Tenascin in Pregnant and Non-Pregnant Rat Uterus: Unique Spatio-Temporal Expression during Decidualization1

Abstract

Tenascin is a large extracellular matrix (ECM) protein generally restricted to developing embryonic tissues and tissues undergoing remodelling in the adult, but it has been suggested that tenascin is immunomodulatory. In this study we have used indirect immunofluorescence to investigate the distribution of tenascin within the uteri of pregnant and non-pregnant rats. The non-pregnant uterus expressed tenascin in the stroma around the glands, but only the subluminal stroma showed cyclical variations. Dependence of the latter on progesterone was verified in ovariectomized animals supplemented with steroid hormones. During early pregnancy, the uterine circular smooth muscle maintained an intense expression of tenascin. In the decidualizing endometrium, tenascin expression showed dramatic changes that reflected the regionalization of the decidualization process. On Day 6 (blastocyst attachment), tenascin immunoreactivity was prominent in the primary decidualization zone immediately surrounding the conceptus. On Day 7, expression had increased within the secondary decidua that had developed throughout the antimesometrial endometrium. By Day 8, the antimesometrial decidua showed diminished tenascin immunoreactivity; expression became largely confined to the ECM of the developing decidua in the mesometrial region, where levels were high. On Day 10, the well-developed mesometrial decidua was negative. Interestingly, tenascin expression was up-regulated in the walls of the vessels in the metrial gland within the mesometrial triangle beginning on Day 10 of pregnancy. From these studies we conclude that tenascin expression may be an important reflection of the dynamics involved with tissue restructuring during early pregnancy and may play a role in immunomodulation, since expression of this protein in the mesometrial decidua coincides with the presence of differentiating natural killer cell lineage lymphocytes in the same region.

The change in tenascin expression in mouse uterus during early pregnancy

“…Compared with TN expression in the subepithelial region, the smooth muscle showed a constant TN expression from Day 1 to Day 5. The prominent expression of TN around the smooth muscle was also reported to be a constant feature during the different stages of the cycle and in ovariectomized rats (12). Therefore, we speculate that the expression of TN in the smooth muscle is not under steroid hormone control but is an important reflection of the dynamics of the expansion of the tissue due to decidua formation in early pregnancy.…”

Gene expression profiling of bovine endometrium during the oestrous cycle: detection of molecular pathways involved in functional changes

“…Furthermore, a role during pregnancy or the implantation process was shown or assumed for APOE (apolipoprotein E) (Overbergh et al 1995), CLDN10 (claudin 10) (Wang et al 2004), EFNA1 (ephrin A1) (Fujiwara et al 2002), FBLN1 (fibulin 1) (Haendler et al 2004), fibronectin (Rider et al 1992), GJA1 (Gabriel et al 2004), LGALS1 (Maquoi et al 1997), MGP (matrix gla protein) (Spencer et al 1999), MMP2 (matrix metalloproteinase 2) (Goffin et al 2003), PENK (Jin et al 1988), PLA2 G10 (phospholipase A2) (Goff 2004), SERPINA1 (Marshall & Braye 1987), TNC (Michie & Head 1994) and UTMP (Hansen 1998).…”

MiR‐98 is involved in rat embryo implantation by targeting Bcl‐xl

“…However, miR-98 expression showed a decreasing trend in the uterus of the ovariectomized pregnant rat treated by progesterone. It is different in gene expression patterns and hormonal levels in rat uterus between pregnancy and non-pregnancy [17,18], which may be one of the reasons that results in the contradictory results.…”