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Judith E Cartwright - One of the best experts on this subject based on the ideXlab platform.
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decidual natural killer cells regulate vessel stability implications for impaired Spiral Artery remodelling
Journal of Reproductive Immunology, 2015Co-Authors: Rupsha Fraser, Guy St J Whitley, B Thilaganathan, Judith E CartwrightAbstract:Decidual NK (dNK) cells are present during uterine Spiral Artery remodelling, an event that is crucial for successful placentation and the provision of an adequate blood supply to the developing fetus. Spiral Artery remodelling is impaired in the pregnancy complication pre-eclampsia. Although dNK cells are known to play active roles at the maternal–fetal interface, little is known about their effect on endothelial integrity, an important component of vessel stability. We present a study in which we have modelled dNK–endothelium interactions, using first-trimester dNK cells isolated from both normal pregnancies and those with impaired Spiral Artery remodelling. dNK cells were isolated from first-trimester pregnancies, screened by uterine Artery Doppler ultrasound to determine resistance indices (RI) that relate to the extent of Spiral Artery remodelling. dNK culture supernatant from normal-RI pregnancies (but not high-RI pregnancies) destabilised endothelial tube-like structures in Matrigel, and normal-RI dNK cells induced endothelial intercellular adhesion molecule-1 and tumour necrosis factor-α expression to a greater extent than high-RI dNK cells. We have established a functional role for dNK cells in the disruption of endothelial structures and have suggested how impairment of this process may be contributing to the reduced vessel remodelling in pregnancies with a high uterine Artery resistance index. These findings have implications for our understanding of the pathology of pre-eclampsia and other pregnancy disorders where remodelling is impaired.
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increased angiogenic factor secretion by decidual natural killer cells from pregnancies with high uterine Artery resistance alters trophoblast function
Human Reproduction, 2014Co-Authors: Alison E Wallace, Rupsha Fraser, Guy St J Whitley, Alan P Johnstone, S Gurung, Sonu S Goulwara, Judith E CartwrightAbstract:participants/materials, setting, methods: A multiplex assay was used to assess dNK cell-secreted factors. SGHPL-4 cell functions were assessed using time-lapse microscopy, 3D invasion assays, endothelial-like tube formation ability and western blot analysis. mainresultsandtheroleofchance:The expression levels of PLGF (P , 0.01), sIL-2R (P , 0.01), endostatin (P , 0.05) and angiogenin (P , 0.05) were significantly increased by dNK cells from high-risk pregnancies. Endostatin significantly decreased SGHPL-4 invasion (P , 0.05), SGHPL-4 tube formation (P , 0.05) and SGHPL-4 Akt ser473 phosphorylation (P , 0.05). Angiogenin significantly decreased SGHPL4 invasion (P , 0.05), but increased SGHPL-4 tube formation (P , 0.01) and decreased SGHPL-4 Akt ser473 phosphorylation (P , 0.05). limitations, reasons forcaution: The culture of dNK cells and protein concentrations in vitro may not fully represent the in vivo situation. Although SGHPL-4 cells are extravillous trophoblast derived, further studies would be needed to confirm the roles of angiogenin and endostatin in vivo. wider implications of the findings: The altered expression of secreted factors of dNK cells may contribute to pregnancy disorders associated with poor Spiral Artery remodelling.
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impaired decidual natural killer cell regulation of vascular remodelling in early human pregnancies with high uterine Artery resistance
The Journal of Pathology, 2012Co-Authors: Rupsha Fraser, Guy St J Whitley, B Thilaganathan, Alan P Johnstone, Amanda J Host, N J Sebire, Judith E CartwrightAbstract:During human pregnancy, natural killer (NK) cells accumulate in the maternal decidua, but their specific roles remain to be determined. Decidual NK (dNK) cells are present during trophoblast invasion and uterine Spiral Artery remodelling. These events are crucial for successful placentation and the provision of an adequate blood supply to the developing fetus. Remodelling of Spiral arteries is impaired in the dangerous pregnancy complication pre-eclampsia. We studied dNK cells isolated from pregnancies at 9–14 weeks' gestation, screened by uterine Artery Doppler ultrasound to determine resistance indices which relate to the extent of Spiral Artery remodelling. dNK cells were able to promote the invasive behaviour of fetal trophoblast cells, partly through HGF. Cells isolated from pregnancies with higher resistance indices were less able to do this and secreted fewer pro-invasive factors. dNK cells from pregnancies with normal resistance indices could induce apoptotic changes in vascular smooth muscle and endothelial cells in vitro, events of importance in vessel remodelling, partly through Fas signalling. dNK cells isolated from high resistance index pregnancies failed to induce vascular apoptosis and secreted fewer pro-apoptotic factors. We have modelled the cellular interactions at the maternal-fetal interface and provide the first demonstration of a functional role for dNK cells in influencing vascular cells. A potential mechanism contributing to impaired vessel remodelling in pregnancies with a higher uterine Artery resistance is presented. These findings may be informative in determining the cellular interactions contributing to the pathology of pregnancy disorders where remodelling is impaired, such as pre-eclampsia. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Trophoblast- and Vascular Smooth Muscle Cell-Derived MMP-12 Mediates Elastolysis during Uterine Spiral Artery Remodeling
The American journal of pathology, 2010Co-Authors: Lynda K. Harris, Judith E Cartwright, Guy St J Whitley, Samantha D. Smith, Rosemary J. Keogh, Rebecca L. Jones, Philip N. Baker, Martin Knöfler, John D. AplinAbstract:During the first trimester of pregnancy, the uterine Spiral arteries are remodeled, creating heavily dilated conduits that lack maternal vasomotor control but allow the placenta to meet an increasing requirement for nutrients and oxygen. To effect permanent vasodilatation, the internal elastic lamina and medial elastin fibers must be degraded. In this study, we sought to identify the elastolytic proteases involved in this process. Primary first-trimester cytotrophoblasts (CTBs) derived from the placenta exhibited intracellular and membrane-associated elastase activity; membrane-associated activity was primarily attributable to matrix metalloproteinases (MMP). Indeed, Affymetrix microarray analysis and immunocytochemistry implicated MMP-12 (macrophage metalloelastase) as a key mediator of elastolysis. Cultured human aortic smooth muscle cells (HASMCs) exhibited constitutive membrane-associated elastase activity and inducible intracellular elastase activity; these cells also expressed MMP-12 protein. Moreover, a specific inhibitor of MMP-12 significantly reduced CTB- and HASMC-mediated elastolysis in vitro, to 31.7 ± 10.9% and 23.3 ± 8.7% of control levels, respectively. MMP-12 is expressed by both interstitial and endovascular trophoblasts in the first-trimester placental bed and by vascular SMCs (VSMCs) in remodeling Spiral arteries. Perfusion of isolated Spiral Artery segments with CTB-conditioned medium stimulated MMP-12 expression in medial VSMCs. Our data support a model in which trophoblasts and VSMCs use MMP-12 cooperatively to degrade elastin during vascular remodeling in pregnancy, with the localized release of elastin peptides and CTB-derived factors amplifying elastin catabolism.
