Endometrial extracellular vesicles during pregnancy: their regulation by transcription factor RUNX1 and dysregulation by phthalate exposure

During early pregnancy, endometrial stromal cells in the maternal uterus play a crucial role in coordinating significant events necessary for reproductive success by secreting paracrine factors, including extracellular vesicles (EVs) that contain diverse molecular cargo, facilitating critical processes such as embryo implantation, uterine neoangiogenesis, and trophoblast differentiation. The secretion of EVs from endometrial stromal cells is regulated by a conserved pathway involving hypoxia-inducible factor HIF2α, which controls the expression of RAB27B, a vesicular trafficking protein necessary for the release of EVs into the extracellular space. In human endometrial stromal cells (HESCs), runt-related transcription factor RUNX1 has been identified to act upstream of HIF2α to facilitate proper EV secretion and the inclusion of specific protein cargoes, including insulin-like growth factor IGF2. Consequently, EVs collected from HESCs with reduced RUNX1 or IGF2 expression were less effective in promoting angiogenesis or trophoblast differentiation. In a conditional knockout mouse model in which the gene encoding IGF2 was ablated in the maternal uterus, we observed a reduction in litter size and smaller offspring, attributed to defective placental development. Understanding the regulation of the EV signaling pathway and how it can be disrupted is critical, as impairment of cell-to-cell communication within the uterus during early pregnancy can significantly affect placental development and fetal growth. Our study demonstrated that exposure to an environmentally relevant concentration of phthalates, well-known endocrine disruptors, disrupts the EV secretion pathway in HESC by inducing abnormal DNA methylation, which impairs the estrogenic promotion of HIF2α expression. Collectively, these findings highlight the essential role of the RUNX1-HIF2α-RAB27B pathway in mediating the regulation of EV secretion from endometrial stromal cells, emphasizing that disruptions caused by environmental insults or diminished expression of upstream factors or essential protein cargoes can impair EV secretion and hinder key processes vital for placental development and reproductive success.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Molecular & Integrative Physi

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Beal, Jacob Reed

Contributors dc:contributor

• Bagchi, Milan
• Bagchi, Indrani
• Raetzman, Lori
• Flaws, Jodi
• Nelson, Erik

• Extracellular Vesicles
• Phthalates
• Pregnancy
• Placentation

Statement dc:rights

• Copyright 2025 Jacob Beal

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130194

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130194