Epidermal growth factor represses differentiation of mouse trophoblast stem cells into spongiotrophoblast cells via epidermal growth factor receptor

Exploring the molecular underpinnings of macrosomia in gestational diabetes mellitus: The role of EGFR signaling and placental syncytiotrophoblast

Macrosomia, which is frequently associated with gestational diabetes mellitus (GDM), is linked to maternal glycemic control during gestation. When GDM is complicated by macrosomia (GDMM), the placenta exhibits increased mass, underscoring its role as a critical nexus for maternal-fetal nutrient exchange. Despite this recognized correlation, the underlying mechanisms propelling placental hypertrophy have remained elusive. Our study leveraged single-cell RNA transcriptome sequencing of GDMM placental tissues to pinpoint the specific syncytiotrophoblast (SCT) subsets that regulate placental dimensions. Notably, we observed pronounced upregulation of the epidermal growth factor receptor (EGFR) and its corresponding ligands, with a particular emphasis on the autoregulatory cascade involving the glycoprotein hormone alpha subunit (CGA), EGFR, and the transcription factor GATA binding protein 2 (GATA2), as well as perturbations in hormonal homeostasis within the SCT. Furthermore, our cell interaction analysis revealed an enhanced interplay between myeloid cells and SCT3, augmenting the EGFR signaling pathway. These molecular exchanges underscore the pivotal role of the placental immune microenvironment in the etiology of macrosomia, shedding light on the pathophysiology of GDMM and paving the way for novel therapeutic approaches.

Sperm-carried IGF2: towards the discovery of a spark contributing to embryo growth and development

Spermatozoa have been shown to carry key RNAs which, according to animal evidence, seem to play a role in early embryo development. In this context, a potential key growth regulator is insulin-like growth factor 2 (IGF2), a highly conserved paternally expressed imprinted gene involved in cell growth and proliferation which, recent observations indicate, is expressed in human spermatozoa. We herein hypothesized that sperm IGF2 gene expression and transmission at fertilization is required to support early embryo development. To test this hypothesis, we analyzed sperm IGF2 mRNA levels in the same semen aliquot used for homologous assisted reproductive technique (ART) in infertile couples and correlated these levels with embryo morphokinetics. To find a mechanistic explanation for the observed results, the transcriptomes of blastocysts obtained after injection of Igf2 mRNA in mouse parthenotes were analyzed. Sperm IGF2 mRNA negatively correlated with time of 2-cell stage (t2), t3, t4, t5, and time of expanded blastocyst (tEB), independently of maternal age, body mass index, anti-Müllerian hormone levels, and oocyte quality. An IGF2 mRNA index >4.9 predicted the ability of the embryos to reach the blastocyst stage on Day 5, with a sensitivity of 100% and a specificity of 71.6% (AUC 0.845; P < 0.001). In the animal study, transcriptome analysis demonstrated that 65 and 36 genes were, respectively, up- and down-regulated in the experimental group compared to the control group. These genes belong to pathways that regulate early embryo development, thus supporting the findings found in humans. This study has the potential to challenge the longstanding tenet that spermatozoa are simply vehicles carrying paternal DNA. Instead, it suggests that IGF2 mRNA in healthy spermatozoa provides critical support for early embryo development. Pre-ART sperm-carried IGF2 mRNA levels may be used as a marker to predict the chances of obtaining blastocysts to be transferred for infertile couples undergoing ART.

Ferrous-sucrose complex supplementation regulates maternal plasma metabolism and the fecal microbiota composition and improves neonatal immunity and placental glucose transportation by activating the EGF/PI3K/AKT signaling pathways in sows

Pregnancy is a dynamic state involving rapid physiological changes in metabolism, affecting the health and development of the offspring. During pregnancy, the placenta constitutes a physical and immunological barrier to provide fetal nutrition through the maternal blood and prevent the exposure of the fetus to dangerous signals. Metabolic changes in the plasma, the fecal microbiota profile, and functional regulation in the placenta were studied in sows supplied with a ferrous-sucrose complex (FeSuc) from late gestation to parturition. The results revealed that maternal FeSuc supplementation enhanced arginine and proline metabolism, glutathione metabolism, with increased glutamic acid, beta-D-glucosamine, L-proline, 1-butylamine, and succinic acid and reduced sphingosine and chenodeoxycholic acid sulfate levels in the plasma. Moreover, significantly increased abundances of Christensenellaceae_R-7_group, Prevotellaceae_NK3B31_group, and Lachnospiraceae_NK4B4_group were detected in the feces of sows from the FeSuc group (P < 0.05). Spearman's correlation analysis indicated that Prevotellaceae_NK3B31_group abundances were positively correlated with glutamic acid, indoxyl sulfate, acetyl-DL-leucine, and beta-D-glucosamine, while Christensenellaceae_R-7_group was positively correlated with beta-D-glucosamine. Furthermore, maternal FeSuc supplementation significantly increased neonatal glucose (P < 0.01) and iron (P < 0.01) in the neonatal serum, significantly increased IL-10 and TGF-β1 levels in the neonatal liver (P < 0.01) and jejunum (P < 0.05), promoted the transcription of immune molecules in the placenta, and significantly increased the protein expressions of EGF (P < 0.05), PI3K (P < 0.01), p-PI3K (P < 0.001), p-AKT (P < 0.01), and glucose transporter 1 (GLUT1) (P < 0.001) in the placenta. The current study demonstrated that FeSuc supplementation regulated maternal metabolism processes by altering the fecal microbial composition and improved neonatal immunity and placental glucose transportation by activating the EGF/PI3K/AKT signaling pathways in sows.