Obstetrics and Gynaecology - Research Publications

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Author: Lappas, Martha × Author: Lim, Ratana × Author: Nguyen-Ngo, Caitlyn × Start date: 2003 ×

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    The immunoproteasome inhibitor ONX-0914 regulates inflammation and expression of contraction associated proteins in myometrium
    Liong, S ; Lim, R ; Nguyen-Ngo, C ; Barker, G ; Parkington, HC ; Lappas, M (WILEY, 2018-08)
    There are currently no effective treatments to prevent spontaneous preterm labor. The precise upstream biochemical pathways that regulate the transition between uterine quiescence during pregnancy and contractility during labor remain unclear. It is well known however that intrauterine inflammation, including infection, is commonly associated with preterm labor. In this study, we identified the immunoproteasome subunit low-molecular-mass protein (LMP)7 mRNA expression to be significantly upregulated in laboring human myometrium. Silencing LMP7 using siRNA-targeted knockdown of LMP7 and its inhibitor ONX-0914 in human myometrial cells and tissues decreased proinflammatory cytokines (IL-6), cell chemotaxis (CXCL8, CCL2 expression, and THP-1 migration), cell to cell adhesion (ICAM1 expression and myometrial adhesion), contraction-associated proteins (PTGS2, FP, PGE2, and PGF2α), as well as suppressing contractions in myometrial cells and in myometrial tissues obtained from laboring women. In addition, LMP7 silencing reduced NF-κB RelA activity. ONX-0914 alleviated inflammation (CCL3, CXCL1, PTGS2, and IL-6) in myometrium, placenta, fetal brain, amniotic fluid, and maternal serum induced by LPS in pregnant mice. Collectively, our data suggest a novel role for ONX-014 to suppress uterine activation and contractility associated with preterm labor.
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    ATF3 is a negative regulator of inflammation in human fetal membranes
    Lim, R ; Barker, G ; Liong, S ; Nguyen-Ngo, C ; Tong, S ; Kaitu'u-Lino, T ; Lappas, M (W B SAUNDERS CO LTD, 2016-11)
    INTRODUCTION: Infection and inflammation stimulate pro-inflammatory cytokines, prostaglandins and matrix metalloproteinase (MMP)-9, which play a central role in myometrial contractions and rupture of fetal membranes. In human and mouse immune cells, activating transcription factor 3 (ATF3) is a negative regulator of inflammation. No studies have examined the role of ATF3 in human labour. METHODS: Primary amnion cells were used to determine the effect of interleukin (IL)-1β and the bacterial product fibroblast-stimulating lipopeptide (fsl-1) on ATF3 expression, and the effect of ATF3 siRNA on pro-labour mediators. ATF3 expression was assessed in fetal membranes from non-labouring and labouring women at term and preterm, and after preterm pre-labour rupture of membranes (PPROM). RESULTS: IL-1β and fsl-1 significantly increased ATF3 expression. Silencing ATF3 significantly increased IL-1β- or fsl-1-induced expression of pro-inflammatory cytokines (TNF-α, IL-1α, IL-1β, IL-6) and chemokines (IL-8 and monocyte chemoattractant protein-1 (MCP-1)); cyclooxygenase-2 (COX-2) mRNA expression and prostaglandin PGF2α release; and MMP-9 expression. ATF3 expression was decreased in fetal membranes with term labour. There was no effect of preterm labour or PPROM on ATF3 expression. DISCUSSION: ATF3 is a negative regulator of inflammation in human fetal membranes; in primary amnion cells, ATF3 expression is induced by IL-1β and fsl-1, and ATF3 silencing further exacerbates the inflammatory response when stimulated with these factors. Subsequently, ATF3 expression is decreased in fetal membranes after term labour and with preterm chorioamnionitis, conditions closely associated with inflammation and infection. Our data suggest that ATF3 may play a role in the terminal processes of human labour and delivery.
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    Endocan expression is increased in the placenta from obese women with gestational diabetes mellitus
    Murthi, P ; Sarkis, R ; Lim, R ; Nguyen-Ngo, C ; Pratt, A ; Liong, S ; Lappas, M (W B SAUNDERS CO LTD, 2016-12)
    INTRODUCTION: Endocan, a member of the proteoglycan family, is involved in a wide range of diseases including obesity and diabetes. The aim of this study was to determine the effect of (i) maternal obesity and gestational diabetes mellitus (GDM) on placental endocan expression; and (ii) endocan knockdown on markers of inflammation. METHODS: Endocan mRNA and protein expression was determined in human placenta from (i) lean and obese and normal glucose tolerant (NGT) pregnant women (n = 10 patients per group); and (ii) women with GDM and BMI-matched NGT women (n = 40 patients per group). Primary villous trophoblast cells and HUVECs were used to assess the effect of endocan siRNA knockdown on pro-inflammatory cytokines. RESULTS: There was no effect of maternal obesity on placental endocan expression. Further, endocan expression was not different between lean NGT and BMI-matched women with GDM. However, endocan mRNA and protein expression was significantly higher in placenta from obese women with GDM when compared to BMI-matched NGT women. Knockdown of endocan in villous trophoblast cells and HUVECs had no effect on infection- or inflammation-induced expression and secretion of IL-6, IL-8 and MCP-1. DISCUSSION: Endocan expression is increased in the human placenta from obese women with GDM, and in response to pro-inflammatory stimuli. Loss-of-function studies in villous trophoblast cells and HUVECs revealed that endocan is not directly involved in the genesis or in the expression of pro-inflammatory cytokines induced by LPS or IL-1β. Further studies are required to elucidate the functional consequences of increased placental endocan expression in obese GDM pregnancies.