Maternal Tissues Research Articles

Analysis of histone H3K4me3 modifications in bovine placenta derived from different calf-production methods.

In ruminants, the overgrowth of offspring produced by invitro fertilization (IVF) is a common problem. Abnormal epigenetic modifications caused by environmental factors during the early embryonic period are suspected as an aetiology of overgrowth. In this study, we investigated the genome-wide histone H3K4me3 profiles of bovine placentae that play a pivotal role in foetal development and compared their characteristics between artificial insemination (AI)- and IVF-derived samples. Cotyledons were harvested from the placentae obtained at parturition of 5 AI- and 13 IVF-derived calves, and chromatin immunoprecipitation sequencing was performed for H3K4me3. We confirmed no significant maternal tissue contamination in the samples we used. The revealed H3K4me3 profiles reflected the general characteristics of the H3K4me3 modification, which is abundantly distributed in the promoter region of active genes. By extracting common modifications from multiple samples, the genes involved in placenta-specific biological processes could be enriched. Comparison with the H3K4me3 modifications of blastocyst samples was also effective for enriching the placenta-specific features. Principal component analysis suggested the presence of differential H3K4me3 modifications in AI- and IVF-derived samples. The genes contributing to the difference were related to the developmental biological processes. Imprinted genes such as BEGAIN, ZNF215 and DLX5 were among the extracted genes. Principal component and discriminant analyses using only male samples categorized the samples into three groups based on foetal weight and calf-production methods. To our knowledge, this is the first study to profile the genome-wide histone modifications of bovine foetal placentae and reveal their differential characteristics between different calf-production methods.

Cyclic Somatic Embryogenesis in Indonesian Elite Theobroma cacao L. Clones

To date, in vitro somatic embryogenesis is the only option for the mass vegetative propagation of cocoa. The somatic embryogenesis of Indonesian cocoa clones SUL1 and SUL2 was investigated, focusing on primary and cyclic secondary embryogenesis. The study showed that staminode explants were more effective than petal explants in generating primary somatic embryos (SEs), especially when cultured in liquid medium containing 2 mg/L 2,4-D and 0.25 mg/L kinetin, with the staminodes of SUL2 producing a significant number of globular SEs. In contrast, SUL1 showed limited SE production. The study also demonstrated that fragmenting cotyledons and hypocotyls of the SEs of SUL2 and culturing them on an induction medium supplemented with 2,4,5-T and proline resulted in a high yield of secondary SEs. This cyclic embryogenesis process, in which the SEs remained attached to the maternal tissue, facilitated continuous SE production and development. The addition of proline was found to improve the quality of SEs, leading to higher production of well-organized, milky SEs with a better-defined meristematic structure. These results suggest a promising protocol to produce SEs from cocoa, with implications for plant transformation and gene editing applications.

Subunit nanovaccine elicited T cell functional activation controls Trypanosoma cruzi mediated maternal and placental tissue damage and improves pregnancy outcomes in mice

This study investigated a candidate vaccine effect against maternal Trypanosoma cruzi (Tc) infection and improved pregnancy outcomes. For this, TcG2 and TcG4 were cloned in a nanoplasmid optimized for delivery, antigen expression, and regulatory compliance (nano2/4 vaccine). Female C57BL/6 mice were immunized with nano2/4, infected (Tc SylvioX10), and mated 7-days post-infection to enable fetal development during the maternal acute parasitemia phase. Females were euthanized at E12–E17 (gestation) days. Splenic and placental T-cell responses were monitored by flow cytometry. Maternal and placental/fetal tissues were examined for parasites by qPCR and inflammatory infiltrate by histology. Controls included age/immunization-matched non-pregnant females. Nano2/4 exhibited no toxicity and elicited protective IgG2a/IgG1 response in mice. Nano2/4 signaled a splenic expansion of functionally active CD4+ effector/effector memory (Tem) and central memory (Tcm) cells in pregnant mice. Upon challenge infection, nano2/4 increased the splenic CD4+ and CD8+T cells in all mice and increased the proliferation of CD4+Tem, CD4+Tcm, and CD8+Tcm subsets producing IFNγ and cytolytic molecules (PRF1, GZB) in pregnant mice. A balanced serum cytokines/chemokines response and placental immune characteristics indicated that pregnancy prevented the overwhelming damaging immune response in mice. Importantly, pregnancy itself resulted in a significant reduction of parasites in maternal and fetal tissues. Nano2/4 was effective in arresting the Tc-induced tissue inflammatory infiltrate, necrosis, and fibrosis in maternal and placental tissues and improving maternal fertility, placental efficiency, and fetal survival. In conclusion, we show that maternal nano2/4 vaccination is beneficial in controlling the adverse effects of Tc infection on maternal health, fetal survival, and pregnancy outcomes.

