Biology subjects

Bagchi, M. K.

Publications and source records attributed to Bagchi, M. K..

6 recordsLinked to original sources

bioRxiv2026

HIF2α-Regulated Pathways Control Human Extravillous Trophoblast Functions by Modulating Cell-to-Cell Communication Through Extracellular Vesicles

Successful pregnancy in humans requires extravillous trophoblast (EVT) cells to invade the endometrium, remodel maternal tissue, and establish a functional placenta. How trophoblasts communicate with the endometrium to coordinate this remodeling remains poorly understood. We previously demonstrated that human endometrial stromal cells communicate through secreted extracellular vesicles (EVs) at the maternal-fetal interface, but whether trophoblasts engage in reciprocal EV-mediated communication remained unknown. Here, using an in vitro trophoblast stem cell differentiation model, we show that EVT cells secrete EVs carrying protein cargo that regulates endometrial stromal cell remodeling, revealing a previously unrecognized arm of maternal-fetal communication. Hypoxia, a defining feature of early placentation, enhanced EV secretion, EVT differentiation, and trophoblast invasion, and these responses required hypoxia-inducible factor 2 (HIF2). Loss of HIF2 impaired EVT differentiation and significantly reduced EV production. Functionally, EVT-derived EVs altered endometrial stromal cell remodeling, in part through HIF2-regulated cargo proteins including matrix metalloproteinase 2 (MMP2). MMP2 depletion reduced both EVT invasion and EV-mediated stromal remodeling, identifying MMP2 as an important mediator of trophoblast-maternal communication. Strikingly, MMP2 deficiency also redirected trophoblast cell fate toward the syncytiotrophoblast (ST) lineage, accompanied by morphological and molecular genetic hallmarks of syncytialization, revealing an unexpected role for a matrix-remodeling enzyme in trophoblast lineage specification. Together, these findings establish a hypoxia-regulated trophoblast EV signaling pathway that links oxygen sensing to trophoblast differentiation, invasion, and maternal tissue remodeling, and reveal an unexpected connection between extracellular matrix remodeling and trophoblast cell-fate decisions during early placental development.

developmental biology↗

bioRxiv2026

Loss of Glucose Transporter 1 in Mouse Uterine Cells Disrupts Trophoblast Differentiation and Promotes Gestational Diabetes

A successful pregnancy hinges on a finely coordinated dialogue between the maternal endometrium and the implanting embryo. Following embryo attachment to the uterine epithelium, underlying stromal cells undergo a transformation into decidual cells that promote a vascularized maternal-fetal interface and direct trophoblast lineage decisions through paracrine cues. However, the metabolic adaptations that enable decidual cells to support these energetically demanding processes remain poorly understood. Here, using a uterine-specific knockout mouse model, we identify Glucose Transporter 1 (Glut1) as a critical metabolic regulator linking endometrial glucose uptake to reproductive success. We demonstrate that stromal Glut1, induced by hypoxia-inducible factor 2 (Hif2), sustains a Hif2-Rab27b feed-forward circuit that drives vesicular trafficking during pregnancy through the glucose-sensing transcription factor MAX-like protein X (Mlx). Mice lacking endometrial Glut1 are severely subfertile despite normal embryo attachment. Glut1-deficient uteri exhibit impaired stromal extracellular vesicle secretion, defective decidual angiogenesis, and marked dysregulation of trophoblast differentiation, including expansion of trophoblast progenitors, accumulation of glycogen trophoblast cells, and altered placental lactogen production. These placental defects culminate in mid-gestation fetal loss and maternal gestational diabetes mellitus (GDM). Collectively, our findings establish endometrial Glut1 as a metabolic gatekeeper of maternal glucose homeostasis and placentation and introduce a genetically tractable mouse model of spontaneously developing GDM, a disorder affecting nearly one in seven pregnancies worldwide. SIGNIFICANCEThis study uncovers endometrial Glut1 as a previously unrecognized metabolic regulator of placentation, demonstrating that maternal stromal glucose uptake dictates trophoblast fate and maternal glycemic control, and providing the field with its first genetically defined mouse model of spontaneously arising gestational diabetes.

