Exometabolomic Analysis of Decidualizing Human Endometrial Stromal and Perivascular Cells.

Qingfeng Chen,Jieliang Zhou,Jinling Fang,Yie Hou Lee,Maria Diniz-Da-Costa,Seley Gharanei,Emma S Lucas,Sarah L Harden,Keisuke Murakami,Jan J Brosens,Liang Cui

doi:10.3389/fcell.2021.626619

Abstract

Differentiation of endometrial fibroblasts into specialized decidual cells controls embryo implantation and transforms the cycling endometrium into a semi-permanent, immune-protective matrix that accommodates the placenta throughout pregnancy. This process starts during the midluteal phase of the menstrual cycle with decidual transformation of perivascular cells (PVC) surrounding the terminal spiral arterioles and endometrial stromal cells (EnSC) underlying the luminal epithelium. Decidualization involves extensive cellular reprogramming and acquisition of a secretory phenotype, essential for coordinated placental trophoblast invasion. Secreted metabolites are an emerging class of signaling molecules, collectively known as the exometabolome. Here, we used liquid chromatography-mass spectrometry to characterize and analyze time-resolved changes in metabolite secretion (exometabolome) of primary PVC and EnSC decidualized over 8 days. PVC were isolated using positive selection of the cell surface marker SUSD2. We identified 79 annotated metabolites differentially secreted upon decidualization, including prostaglandin, sphingolipid, and hyaluronic acid metabolites. Secreted metabolites encompassed 21 metabolic pathways, most prominently glycerolipid and pyrimidine metabolism. Although temporal exometabolome changes were comparable between decidualizing PVC and EnSC, 32 metabolites were differentially secreted across the decidualization time-course. Further, targeted metabolomics demonstrated significant differences in secretion of purine pathway metabolites between decidualized PVC and EnSC. Taken together, our findings indicate that the metabolic footprints generated by different decidual subpopulations encode spatiotemporal information that may be important for optimal embryo implantation.

Highlights

Cyclical decidualization, i.e., differentiation of endometrial fibroblasts into specialized decidual cells, is a hallmark of menstruating mammals (Brosens et al, 2009; Emera et al, 2012)
The endometrial stromal fraction of 12 midluteal biopsies were separated into SUSD2+ perivascular cells (PVC) and SUSD2− endometrial stromal cells (EnSC) by magneticactivated cell sorting (MACS) (Figure 1)
Several studies have documented the dynamic changes in the EnSC transcriptome, proteome and secretome upon decidualization (Garrido-Gomez et al, 2011; Murakami et al, 2014; Rytkönen et al, 2019), but changes in secreted metabolites that may function as signaling molecules have not yet been characterized

Summary

Introduction

I.e., differentiation of endometrial fibroblasts into specialized decidual cells, is a hallmark of menstruating mammals (Brosens et al, 2009; Emera et al, 2012). Rather than being triggered by an implanting embryo, decidualization in menstruating species is initiated during the midluteal phase of each cycle in response to sustained progesterone signaling and rising intracellular cyclic adenosine monophosphate (cAMP) levels (Gellersen and Brosens, 2014). Decidualization transforms endometrial fibroblasts into secretory cells that are anti-inflammatory (Kuroda et al, 2013; Lucas et al, 2020), resistant to stress signals (Kajihara et al, 2006; Leitao et al, 2010; Lucas et al, 2020), and highly responsive to embryonic cues (Teklenburg et al, 2010; Brosens et al, 2014)

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Results

Conclusion