What is the Optimum Endometrium Needed for Implantation?

Implantation most critical step in reproduction. A complex process where blastocyst becomes intimately connected with maternal endometrium/decidua and requires; Competent embryo at blastocyst stage Receptive endometrium Synchronized dialogue between maternal and embryonic tissues Endometrial Changes for Implantation include architectural, morphological, cytochemical, molecular and genetic. These Changes Induce Endometrial receptivity, which is endometrial lining in a state of readiness for blastocyst implantation. It involves acquisition of adhesion ligands and loss of inhibitory components that may act as a barrier to an attaching embryo. Receptive endometrium is capable of selecting good quality embryos and reject the incompetent embryos. Endometrial Evaluation includes 1. Non-Invasive Assessment of Endometrial Receptivity by USG 2. Detection of abnormal Uterine cavity by 3D USG/SIS, HSG and Hysteroscopy 3. Diagnose Chronic Endometritis by hysteroscopy and Molecular tests? 4. Endometrial Microbiome by molecular tests 5. Endometrial asynchrony - Proteomics and transcriptomics 2D and 3D Ultrasound can Identify patients with poor implantation prognosis but has low predictive value in determining endometrial receptivity and IVF outcome. Ideal endometrial thickness for optimal outcome is between 7-14 mm. No Association was seen between clinical pregnancy rates (CPR) and endometrial pattern for women undergoing in IVF with fresh ET and FET. Minimum Endometrial Volume associated with pregnancy is 1.59 mL – 3D. But most pregnancies occur in volumes of 2-13 mL. Evaluation of endometrial volume is particularly useful in synechiae, adenomyosis and uterine anomalies. Vascularity demonstrated within Zone 3 or within Zones 3 and 4 prior to transfer is associated with good implantation rate. Presence of >3 peristaltic contractions of the sub endometrial myometrium/2 minutes interval on Day of hCG administration associated with poor implantation. Diagnosis of chronic endometritis is based on hysteroscopy, endometrial biopsy with plasma cells being identified histologically and specific treatment is determined based on microbial culture. Existence of non-Lactobacillus bacteria in the endometrium is correlated with negative impacts on reproductive function and should be considered as an emerging cause of implantation failure and pregnancy loss. Endometrial Receptivity Array (ERA) is validated for analysing the expression of 238 genes that are intimately related to endometrial receptivity. Abnormality in endometrial receptivity is displayed a specific gene expression profile. Intrauterine secretory profile directly linked to successful implantation and evaluation of endometrial fluid for cytokine, interleukin and growth factor secretions can be used to assess the endometrium. Conclusion: Identification of one or more of endometrial parameters that definitely indicate receptivity for implantation remains an elusive goal. None of the endometrial receptivity markers have sufficient discriminatory value to act as a diagnostic test for endometrial receptivity based on their ability to predict clinical pregnancy. Due to the dynamic, cyclic nature of the endometrium it may be difficult, to reliably assess endometrial function on the basis of a single test.

Enzymatic Digestion and Single Cell Isolation of Peri-implantation Stage Human Trophoblast Cells.

Recent developments in the in vitro culture of peri-implantation stage human embryos have expanded opportunities to investigate implantation stage human development and trophoblast differentiation in the absence of maternal tissues. Emerging single cell omics analyses have offered researchers new tools to explore unanswered biological questions to new depths. In order to investigate the dynamics of human trophoblast cell differentiation during implantation at the single-cell resolution, efficient cell dissociation approaches of trophoblasts from embryos are necessary. Here, we describe the protocol for extended culture of peri-implantation stage human embryos with enzymatic digestion and manual collection of individual cells for downstream assays.

Methods for Co-culture of Primary Human Extravillous Trophoblast Cells and Uterine Natural Killer Cells.