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inhibition of trophoblast induced Spiral Artery remodeling reduces placental perfusion in rat pregnancy
Hypertension, 2010Co-Authors: Stefan Verlohren, Nele Geusens, Jude S Morton, Iris Verhaegen, Lydia Hering, Florian Herse, Joachim W Dudenhausen, Dominik N Muller, Friedrich C Luft, Judith E CartwrightAbstract:Rats harboring the human angiotensinogen and human renin genes develop preeclamptic features in pregnancy. The preeclamptic rats exhibit a deeper trophoblast invasion associated with a reduced resistance index by uterine Doppler. Doxycycline inhibits matrix metalloproteinase activity. We tested the hypothesis that matrix metalloproteinase inhibition reduces trophoblast invasion with subsequent changes in placental perfusion. Preeclamptic and pregnant control Sprague-Dawley rats were treated with doxycycline (30 mg/kg of body weight orally) from gestational day 12 until day 18. Placental perfusion was assessed using a micromarker contrast agent. The animals were euthanized on day 18 of pregnancy; biometric data were acquired, and trophoblast invasion was analyzed. Doxycycline resulted in intrauterine growth retardation and lighter placentas in both groups. Maternal body weight was not affected. As shown earlier, preeclamptic rats exhibited a deeper endovascular trophoblast invasion. However, doxycycline treatment reduced trophoblast invasion in the preeclamptic rats. The physiological Spiral Artery remodeling, as assessed by the deposition of fibrinoid and alpha-actin in the Spiral Artery contour, was significantly reduced by doxycycline. The vascularity index, as assessed by perfusion measurement of the placenta, was reduced after doxycycline treatment in preeclamptic rats. Thus, matrix metalloproteinase inhibition with doxycycline leads to reduced trophoblast invasion and associated reduced placental perfusion. These studies are the first to show that reducing trophoblast-induced vascular remodeling decreases subsequent placental perfusion. Our model allows the study of dysregulated trophoblast invasion and vascular remodeling in vivo to gain important insights into preeclampsia-related mechanisms.
J N Bulmer - One of the best experts on this subject based on the ideXlab platform.
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uterine Spiral Artery muscle dedifferentiation
Human Reproduction, 2019Co-Authors: Stephen C Robson, Barbara A Innes, Gendie E Lash, A Robson, Joy Yue Zhang, J N BulmerAbstract:STUDY QUESTION Is vascular smooth muscle cell (VSMC) dedifferentiation a feature of uterine Spiral Artery (SpA) remodelling in early human pregnancy? SUMMARY ANSWER Remodelling of human uterine SpAs is associated with dedifferentiation of VSMCs and can be induced in vitro by uterine natural killer (uNK) cells and extravillous trophoblast cells (EVTs). WHAT IS KNOWN ALREADY Uterine SpAs undergo profound morphological changes in normal pregnancy with replacement of the musculoelastic arterial wall structure by fibrinoid containing EVTs. The fate of VSMCs in SpA remodelling is unknown; in guinea pig uterine Artery VSMCs dedifferentiate, remain in the vessel wall and differentiate after parturition to restore the arterial wall. There is increasing evidence that uNK cells play a role in SpA remodelling. We hypothesized that SpA remodelling in human pregnancy is associated with VSMC dedifferentiation, initiated by uNK cell-derived growth factors. STUDY DESIGN, SIZE, DURATION Formalin fixed, paraffin embedded placental bed biopsies were immunostained for angiogenic growth factor (AGF) receptors and markers of VSMC differentiation. An in vitro model of SpA remodelling using chorionic plate arteries (CPAs) was used to test the effect of different cell types and AGFs on VSMC differentiation. PARTICIPANTS/MATERIALS, SETTING, METHODS Placental bed biopsies were immunostained for vascular endothelial growth factor receptors 1-3 (VEGF-R1, VEGF-R2, VEGF-R3), transforming growth factor beta 1 receptors I and II (TGF-βRI, TGF-βRII), interferon gamma receptors 1 and 2 (IFN-γR1, IFN-γR2), Tie2, α-smooth muscle actin (α-SMA), H-caldesmon (H-Cal), myosin heavy chain (MyHC), osteopontin and smoothelin. Staining intensity was assessed using a modified quickscore. Expression by VSMCs of the AGF receptors was confirmed by laser capture microdissection and real-time RT-PCR of non-remodelled SpAs, after laser removal of the endothelium. As an in vitro model, VSMC differentiation was assessed in CPAs by immunohistochemistry after culture in uNK cell-conditioned medium (CM), EVT-CM, uNK cell/EVT co-culture CM, Ang-1, Ang-2, IFN-γ, VEGF-A and VEGF-C, and after blocking of both Ang-1 and Ang-2 in uNK-CM. MAIN RESULTS AND THE ROLE OF CHANCE SpA VSMC expression of Tie-2 (P = 0.0007), VEGF-R2 (P = 0.005) and osteopontin (P = 0.0001) increased in partially remodelled SpAs compared with non-remodelled SpAs, while expression of contractile VSMC markers was reduced (α-SMA P < 0.0001, H-Cal P = 0.03, MyHC P = 0.03, smoothelin P = 0.0001). In the in vitro CPA model, supernatants from purified uNK cell (H-Cal P < 0.0001, MyHC P = 0.03, α-SMA P = 0.02, osteopontin P = 0.03), EVT (H-Cal P = 0.0006, MyHC P = 0.02, osteopontin P = 0.01) and uNK cell/EVT co-cultures (H-Cal P = 0.001, MyHC P = 0.05, osteopontin P = 0.02) at 12-14 weeks, but not 8-10 weeks, gestational age induced reduced expression of contractile VSMC markers and increased osteopontin expression. Addition of exogenous (10 ng/ml) Ang-1 (P = 0.006) or Ang-2 (P = 0.009) also reduced H-Cal expression in the CPA model. Inhibition of Ang-1 (P = 0.0004) or Ang-2 (P = 0.004) in uNK cell supernatants blocked the ability of uNK cell supernatants to reduce H-Cal expression. LIMITATIONS, REASONS FOR CAUTION This is an in vitro study and the role of uNK cells, Ang-1 and Ang-2 in SpA remodelling in vivo has not yet been shown. WIDER IMPLICATIONS OF THE FINDINGS VSMC dedifferentiation is a feature of early SpA remodelling and uNK cells and EVT play key roles in this process by secretion of Ang-1 and Ang-2. This is one of the first studies to suggest a direct role for Ang-1 and Ang-2 in VSMC biology. