Isolation and Characterization of a 30-kDa Endometrial Glycoprotein Synthesized during the Estrous Cycle and Early Pregnancy of the Pig1

Abstract

Endometrial polypeptide synthesis, which is regulated through ovarian steroid secretion and steroid production by the developing conceptus, not only provides the necessary secretory components vital to conceptus development but also presents the adhesive changes in the epithelial surface essential for conceptus attachment. In the present study, a 30-kDa, basic endometrial glycoprotein (pGP30) was isolated and characterized during the estrous cycle and early pregnancy of the pig. Uterine flushings and endometrial culture media were obtained from gilts on Days 0, 5, 10, 12, 15, and 18 of the estrous cycle and Days 10, 12, 15, and 18 of pregnancy. A polyclonal antibody was generated to pGP30 after isolation of medium from Day 15 pregnant endometrial cultures separated by gel filtration and PAGE. Western blot analysis indicated that the antiserum reacted with isoforms of pGP30 and cross-reacted with a 90-kDa component in serum that was not removed after cleavage of the oligosaccharide chains from the 90-kDa glycoprotein. Antiserum did not detect a 30-kDa band in media from cultures of kidney, fat, heart, muscle, liver, or serum; however, heart and muscle did contain bands of different molecular masses that cross-reacted with the antiserum. Multiple bands of higher molecular mass (35-40 kDa) were detected in the endometrial cultures from gilts on Days 0 through 10 of the estrous cycle. Treatment of ovariectomized gilts with estradiol-17 beta stimulated a similar response. During the mid- to late luteal phase of the estrous cycle (Days 12-18), the 30-kDa band as well as an additional 32-kDa band was present on Western blots. Administration of progesterone for 14 days stimulated the synthesis of both the 30- and 32-kDa products in ovariectomized gilts. However, only the pGP30 was detected on Days 12-18 of pregnancy. Immunocytochemical localization with antiserum to pGP30 indicated that the glycoprotein is present in the endometrial epithelium, with the surface epithelium demonstrating the strongest reaction product. Discrete changes in staining and cellular localization were observed during the early stages of the estrous cycle (Days 0-5) and the midluteal (Day 10) phase. A similar response was achieved with administration of steroids to ovariectomized gilts. Data indicate that discrete changes in epithelial synthesis of the endometrial glycoprotein occur at the time of conceptus trophoblastic elongation and placental attachment in the pig.

Effects of long-term progesterone on developmental and functional aspects of porcine uterine epithelia and vasculature: progesterone alone does not support development of uterine glands comparable to that of pregnancy

“…The glycocalyx and integrins are prominent at this surface (Bowen et al 1996, Sant'Ana et al 2009). Surface glycoproteins, including galactosamines, and integrins, including a v , are important to conceptus attachment in the pig (Dantzer 1985, Geisert et al 1995, Bowen et al 1996, Effects of progesterone on tight junctional complexes of uterine LE and GE. Immunofluorescence localization of zona occludin-1 (occludin-1), zona occludin-2 (occludin-2), claudin-3, and claudin-4 on day 40 endometria from ovariectomized gilts treated with corn oil or progesterone is shown.…”

The influence of estradiol and progesterone on the concentrations of uterine oxytocin receptors and plasma PGFM in response to oxytocin in ovariectomized gilts

“…In the other groups studied, plasma PGFM levels increased in response to OT only in individual females. Plasma E 2 , P 4 , OT and baseline PGFM levels on the day of OT injection were 8.00 p.m. Doses and the schedule of EB and P 4 injection were chosen for the assurance of plasma E 2 and P 4 concentrations typical for the oestrous cycle in gilts [15,52]. The detailed schedule of treatment is given in Table I.…”

“…These estrogens may cause an increase in the synthesis of endometrial glycoproteins, i.e. the 30-kDa glycoprotein [15]. It is possible that adrenal estrogens in OVX gilts may be involved in uterine OTR synthesis.…”

“…However, in pigs, luteolysis is not preceded by a temporal increase in endometrial OTR [29,33]. In sows, the concentration of plasma PGF 2a metabolite (PGFM) significantly increased in response to the OT administered around luteolysis (days [14][15][16], but there is no response during the early luteal phase (days 4-6) and a weak response is found in the mid-luteal phase (days 9-12) of the oestrous cycle [6,20]. These data indirectly suggest that cyclic changes of estrogens (E 2 ) and the P 4 level during the oestrous cycle may influence uterine OTR concentration and PGF 2a response to OT.…”

ESTUDIO LECTINHISTOQUÍMICO DEL ÚTERO DE ALPACAS (Vicugna pacos) BAJO TRATAMIENTO SUPEROVULATORIO.

“…En el ratón, cerdo, asno, caballo y camello se conoce que la presencia de glicoconjugados en la interfase materno-fetal es de gran importancia, ya que permitirían las interacciones entre los componentes placentarios fetales y maternos, jugando un rol importante en la implantación y en el mantenimiento de la gestación (Richa et al, 1985;Cross et al, 1994;Geisert et al, 1995;Jones et al, 2000;Koncurat et al, 2004). Asimismo, alteraciones en el patrón de glicosilación podrían afectar el proceso de implantación (García et al, 2007).…”