secretion of the major progesterone-induced proteins of the sheep uterus by caruncular and intercaruncular endometrium of the pregnant ewe from days 20–140 of gestation

Stanniocalcin (STC) is a hormone in fish that regulates calcium levels. Mammals have two orthologs of STC with roles in calcium and phosphate metabolism and perhaps cell differentiation. In the kidney and gut, STC regulates calcium and phosphate homeostasis. In the mouse uterus, Stc1 increases in the mesometrial decidua during implantation. These studies determined the effects of pregnancy and related hormones on STC expression in the ovine uterus. In Days 10-16 cyclic and pregnant ewes, STC1 mRNA was not detected in the uterus. Intriguingly, STC1 mRNA appeared on Day 18 of pregnancy, specifically in the endometrial glands, increased from Day 18 to Day 80, and remained abundant to Day 120 of gestation. STC1 mRNA was not detected in the placenta, whereas STC2 mRNA was detected at low abundance in conceptus trophectoderm and endometrial glands during later pregnancy. Immunoreactive STC1 protein was detected predominantly in the endometrial glands after Day 16 of pregnancy and in areolae that transport uterine gland secretions across the placenta. In ovariectomized ewes, long-term progesterone therapy induced STC1 mRNA. Although interferon tau had no effect on endometrial STC1, intrauterine infusions of ovine placental lactogen (PL) increased endometrial gland STC1 mRNA abundance in progestinized ewes. These studies demonstrate that STC1 is induced by progesterone and increased by a placental hormone (PL) in endometrial glands of the ovine uterus during conceptus (embryo/fetus and extraembryonic membranes) implantation and placentation. Western blot analyses revealed the presence of a 25-kDa STC1 protein in the endometrium, uterine luminal fluid, and allantoic fluid. The data suggest that STC1 secreted by the endometrial glands is transported into the fetal circulation and allantoic fluid, where it is hypothesized to regulate growth and differentiation of the fetus and placenta, by placental areolae.

Section: Stc1 In the Ovine Uterusmentioning

confidence: 97%

Stanniocalcin (STC) in the Endometrial Glands of the Ovine Uterus: Regulation by Progesterone and Placental Hormones1

Song

Bazer

Wagner

et al. 2006

“…The ELISA was performed as previously described [30]. Antigen (UTM-proteins or uterine fluid) was coated at a concentration of 10 ptg/ml; blocker was 1% (w/ v) gelatin; primary antibodies used were mouse monoclonal antibody to UTM-proteins, rabbit antibody to TGF3, or rabbit antiserum to T-cell suppressor factor; alkalinephosphatase-conjugated second antibodies were goat antimouse IgG (for anti-UTM-proteins) or goat anti-rabbit IgG (for other antibodies).…”

Section: Presence Of Tgf(3 and T-cell Suppressor Factor In Uterine Fluidmentioning

confidence: 99%

“…Another goal was to further characterize the biochemical properties of MS. Unilaterally pregnant ewes were used as a source of uterine fluid because these ewes have large amounts of uterine fluid that contains lymphocyte-inhibitory activity that has biochemical characteristics almost identical to inhibitory activity in uterine fluid from progesterone-treated ewes [21,24]. Furthermore, the ligation is not believed to alter types of proteins produced by the endometrium because the electrophoretic pattern of proteins produced by the endometrium of the ligated uterine horn is very similar to that of the nonligated, pregnant uterine horn [30,35].…”

Section: Introductionmentioning

confidence: 98%

“…These proteins, usually termed the uterine milk proteins (UTM-proteins), are a pair of related glycoproteins of basic isoelectric point having molecular weights of 55 000 and 57 000 [27]. The UTM-proteins show sequence homology with members of the serpin superfamily of protease inhibitors [28], are the most abundant proteins in uterine fluid of pregnant ewes [29,30], and can be induced by treatment with progesterone [29,31,32]. Related proteins are found in uterine fluid of cows [32] and pigs [33].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identification of the Predominant Proteins in Uterine Fluids of Unilaterally Pregnant Ewes that Inhibit Lymphocyte Proliferation1