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by a grant from British Biotechnology and Biosciences Research Council (BB/E016790/1). The authors have no competing interests to declare.
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Spiral Artery remodeling and trophoblast invasion in preeclampsia and fetal growth restriction relationship to clinical outcome
Hypertension, 2013Co-Authors: Fiona Lyall, Stephen C Robson, J N BulmerAbstract:Failure to transform uteroplacental Spiral arteries is thought to underpin disorders of pregnancy, including preeclampsia and fetal growth restriction (FGR). In this study, Spiral Artery remodeling and extravillous-cytotrophoblast were examined in placental bed biopsies from normal pregnancy (n=25), preeclampsia (n=22), and severe FGR (n=10) and then compared with clinical parameters. Biopsies were immunostained to determine vessel wall integrity, extravillous-cytotrophoblast location/density, periarterial fibrinoid, and endothelium. Muscle disruption was reduced in myometrial Spiral arteries in preeclampsia ( P =0.0001) and FGR ( P =0.0001) compared with controls. Myometrial vessels from cases with birth weight P P P P 5th percentile. Fewer extravillous-cytotrophoblast surrounded both decidual and myometrial vessels in the normal group and preeclampsia group compared with the FGR group ( P =0.001). For myometrial vessels, the normal group contained more intramural extravillous-cytotrophoblast than in preeclampsia ( P =0.015). Decidual vessels in the FGR group had less fibrinoid deposition compared with controls ( P =0.013). For myometrial vessels, less fibrinoid was deposited in both the preeclampsia group ( P =0.0001) and the FGR group ( P =0.01) when compared with controls, and less fibrinoid was deposited in the preeclampsia group when compared with FGR group ( P 5th percentile ( P
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altered expression of interleukin 6 interleukin 8 and their receptors in decidua of women with sporadic miscarriage
Human Reproduction, 2013Co-Authors: Hedele Pitman, J N Bulmer, Stephen C Robson, Barbara A Innes, Gendie E LashAbstract:Study question Are alterations in decidual expression of interleukin (IL)-6 and IL-8 associated with sporadic miscarriage? Summary answer IL-6 and IL-8 secretion from decidual uterine natural killer (uNK) cells and macrophages isolated from women with spontaneous miscarriage was reduced compared with normal controls. What is known already Miscarriage is a common gynaecological problem with huge financial and personal implications. Eleven to twenty per cent of all clinically recognized pregnancies are lost before the 20th week of gestation, with miscarriages often being divided into early (≤ 12 completed weeks from last menstrual period) and late (≥ 13 weeks). Spiral Artery remodelling is a key feature of early pregnancy; failure of this process has been implicated in sporadic miscarriage. The molecular triggers that initiate Spiral Artery remodelling are not clear, although cytokines such as IL-6 and IL-8 may play a role. Study design, size, duration This was a laboratory-based study using decidual and placental bed biopsy samples from women with sporadic miscarriage (n = 30) and termination of pregnancy controls (n = 30). Participants/materials, setting, methods Total adherent decidual cells, CD10(+) stromal cells, CD14(+) macrophages and CD56(+) uNK cells were isolated from decidua from apparently normal pregnancies that were terminated at either 8-10 or 12-14 weeks' gestation. In addition, CD14(+) macrophages and CD56(+) uNK cells were isolated from decidua from sporadic miscarriage at 8-10 weeks' gestation. Secreted IL-8 was measured in all isolated cell populations, while IL-6 was measured in CD14(+) macrophages and CD56(+) uNK cells from both sporadic miscarriage and normal controls. Placental bed biopsies were taken from women after sporadic miscarriage or termination of pregnancy at ≤ 12 completed weeks' or >13 weeks' gestational age, formalin-fixed, paraffin-embedded and immunostained for IL-6, IL-6Rα, GP130, IL-8, CXCR1, CXCR2 and CD13 (aminopeptidase N). Staining intensity for each factor was assessed in extravillous trophoblast cell populations, myometrial and decidual stroma, myometrial and decidual Spiral arteries and decidual glandular epithelium. A CPA model was used to assess the potential role of IL-6 and IL-8 in Spiral Artery remodelling. Main results and the role of chance IL-8 was secreted by total adherent decidual cells, CD10(+) stromal cells and CD14(+) macrophages at both 8-10 and 12-14 weeks' gestation, with CD14(+) cells secreting the highest levels. Both CD14(+) and CD56(+) cells isolated from decidua of early sporadic miscarriage produced