The mechanisms by which sex is determined, and how a sexual phenotype is stably maintained during adulthood, have been the focus of vigorous scientific inquiry. Resources common to the biomedical field (automated staining and imaging platforms) were leveraged to provide the first immunofluorescent data for a reptile species with temperature induced sex reversal. Two four-plex immunofluorescent panels were explored across three sex classes (sex reversed ZZf females, normal ZWf females, and normal ZZm males). One panel was stained for chromatin remodeling genes JARID2 and KDM6B, and methylation marks H3K27me3, and H3K4me3 (Jumonji Panel). The other CaRe panel stained for environmental response genes CIRBP and RelA, and H3K27me3 and H3K4me3. Our study characterized tissue specific expression and cellular localization patterns of these proteins and histone marks, providing new insights to the molecular characteristics of adult gonads in a dragon lizard Pogona vitticeps. The confirmation that mammalian antibodies cross react in P. vitticeps paves the way for experiments that can take advantage of this new immunohistochemical resource to gain a new understanding of the role of these proteins during embryonic development, and most importantly for P. vitticeps, the molecular underpinnings of sex reversal.

Summary sentence

Immunostaining of important chromatin modifiers, histone marks, and environmental response proteins across the three functional sexes in Pogona vitticeps shows protein dynamics differ between males, females, and sex reversed females.

Endometrial stromal cells remodeling is critical during human pregnancy. Growth hormone-releasing hormone and its functional receptor have been shown to be expressed in gynecological cancer cells and eutopic endometrial stromal cells. Recent studies have demonstrated the potential clinical uses of antagonists of growth hormone-releasing hormone as effective antitumor agents because of its directly antagonistic effect on the locally produced growth hormone-releasing hormone in gynecological tumors. However, the impact of growth hormone-releasing hormone antagonists on normal endometrial stromal cell growth remained to be elucidated. The aim of this study was to investigate the effect of a growth hormone-releasing hormone antagonist (JMR-132) on cell proliferation and apoptosis of human decidual stromal cells and the underlying molecular mechanisms. Our results showed that growth hormone-releasing hormone and the splice variant 1 of growth hormone-releasing hormone receptor are expressed in human decidual stromal cells isolated from the decidual tissues of early pregnant women receiving surgical abortion. In addition, treatment of stroma cells with JMR-132 induced cell apoptosis with increasing cleaved caspase-3 and caspase-9 activities and decrease cell viability in a time- and dose-dependent manner. Using a dual inhibition approach (pharmacological inhibitors and siRNA-mediated knockdown), we showed that JMR-132-induced activation of apoptotic signals are mediated by the activation of ERK1/2 and JNK signaling pathways and the subsequent upregulation of GADD45alpha. Taken together, JMR-132 suppresses cell survival of decidual stromal cells by inducing apoptosis through the activation of ERK1/2- and JNK-mediated upregulation of GADD45alpha in human endometrial stromal cells. Our findings provide new insights into the potential impact of growth hormone-releasing hormone antagonist on the decidual programming in humans.

The decidua is a hallmark of reproduction in many placental mammals. Differentiation of decidual stromal cells is known to be induced by progesterone and the cyclic AMP/protein kinase A (cAMP/PKA) pathway. Several candidates have been identified as the physiological stimulus for adenylyl cyclase activation, but their relative importance remains unclear. To bypass this uncertainty, the standard approach for in vitro experiments uses membrane-permeable cAMP and progestin. We phylogenetically infer that prostaglandin E₂ (PGE₂) likely was the signal that ancestrally induced decidualization in conjunction with progesterone. This suggests that PGE₂ and progestin should be able to activate the core gene regulatory network of decidual cells. To test this prediction, we performed a genome-wide study of gene expression in human endometrial fibroblasts decidualized with PGE₂ and progestin. Comparison to a cAMP-based protocol revealed shared activation of core decidual genes and decreased induction of senescence-associated genes. Single-cell transcriptomics of PGE₂-mediated decidualization revealed a distinct, early-activated state transitioning to a differentiated decidual state. PGE₂-mediated decidualization was found to depend upon progestin-dependent induction of PGE₂ receptor 2 (PTGER2) which in turn leads to PKA activation upon PGE₂ stimulation. Progesterone-dependent induction of PTGER2 is absent in opossum, an outgroup taxon of placental mammals which is incapable of decidualization. Together, these findings suggest that the origin of decidualization involved the evolution of progesterone-dependent activation of the PGE₂/PTGER2/PKA axis, facilitating entry into a PKA-dominant rather than AKT-dominant cellular state. We propose the use of PGE₂ for in vitro decidualization as an alternative to 8-Br-cAMP.

Summary sentence

In vitro decidualization of human endometrial stromal fibroblasts with PGE₂ and progestin induces a different but genuine decidual cell state through PTGER2-dependent PKA activation when compared to the conventional cyclic AMP/MPA protocol.

