PARENT SESSION
IMPLANTATION AND PREGNANCY - A

Monday, August 2, 2004
10:30 AM–12:30 PM
Buchanan Courtyard

(272) EXPRESSION OF THE STATHMIN FAMILY GENES IN THE UTERUS DURING EARLY PREGNANCY OF MOUSE AND THEIR FUNCTIONS.

Yoshie, Mikihiro¹, Tamura, Kazuhiro¹, Hara, Takahiko², Kogo, Hiroshi¹, ¹ Department of Endocrine Pharmacology, Tokyo University of Pharmacy & Life Science, Tokyo, Japan² The Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

ABSTRACT- We have previously found using rats that stathmin, a cytosolic phosphoprotein that regulates microtubule depolymerization and the cell cycle, is expressed at the sites of embryo implantation in the endometrium. In the present study, we examined the expression and localization of stathmin in mouse uterus during the peri-implantation period. Stathmin protein was abundantly expressed in the glandular epithelium and stroma on Day 3 of pregnancy. On Day 5, the day of implantation, stathmin protein was only found in stromal cells. After the initiation of implantation, the intense expression of stathmin was primarily limited to the decidual cells surrounding the implanted embryo on Day 7. The levels of stathmin protein increased within 24 hours after decidual stimulus by oil infusion for the induction of deciduoma formation in the artificial decidualization model. To address the functions of uterine stathmin during pregnancy, number of implantation sites, weight of artificially induced deciduoma, decidual markers (desmin, cyclin D3 and alkaline phosphatase) expressions, and number of newborn pups were analyzed in stathmin-knockout mice. Stathmin-deficient mice delivered a significantly reduced number of neonates, compared with that in wild-type mice. Expressions of the decidual markers were indistinguishable between in knockout mice and wild-type mice. The number of implantation sites and the weight of artificially induced deciduoma in stathmin-deficient mice were comparable to those in wild-type mice. When we examined the uterine expression pattern of the stathmin family genes, SCG10, SCG10-like protein (SCLIP) and RB3 during the peri-implantation period, we observed that SCG10 mRNA was highly expressed in the uterus on Days 7 and 8 in both wild-type and stathmin-deficient mice. Furthermore, the levels of SCLIP and RB3 mRNA in the uterus were higher in stathmin-deficient mice than in wild-type mice. These results suggest a compensatory role of the family members for the normal pregnancy approaching term in mice in addition to a role of stathmin family genes for implantation.

KEY WORDS: implantation , stathmin family, decidualization