Expression of tenascin-C in stromal cells of the murine uterus during early pregnancy: Induction by interleukin-1 alpha, prostaglandin E-2, and prostaglandin F-2 alpha

Tenascin-C (TN-C), an extracellular matrix glycoprotein, is known to be exp ressed in uterine stroma in the peri-implantation period. Examination of th e spatiotemporal pattern during early pregnancy using immunohistochemistry and in situ hybridization revealed TN-C expression in the stroma beneath th e luminal epithelia of the murine endometrium on Days 0 and 1 of pregnancy, subsequent disappearance, and reappearance on Day 4. After decidualization , tissue around the deciduoma was positive. In situ hybridization demonstra ted TN-C production by the stromal cells adjacent to the epithelia. To inve stigate the regulation of TN-C expression in vitro, murine uterine stromal and epithelial cells were isolated and cultured. Addition of interleukin-1 alpha (IL-1 alpha) and prostaglandin E-2 (PGE(2)) and E-2 alpha (PGF(2 alph a)) induced TN-C expression in the stromal cells at both protein and mRNA l evels, while the sex steroid hormones, progesterone and beta -estradiol, ex erted little effect. Immunohistochemistry using anti-IL-1 alpha antibody sh owed epithelial cells to be positive on Days 2-4 of pregnancy, and addition of progesterone but not beta -estradiol enhanced IL-1 alpha expression in epithelial cells in vitro. In a culture insert system, TN-C expression by s tromal cells cocultured with epithelial cells was induced by addition of pr ogesterone alone that was blocked by additions of anti-IL-1 alpha antibody. Collectively, these findings indicate that TN-C expression in the preimpla ntation period is under the central of progesterone, but not directly, poss ibly by the paracrine and autocrine intervention of IL-1 alpha secreted by epithelial cells and PGE, and PGF(2 alpha) secreted by stromal cells.