During early pregnancy, fetal-derived extravillous trophoblast cells (EVT) from the placenta invade the maternal decidua and inner third of the uterus where they establish fetal tolerance and remodel the uterine spiralarteries, which ensures establishment of a successful pregnancy. Aberrant EVT invasion and spiral artery remodeling is associated with a number of pregnancy complications including miscarriage, preeclampsia, fetal growth restriction, and placenta accrete. During invasion of the maternal tissues, the EVT interact with a number of different cell types including the decidual leukocytes. EVT express HLA-C, HLA-G, HLA-E, and HLA-F and interact with uterine natural killer (uNK) cells through a series of different receptors. Epidemiological evidence suggests that different combinations of HLA-C and killer cell Ig-like receptor (KIR) haplotypes impact pregnancy success. Therefore, there is much interest in the functional consequence of interactions between EVT and uNK cells, and several different methodologies have been used to isolate these different cell types and their co-culture.

Heavy consumption of garlic (Allium sativum) exert nephro- and pulmonary toxicity at maternal and embryonic level in the Albino rats

ABSTRACT Despite the health benefits of herbals, random misuse of such therapy without consult tends to participate in public health issues. This study describes the nephro-and pulmonary toxicity effects of heavy consumption of garlic (Allium sativum) during developmental period. Two groups of ten healthy pregnant female Albino rats each were formed from the 20 in total. Gavages of distilled water were administered to the control group. Since garlic group rats orally received garlic aqueous extract (GAE) 1 ml/rat daily from gestational day (GD) 6 to 19. Kidney functions and lipid biomarkers were assayed along with histopathological investigations. Our results confirmed that the group that received garlic had significantly increased serum levels of urea, cholesterol, triglycerides and LDL. Moreover, the foetal and maternal tissues of the kidney and lung exhibited a varying degree of histopathological manifestations characterized by kidney necrosis and lung haemorrhage, severe congestion, and thickening of the blood vessels. Renal and pulmonary fibrosis were detectable by Masson’s trichrome. A positive expression of the foetal kidney and placental tissues towards Bax protein was noticed. In conclusion, depending on existing findings, the administration of higher concentrations of garlic could explode renal and pulmonary toxicity and decrease the rat’s weight.

The distribution and metabolism of hexabromocyclododecane isomers varies in the tissues of Nibea albiflora

Hexabromocyclododecanes (HBCDs), as brominated flame retardants, have increasingly drawn concern due to their detection in various marine organisms in recent years. The present test investigated the selective accumulation, depuration, and bioisomerization of HBCDs in different tissues and organs of Nibea albiflora, as well as the genetic metabolic behavior of HBCDs between parents and offspring. In a semi-static water environment, N. albiflora were exposed to individual HBCD diastereoisomers (α-HBCD, β-HBCD, or γ-HBCD) at a concentration of 0.4 μg/L for bioaccumulation, followed by clean food for depuration. During the exposure period, the highest concentrations of these HBCDs were observed in the intestine and gill of N. albiflora. α-HBCD was detected in all exposure groups, suggesting that both β-HBCD and γ-HBCD could be bioisomerized to α-HBCD in N. albiflora. In addition, there was no bioisomerization of α-HBCD to either β-HBCD or γ-HBCD, and there was no bioisomerization between β-HBCD and γ-HBCD. The half-lives (t1/2) were variable among different diastereoisomers, following an order of α-HBCD > γ-HBCD > β-HBCD. The most rapid depuration rate of HBCDs was discovered in the liver while muscle showed the least. Additionally, prior to spawning, the parent fish were exposed to contaminated feed (silkworms sprayed with 200 μL of a 30 μg/mL HBCD solution) for 6 days. By comparing the HBCDs concentrations in the maternal gonad, fertilized eggs, hatching eggs, larvae, and juveniles, it was determined that the maternal transfer coefficients for HBCDs were approximately 1, indicating dynamic equilibrium of HBCDs throughout the process from maternal tissue to progeny development. Differences in HBCDs pattern between organs observed in the experiment support a proposal of an organ-specific diastereomer accumulation.

Dynamic transcriptome landscape of maize pericarp development.