physiology↗

bioRxiv2025

Human Decidual RUNX1 Promotes Angiogenesis and Trophoblast Differentiation by Regulating Extracellular Vesicle Signaling

During early pregnancy, human endometrial stromal cells differentiate into secretory decidual cells via a process regulated by ovarian steroid hormones. Decidual cells play a crucial role by secreting various factors that support essential events in forming a functional placenta, including uterine angiogenesis and the differentiation and development of trophoblasts. We previously reported that the conditional ablation of the transcription factor RUNX1 in the mouse uterus leads to subfertility due to insufficient maternal angiogenesis and impaired trophoblast differentiation. In this study, we examined the role of RUNX1 in facilitating communication mechanisms among human decidual cells and other cell types present in the pregnant uterus. We demonstrated that RUNX1 regulates the conserved HIF2-RAB27B pathway in primary human endometrial stromal cells (HESC) during decidualization, which promotes the secretion of extracellular vesicles (EVs) by these cells. Consequently, the depletion of RUNX1 in HESC led to reduced EV secretion. Mass spectrometry identified several cargo proteins in decidual EVs, including ANGPTL2 and IGF2, which could regulate angiogenesis or trophoblast differentiation. We found that RUNX1 directly regulates their expression, resulting in partial changes to these cargoes when it is absent. We observed that delivering EVs lacking ANGPTL2 or IGF2 to human endothelial cells significantly decreased the formation of vascular networks compared to introducing control EVs carrying these factors. Furthermore, adding IGF2-depleted EVs to human trophoblast cells inhibited their differentiation into the extravillous trophoblast lineage. These findings collectively highlight the crucial role of decidual RUNX1 in promoting essential cell-cell interactions for angiogenesis and trophoblast differentiation during placenta formation.

physiology↗

bioRxiv2024

Phthalates Impair Estrogenic Regulation of HIF2α and Extracellular Vesicle Secretion by Human Endometrial Stromal Cells

Di(2-ethylhexyl) phthalate (DEHP), a known endocrine-disrupting chemical, is a plasticizer found in many common consumer products. High levels of DEHP exposure have been linked to adverse pregnancy outcomes, yet little is known about how it affects human uterine functions. We previously reported that the estrogen-regulated transcription factor hypoxia-inducible factor 2 alpha (HIF2) promotes the expression of Rab27b, which controls the trafficking and secretion of extracellular vesicles (EVs). EVs facilitate communication between multiple cell types within the pregnant uterus, ensuring reproductive success. In this study, we report that exposure of differentiating primary human endometrial stromal cells (HESC) to an environmentally relevant concentration (1 g/mL) of DEHP or its primary metabolite mono(2-ethylhexyl) phthalate (MEHP) markedly reduces the expression of HIF2. We also observed a concomitant decrease in RAB27B expression, reducing EV secretion from HESC. Interestingly, we found that DEHP or MEHP exposure disrupts estrogenic regulation of the HIF2/Rab27b signaling pathway. Estrogen receptor alpha (ER) could no longer bind to the HIF2 regulatory region following phthalate treatment, and epigenetic analysis suggested that this may be due to hypermethylation of nearby CpG islands. Further investigation revealed a potential interaction between ER and the transcription factor Sp1 within the HIF2 regulatory region, which is affected by the inhibition of Sp1 binding to the phthalate-induced hypermethylated DNA. Additionally, our results suggest that the abnormal DNA methylation is likely due to increased expression of the DNA methyltransferase 1 (DNMT1) gene in response to phthalate exposure. Overall, this study provides valuable mechanistic insights into how phthalate-induced differential DNA methylation disrupts estrogenic regulation of the HIF2 gene and, consequently, EV secretion during HESC differentiation. This knowledge is crucial for our understanding of how phthalates may cause adverse reproductive outcomes by disrupting the hormonal regulation of cell-to-cell communication within the pregnant uterus.