lower IL-6 (P = 0.04, P = 0.01, respectively) and IL-8 levels (P = 0.0007, P = 0.002, respectively) compared with normal cases. In addition, altered expression of IL-6, IL-8 and their receptors was observed in various cell types in placental bed (myometrial stroma, glandular epithelium, interstitial extravillous trophoblast cells, vascular smooth muscle cells and endothelial cells) in sporadic miscarriage, particularly from later gestational ages. IL-6 and IL-8 disrupted vascular smooth muscle morphology and organization in an in vitro model of Spiral Artery remodelling. Limitations, reasons for caution By the nature of sampling at the time of miscarriage, it was not possible to ascertain the cause or effect in the observed alterations of levels of IL-6 and IL-8 in sporadic miscarriage. Wider implications of the findings Alterations in the expression of IL-6, IL-8 and their receptors may be associated with the aetiology of sporadic miscarriage, especially given the potential role of these cytokines in the regulation of trophoblast invasion and Spiral Artery remodelling. Study funding/competing interest(s) This project was supported by funding from Wellbeing of Women (RG1000). The authors have no competing interests to declare. Trial registration number Not applicable.
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corin an enzyme with a putative role in Spiral Artery remodeling is up regulated in late secretory endometrium and first trimester decidua
Human Reproduction, 2013Co-Authors: Tuuhevaha J Kaituulino, J N Bulmer, Evdokia Dimitriadis, Laura Tuohey, Peter Rogers, Ellen Menkhorst, Michelle Van Sinderen, Jane E Girling, Natalie J Hannan, Stephen TongAbstract:STUDY QUESTION: What is the nature of cellular Corin expression in human gestational tissues? SUMMARY ANSWER: CORIN is expressed in non-pregnant late secretory phase endometrium, first trimester human implantation sites and is up-regulated with decidualization ex vivo. WHAT IS KNOWN ALREADY: Adequate trophoblast invasion and Spiral Artery remodeling/transformation is critical for successful implantation. CORIN, best known for its role in activating atrial natruietic peptide (ANP) to regulate blood pressure, has recently been proposed to be centrally involved in trophoblast invasion and Spiral Artery remodeling. It is postulated that ANP, activated by CORIN, promotes trophoblast invasion and that a deficiency causes pre-eclampsia. Mice deficient in either Corin or ANP displayed poor trophoblast invasion, impaired Spiral Artery remodeling and phenocopied human pre-eclampsia. However, the precise cellular localization of CORIN within human gestational tissues has not been well characterized. STUDY DESIGN, SIZE, DURATION: We measured CORIN protein localization in a number of human gestational tissues relevant to early embryo/placental implantation: non-pregnant (NP) endometrial biopsies (n = 5 per phase of the menstrual cycle), first trimester placental bed biopsies (n = 12) and pre-term control (n = 10) and severe early onset preeclamptic placentas (n = 15). Endometrial stromal cells were isolated from human endometrial biopsies (n = 5) and induced to decidualize ex vivo. Finally, CORIN concentrations were measured in serum obtained from pregnant women during the first trimester of whom, 56 subsequently ended up with a healthy term delivery (controls), 18 developed fetal growth restriction (FGR) and 21 had a miscarriage. PARTICIPANTS/MATERIALS, SETTING, METHODS: We performed immunohistochemistry to assess CORIN localization. Changes in Corin mRNA expression in human endometrial stromal cells decidualized ex vivo were measured by quantitative RT-PCR, and levels of CORIN within human sera were measured by ELISA. MAIN RESULTS AND THE ROLE OF CHANCE: CORIN was expressed in both NP late secretory phase endometrium and first trimester decidua within placental bed biopsies. Importantly, decidualization of primary human endometrial cells ex vivo significantly increased Corin expression (P < 0.05). CORIN was also detected within the villous cytotrophoblast, but there was no change in mRNA levels in placentas complicated by severe preterm pre-eclampsia when compared with pre-term controls. Although CORIN was detected in first trimester serum, levels did not change across gestation, nor could they predict miscarriage or FGR (other disorders of impaired placental invasion). LIMITATIONS, REASONS FOR CAUTION: Owing to the fact that we utilized early pregnancy human specimens, this is mainly a descriptive study with a limited amount of functional experiments. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to thoroughly characterize Corin mRNA and protein expression in human gestational tissue. Our findings support recent data from murine studies collectively suggesting that CORIN plays a critical role in trophoblast migration and Spiral Artery remodeling during early pregnancy in humans. Therefore, further studies of CORIN biology in early pregnancy may identify new therapeutic targets to improve implantation quality in early pregnancy and potentially reduce the rates of pregnancy complications caused by inadequate implantation (pre-eclampsia, FGR and miscarriage). STUDY FUNDING/COMPETING INTEREST(S): This study was supported by The National Health and Medical Research Council of Australia (Salary support #490970, #490995). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors declare that no competing interests exist.
