Obstetrics and Gynaecology - Research Publications
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ItemEpithelial-to-Mesenchymal Transition Supports Ovarian Carcinosarcoma Tumorigenesis and Confers Sensitivity to Microtubule Targeting with Eribulin(AMER ASSOC CANCER RESEARCH, 2022-12-01)UNLABELLED: Ovarian carcinosarcoma (OCS) is an aggressive and rare tumor type with limited treatment options. OCS is hypothesized to develop via the combination theory, with a single progenitor resulting in carcinomatous and sarcomatous components, or alternatively via the conversion theory, with the sarcomatous component developing from the carcinomatous component through epithelial-to-mesenchymal transition (EMT). In this study, we analyzed DNA variants from isolated carcinoma and sarcoma components to show that OCS from 18 women is monoclonal. RNA sequencing indicated that the carcinoma components were more mesenchymal when compared with pure epithelial ovarian carcinomas, supporting the conversion theory and suggesting that EMT is important in the formation of these tumors. Preclinical OCS models were used to test the efficacy of microtubule-targeting drugs, including eribulin, which has previously been shown to reverse EMT characteristics in breast cancers and induce differentiation in sarcomas. Vinorelbine and eribulin more effectively inhibited OCS growth than standard-of-care platinum-based chemotherapy, and treatment with eribulin reduced mesenchymal characteristics and N-MYC expression in OCS patient-derived xenografts. Eribulin treatment resulted in an accumulation of intracellular cholesterol in OCS cells, which triggered a downregulation of the mevalonate pathway and prevented further cholesterol biosynthesis. Finally, eribulin increased expression of genes related to immune activation and increased the intratumoral accumulation of CD8+ T cells, supporting exploration of immunotherapy combinations in the clinic. Together, these data indicate that EMT plays a key role in OCS tumorigenesis and support the conversion theory for OCS histogenesis. Targeting EMT using eribulin could help improve OCS patient outcomes. SIGNIFICANCE: Genomic analyses and preclinical models of ovarian carcinosarcoma support the conversion theory for disease development and indicate that microtubule inhibitors could be used to suppress EMT and stimulate antitumor immunity.
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ItemHepatitis A virus cellular receptor 2 (HAVCR2) is decreased with viral infection and regulates pro-labour mediators OA(WILEY, 2017-07)PROBLEM: Intrauterine infection caused by viral infection has been implicated to contribute to preterm birth. Hepatitis A virus cellular receptor 2 (HAVCR2) regulates inflammation in non-gestational tissues in response to viral infection. METHOD OF STUDY: The aims of this study were to determine the effect of: (i) viral dsRNA analogue polyinosinic:polycytidylic acid (poly(I:C)) on HAVCR2 expression; and (ii) HAVCR2 silencing by siRNA (siHAVCR2) in primary amnion and myometrial cells on poly(I:C)-induced inflammation. RESULTS: In human foetal membranes and myometrium, HAVCR2 mRNA and protein expression was decreased when exposed to poly(I:C). Treatment of primary amnion and myometrial cells with poly(I:C) significantly increased the expression and release of pro-inflammatory cytokines TNF, IL1A, IL1B and IL6; the expression of chemokines CXCL8 and CCL2; the expression and secretion of adhesion molecules ICAM1 and VCAM1; and PTGS2 and PTGFR mRNA expression and the release of prostaglandin PGF2α . This increase was significantly augmented in cells transfected with siHAVCR2. Furthermore, mRNA expression of anti-inflammatory cytokines IL4 and IL10 was significantly decreased. CONCLUSION: Collectively, our data suggest that HAVCR2 regulates cytokines, chemokines, prostaglandins and cell adhesion molecules in the presence of viral infection. This suggests a potential for HAVCR2 activators as therapeutics for the management of preterm birth associated with viral infections.
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ItemTRADD, TRAF2, RIP1 and TAK1 are required for TNF--induced pro-labour mediators in human primary myometrial cells(WILEY, 2017-07)PROBLEM: TNF-α plays a central role in the processes of human labour and delivery. This study sought to determine the role of the adaptor proteins TNFR1-associated death domain protein (TRADD), TNF receptor-associated factor 2 (TRAF2), receptor interacting protein 1 (RIP1) and transforming growth factor beta-activated kinase 1 (TAK1) in TNF-α-induced formation of pro-labour mediators. METHOD OF STUDY: Human primary myometrial cells were transfected with siRNA against TRADD (siTRADD), TRAF2 (siTRAF2), RIP1 (siRIP1) or TAK1 (siTAK1), treated with TNF-α, and assayed for pro-inflammatory mediators expression. RESULTS: siTRADD, siTRAF2, siRIP1 and siTAK1 significantly decreased TNF-α-induced IL-1α, IL-1β, IL-6, IL-8, MCP-1 mRNA expression and release of IL-6, IL-8 and MCP-1; and cyclooxygenase (COX)-2 expression and release of prostaglandin PGF2α . There was a significant attenuation of TNF-α-induced expression of adhesion molecules ICAM-1 and VCAM-1 mRNA with siTRADD, siTRAF2 or siRIP1. siTRADD and siRIP1 significantly attenuated TNF-α-induced MMP-9 mRNA expression and release and nuclear factor κB (NF-κB) transcriptional activity. There was a significant increase in TNF-α-induced sVCAM-1 release, MMP-9 mRNA expression and NF-κB activity with siTAK1. CONCLUSION: TRADD, TRAF2, RIP1 and TAK1 are involved in TNF-α signalling in human myometrium. Further studies are required to determine whether inhibition of these proteins can prevent preterm birth.