As a maternal tissue, the pericarp supports and protects for other components of seed, such as embryo and endosperm. Despite the importance of maize pericarp in seed, the genome-wide transcriptome pattern throughout maize pericarp development has not been well characterized. Here, we developed RNA-seq transcriptome atlas of B73 maize pericarp development based on 21 samples from 5 days before fertilization (DBP5) to 32 days after fertilization (DAP32). A total of 25 346 genes were detected in programming pericarp development, including 1887 transcription factors (TFs). Together with pericarp morphological changes, the global clustering of gene expression revealed four developmental stages: undeveloped, thickening, expansion and strengthening. Coexpression analysis provided further insights on key regulators in functional transition of four developmental stages. Combined with non-seed, embryo, endosperm, and nucellus transcriptome data, we identified 598 pericarp-specific genes, including 75 TFs, which could elucidate key mechanisms and regulatory networks of pericarp development. Cell wall related genes were identified that reflected their crucial role in the maize pericarp structure building. In addition, key maternal proteases or TFs related with programmed cell death (PCD) were proposed, suggesting PCD in the maize pericarp was mediated by vacuolar processing enzymes (VPE), and jasmonic acid (JA) and ethylene-related pathways. The dynamic transcriptome atlas provides a valuable resource for unraveling the genetic control of maize pericarp development.

Regulation of Immune Checkpoint Antigen CD276 (B7-H3) on Human Placenta-Derived Mesenchymal Stromal Cells in GMP-Compliant Cell Culture Media.

Therapies utilizing autologous mesenchymal cell delivery are being investigated as anti-inflammatory and regenerative treatments for a broad spectrum of age-related diseases, as well as various chronic and acute pathological conditions. Easily available allogeneic full-term human placenta mesenchymal stromal cells (pMSCs) were used as a potential pro-regenerative, cell-based therapy in degenerative diseases, which could be applied also to elderly individuals. To explore the potential of allogeneic pMSCs transplantation for pro-regenerative applications, such cells were isolated from five different term-placentas, obtained from the dissected maternal, endometrial (mpMSCs), and fetal chorion tissues (fpMSCs), respectively. The proliferation rate of the cells in the culture, as well as their shape, in vitro differentiation potential, and the expression of mesenchymal lineage and stem cell markers, were investigated. Moreover, we studied the expression of immune checkpoint antigen CD276 as a possible modulation of the rejection of transplanted non-HLA-matched homologous or even xeno-transplanted pMSCs. The expression of the cell surface markers was also explored in parallel in the cryosections of the relevant intact placenta tissue samples. The expansion of pMSCs in a clinical-grade medium complemented with 5% human platelet lysate and 5% human serum induced a significant expression of CD276 when compared to mpMSCs expanded in a commercial medium. We suggest that the expansion of mpMSCs, especially in a medium containing platelet lysate, elevated the expression of the immune-regulatory cell surface marker CD276. This may contribute to the immune tolerance towards allogeneic pMSC transplantations in clinical situations and even in xenogenic animal models of human diseases. The endurance of the injected comparably young human-term pMSCs may promote prolonged effects in clinical applications employing non-HLA-matched allogeneic cell therapy for various degenerative disorders, especially in aged adults.

Protective effect of Angelica sinensis polysaccharide on pregnant rats suffering from iron deficiency anemia via regulation of the hepcidin-FPN1 axis

Iron deficiency anemia (IDA) is a common micronutrient deficiency among pregnant women with deleterious maternal and fetal outcomes. Angelica sinensis polysaccharide (ASP) has been shown to reduce hepcidin expression in IDA rats. However, the role of ASP in the treatment of IDA during pregnancy and its potential mechanisms have not been investigated. Moreover, the effect of ASP on duodenal iron absorption is not clear. The aim of this study was to investigate the preventive efficacy of ASP against IDA during pregnancy and clarify the underlying mechanisms. Our results showed that ASP improved maternal hematological parameters, increased serum iron, maternal tissue iron, and fetal liver iron content, and improved pregnancy outcomes. Additionally, ASP combated oxidative stress caused by iron deficiency by improving the body's antioxidant capacity. Western blot results demonstrated that ASP downregulated hepcidin expression by blocking the BMP6/SMAD4, JAK2/STAT3 and TfR2/HFE signaling pathways, which in turn increased the expression of FPN1 in the liver, spleen, and duodenum and promoted iron cycling in the body. Furthermore, ASP increased the expression of DMT1 and Dcytb in the duodenum, thereby facilitating duodenal iron uptake. Our results suggest that ASP is a potential agent for the prevention and treatment of IDA during pregnancy.