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uterine natural killer cells initiate Spiral Artery remodeling in human pregnancy
The FASEB Journal, 2012Co-Authors: Andrew Robson, Lynda K. Harris, Philip N. Baker, John D. Aplin, Stephen C Robson, Barbara A Innes, Gendie E Lash, Mais M Aljunaidy, J N BulmerAbstract:Uterine Spiral Artery remodeling is required for successful human pregnancy; impaired remodeling is associated with pregnancy complications, including late miscarriage, preeclampsia, and fetal growth restriction. The molecular triggers of remodeling are not known, but it is now clear that there are "trophoblast-independent" and "trophoblast-dependent" stages. Uterine natural killer (uNK) cells are abundant in decidualized endometrium in early pregnancy; they surround Spiral arteries and secrete a range of angiogenic growth factors. We hypothesized that uNK cells mediate the initial stages of Spiral Artery remodeling. uNK cells and extravillous trophoblast (EVT) cells were isolated from early pregnancy decidua and placenta. Chorionic plate arteries from full-term placentas and Spiral arteries from nonpregnant myometrium were cultured with angiogenic growth factors or conditioned medium (CM) from uNK cells or EVT or uNK cell/EVT cocultures. In both vessel models, uNK cell CM induced disruption of vascular smooth muscle cells (VSMCs) and breakdown of extracellular matrix components. Angiopoietin (Ang)-1, Ang-2, interferon-γ, and VEGF-C also disrupted VSMC integrity with an Ang-2 inhibitor abrogating the effect of uNK cell CM. These results provide compelling evidence that uNK cells contribute to the early stages of Spiral Artery remodeling; failure of this process could contribute to pregnancy pathology.
Stephen C Robson - One of the best experts on this subject based on the ideXlab platform.
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uterine Spiral Artery muscle dedifferentiation
Human Reproduction, 2019Co-Authors: Stephen C Robson, Barbara A Innes, Gendie E Lash, A Robson, Joy Yue Zhang, J N BulmerAbstract:STUDY QUESTION Is vascular smooth muscle cell (VSMC) dedifferentiation a feature of uterine Spiral Artery (SpA) remodelling in early human pregnancy? SUMMARY ANSWER Remodelling of human uterine SpAs is associated with dedifferentiation of VSMCs and can be induced in vitro by uterine natural killer (uNK) cells and extravillous trophoblast cells (EVTs). WHAT IS KNOWN ALREADY Uterine SpAs undergo profound morphological changes in normal pregnancy with replacement of the musculoelastic arterial wall structure by fibrinoid containing EVTs. The fate of VSMCs in SpA remodelling is unknown; in guinea pig uterine Artery VSMCs dedifferentiate, remain in the vessel wall and differentiate after parturition to restore the arterial wall. There is increasing evidence that uNK cells play a role in SpA remodelling. We hypothesized that SpA remodelling in human pregnancy is associated with VSMC dedifferentiation, initiated by uNK cell-derived growth factors. STUDY DESIGN, SIZE, DURATION Formalin fixed, paraffin embedded placental bed biopsies were immunostained for angiogenic growth factor (AGF) receptors and markers of VSMC differentiation. An in vitro model of SpA remodelling using chorionic plate arteries (CPAs) was used to test the effect of different cell types and AGFs on VSMC differentiation. PARTICIPANTS/MATERIALS, SETTING, METHODS Placental bed biopsies were immunostained for vascular endothelial growth factor receptors 1-3 (VEGF-R1, VEGF-R2, VEGF-R3), transforming growth factor beta 1 receptors I and II (TGF-βRI, TGF-βRII), interferon gamma receptors 1 and 2 (IFN-γR1, IFN-γR2), Tie2, α-smooth muscle actin (α-SMA), H-caldesmon (H-Cal), myosin heavy chain (MyHC), osteopontin and smoothelin. Staining intensity was assessed using a modified quickscore. Expression by VSMCs of the AGF receptors was confirmed by laser capture microdissection and real-time RT-PCR of non-remodelled SpAs, after laser removal of the endothelium. As an in vitro model, VSMC differentiation was assessed in CPAs by immunohistochemistry after culture in uNK cell-conditioned medium (CM), EVT-CM, uNK cell/EVT co-culture CM, Ang-1, Ang-2, IFN-γ, VEGF-A and VEGF-C, and after blocking of both Ang-1 and Ang-2 in uNK-CM. MAIN RESULTS AND THE ROLE OF CHANCE SpA VSMC expression of Tie-2 (P = 0.0007), VEGF-R2 (P = 0.005) and osteopontin (P = 0.0001) increased in partially remodelled SpAs compared with non-remodelled SpAs, while expression of contractile VSMC markers was reduced (α-SMA P < 0.0001, H-Cal P = 0.03, MyHC P = 0.03, smoothelin P = 0.0001). In the in vitro CPA model, supernatants from purified uNK cell (H-Cal P < 0.0001, MyHC P = 0.03, α-SMA P = 0.02, osteopontin P = 0.03), EVT (H-Cal P = 0.0006, MyHC P = 0.02, osteopontin P = 0.01) and uNK cell/EVT co-cultures (H-Cal P = 0.001, MyHC P = 0.05, osteopontin P = 0.02) at 12-14 weeks, but not 8-10 weeks, gestational age induced reduced expression of contractile VSMC markers and increased osteopontin expression. Addition of exogenous (10 ng/ml) Ang-1 (P = 0.006) or Ang-2 (P = 0.009) also reduced H-Cal expression in the CPA model. Inhibition of Ang-1 (P = 0.0004) or Ang-2 (P = 0.004) in uNK cell supernatants blocked the ability of uNK cell supernatants to reduce H-Cal expression. LIMITATIONS, REASONS FOR CAUTION This is an in vitro study and the role of uNK cells, Ang-1 and Ang-2 in SpA remodelling in vivo has not yet been shown. WIDER IMPLICATIONS OF THE FINDINGS VSMC dedifferentiation is a feature of early SpA remodelling and uNK cells and EVT play key roles in this process by secretion of Ang-1 and Ang-2. This is one of the first studies to suggest a direct role for Ang-1 and Ang-2 in VSMC biology. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by a grant from British Biotechnology and Biosciences Research Council (BB/E016790/1). The authors have no competing interests to declare.
