Stromal fibroblasts from perimenopausal endometrium exhibit a different transcriptome than those from the premenopausal endometrium

Abstract

Human endometrium undergoes extensive regeneration on a cyclic basis in premenopausal women and likely occurs through the contribution of stem/progenitor cells. Menopause results in the permanent cessation of menstrual cycles and is preceded by perimenopause, a period of several years in which endocrine and biological changes occur and is a period of risk for endometrial proliferative disorders. The objectives of this study were to identify endometrial mesenchymal stem cells (eMSC) and endometrial stromal fibroblasts (eSF) in endometrium of perimenopausal women and perform expression profile analysis of perimenopausal eMSC and eSF to gain insight into the biology of stem/progenitor and lineage cell populations during the transition to menopause. Endometrial tissue was collected from perimenopausal and premenopausal women (n = 9 each). Microarray analysis was performed on fluorescence-activated cell sorting-isolated eSF and eMSC, and data were validated by quantitative real-time PCR. Principal component analysis showed that cells clustered into three distinct groups in 3-dimensional space: perimenopausal eMSC and premenopausal eMSC clustered together, while perimenopausal eSF and premenopausal eSF formed two discrete clusters separate from eMSC. Hierarchical clustering revealed a branching pattern consistent with principle clustering analysis results, indicating that eMSC from premenopausal and perimenopausal women exhibit similar transcriptomic signatures. Pathway analysis revealed dysregulation of cytoskeleton, proliferation, and survival pathways in perimenopausal vs. premenopausal eSF. These data demonstrate that cell populations have altered gene expression in perimenopausal vs. premenopausal endometrium, and that perimenopausal eSF had altered pathway activation when compared to premenopausal eSF. This study provides insight into aging endometrium with relevance to function in reproductively older women.

Keywords: endometrial mesenchymal stem cell; endometrium; fibroblast; menopause; microarray; small nucleolar RNA.

Figure 1.

PCA and HC. (A) Endometrial cell populations from perimenopausal (PeriM) and premenopausal (PreM) women clustered in PCA by cell type, with endometrial mesenchymal stem cells (eMSC) from PeriM and PreM women clustering together, and endometrial stromal fibroblasts (eSF) forming two discrete clusters separate from eMSC. (B) HC analysis of the differentially expressed genes (≥2.0-fold change, P < 0.05) between eMSC and eSF in PeriM and PreM women.

Figure 2.

Differentially expressed genes from experimental groups. Venn diagram showing overlap of differentially expressed genes (P < 0.05, >1.5-fold change or <-1.5-fold change) between eSF and eMSC from PreM and PeriM women immediately after FACS isolation [38].

Figure 3.

Localization of eMSC in PeriM endometrium by indirect immunofluorescence. Sections of endometrial biopsies from PeriM women were labeled for CD146 and PDGFRB. CD146 was localized to all perivascular cells, whereas PDGFRB showed a wider distribution on endometrial stromal cells as well as some perivascular cells. Staining for PDGFRB was absent in glandular epithelial cells. Colocalization of CD146 and PDGFRB (eMSC; arrow) was observed in a perivascular location. GE, glandular epithelium; BV, blood vessel; ST, stroma; eMSC, endometrial mesenchymal stem cell. Original magnification ×100.