Spatial and temporal characterization of endometrial mesenchymal stem-like cells activity during the menstrual cycle

Abstract

The human endometrium is a highly dynamic tissue with the ability to cyclically regenerate during the reproductive life. Endometrial mesenchymal stem-like cells (eMSCs) located throughout the endometrium have shown to functionally contribute to endometrial regeneration. In this study we examine whether the menstrual cycle stage and the location in the endometrial bilayer (superficial and deep portions of the endometrium) has an effect on stem cell activities of eMSCs (CD140bCD146 cells). Here we show the percentage and clonogenic ability of eMSCs were constant in the various stages of the menstrual cycle (menstrual, proliferative and secretory). However, eMSCs from the menstrual endometrium underwent significantly more rounds of self-renewal and enabled a greater total cell output than those from the secretory phase. Significantly more eMSCs were detected in the deeper portion of the endometrium compared to the superficial layer but their clonogenic and self-renewal activities remained similar. Our findings suggest that eMSCs are activated in the menstrual phase for the cyclical regeneration of the endometrium.

Revealing Cellular Heterogeneity andIn VitroDifferentiation Trajectory of Cultured Human Endometrial Mesenchymal-like Stem Cells Using Single-cell RNA Sequencing

“…Intriguingly, the SP4 cells had the highest proliferation capacity and were enriched in the menstrual phase samples (chi-squared test, p < 0.0001). We have demonstrated that eMSCs from the menstrual phase have a higher proliferation ability than those from the secretory phase [8], and may be attributed to the enrichment of the SP4 cells in the menstrual phase. In addition, SP1 and SP4 showed a transdifferentiation potential to the epithelial cell lineage (Figure S4B).…”

“…Endometrial aspirates from the menstrual phase of three women and four full-thickness endometrium from the secretory phase of four women were used in this study (Table S1). After enzyme dispersion of the tissues, the CD140b + CD146 + cells were obtained from endometrial stromal cells by serial magnetic microbeading [8,10]. They were subjected to scRNA-seq on a 10X genomics platform.…”

“…Isolation of eMSCs (CD140b + CD146 + cells) was conducted with two separate positive magnetic bead selections [8]. Stromal cells were incubated with Phycoerythrin (PE)conjugated anti-CD140b antibody at 4 o C for 45 minutes.…”

“…Our recent study shows the presence of cellular heterogeneity in eMSCs. Apart from inter-donor variation in clonogenic ability of eMSCs, a higher proliferative ability is found in eMSCs from endometrium at the menstrual phase than those from other phases of the cycle, suggesting the presence of a quiescent subpopulation and an activated subpopulation [8]. Thus, knowledge on the cellular heterogeneity of in vitro expanded eMSCs is urgently needed for standardization before applying the cells in clinical therapy.…”

Understanding the Regulatory Mechanisms of Endometrial Cells on Activities of Endometrial Mesenchymal Stem-Like Cells During Menstruation

“…The isolation procedure of endometrial cells was carried out as described [5]. The tissues were minced and digested with PBS containing collagenase type III (0.3 mg/ml, Worthington Biochemical Corporation, NJ, USA) and deoxyribonuclease type I (40 μg/ml, Worthington Biochemical Corporation) for one hour at 37 o C. Red blood cells were removed using Ficoll-Paque (GE Healthcare, Uppsala, Sweden) densitygradient centrifugation.…”