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Spiral Artery remodeling and trophoblast invasion in preeclampsia and fetal growth restriction relationship to clinical outcome
Hypertension, 2013Co-Authors: Fiona Lyall, Stephen C Robson, J N BulmerAbstract:Failure to transform uteroplacental Spiral arteries is thought to underpin disorders of pregnancy, including preeclampsia and fetal growth restriction (FGR). In this study, Spiral Artery remodeling and extravillous-cytotrophoblast were examined in placental bed biopsies from normal pregnancy (n=25), preeclampsia (n=22), and severe FGR (n=10) and then compared with clinical parameters. Biopsies were immunostained to determine vessel wall integrity, extravillous-cytotrophoblast location/density, periarterial fibrinoid, and endothelium. Muscle disruption was reduced in myometrial Spiral arteries in preeclampsia ( P =0.0001) and FGR ( P =0.0001) compared with controls. Myometrial vessels from cases with birth weight P P P P 5th percentile. Fewer extravillous-cytotrophoblast surrounded both decidual and myometrial vessels in the normal group and preeclampsia group compared with the FGR group ( P =0.001). For myometrial vessels, the normal group contained more intramural extravillous-cytotrophoblast than in preeclampsia ( P =0.015). Decidual vessels in the FGR group had less fibrinoid deposition compared with controls ( P =0.013). For myometrial vessels, less fibrinoid was deposited in both the preeclampsia group ( P =0.0001) and the FGR group ( P =0.01) when compared with controls, and less fibrinoid was deposited in the preeclampsia group when compared with FGR group ( P 5th percentile ( P
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altered expression of interleukin 6 interleukin 8 and their receptors in decidua of women with sporadic miscarriage
Human Reproduction, 2013Co-Authors: Hedele Pitman, J N Bulmer, Stephen C Robson, Barbara A Innes, Gendie E LashAbstract:Study question Are alterations in decidual expression of interleukin (IL)-6 and IL-8 associated with sporadic miscarriage? Summary answer IL-6 and IL-8 secretion from decidual uterine natural killer (uNK) cells and macrophages isolated from women with spontaneous miscarriage was reduced compared with normal controls. What is known already Miscarriage is a common gynaecological problem with huge financial and personal implications. Eleven to twenty per cent of all clinically recognized pregnancies are lost before the 20th week of gestation, with miscarriages often being divided into early (≤ 12 completed weeks from last menstrual period) and late (≥ 13 weeks). Spiral Artery remodelling is a key feature of early pregnancy; failure of this process has been implicated in sporadic miscarriage. The molecular triggers that initiate Spiral Artery remodelling are not clear, although cytokines such as IL-6 and IL-8 may play a role. Study design, size, duration This was a laboratory-based study using decidual and placental bed biopsy samples from women with sporadic miscarriage (n = 30) and termination of pregnancy controls (n = 30). Participants/materials, setting, methods Total adherent decidual cells, CD10(+) stromal cells, CD14(+) macrophages and CD56(+) uNK cells were isolated from decidua from apparently normal pregnancies that were terminated at either 8-10 or 12-14 weeks' gestation. In addition, CD14(+) macrophages and CD56(+) uNK cells were isolated from decidua from sporadic miscarriage at 8-10 weeks' gestation. Secreted IL-8 was measured in all isolated cell populations, while IL-6 was measured in CD14(+) macrophages and CD56(+) uNK cells from both sporadic miscarriage and normal controls. Placental bed biopsies were taken from women after sporadic miscarriage or termination of pregnancy at ≤ 12 completed weeks' or >13 weeks' gestational age, formalin-fixed, paraffin-embedded and immunostained for IL-6, IL-6Rα, GP130, IL-8, CXCR1, CXCR2 and CD13 (aminopeptidase N). Staining intensity for each factor was assessed in extravillous trophoblast cell populations, myometrial and decidual stroma, myometrial and decidual Spiral arteries and decidual glandular epithelium. A CPA model was used to assess the potential role of IL-6 and IL-8 in Spiral Artery remodelling. Main results and the role of chance IL-8 was secreted by total adherent decidual cells, CD10(+) stromal cells and CD14(+) macrophages at both 8-10 and 12-14 weeks' gestation, with CD14(+) cells secreting the highest levels. Both CD14(+) and CD56(+) cells isolated from decidua of early sporadic miscarriage produced lower IL-6 (P = 0.04, P = 0.01, respectively) and IL-8 levels (P = 0.0007, P = 0.002, respectively) compared with normal cases. In addition, altered expression of IL-6, IL-8 and their receptors was observed in various cell types in placental bed (myometrial stroma, glandular epithelium, interstitial extravillous trophoblast cells, vascular smooth muscle cells and endothelial cells) in sporadic miscarriage, particularly from later gestational ages. IL-6 and IL-8 disrupted vascular smooth muscle morphology and organization in an in vitro model of Spiral Artery remodelling. Limitations, reasons for caution By the nature of sampling at the time of miscarriage, it was not possible to ascertain the cause or effect in the observed alterations of levels of IL-6 and IL-8 in sporadic miscarriage. Wider implications of the findings Alterations in the expression of IL-6, IL-8 and their receptors may be associated with the aetiology of sporadic miscarriage, especially given the potential role of these cytokines in the regulation of trophoblast invasion and Spiral Artery remodelling. Study funding/competing interest(s) This project was supported by funding from Wellbeing of Women (RG1000). The authors have no competing interests to declare. Trial registration number Not applicable.