Graphical Abstract

Despite aquaporin water channels (AQPs) play a critical role in maintaining water homeostasis in female reproductive tract and prompt a gradual increase in water content in cervical edema as pregnancy progressed, their relationship with macrophage infiltration and collagen content in human cervical remodeling need to be further investigated. This is the first study to examine the expression and localization of AQP3, AQP4, AQP5, AQP8, and macrophages simultaneously in human cervical ripening. The immunoreactivity of these AQPs was 2.6 to 6-fold higher on gestational weeks 26 (GD26W) than that on GD6W and GD15W, but AQP4 expression on GD39W dropped a similar extent on GD15W, other AQPs continued to rise on GD39W. The AQP3, AQP4, and AQP5 intensity seemed more abundant in cervical stroma than in the perivascular area on GD26W; the distribution of AQP3, AQP5, and AQP8 in cervical stroma was equivalent to that in the perivascular area on GD39W. Macrophage numbers were 1.7-fold higher in subepithelium region and 3.0-fold higher in center area on GD26W than that on GD15W; such numbers remained elevated on GD39W. The electron micrographs showed that cervical extensibility increased significantly on GD26W and GD39W accompanied with increased macrophage infiltration, cervical water content, and much more space among collagen fibers. These findings suggest that the upregulation of AQPs expression in human cervix is closely related to enhanced macrophage infiltration during pregnancy; there may be a positive feedback mechanism between them to lead the increase of water content and the degradation of collagen.

Summary sentence

The increase of AQPs expression in human cervix remodeling is closely related to enhanced inflammatory responses and macrophage infiltration; there may be a positive feedback mechanism between them.

The complex physiologic process of parturition includes the onset of labor, which requires the orchestrated stimulation of a common pathway involving uterine contractility, cervical ripening, and chorioamniotic membrane activation. However, the labor-specific processes taking place in these tissues have limited use as predictive biomarkers unless they can be probed in non-invasive samples, such as the peripheral blood. Herein, we utilized a transcriptomic dataset to assess labor-specific changes in the peripheral blood of women who delivered at term. We identified a set of genes that were differentially expressed with labor and enriched for immunological processes, and these gene expression changes were strongly correlated with results from prior studies, providing in silico validation of our findings. We then identified significant correlations between labor-specific transcriptomic changes in the maternal circulation and those detected in the chorioamniotic membranes, myometrium, and cervix of women at term, demonstrating that tissue-specific labor signatures are partly mirrored in the peripheral blood. Finally, we demonstrated a significant overlap between the peripheral blood transcriptomic changes in term parturition and those observed in asymptomatic women, prior to the diagnosis of preterm prelabor rupture of the membranes, who ultimately delivered preterm. Collectively, we provide evidence that the normal process of labor at term is characterized by a unique immunological expression signature, which may serve as a useful tool for assessing labor status and for potentially identifying women at risk for preterm birth.

Summary sentence: The maternal peripheral blood transcriptome undergoes labor-specific changes that correlate with those in the chorioamniotic membranes, myometrium, and cervix and partially overlap with those observed in asymptomatic women prior to preterm birth.

We evaluated the influence of the hyperglycemic intrauterine environment and postweaning consumption of a high-fat diet (HFD) on the glycemia, insulin, lipid, and immunological profile of rat offspring in adulthood. Female rats received citrate buffer (Control—C) or Streptozotocin (a beta cell-cytotoxic drug to induce diabetes—D) on postnatal day 5. In adulthood, these rats were mated to obtain female offspring, who were fed a standard diet (SD) or HFD from weaning to adulthood (n = 10 rats/group). OC/SD and OC/HFD represent female offspring of control mothers and received SD or HFD, respectively; OD/SD and OD/HFD represent female offspring of diabetic mothers and received SD or HFD, respectively. At adulthood, the oral glucose tolerance test (OGTT) was performed and, next, the rats were anesthetized and euthanized. Pancreas was collected and analyzed, and adipose tissue was weighted. Blood samples were collected to determine biochemical and immunological profiles. The food intake was lower in HFD-fed rats and visceral fat weight was increased in the OD/HFD group. OC/HFD, OD/SD, and OD/HFD groups presented glucose intolerance and lower insulin secretion during OGTT. An impaired pancreatic beta-cell function was shown in the adult offspring of diabetic rats, regardless of diet. Interleukin (IL)-6 and IL-10 concentrations were lower in the OD/HFD group and associated to a low-grade inflammatory condition. The fetal programming was responsible for impaired beta cell function in experimental animals. The association of maternal diabetes and postweaning HFD are responsible for greater glucose intolerance, impaired insulin secretion and immunological change.

Summary sentence

Summary Sentence The association of maternal diabetes and postweaning HFD causes glucose intolerance due to β-cell disarrangement and impaired insulin secretion, and immunological changes in adult offspring.

Graphical Abstract