Biology subjects

Stephens, K. K.

Publications and source records attributed to Stephens, K. K..

3 recordsLinked to original sources

bioRxiv2026

Method for modeling oviduct function and impact on embryonic development

Direct experimental analysis of the mammalian oviduct is constrained by limited tissue access and the short lifespan of ex vivo preparations. Extracellular matrix-embedded three-dimensional epithelial organoids provide longer-term in vitro models. However, their inward-facing apical surface and the absence of supporting stromal cells limit physiological studies of the oviduct, including ciliary activity and maternal-embryonic interactions. Here, we provide a step-wise protocol detailing the generation of mouse and human oviductal assembloids in which epithelial cells form an outward-facing (apical-out) layer around a stromal core. Epithelial and stromal cells from adult mouse oviducts or human Fallopian tubes are isolated, expanded separately, and subsequently aggregated in a rotational culture system. The protocol also outlines morphological and immunostaining criteria for confirming cellular organization, whole-mount detection of external cilia, measurement of ciliary beat frequency, and co-culture of mouse assembloids with preimplantation embryos. Mouse and human assembloids retained epithelial and stromal identity and displayed cilia at the accessible outer surface. In a proof-of-concept experiment, embryos co-cultured with the assembloids developed to blastocysts at a rate similar to that of in vivo-derived blastocysts. This reductionist system provides a straightforward and tractable model to investigate oviduct physiology and embryo-maternal communication while allowing direct manipulation and observation of the epithelial interface. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=148 SRC="FIGDIR/small/743297v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1acb462org.highwire.dtl.DTLVardef@17695f8org.highwire.dtl.DTLVardef@6fd6c3org.highwire.dtl.DTLVardef@7cc470_HPS_FORMAT_FIGEXP M_FIG C_FIG SummaryThe protocol for generating mouse and human oviductal assembloids by combining epithelial and stromal cells for studying oviductal function in an in vitro setting.

cell biology↗

bioRxiv2025

Vaginal epithelial estrogen receptor α coordinates glycogen deposition, microbial stability, and pH regulation in mice

Estrogen plays a central role in regulating the vaginal environment, but the specific contribution of epithelial estrogen receptor (ESR1) to microbial and biochemical homeostasis has not been fully defined. In our previous work, we showed that epithelial ESR1 is indispensable for estrogen-induced epithelial proliferation, cornification, and MUC1 expression. Here, using mice with conditional deletion of Esr1 in vaginal epithelial cells, called epithelial Esr1d/d, we extend these findings to demonstrate that epithelial ESR1 also regulates glycogen deposition, luminal pH, and microbial stability. Compared to control littermates, epithelial Esr1d/d mice reduced glycogen abundance, elevated vaginal pH, and a compositional shift in the vaginal microbiome, marked by enrichment of Comamonadaceae and loss of Lactobacillus species, without significant differences in alpha diversity. These changes parallel features of postmenopausal dysbiosis in women. Together, our findings identify epithelial ESR1 as a master regulator of multiple pathways that sustain vaginal homeostasis, integrating epithelial metabolism, barrier function, and host-microbe interactions. This work provides a mechanistic framework to understand postmenopausal vaginal dysbiosis and suggests epithelial estrogen signaling as a potential therapeutic target for genitourinary syndrome of menopause. Significance StatementThe vaginal environment is essential for reproductive and gynecologic health, yet the mechanisms by which estrogen shapes this niche remain incompletely understood. We show that epithelial estrogen receptor (ESR1) regulates glycogen deposition, luminal pH, and microbial composition in the murine vagina. Loss of epithelial ESR1 reduced glycogen and increased luminal pH without altering overall microbial diversity, but shifted community structure toward enrichment of Comamonadaceae, a family associated with neutral to mildly alkaline environments. These findings identify epithelial ESR1 as a key regulator of the metabolic and physicochemical conditions that maintain vaginal microbial balance and provide a mechanistic framework for understanding postmenopausal dysbiosis.

physiology↗

bioRxiv2020

Cell-type specific analysis of physiological action of estrogen in mouse oviducts

One of the endogenous estrogens, 17{beta}-estradiol (E2) is a female steroid hormone secreted from the ovary. It is well established that E2 causes biochemical and histological changes in the uterus. The oviduct response to E2 is virtually unknown in an in vivo environment. In this study, we assessed the effect of E2 on each oviductal cell type, using an ovariectomized-hormone-replacement mouse model, single cell RNA-sequencing (scRNA-seq), in situ hybridization, and cell-type-specific deletion in mice. We found that each cell type in the oviduct responded to E2 distinctively, especially ciliated and secretory epithelial cells. The treatment of exogenous E2 did not drastically alter the transcriptomic profile from that of endogenous E2 produced during estrus. Moreover, we have identified and validated genes of interest in our datasets that may be used as cell- and region-specific markers in the oviduct. Insulin-like growth factor 1 (Igf1) was characterized as an E2-target gene in the mouse oviduct and was also expressed in human Fallopian tubes. Deletion of Igf1 in progesterone receptor (Pgr)-expressing cells resulted in female subfertility, partially due to an embryo developmental defect and embryo retention within the oviduct. In summary, we have shown that oviductal cell types are differentially regulated by E2 and support gene expression changes that are required for normal embryo development and transport in mouse models.

cell biology↗