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uterine natural killer cells initiate Spiral Artery remodeling in human pregnancy
The FASEB Journal, 2012Co-Authors: Andrew Robson, Lynda K. Harris, Philip N. Baker, John D. Aplin, Stephen C Robson, Barbara A Innes, Gendie E Lash, Mais M Aljunaidy, J N BulmerAbstract:Uterine Spiral Artery remodeling is required for successful human pregnancy; impaired remodeling is associated with pregnancy complications, including late miscarriage, preeclampsia, and fetal growth restriction. The molecular triggers of remodeling are not known, but it is now clear that there are "trophoblast-independent" and "trophoblast-dependent" stages. Uterine natural killer (uNK) cells are abundant in decidualized endometrium in early pregnancy; they surround Spiral arteries and secrete a range of angiogenic growth factors. We hypothesized that uNK cells mediate the initial stages of Spiral Artery remodeling. uNK cells and extravillous trophoblast (EVT) cells were isolated from early pregnancy decidua and placenta. Chorionic plate arteries from full-term placentas and Spiral arteries from nonpregnant myometrium were cultured with angiogenic growth factors or conditioned medium (CM) from uNK cells or EVT or uNK cell/EVT cocultures. In both vessel models, uNK cell CM induced disruption of vascular smooth muscle cells (VSMCs) and breakdown of extracellular matrix components. Angiopoietin (Ang)-1, Ang-2, interferon-γ, and VEGF-C also disrupted VSMC integrity with an Ang-2 inhibitor abrogating the effect of uNK cell CM. These results provide compelling evidence that uNK cells contribute to the early stages of Spiral Artery remodeling; failure of this process could contribute to pregnancy pathology.
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uterine natural killer cells initiate Spiral Artery remodeling in human pregnancy
The FASEB Journal, 2012Co-Authors: Andrew Robson, Lynda K. Harris, Philip N. Baker, John D. Aplin, Stephen C Robson, Barbara A Innes, Gendie E Lash, Mais M Aljunaidy, J N BulmerAbstract:Uterine Spiral Artery remodeling is required for successful human pregnancy; impaired remodeling is associated with pregnancy complications, including late miscarriage, preeclampsia, and fetal growth restriction. The molecular triggers of remodeling are not known, but it is now clear that there are “trophoblast-independent” and “trophoblast-dependent” stages. Uterine natural killer (uNK) cells are abundant in decidualized endometrium in early pregnancy; they surround Spiral arteries and secrete a range of angiogenic growth factors. We hypothesized that uNK cells mediate the initial stages of Spiral Artery remodeling. uNK cells and extravillous trophoblast (EVT) cells were isolated from early pregnancy decidua and placenta. Chorionic plate arteries from full-term placentas and Spiral arteries from nonpregnant myometrium were cultured with angiogenic growth factors or conditioned medium (CM) from uNK cells or EVT or uNK cell/EVT cocultures. In both vessel models, uNK cell CM induced disruption of vascular s...
Guy St J Whitley - One of the best experts on this subject based on the ideXlab platform.
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decidual natural killer cells regulate vessel stability implications for impaired Spiral Artery remodelling
Journal of Reproductive Immunology, 2015Co-Authors: Rupsha Fraser, Guy St J Whitley, B Thilaganathan, Judith E CartwrightAbstract:Decidual NK (dNK) cells are present during uterine Spiral Artery remodelling, an event that is crucial for successful placentation and the provision of an adequate blood supply to the developing fetus. Spiral Artery remodelling is impaired in the pregnancy complication pre-eclampsia. Although dNK cells are known to play active roles at the maternal–fetal interface, little is known about their effect on endothelial integrity, an important component of vessel stability. We present a study in which we have modelled dNK–endothelium interactions, using first-trimester dNK cells isolated from both normal pregnancies and those with impaired Spiral Artery remodelling. dNK cells were isolated from first-trimester pregnancies, screened by uterine Artery Doppler ultrasound to determine resistance indices (RI) that relate to the extent of Spiral Artery remodelling. dNK culture supernatant from normal-RI pregnancies (but not high-RI pregnancies) destabilised endothelial tube-like structures in Matrigel, and normal-RI dNK cells induced endothelial intercellular adhesion molecule-1 and tumour necrosis factor-α expression to a greater extent than high-RI dNK cells. We have established a functional role for dNK cells in the disruption of endothelial structures and have suggested how impairment of this process may be contributing to the reduced vessel remodelling in pregnancies with a high uterine Artery resistance index. These findings have implications for our understanding of the pathology of pre-eclampsia and other pregnancy disorders where remodelling is impaired.
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increased angiogenic factor secretion by decidual natural killer cells from pregnancies with high uterine Artery resistance alters trophoblast function
Human Reproduction, 2014Co-Authors: Alison E Wallace, Rupsha Fraser, Guy St J Whitley, Alan P Johnstone, S Gurung, Sonu S Goulwara, Judith E CartwrightAbstract:participants/materials, setting, methods: A multiplex assay was used to assess dNK cell-secreted factors. SGHPL-4 cell functions were assessed using time-lapse microscopy, 3D invasion assays, endothelial-like tube formation ability and western blot analysis. mainresultsandtheroleofchance:The expression levels of PLGF (P , 0.01), sIL-2R (P , 0.01), endostatin (P , 0.05) and angiogenin (P , 0.05) were significantly increased by dNK cells from high-risk pregnancies. Endostatin significantly decreased SGHPL-4 invasion (P , 0.05), SGHPL-4 tube formation (P , 0.05) and SGHPL-4 Akt ser473 phosphorylation (P , 0.05). Angiogenin significantly decreased SGHPL4 invasion (P , 0.05), but increased SGHPL-4 tube formation (P , 0.01) and decreased SGHPL-4 Akt ser473 phosphorylation (P , 0.05). limitations, reasons forcaution: The culture of dNK cells and protein concentrations in vitro may not fully represent the in vivo situation. Although SGHPL-4 cells are extravillous trophoblast derived, further studies would be needed to confirm the roles of angiogenin and endostatin in vivo. wider implications of the findings: The altered expression of secreted factors of dNK cells may contribute to pregnancy disorders associated with poor Spiral Artery remodelling.
