Galactose-binding lectins as markers of pregnancy-related glycoproteins

Abstract

Protein extracts from pregnant mouse endometria were compared with those obtained from non-pregnant and pseudopregnant mice to detect early pregnancy-specific galactose-rich glycoproteins. Gradient gel electrophoresis combined with lectin overlay and lectin histochemistry were used to identify Ricinus communis I (RCA-I), R. communis II (RCA-II) and Cytisus scoparius (CSA) lectin binding glycoproteins. Using this approach, galactose-rich glycoproteins were identified that were maximally expressed in the estrus phase of non-pregnant endometria and also those that had peak expression in pregnancy. Lectin histochemistry revealed pregnancy related changes in three portions of mouse endometrium: endometrial glands, luminal epithelium and its basement membrane. Two major glycoproteins (RCA-I reactive 64 kDa and RCA-II reactive 35 kDa) were specifically expressed in peri-implantation endometrium on days 3 and 4 of pregnancy. The appearance of these glycoproteins during the period of the implantation window in mouse suggests that they could serve as markers of uterine receptivity to the implanting blastocyst.

Ultrastructural studies of glycan changes in the apical surface of the uterine epithelium during pre-ovulatory and pre-implantation stages in the marmoset monkey

“…Furthermore, the limited evidence available on the apical uterine epithelial surface in primates is conflicting mostly because of the different methods used in the LM studies. In view of the substantial evidence for cyclic changes to the uterine epithelial surface in rodents (Anderson et al, 1986;Bukers et al, 1990;Chavez and Anderson, 1985;Horvat, 1993;Murphy and Turner, 1991), the present investigation explored the changes in surface carbohydrates at various stages of the primate reproductive cycle.…”

“…Ricin or castor oil bean lectins, RCA-I and RCA-II, that bind ␤-D-gal and ␤-D-gal/galNAc residues, appear to be more frequently used compared with SBA and overall show conflicting staining for uterine epithelial cell surfaces across a wide range of mammalian species (Akif et al, 1995;Anderson et al, 1990;Bukers et al, 1990;Chavez and Anderson, 1985;Horvat, 1993;Zhou et al, 1994). As in the marmoset, there is reported maximal uterine epithelial surface staining with gal/galNAc at pre-implantation in the macaque (Anderson et al, 1990) and rabbit (Bukers et al, 1990) but minimal staining at this time in the mouse (Chavez and Anderson, 1985) and pig (Zhou et al, 1994).…”

“…The range of carbohydrates that typically constitute a plasma membrane glycocalyx has largely been unexplored in primate studies. Although there is convincing evidence in primates to support cyclic changes in glycans in endometrial glands and stroma (Anderson et al, 1986(Anderson et al, , 1990Bychkov and Toto, 1986;Duncan et al, 1988;Horvat, 1993;Jones et al, 1998;Kupryjanczyk, 1989), the changes in carbohydrates associated with a receptive uterine epithelial glycocalyx remain unknown.…”

Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity.

“…After electrophoresis, proteins were transferred electrophoretically onto nitrocellulose paper in transfer buffer and processed for lectin overlay blotting as described by Horvat (1993). After transfer at constant voltage for a total of 200 Vhr, nitrocellulose papers were stained with Fast Green, destained, and washed in 0.1% TEST (100 mM Tis-HC1, 150 mM NaCI, 0.1% Tween 20, pH 8).…”

“…This indicates that some glycoproteins are under hormonal control in some but not in all reproductive organs. The same applies to the 78 KD glycoprotein (#8), which is expressed in all phases of the cycle in vagina but is estrus-specific in the uterus (Horvat, 1993).…”