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Biology subjects

Quenby, S.

Publications and source records attributed to Quenby, S..

3 recordsLinked to original sources

Stalling of the endometrial decidual reaction determines the recurrence risk of miscarriage risk

In each menstrual cycle, progesterone acting on estrogen-primed endometrium elicits an inflammatory decidual reaction, rendering it poised for embryo implantation and transformation into the decidua of pregnancy. Here, we show that the sequential functions of the decidual reaction - implantation and decidualization - pivot on the time-sensitive loss of progesterone-resistant stromal cells that form a transient implantation niche and reciprocal expansion of progesterone-responsive pre-decidual cells. In parallel, proliferation and differentiation increase the abundance of immunotolerant uterine natural killer (uNK) cells. Examination of pre-pregnancy endometrial biopsies from 924 women revealed that the frequency of cycles culminating in a blunted or stalled decidual reaction closely aligns with the age-independent recurrence risk of miscarriage. Further, analysis of 632 biopsies obtained in different cycles from 316 women indicated that prior miscarriages disrupt intercycle endometrial homeostasis, an observation supported by modelling the impacts of prolonged decidual inflammation in three-dimensional endometrial assembloids. Although stalling of the decidual reaction is often accompanied by a poor expansion of immunotolerant uNK cells, miscarriages do not impact intercycle uNK cell dynamics. Our findings indicate that intrinsic uterine mechanisms hardwire the recurrence risk of miscarriage, underscoring the need for pre-pregnancy diagnostics and therapeutics. One Sentence SummaryThe frequency of menstrual cycles culminating in a suboptimal decidual reaction determines the recurrence risk of miscarriage.

physiology↗

Characterization of highly proliferative decidual precursor cells during the window of implantation in human endometrium

Pregnancy depends on the wholesale transformation of the endometrium, a process driven by differentiation of endometrial stromal cells (EnSC) into specialist decidual cells. Upon embryo implantation, decidual cells impart the tissue plasticity needed to accommodate a rapidly growing conceptus and invading placenta, although the underlying mechanisms are unclear. Here we characterize a discrete population of highly proliferative mesenchymal cells (hPMC) in midluteal human endometrium, coinciding with the window of embryo implantation. Single-cell transcriptomics demonstrated that hPMC express genes involved in chemotaxis and vascular transmigration. Although distinct from resident EnSC, hPMC also express genes encoding pivotal decidual transcription factors and markers, most prominently prolactin. We further show that hPMC are enriched around spiral arterioles, scattered throughout the stroma, and occasionally present in glandular and luminal epithelium. The abundance of hPMC correlated with the in vitro colony-forming unit activity of midluteal endometrium and, conversely, clonogenic cells in culture express a gene signature partially conserved in hPMC. Cross-referencing of single-cell RNA-sequencing data sets indicated that hPMC differentiate into a recently discovered decidual subpopulation in early pregnancy. Finally, we demonstrate that recurrent pregnancy loss is associated with hPMC depletion. Collectively, our findings characterize midluteal hPMC as novel decidual precursors that are likely derived from circulating bone marrow-derived mesenchymal stem/stromal cells and integral to decidual plasticity in pregnancy. Significance statementTransformation of cycling endometrium into the decidua of pregnancy requires extensive tissue remodeling. Perturbations in this process lead to breakdown of the maternal-fetal interface and miscarriage. Here we report the characterization of decidual precursor cells during the window of implantation. We demonstrate that decidual precursors are clonogenic and primed for exponential growth. They likely originate from bone marrow-derived MSC and give rise to a distinct decidual subpopulation in pregnancy. Recurrent pregnancy loss is associated with loss of decidual precursor cells prior to conception, raising the possibility that they can be harnessed for the prevention of pregnancy disorders, including miscarriages and preterm labor.

cell biology↗

Clearance of senescent decidual cells by uterine natural killer cells drives endometrial remodeling during the window of implantation

In cycling human endometrium, menstruation is followed by rapid estrogen-dependent growth. Upon ovulation, progesterone and rising cellular cAMP levels activate the transcription factor Forkhead box O1 (FOXO1) in endometrial stromal cells (EnSCs), leading to cell cycle exit and differentiation into decidual cells that control embryo implantation. Here we show that FOXO1 also causes acute senescence of a subpopulation of decidualizing EnSCs in an IL-8 dependent manner. Selective depletion or enrichment of this subpopulation revealed that decidual senescence drives the transient inflammatory response associated with endometrial receptivity. Further, senescent cells prevent differentiation of endometrial mesenchymal stem cells in decidualizing cultures. As the cycle progresses, IL-15 activated uterine natural killer (uNK) cells selectively target and clear senescent decidual cells through granule exocytosis. Our findings reveal that acute decidual senescence governs endometrial rejuvenation and remodeling at embryo implantation, and suggest a critical role for uNK cells in maintaining homeostasis in cycling endometrium.

cell biology↗