|Kayser, Jean Patrick|
|Vallet, Jeffrey - Jeff|
Submitted to: Reproduction
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2005
Publication Date: 2/2/2006
Citation: Kayser, J-P.R., Kim, J.G., Cerny, R.L., Vallet, J.L. 2006. Global characterization of porcine intrauterine proteins during early pregnancy. Reproduction. 132(2):379-388. Interpretive Summary: Establishment of pregnancy early in gestation is a critical process for the continued success of the developing embryo. Uterine secretions play an important role in timing uterine receptivity and early development of the embryo which includes embryo remodeling and development of the placenta. Several highly abundant proteins in uterine fluid have been identified. However, most of the proteins found in the uterine lumen during early pregnancy have not been identified. Obtaining information on proteins has been limited by the ability to measure and identify proteins with high throughput. In this study, we combined gel-based protein separation techniques with mass spectrometry to identify proteins in the uterine lumen that change between day 10 and 13 of the cycle or pregnancy in order to provide clues to biological processes occurring during this period. Our results show that concentrations of many proteins within the intrauterine environment during this period are not dependent on pregnancy. Many of the proteins identified could play roles in regulation of either the inside surface of the uterus or the outside surface of the embryo during early pregnancy and could, therefore, be involved in the interaction between the two.
Technical Abstract: Total protein secreted in the intrauterine lumen increases between day 10 and 13 post estrus in both cyclic and pregnant gilts. The objective of this experiment was to identify those intrauterine proteins whose secretion changes during this time period. Sixteen mature gilts were either mated (day 0) or remained cyclic and were slaughtered at either day 10 or day 13 (n = 4 per status by day). At slaughter, each uterine horn was flushed with 20 mL of minimal essential medium. Flushings were dialyzed extensively against distilled water. A 0.5 mL aliquot of each was lyophilized, subjected to two-dimensional PAGE, and protein spots were identified following Coomassie staining of each gel. Densitometry was used to compare relative amounts of each spot. After statistical analysis, spots that differed due to either day, status or day by status interaction were excised and digested in-gel with trypsin. The resulting peptides were analyzed by tandem mass spectrometry (MS/MS). Using MS/MS data, protein identification for each spot was attempted. There were 280 matching spots, 132 were significantly (P < 0.05 or 0.01) affected by pregnancy status, day or the day by status interaction. Most (73%) spots increased from day 10 to day 13 with no effect of pregnancy. Several spots were identified as proteases or their inhibitors. Others potentially modify glycolipids and/or glycoproteins. These results indicate that concentrations of many proteins within the intrauterine environment during early pregnancy are independent of the conceptus. Many of the proteins present could play roles in regulation of the endometrial or conceptus glycocalyx during early pregnancy.