Spatial transcriptomics uncover sucrose post-phloem transport during maize kernel development

Maize kernels are complex biological systems composed of three genetic sources, namely maternal tissues, progeny embryos, and progeny endosperms. The lack of gene expression profiles with spatial information has limited the understanding of the specific functions of each cell population, and hindered the exploration of superior genes in kernels. In our study, we conduct microscopic sectioning and spatial transcriptomics analysis during the grain filling stage of maize kernels. This enables us to visualize the expression patterns of all genes through electronical RNA in situ hybridization, and identify 11 cell populations and 332 molecular marker genes. Furthermore, we systematically elucidate the spatial storage mechanisms of the three major substances in maize kernels: starch, protein, and oil. These findings provide valuable insights into the functional genes that control agronomic traits in maize kernels.

Role of Endometrial Extracellular Vesicles in Mediating Cell-to-Cell Communication in the Uterus: A Review.

There are several critical events that occur in the uterus during early pregnancy which are necessary for the establishment and maintenance of pregnancy. These events include blastocyst implantation, uterine decidualization, uterine neoangiogenesis, differentiation of trophoblast stem cells into different trophoblast cell lineages, and formation of a placenta. These processes involve several different cell types within the pregnant uterus. Communication between these cell types must be intricately coordinated for successful embryo implantation and the formation of a functional maternal-fetal interface in the placenta. Understanding how this intricate coordination transpires has been a focus of researchers in the field for many years. It has long been understood that maternal endometrial tissue plays a key role in intercellular signaling during early pregnancy, sending signals to nearby tissues in a paracrine manner. Recently, insights have been obtained into the mechanisms by which these signaling events occur. Notably, the endometrium has been shown to secrete extracellular vesicles (EVs) that contain crucial cargo (proteins, lipids, RNA, miRNA) that are taken up by recipient cells to initiate a response leading to the occurrence of critical events during implantation and placentation. In this review, we aim to summarize the role that endometrium-derived EVs play in mediating cell-to-cell communications within the pregnant uterus to orchestrate the events that must occur to establish and maintain pregnancy. We will also discuss how aberrant endometrial EV signaling may lead to pathophysiological conditions, such as endometriosis and infertility.

Two ABCI family transporters, OsABCI15 and OsABCI16, are involved in grain-filling in rice

Seed development is critical for plant reproduction and crop yield, with panicle seed-setting rate, grain-filling, and grain weight being key seed characteristics for yield improvement. However, few genes are known to regulate grain filling. Here, we identify two adenosine triphosphate (ATP)-binding cassette (ABC)I-type transporter genes, OsABCI15 and OsABCI16, involved in rice grain-filling. Both genes are highly expressed in developing seeds, and their proteins are localized to the plasma membrane and cytosol. Interestingly, knockout of OsABCI15 and OsABCI16 results in a significant reduction in seed-setting rate, caused predominantly by the severe empty pericarp phenotype, which differs from the previously reported low seed-setting phenotype resulting from failed pollination. Further analysis indicates that OsABCI15 and OsABCI16 participate in ion homeostasis and likely export ions between filial tissues and maternal tissues during grain filling. Importantly, overexpression of OsABCI15 and OsABCI16 enhances the seed-setting rate and grain yield in transgenic plants and decreases ion accumulation in brown rice. Moreover, the OsABCI15/16 orthologues in maize exhibit a similar role in kernel development, as demonstrated by their disruption in transgenic maize. Therefore, our findings reveal the important roles of two ABC transporters in cereal grain filling, highlighting their value in crop yield improvement.

