Effect of Steroids on HOXA10 mRNA and Protein Expression and Prostaglandin Production in the Porcine Endometrium

2011

Reproduction

Self Cite

Ovarian progesterone induces essential changes leading to a temporary state of uterine receptivity for conceptus implantation. Estrogens secreted by the porcine conceptus on days 11 and 12 of pregnancy provide the initial signal for maternal recognition of pregnancy and maintenance of a functional corpus luteum (CL) for continued production of progesterone. As prostaglandins F 2a (PGF 2a ) and E 2 (PGE 2 ) exert opposing actions on the CL, a tight control over their synthesis and secretion is critical either for the initiation of luteolysis or maintenance of pregnancy. One of the supportive mechanisms by which conceptus inhibits luteolysis is changing PG synthesis in favor of luteoprotective PGE 2 . Conceptus PGE 2 could be amplified by PGE 2 feedback loop in the endometrium. In pigs, as in other species, implantation and establishment of pregnancy is associated with upregulation of expression of proinflammatory factors, which include cytokines, growth factors, and lipid mediators. The conceptus produces inflammatory mediators: interferon g and interferon d, interleukins IL1B and IL6, and PGs, which probably activate inflammatory pathways in the endometrium. The endometrium responds to these embryonic signals by enhancing further progesterone-induced uterine receptivity. Understanding the mechanisms of pregnancy establishment is required for translational research to increase reproductive efficiencies and fertility in humans and animals.

Section: Uterine Receptivity Markers Involved In Pg Synthesismentioning

confidence: 90%

Novel insights into the mechanisms of pregnancy establishment: regulation of prostaglandin synthesis and signaling in the pig

2011

Reproduction

Self Cite

“…In pigs, HOXA10 protein was localized in the uterine LE and GE, but also stroma and blood vessels of the uterus, and increased endometrial HOXA10 expression was detected on days 12-15 of pregnancy (Blitek et al 2010a). Moreover, the abundance of HOXA10 transcripts was stimulated by oestrogen in endometrial explants (Blitek et al 2010b) and by conceptus-derived products in uterine LE of the pig (Blitek et al 2011). Higher HOXA10 content in response to oestrogen and conceptus products was accompanied by elevated PTGS2 expression and PGE 2 secretion from endometrial cells of the pig (Blitek et al 2010b;.…”

Section: Proinflammatory Environment During Implantation Periodmentioning

confidence: 96%

“…2010a). Moreover, the abundance of HOXA10 transcripts was stimulated by oestrogen in endometrial explants (Blitek et al. 2010b) and by conceptus‐derived products in uterine LE of the pig (Blitek et al.…”

Section: Implantation Periodmentioning

confidence: 99%

“…2011). Higher HOXA10 content in response to oestrogen and conceptus products was accompanied by elevated PTGS2 expression and PGE 2 secretion from endometrial cells of the pig (Blitek et al. 2010b; 2011).…”

Section: Implantation Periodmentioning

confidence: 99%

“…Progesterone stimulates transformation of the endometrium into secretory tissue to create an environment permissive to early embryonic development, implantation, placentation and foetal development (Spencer et al 2004). It was demonstrated that progesterone increases the expres-sion of calbindin-D9k (intracellular calcium-binding protein; Yun et al 2004) and a4, a5 and b1 integrin subunits (Bowen et al 1996), as well as HOXA10 and PTGS2 (Blitek et al 2010b) in the porcine uterus. Moreover, total protein content, including RBP, measured in the uterine lumen is controlled by maternal progesterone (Vallet et al 1998).…”

Section: Role Of Progesterone In Establishing Uterine Receptivity To mentioning

confidence: 99%

See 2 more Smart Citations

Mechanisms for the Establishment of Pregnancy in the Pig

Ziȩcik

Reprod Domestic Animals

Kaczmarek

et al. 2011

ContentsEstablishment of pregnancy in pigs requires continuous function of corpora lutea and endometrial preparation for embryo implantation. Progesterone regulates expression of many proteins necessary for endometrial remodelling and embryo-maternal communications. Attaining the uterine receptivity involves progesterone priming and loss of progesterone receptors in the uterine epithelium before days 10-12 after oestrus. Spermatozoa and oocytes in oviduct alter secretion of specific proteins that exert beneficial effect on gametes and embryos. Moreover, an appropriate leucocyte activation and maintenance of delicate cytokine balance within the oviduct and uterus are important for early pregnancy. This early local immune response is rather mediated by seminal plasma components. These components also influence prostaglandin (PG) synthesis in the oviduct that is important for gamete and embryo transport. Pregnancy establishment requires the biphasic pattern of oestrogen secretion by conceptuses on days 11-12 and 15-30. Conceptus affects lipid signalling system consisting of prostaglandins and lysophosphatic acid. PG synthesis is changed by conceptus signals in favour of luteoprotective PGE 2 . Additionally, existence of PGE 2 positive feedback loop in the endometrium contributes to increased PGE 2 ⁄ PGF 2a ratio during the peri-implantation period. PGE 2 through endometrial PGE 2 receptor (PTGER2) elevates the expression of enzymes involved in PGE 2 synthesis. Higher PGE 2 secretion in uterine lumen coincides with the elevated expression of HOXA10 transcription factor critical for implantation. A stable adhesion between conceptus and endometrium requires reduction in mucin-1 on the apical surface of epithelium and integrin activation by extracellular matrix proteins. Furthermore, growth factors, cytokines and its receptors are involved in embryo-maternal interactions.

Embryo‐maternal dialogue during pregnancy establishment and implantation in the pig

Molecular Reproduction Devel

Kaczmarek

Blitek

et al. 2017

Self Cite

107

Porcine conceptuses secrete pregnancy-recognition signals (estrogens, including estradiol-17β) that inhibit luteolysis, thereby prolonging progesterone production by corpora lutea. The supportive mechanism by which the conceptus also inhibits luteolysis is by shifting endometrial prostaglandin (PG) synthesis to luteoprotective PGE2.Progesterone stimulates endometrial production of factors that are essential for conceptus development. Priming the uterus by progesterone and loss of progesterone receptors from the uterine epithelium by Day 10-12 after estrus are key for achieving endometrial receptivity for implantation. Conceptus implantation involves a series of events, many resembling the inflammatory reaction, that are greatly influenced by cytokines, growth factors, and prostaglandins. We herein present a novel, dual role for PGF2α in corpora lutea that depends on the acquisition of luteolytic sensitivity, based on the knowledge that PGF2α triggers pathways involved in luteolysis during the estrous cycle or/and may have an alternative function in maintaining progesterone synthesis during pregnancy. We also point out a new role for PGF2α that, together with PGE2, can act as embryonic signal mediators. PGF2α, which until recently was considered undesirable for promoting pregnancy, is now known to stimulate conceptus-maternal interactions and angiogenesis in the endometrium. This function is in line with other important prostaglandin functions, such as stimulating adhesion of trophoblasts (PGE2, PGI2) as well as endometrial vascular functions and trophoblast cell proliferation (PGI2).