Skopets

Hansen

1993

Uterine fluid from unilaterally pregnant ewes contains activity inhibitory to lymphocyte proliferation. The molecules responsible for this activity may thereby regulate uterine immune responses during pregnancy. The purpose of the experiment described here was to identify the major protein in uterine fluid responsible for this activity. When uterine fluid was fractionated by a combination of cation exchange chromatography, gel filtration, and lectin affinity chromatography, the majority of the lymphocyte activity co-migrated with a pair of proteins previously identified as related, serpin-like glycoproteins. Together, this pair of proteins, called the uterine milk proteins (UTM-proteins), are the predominant endometrial secretory protein produced under the influence of progesterone. Preparations of uterine protein highly enriched for the UTM-proteins inhibited lymphocyte proliferation induced by phytohemagglutinin, concanavalin A, and mixed lymphocyte reactions but did not inhibit proliferation induced by pokeweed mitogen. In some experiments, UTM-proteins also reduced viability of cultured lymphocytes. Another previously described lymphocyte-inhibitory factor, megasuppressin, was also observed. Megasuppressin, which eluted at an apparent molecular weight of greater than 4 x 10(6) even after treatment with urea, guanidine-HCl, and beta-mercaptoethanol, was a more potent inhibitor of lymphocyte proliferation than UTM-proteins. Megasuppressin is not very abundant, however, and probably is responsible for only a small fraction of the lymphocyte inhibitory activity in uterine fluid. The majority of lymphocyte-inhibitory activity is caused by the UTM-proteins or by a molecule that co-purifies in trace amounts with UTM-proteins.

“…In fact, since conceptuses of large domestic farm animals undergo noninvasive epitheliochorial placentation and the uterine epithelium is never eroded during pregnancy, uterine secretions may be required for nutritional support of the conceptus throughout gestation [1]. For this reason, uterine secretions of cattle [3][4][5][6][7][8], sheep [9][10][11][12], and pigs [13][14][15][16][17] have received considerable attention.…”

Section: Introductionmentioning

confidence: 99%

Retinol-Binding Protein Gene Expression in Cyclic and Pregnant Endometrium of Pigs, Sheep, and Cattle1

Harney

Ott

Geisert

et al. 1993

Retinol-binding protein (RBP) is a major secretory product of conceptuses and endometrium of the large domestic animals. The present study examined the abundance of RBP mRNA in cyclic and early pregnant endometrium of pigs, sheep, and cattle and confirmed the presence of RBP mRNA in preiimplantation conceptuses of the large domestic animals. Northern blot analysis, using porcine liver RBP cDNA as the probe, detected a 1.0-1.1-kb transcript in conceptuses and endometrium collected during the preiimplantation period of pregnancy in pigs (Day 15), sheep (Day 16), and cows (Day 18). Slot-blot analysis of RBP mRNA in endometrium of pigs, sheep, and cows indicated differential RBP gene expression across days and statuses in pigs and sheep and across days alone in cows. In pigs, RBP gene expression was low to undetectable at Days 0, 5, and 10 of the estrous cycle and Day 10 of pregnancy. Levels of RBP mRNA increased (p < 0.06) from Days 10 to 12 and further (p < 0.001) to Day 15 across both statuses. At Day 18, RBP mRNA levels decreased (p < 0.01) in cyclic pigs but remained elevated in endometrium of pregnant pigs. In sheep, levels of RBP mRNA increased between Days 10 and 12 and 14 in both cyclic and pregnant ewes; however, between Days 14 and 16, RBP mRNA levels remained elevated in cyclic endometrium but decreased (p < 0.01) in endometrium of pregnant ewes. In a second experiment, RBP mRNA levels increased (p < 0.01) between Days 0-5 and Days 13-15 of the estrous cycle.(ABSTRACT TRUNCATED AT 250 WORDS)