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ItemObesity in older adults: Effect of degree of weight loss on cardiovascular markers and medications(WILEY, 2019-08)Obesity worsens the age-related tendency towards cardiovascular disease and diabetes. Older adults are vulnerable to medication adverse effects. Intentional weight loss in older adults with obesity has been shown to improve cardiovascular and glycaemic markers. The effect of rapid weight loss induced by very-low-calorie diets (VLCDs) on these markers has not been evaluated in this group. In this 12-week study, participants were randomized to one of healthy eating, hypocaloric diet or VLCD, all combined with three times weekly exercise (Ex/HE, Ex/Diet, Ex/VLCD, respectively). The effects of these interventions on weight, blood pressure, lipids, glucose and HbA1c , inflammatory markers and cardiovascular and diabetes medication changes were measured. Weight loss was 3.7%, 5.1% and 11.1% in Ex/HE, Ex/Diet and Ex/VLCD, respectively. There were significant improvements in HbA1c in all groups, but by the greatest degree in Ex/VLCD (0.18 ± 0.07%, 0.18 ± 0.06% and 0.59 ± 0.13%, respectively). Similar patterns were seen in total cholesterol (0.13 ± 0.15, 0.21 ± 0.11 and 0.53 ± 0.13 mmol/L, respectively, P = .047), triglycerides (0.35 ± 0.13, 0.20 ± 0.10 and 0.51 ± 0.09 mmol/L, respectively, P = .011) and systolic blood pressure (9 ± 2, 2 ± 3 and 14 ± 3 mmHg respectively, P = .025). There were no between-group differences in fasting glucose, high-density lipoprotein (HDL) cholesterol, LDL-C and inflammatory markers. Reductions in anti-hypertensive or diabetes medication were made in 4/29, 7/36 and 16/37 participants in Ex/HE, Ex/Diet and Ex/VLCD, respectively (P = .017). Significant weight loss achieved with a VLCD gave rise to improvements in multiple cardiovascular risk markers, despite reduction in medication. Weight loss is an under-utilized method of cardiovascular risk management in this group.
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ItemExpression and function of macrophage-inducible C-type lectin (Mincle) in inflammation driven parturition in fetal membranes and myometrium.(Oxford University Press (OUP), 2019-07)The pivotal role of inflammatory processes in human parturition is well known, but not completely understood. We have performed a study to examine the role of macrophage-inducible C-type lectin (Mincle) in inflammation-associated parturition. Using human samples, we show that spontaneous labour is associated with up-regulated Mincle expression in the myometrium and fetal membranes. Mincle expression was also increased in fetal membranes and myometrium in the presence of pro-labour mediators, the proinflammatory cytokines interleukin (IL)-1B and tumour necrosis factor (TNF), and Toll-like receptor (TLR) ligands fsl-1, poly(I:C), lipopolysaccharide (LPS) and flagellin. These clinical studies are supported by mouse studies, where an inflammatory challenge in a mouse model of preterm birth increased Mincle expression in the uterus. Importantly, elimination of Mincle decreased the effectiveness of proinflammatory cytokines and TLR ligands to induce the expression of pro-labour mediators; namely, proinflammatory cytokines and chemokines, contraction-associated proteins and prostaglandins, and extracellular matrix remodelling enzymes, matrix metalloproteinases. The data presented in this study suggest that Mincle is required when inflammatory activation precipitates parturition.