pharmacology and toxicology↗

bioRxiv2024

Long-term dietary exposure to a mixture of phthalates enhances estrogen and beta-catenin signaling pathways, leading to endometrial hyperplasia in mice

Phthalates, synthetic chemicals widely utilized as plasticizers and stabilizers in various consumer products, present a significant concern due to their persistent presence in daily human life. While past research predominantly focused on individual phthalates, real-life human exposure typically encompasses complex mixtures of these compounds. The cumulative effects of prolonged exposure to phthalate mixtures on uterine health remain poorly understood. To address this knowledge gap, we conducted studies utilizing adult female mice exposed to a phthalate mixture for 6 and 12 months through ad libitum chow consumption. We previously reported that continuous exposure to this phthalate mixture for 6 months led to uterine fibrosis. In this study, we show that the exposure, when continued beyond 6 months to 1 year, caused fibrotic uteri to display hyperplasia with a significant increase in gland to stroma ratio. Endometrial hyperplasia is commonly caused by unopposed estrogen action, which promotes increased expression of pro-inflammatory cytokines and chemokines and proliferation of the endometrial epithelial cells. Indeed, RNA sequencing analysis revealed a marked upregulation of several estrogen-regulated genes, Wnt ligands that are involved in oncogenic pathways, as well as chemokines, in phthalate-exposed uterine tissues. Consequently, the exposed uteri exhibited increased proliferation of endometrial epithelial cells, and a heightened inflammatory response indicated by extensive homing of macrophages. Further studies revealed a marked enhancement of the Wnt/{beta}-Catenin signaling pathway, potentially contributing to the development of endometrial hyperplasia. Collectively, this study underscores the significance of understanding the exposure to environmental factors in the pathogenesis of endometrial disorders.

physiology↗

bioRxiv2023

Runx1 regulates critical factors that control uterine angiogenesis and trophoblast differentiation during placental development

During early pregnancy in humans and rodents, uterine stromal cells undergo a remarkable differentiation to form the decidua, a transient maternal tissue that supports the growing fetus. It is important to understand the key decidual pathways that orchestrate the proper development of the placenta, a key structure at the maternal-fetal interface. We discovered that ablation of expression of the transcription factor Runx1 in decidual stromal cells in a conditional Runx1-null mouse model (Runx1d/d) causes fetal lethality during placentation. Further phenotypic analysis revealed that uteri of pregnant Runx1d/d mice exhibited severely compromised decidual angiogenesis, and a lack of trophoblast differentiation and migration, resulting in impaired spiral artery remodeling. Gene expression profiling using uteri from Runx1d/d and control mice revealed that Runx1 directly controls the decidual expression of the gap junction protein connexin 43 (also known as GJA1), which was previously shown to be essential for decidual angiogenesis. Our study also revealed a critical role of Runx1 in controlling insulin-like growth factor (IGF) signaling at the maternal-fetal interface. While Runx1-deficiency drastically reduced the production of IGF2 by the decidual cells, we observed concurrent elevated expression of the IGF-binding protein 4 (IGFBP4), which regulates the bioavailability of IGFs thereby controlling trophoblast differentiation. We posit that dysregulated expression of GJA1, IGF2, and IGFBP4 in Runx1d/d decidua contributes to the observed defects in uterine angiogenesis, trophoblast differentiation, and vascular remodeling. This study therefore provides unique insights into key maternal pathways that control the early phases of maternal-fetal interactions within a critical window during placental development. SignificanceA clear understanding of the maternal pathways that ensure coordination of uterine differentiation and angiogenesis with embryonic growth during the critical early stages of placenta formation still eludes us. The present study reveals that the transcription factor Runx1 controls a set of molecular, cellular, and integrative mechanisms that mediate maternal adaptive responses controlling uterine angiogenesis, trophoblast differentiation, and resultant uterine vascular remodeling, which are essential steps during placenta development.

physiology↗