Mare stromal endometrial cells differentially modulate inflammation depending on oestrus cycle status: an in vitro study

The modulation of inflammation is pivotal for uterine homeostasis. Here we evaluated the effect of the oestrus cycle on the expression of pro-inflammatory and anti-inflammatory markers in a cellular model of induced fibrosis. Mare endometrial stromal cells isolated from follicular or mid-luteal phase were primed with 10 ng/mL of TGFβ alone or in combination with either IL1β, IL6, or TNFα (10 ng/mL each) or all together for 24 h. Control cells were not primed. Messenger and miRNA expression were analyzed using real-time quantitative PCR (RT-qPCR). Cells in the follicular phase primed with pro-inflammatory cytokines showed higher expression of collagen-related genes (CTGF, COL1A1, COL3A1, and TIMP1) and mesenchymal marker (SLUG, VIM, CDH2, and CDH11) genes; p < 0.05. Cells primed during the mid-luteal overexpressed genes associated with extracellular matrix, processing, and prostaglandin E synthase (MMP2, MMP9, PGR, TIMP2, and PTGES; p < 0.05). There was a notable upregulation of pro-fibrotic miRNAs (miR17, miR21, and miR433) in the follicular phase when the cells were exposed to TGFβ + IL1β, TGFβ + IL6 or TGFβ + IL1β + IL6 + TNFα. Conversely, in cells from the mid-luteal phase, the treatments either did not or diminished the expression of the same miRNAs. On the contrary, the anti-fibrotic miRNAs (miR26a, miR29b, miR29c, miR145, miR378, and mir488) were not upregulated with treatments in the follicular phase. Rather, they were overexpressed in cells from the mid-luteal phase, with the highest regulation observed in TGFβ + IL1β + IL6 + TNFα treatment groups. These miRNAs were also analyzed in the extracellular vesicles secreted by the cells. A similar trend as seen with cellular miRNAs was noted, where anti-fibrotic miRNAs were downregulated in the follicular phase, while notably elevated pro-fibrotic miRNAs were observed in extracellular vesicles originating from the follicular phase. Pro-inflammatory cytokines may amplify the TGFβ signal in the follicular phase resulting in significant upregulation of extracellular matrix-related genes, an imbalance in the metalloproteinases, downregulation of estrogen receptors, and upregulation of pro-fibrotic factors. Conversely, in the luteal phase, there is a protective role mediated primarily through an increase in anti-fibrotic miRNAs, a decrease in SMAD2 phosphorylation, and reduced expression of fibrosis-related genes.

Mouse endometrial stromal cells and progesterone inhibit the activation and regulate the differentiation and antibody secretion of mouse B cells

The regulation mechanism for the B cells in the female reproductive tract (FRT) is unclear now. The aim of this study was to analysis the effect of progesterone and mouse endometrium stromal cells (ESCs) on B cells and explore it roles in modulating B cells-mediated immune responses. We primary isolated mouse ESCs from endometrium of BALB/c mice and B cells from spleen cells of BALB/c mice, and then constructed these two kind of cells co-culture system, and treated with or without progesterone. We found that both treatment with progesterone and co-culture with ESCs reduced the expression of co-stimulatory molecules CD80 and CD86 on mouse B cells from spleen cells. In addition, the expression of CD138 (syndecan-1) on B cells was increased after co-culture with ESCs, however, progesterone could partly reduce this effect. Unlike progesterone, ESCs alone promoted the proliferation and stimulated the secretion level of antibodies IgG and IgA of B cells. Our current results progesterone and ESCs could inhibit the activation of B cells through deceasing CD80 and CD86 expression, regulated the differentiation status of B cells by up-regulating the expression of CD138 together, and might further inhibit the antigen presentation function of B cells, which is beneficial to the establishment of fertilization and pregnancy. In addition, ESCs also promoted the proliferation and antibody secretion, which might participate in the resisting infections during non pregnancy and pregnancy.