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ItemThe immunoproteasome inhibitor ONX-0914 regulates inflammation and expression of contraction associated proteins in myometrium(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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ItemNOD-like receptor pyrin domain-containing-3 (NLRP3) regulates inflammation-induced pro-labor mediators in human myometrial cells(WILEY, 2018-04)PROBLEM: Inflammation plays a major role in preterm birth. Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3) plays a role in inflammatory diseases. The aims of this study were to determine the effect of term labor on the expression of NLRP3 in human myometrium and the effect of NLRP3 silencing on pro-labor mediators in myometrial cells. METHOD OF STUDY: NLRP3 expression was assessed in myometrium from non-laboring and laboring women by qRT-PCR and Western blotting. Human primary myometrial cells were transfected with NLRP3 siRNA (siNLRP3), treated with pro-inflammatory cytokines and toll-like receptor (TLR) ligands, and assayed for pro-inflammatory mediators' expression. RESULTS: NLRP3 expression was higher in myometrium after term spontaneous labor and by TNF, IL1B, fsl-1, and flagellin. In siNLRP3-transfected cells, there was a significant decrease in the expression of pro-inflammatory cytokines (IL1A, IL6), chemokines (CXCL8, CCL2), and adhesion molecules (ICAM1 and VCAM1) stimulated with IL1B, TNF, or TLR ligands; decrease in IL1B-stimulated PTGS2 and PTGFR mRNA expression and PGF2α release; and increase in TNF-stimulated myometrial gel shrinkage as assessed by an in vitro cell contraction assay. CONCLUSION: NLRP3 is increased with labor in myometrial, and knockdown of NLRP3 is associated with an attenuation of inflammation-induced expression of pro-inflammatory and pro-labor mediators in human myometrium.
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ItemAtypical natural killer T-cell receptor recognition of CD1d-lipid antigens(NATURE PUBLISHING GROUP, 2016-02)Crucial to Natural Killer T (NKT) cell function is the interaction between their T-cell receptor (TCR) and CD1d-antigen complex. However, the diversity of the NKT cell repertoire and the ensuing interactions with CD1d-antigen remain unclear. We describe an atypical population of CD1d-α-galactosylceramide (α-GalCer)-reactive human NKT cells that differ markedly from the prototypical TRAV10-TRAJ18-TRBV25-1(+) type I NKT cell repertoire. These cells express a range of TCR α- and β-chains that show differential recognition of glycolipid antigens. Two atypical NKT TCRs (TRAV21-TRAJ8-TRBV7-8 and TRAV12-3-TRAJ27-TRBV6-5) bind orthogonally over the A'-pocket of CD1d, adopting distinct docking modes that contrast with the docking mode of all type I NKT TCR-CD1d-antigen complexes. Moreover, the interactions with α-GalCer differ between the type I and these atypical NKT TCRs. Accordingly, diverse NKT TCR repertoire usage manifests in varied docking strategies and specificities towards CD1d-α-GalCer and related antigens, thus providing far greater scope for diverse glycolipid antigen recognition.
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ItemDREAM Is Involved in the Genesis of Inflammation-Induced Prolabour Mediators in Human Myometrial and Amnion Cells(HINDAWI LTD, 2018)Preterm birth is the primary cause of perinatal morbidity and mortality worldwide. Inflammation induces a cascade of events leading to preterm birth by activating nuclear factor-κB (NF-κB). In nongestational tissues, downstream regulatory element antagonist modulator (DREAM) regulates NF-κB activity. Our aims were to analyse DREAM expression in myometrium and fetal membranes obtained at term and preterm and to determine the effect of DREAM inhibition on prolabour mediators in primary myometrial and amnion cells. DREAM mRNA expression was significantly higher in fetal membranes obtained after spontaneous labour compared to nonlabour and in amnion from women with histological preterm chorioamnionitis when compared to amnion from women without chorioamnionitis. In primary myometrial and amnion cells, the effect of DREAM silencing by siRNA was a significant decrease in the expression of proinflammatory cytokine IL-6, the chemokines IL-8 and MCP-1, the adhesion molecule ICAM-1, MMP-9 mRNA expression and activity, and NF-κB transcriptional activity when stimulated with the proinflammatory cytokine IL-1β, the bacterial products fsl-1 or flagellin, or the viral dsRNA analogue poly(I:C). These data suggest that, in states of heightened inflammation, DREAM mRNA expression is increased and that, in myometrial and amnion cells, DREAM regulates proinflammatory and prolabour mediators which may be mediated via NF-κB.
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ItemInhibition of GPR91 Reduces Inflammatory Mediators Involved in Active Labor in Myometrium(HINDAWI LTD, 2020-04-15)RESULTS: GPR91 mRNA expression was significantly higher in myometrium from women during term spontaneous labor compared to no labor. Likewise, in mice, GPR91 mRNA expression was significantly upregulated in myometrium during inflammation-induced preterm labor compared to preterm no labor. In myometrial cells, IL1B and TNF significantly increased GPR91 mRNA expression. Knockdown of GPR91 by siRNA in myometrial cells significantly suppressed the secretion and/or expression of IL1B- and TNF-induced proinflammatory cytokines (GM-CSF, IL1A, IL1B, and IL6) and chemokines (CXCL8 and CCL2), myometrial contractility (expression of the contraction-associated proteins PTGFR and CX43, secretion of the uterotonic PGF2α , and in situ collagen gel contraction), and the transcription factor NF-κB. CONCLUSION: Our findings demonstrate that GPR91 is involved in the genesis of proinflammatory and prolabor mediators induced by IL1B or TNF and collectively suggest that GPR91 may contribute to augmentation of the labor processes.