670: Mesenchymal stem cells suppress inflammatory cytokines in lipopolysaccharide exposed preterm human pregnant myometrial cells

Abstract

Bone marrow derived mesenchymal stem cells (MSC) exert immunosuppressive effects that have broadened the treatment of inflammatory conditions such as myocardial infraction, multiple sclerosis and diabetes. Intrauterine infection associated with inflammation is a cause of preterm birth (PTB). Lipopolysaccharide (LPS)-based models of PTB increase levels of pro-inflammatory cytokine IL-6. MSC exert suppression through anti-inflammatory cytokine TGF-β1. We have previously reported that MSC can suppress the inflammatory response in term human myometrial (MYO) cells (AJOG 689) The objective of this study was to determine the cytokine response in human pregnant preterm myometrial cells exposed to LPS and treated with MSC. Preterm (PT) and term (T) human myometrial tissues were obtained at the time of cesarean delivery. The LPS model of PTB involved exposing MYO cells to 5 μg/ml LPS for 4 h followed by 1 μg/ml LPS for 24 h. These MYO cells were then treated with MSC for 24 h. Cell culture supernatants were collected to measure IL-6 and TGF-β1 levels by ELISA. Comparisons between groups was performed using two way ANOVA. PT cells were obtained from 4 women 34-35 weeks pregnant and T cells from 3 women 38-39 weeks pregnant. In unexposed MYO cells, basal levels of IL-6 were significantly higher in PT than T cells, (PT MYO: 1267.3 ± 435.7 vs. T MYO: 203.1 ± 90.9, pg/ml, p<0.01, Fig 1). When exposed to LPS, PT cells expressed significantly higher IL-6 levels compared to unexposed PT cells, (LPS: 3335.8 ± 280.4 vs. PT MYO: 1267.3 ± 435.7 pg/ml, p< 0.01). Treatment with MSC significantly suppressed IL-6 expression in PT cells exposed to LPS (LPS 3335.8 ± 280.4 vs LPS+MSC: 525.2 ± 78.3 pg/ml, p<0.01). MSC treatment resulted in significantly increased levels of TGF-β1 with and without exposure to LPS, (LPS+MSC: 884.7 ± 179.4 vs. MSC: 881.2 ±139.0 vs. PT MYO: 40.8 ± 3.5 pg/ml, p<0.01, Fig 2). Suppressive effects of MSC was significantly higher in PT than in T cells. In our LPS model of PTB, MSC treatment resulted in a 6-fold suppression in inflammatory cytokine IL-6 and a 20-fold increase in anti-inflammatory cytokine TGF-β1. Therefore, these immunosuppressive potential of MSC provide innovative opportunities for cell mediated therapeutics in inflammation-based PTB.