Gestational Weight Gain Is Associated with the Expression of Genes Involved in Inflammation in Maternal Visceral Adipose Tissue and Offspring Anthropometric Measures

Background: Adequate gestational weight gain (GWG) is essential for maternal and fetal health. GWG may be a sign of higher visceral adipose tissue (VAT) accretion. A higher proportion of VAT is associated with an inflammatory process that may play a role in the fetal programming of obesity. This study aimed to (1) compare the expression of genes involved in inflammatory responses (TLR2, TLR4, NFκB, IKKβ, IL-1RA, IL-1β, IL-6, IL-10, TNF-α) in the VAT of pregnant women according to GWG and (2) explore whether VAT inflammation and GWG are related to offspring anthropometric measures. Material and methods: 50 women scheduled for cesarean section who delivered term infants were included in the study. We collected maternal omental VAT, and the expression of genes was examined with RT-qPCR. Results: Women with excessive and with adequate GWG had significantly higher expressions of most inflammatory genes than women with insufficient GWG. Neonates from mothers with excessive GWG had greater birth weight and chest circumference than those from mothers with insufficient GWG. GWG was positively correlated with fetal birth weight. Conclusions: The VAT expression of most genes associated with inflammatory pathways was higher in excessive and adequate GWG than in pregnant women with insufficient GWG. Moreover, GWG was found to be positively associated with newborn weight.

Crucial role of corticotropin-releasing hormone, corticotropin-releasing hormone -binding protein, mir-200c, and mir-181a in preterm delivery: A case-control study.

Preterm birth before 37 wk of gestation is called premature birth. Corticotropin-releasing hormone (CRH) and CRH-binding protein (BP) act on various maternal and fetal tissues during pregnancy, such as the myometrium, which regulates the transition from the dormant phase of the uterus to the active phase. Studies have shown that mir-200c and mir-181a interact with CRH and CRH-BP. The present study aimed to investigate the expression of mir-200c, mir-181a, CRH, and CRH-BP in women with a history of preterm birth. In this case-control study, the gene expression level of mir-200c, mir-181a, CRH, and CRH-BP in placental tissue samples obtained from 48 women with a history of preterm labor was assessed in the Mojibian hospital of Yazd, Iran, from January to March 2023. Differences between mir-200c, mir-181a CRH, and CRH-BP gene expressions among cases and controls were assessed. The outcomes indicated that the expression of CRH increased with going on to the regular parturition time (p 0.001). While outcomes indicated, CRH-BP decreased with going on to the regular parturition time (p 0.001). In addition, the results showed that the expression of mir-181a increased and mir-200c decreased with approaching the normal delivery time (p 0.001). In conclusion, the expressions of mir-200c, mir-181a, CRH, and CRH-BP were dissimilar in different weeks of gestation. It could be proposed to use mir-200c, mir-181a, CRH, and CRH-BP as biomarkers to weigh the exact delivery time, which could minimize the side effects of preterm labor for the mother and fetus.

Maternal transmission of bacterial microbiota during embryonic development in a viviparous lizard.

The maternal transmission of microbiota during embryonic development of vertebrates is still poorly understood. Here, we used high-throughput sequencing of the 16S rRNA bacterial genes to determine the bacterial communities in the gastrointestinal tract and amniotic environment, i.e., the amniotic fluid, amniotic membrane and extraembryonic yolk, of embryos at the last stage of development of the viviparous lizard Sceloporus grammicus Wiegmann, 1828. We compared these communities to those found in the maternal intestine, mouth, cloaca, and the aseptic ventral skin as a control of the aseptic technique. Our results showed that bacterial 16S rRNA genes were present in the embryos of S. grammicus. Their diversity was lower and more similar in composition between individuals than those found in the maternal tissues. This suggests that a strong control exists on the transmission of bacteria from the mother to the embryos. We found 78% of the embryonic amplicon sequence variants (ASVs) in the maternal bacterial microbiota, suggesting that the transmission of bacteria from the mother to the embryos is a continuous process and some bacteria may have been transferred during early embryonic stages. The embryonic bacteria were found to overlap mostly with those found in the mouth and aseptic ventral skin of the mother, although it is difficult to conclude that the shared ASVs originated from these maternal tissues. Our study provides evidence of microbiota vertical transfer during embryonic development in the animal kingdom. It also highlights that this maternal transmission could be included in the maternal effects that impact the offspring.IMPORTANCEWe investigated the presence and diversity of bacteria in the embryos of the viviparous lizard Sceloporus grammicus and their amniotic environment. We compared this diversity to that found in the maternal intestine, mouth, and cloaca. We detected bacterial DNA in the embryos, albeit with a lower bacterial species diversity than found in maternal tissues. Most of the bacterial species detected in the embryos were also found in the mother, although not all of them. Interestingly, we detected a high similarity in the composition of bacterial species among embryos from different mothers. These findings suggest that there may be a mechanism controlling the transmission of bacteria from the mother to the embryo. Our results highlight the possibility that the interaction between maternal bacteria and the embryo may affect the development of the lizards.

