, the granulin/epithelin precursor, and particularly high transcript levels are found in granulocytes from inflammatory exudates, kidney, and male and female genital tracts. Previously, we demonstrated that acrogranin regulates the growth and development of preimplantation mouse embryos in vitro. To determine if acrogranin is important during the peri-implantation period, we used the mouse model of normal and delayed implantation to examine acrogranin protein and mRNA expression by western blotting, real-time RT-PCR analysis, immunohistochemistry and in situ hybridization. During normal pregnancy, acrogranin protein and mRNA expression patterns were strongly localized in the implantation chamber around the embryo and signals were very weak or absent in the inter-implantation site (tissue between two normal implantation sites). When temporally evaluated, acrogranin protein and mRNA amounts in female adult mice were low before pregnancy and before implantation, increased 6-8 fold during implantation, and decreased again thereafter to previous levels. When implantation was delayed by ovariectomy and progesterone administration, acrogranin protein expression was low but increased after embryo reactivation with estrogens injection. These data show that acrogranin is temporally and spatially expressed in the peri-implantation zone of the uterus predominantly and is up-regulated by embryo attachment; suggesting that this growth factor is a marker of implantation.

KEY WORDS: Acrogranin, Granulins, Epithelins, Implantation