Effect of steroid hormones on tissue remodelling and progesterone receptors in the uterus of seasonally anoestrous brushtail possums (Trichosurus vulpecula)

Abstract

This study describes progesterone receptor (PR) location within uterine cells and associated morphological changes to the uterine luminal and glandular epithelium in seasonally anoestrous brushtail possums treated with oestradiol and/or progesterone. Twenty-four adult female possums (n 5 6/group) were treated with oestradiol, progesterone, oestradiol followed by progesterone or with the oil vehicle alone for 6-day periods. Uterine tissue was recovered, weighed and processed for light and transmission electron microscopy and for immunohistochemistry for PRs. Stereological techniques were used to quantify epithelial cell and constituent volumes for both luminal and glandular tissues. Plasma concentrations of oestradiol and progesterone were determined by radioimmunoassay. Mean uterine wet weights were significantly heavier (P < 0.001) following oestradiol/progesterone treatment and maximum gland dilation, cellular and stromal growth, maximum cell height, and cell and constituent volumes were recorded after this treatment regimen. Cell nuclei and debris were commonly observed in gland lumina, and nuclear PRs were found predominantly in stromal cells following oestradiol-only treatment. Sequential treatment with oestradiol and then progesterone caused a decline in the number of positively stained cells. Epithelial cells contained extensive secretory organelles and degenerating cells were common within the glands. Oestradiol treatment induced cell and cell constituent growth and promoted PR formation in anoestrous possum uterine tissue. Subsequent exposure to progesterone stimulated uterine tissues to reach maximum wet weights and led to the cellular maturation necessary to remodel the uterus in preparation for pregnancy.

Progesterone-driven local regulatory T cell induction does not prevent fetal loss in the CBA/J×DBA/2J abortion-prone model

“…Being one of the most prominent pregnancy hormones, P4 was reported not only to promote decidualization of endometrial stroma cells 18 and to support tissue remodeling processes, 19 but also to affect the viability and function of several immune cell populations. Being one of the most prominent pregnancy hormones, P4 was reported not only to promote decidualization of endometrial stroma cells 18 and to support tissue remodeling processes, 19 but also to affect the viability and function of several immune cell populations.…”

“…Female sex hormones are best known for their pregnancy supportive functions, including both endocrine and immunologic effects. Being one of the most prominent pregnancy hormones, P4 was reported not only to promote decidualization of endometrial stroma cells 18 and to support tissue remodeling processes, 19 but also to affect the viability and function of several immune cell populations. With regard to its immune modulatory function, the influence of P4 on T cells, B cells, and NK cells has been widely discussed in the literature 20,21 and there is evidence that P4 supplementation in humans suffering from pregnancy complications and in relevant rodent models promotes fetal survival by influencing uterine homing, number, and activity of these immune cell subsets.…”

Uterine expression of cp4 gene homolog in the Stripe‐faced Dunnart, Sminthopsis macroura: Relationship with conceptus development and progesterone profile

“…Classically, pre-implantation endometrial epithelial protein synthesis and secretion is described as being regulated by progesterone (Bazer and Slayden, 2008), with limited regulation by pre-and post-ovulatory oestrogen, partly through the up-regulation of progesterone receptors . Certainly, in vivo injections of either oestradiol or progesterone induce the production of secretory products by the anoestrous glandular epithelium in T. vulpecula (Sizemore et al, 2004) and M. eugenii (Renfree, 1973;Shaw and Renfree, 1986), and in vivo injections of oestradiol during the follicular phase prolong shell secretion during the luteal phase in T. vulpecula (Hughes, 1974). Here, increased sm-cp4 expression was found following incubation with high levels of progesterone or when basal progesterone was included with the oestradiol culture treatments, suggesting that sm-cp4 expression is regulated by progesterone and Figure 3.…”

Uterine molecular changes for non‐invasive embryonic attachment in the marsupials Macropus eugenii (Macropodidae) and Trichosurus vulpecula (Phalangeridae)

“…Stage 1 of M. eugenii pregnancy followed reactivation of the embryo after developmental arrest (Renfree, 1993;Renfree & Shaw, 2000, 2014Tyndale-Biscoe & Renfree, 1987). Stage 1 of T. vulpecula pregnancy followed behavioural oestrus (Pilton & Sharman, 1962;Sizemore et al, 2004;Tyndale-Biscoe, 2005) Stage 3 (12-14d post-oestrus; n = 4), Stage 4 (15-17.5d post-oestrus; n = 1).…”

“…Trichosurus vulpecula has an oestrous cycle of 28 days (Tyndale‐Biscoe, ), a 17.5‐day gestation period (Pilton & Sharman, ; Sizemore, Hurst, & McLeod, ), and does not undergo developmental arrest. Like M. eugenii , T. vulpecula is monovular, and ovulation of a single egg occurs 1–2 days after oestrus.…”