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks’ gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

OR06-02 Placental Distribution Of Polybrominated Diphenyl Ethers (Pbdes) And Thyroid Hormones Across Gestation In PBDE-exposed Wistar Rats

Abstract Disclosure: S. Gaballah: None. B. Horman: None. G. St Armour: None. K. Hoffman: None. H.B. Patisaul: None. H. Stapleton: None. In utero exposure to polybrominated diphenyl ethers (PBDEs) has been linked to adverse pregnancy and fetal health outcomes, including altered thyroid hormone (TH) levels. Despite their phase out, PBDEs are still measured in newborn cord blood. While evidence suggests that PBDEs can cross the placental barrier, few studies have assessed differences in PBDE or TH accumulation in the maternally and fetally-derived placental tissue layers or studied fetal sex-differences. To address these gaps, we conducted a controlled exposure study in Wistar rats (n=8 per treatment and gestational day (GD)). From GD2, pregnant dams were exposed daily to sesame oil vehicle, a low dose, or high dose mixture of 10 PBDEs. The low dose represents the 95th percentile of PBDEs measured in U.S. house dust, and the high dose is ∼20X higher. At GD15 and GD20, dams were sacrificed and placental tissues were micro-dissected into maternally and fetally-derived layers. Tissues were analyzed for PBDEs and for T3, rT3, and T4 using mass spectrometry. BDEs 47, 99, 100, and 209 were frequently detected in the fetal and maternal tissues. Higher concentrations of BDEs 99, 100, and 209 were measured in the fetal placenta on GD 15; however, this trend flipped at GD20, with higher maternal concentrations of BDEs 47, 99, and 209. This shift appears to be related to changes in the mass of the maternal and fetal layers during gestation and not to different partioning processes. Only BDE 99 was significantly different between the two layers, in both sexes. At both timepoints, T3 levels were several-fold higher in maternal tissues than fetal, but T3 decreased in maternal tissues by GD20. No sex differences were observed. In general, we observed a significant difference in maternal and fetal T3 levels at GD15 and GD20 in control, low, and high dose-exposed animals. At GD15, there was a significant difference between maternal and fetal female placental T4 levels (p=0.0237) and a suggestive difference in males (p=0.081) in the high dose group, as well as a significant effect of sex between the fetal tissues in the low dose group (p=0.0044). T4 was only detected in the fetal side at GD20, with no significant effects of treatment or sex. These results highlight the rapid developmental changes throughout gestation between the maternal and fetal placenta. Overall, these data highlight that PBDE accumulation in Wistar rats changes across gestation, causing disruption of TH levels in maternal and fetal tissues, and that sex-specific differences may be contributing to differential accumulation patterns in male and female-associated placentas. Coupled with rapid morphological changes in the fetal and maternal layers during placental growth, in utero PBDE exposure may result in adverse impacts on placental TH regulation and fetal health. Presentation: Thursday, June 15, 2023

Microscopic exploration into the behavior of giant cells in placentomes of buffalo (Bubalus bubalis)

The present study was conducted on placentomes of 31 pregnant buffaloes ranging from 38 to 243 days of gestation to explore the microscopic details of giant cells and their behavior in buffalo placentomes. Various histological and histochemical stains used in the study revealed its structural and chemical details. The study revealed that giant cells played a major role in transplacental transfer of nutrients and other metabolites required by the fetal and maternal tissues. High polysaccharide content and intense enzymatic reaction indicated high metabolic activity of the giant cells in the placenta. The migratory nature of giant cells observed in the present study revealed its role in transfer of metabolites. The cytoplasmic processes observed in the study indicated its fusion with the cryptal epithelium as a medium of transfer of metabolites and formation of multinucleated giant cells. Strong acid phosphates activity can be correlated with its erythrophagocytic nature as a medium of transfer of iron molecules to the developing fetus.