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impaired decidual natural killer cell regulation of vascular remodelling in early human pregnancies with high uterine Artery resistance
The Journal of Pathology, 2012Co-Authors: Rupsha Fraser, Guy St J Whitley, B Thilaganathan, Alan P Johnstone, Amanda J Host, N J Sebire, Judith E CartwrightAbstract:During human pregnancy, natural killer (NK) cells accumulate in the maternal decidua, but their specific roles remain to be determined. Decidual NK (dNK) cells are present during trophoblast invasion and uterine Spiral Artery remodelling. These events are crucial for successful placentation and the provision of an adequate blood supply to the developing fetus. Remodelling of Spiral arteries is impaired in the dangerous pregnancy complication pre-eclampsia. We studied dNK cells isolated from pregnancies at 9–14 weeks' gestation, screened by uterine Artery Doppler ultrasound to determine resistance indices which relate to the extent of Spiral Artery remodelling. dNK cells were able to promote the invasive behaviour of fetal trophoblast cells, partly through HGF. Cells isolated from pregnancies with higher resistance indices were less able to do this and secreted fewer pro-invasive factors. dNK cells from pregnancies with normal resistance indices could induce apoptotic changes in vascular smooth muscle and endothelial cells in vitro, events of importance in vessel remodelling, partly through Fas signalling. dNK cells isolated from high resistance index pregnancies failed to induce vascular apoptosis and secreted fewer pro-apoptotic factors. We have modelled the cellular interactions at the maternal-fetal interface and provide the first demonstration of a functional role for dNK cells in influencing vascular cells. A potential mechanism contributing to impaired vessel remodelling in pregnancies with a higher uterine Artery resistance is presented. These findings may be informative in determining the cellular interactions contributing to the pathology of pregnancy disorders where remodelling is impaired, such as pre-eclampsia. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Trophoblast- and Vascular Smooth Muscle Cell-Derived MMP-12 Mediates Elastolysis during Uterine Spiral Artery Remodeling
The American journal of pathology, 2010Co-Authors: Lynda K. Harris, Judith E Cartwright, Guy St J Whitley, Samantha D. Smith, Rosemary J. Keogh, Rebecca L. Jones, Philip N. Baker, Martin Knöfler, John D. AplinAbstract:During the first trimester of pregnancy, the uterine Spiral arteries are remodeled, creating heavily dilated conduits that lack maternal vasomotor control but allow the placenta to meet an increasing requirement for nutrients and oxygen. To effect permanent vasodilatation, the internal elastic lamina and medial elastin fibers must be degraded. In this study, we sought to identify the elastolytic proteases involved in this process. Primary first-trimester cytotrophoblasts (CTBs) derived from the placenta exhibited intracellular and membrane-associated elastase activity; membrane-associated activity was primarily attributable to matrix metalloproteinases (MMP). Indeed, Affymetrix microarray analysis and immunocytochemistry implicated MMP-12 (macrophage metalloelastase) as a key mediator of elastolysis. Cultured human aortic smooth muscle cells (HASMCs) exhibited constitutive membrane-associated elastase activity and inducible intracellular elastase activity; these cells also expressed MMP-12 protein. Moreover, a specific inhibitor of MMP-12 significantly reduced CTB- and HASMC-mediated elastolysis in vitro, to 31.7 ± 10.9% and 23.3 ± 8.7% of control levels, respectively. MMP-12 is expressed by both interstitial and endovascular trophoblasts in the first-trimester placental bed and by vascular SMCs (VSMCs) in remodeling Spiral arteries. Perfusion of isolated Spiral Artery segments with CTB-conditioned medium stimulated MMP-12 expression in medial VSMCs. Our data support a model in which trophoblasts and VSMCs use MMP-12 cooperatively to degrade elastin during vascular remodeling in pregnancy, with the localized release of elastin peptides and CTB-derived factors amplifying elastin catabolism.
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pre eclampsia fitting together the placental immune and cardiovascular pieces
The Journal of Pathology, 2010Co-Authors: Joanna L James, Guy St J Whitley, Judith E CartwrightAbstract:The success of pregnancy is a result of countless ongoing interactions between the placenta and the maternal immune and cardiovascular systems. Pre-eclampsia is a serious pregnancy complication that arises from multiple potential aberrations in these systems. The pathophysiology of pre-eclampsia is established in the first trimester of pregnancy, when a range of deficiencies in placentation affect the key process of Spiral Artery remodelling. As pregnancy progresses to the third trimester, inadequate Spiral Artery remodelling along with multiple haemodynamic, placental and maternal factors converge to activate the maternal immune and cardiovascular systems, events which may in part result from increased shedding of placental debris. As we understand more about the pathophysiology of pre-eclampsia, it is becoming clear that the development of early- and late-onset pre-eclampsia, as well as intrauterine growth restriction (IUGR), does not necessarily arise from the same underlying pathology.
John D. Aplin - One of the best experts on this subject based on the ideXlab platform.
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elastin derived peptides stimulate trophoblast migration and invasion a positive feedback loop to enhance Spiral Artery remodelling
Molecular Human Reproduction, 2015Co-Authors: Michelle Desforges, Lynda K. Harris, John D. AplinAbstract:Elastin breakdown in the walls of uterine Spiral arteries during early pregnancy facilitates their transformation into dilated, high-flow, low-resistance channels. Elastin-derived peptides (EDP) can influence cell migration, invasion and protease activity, and so we hypothesized that EDP released during elastolysis promote extravillous trophoblast (EVT) invasion and further elastin breakdown. Treatment of the trophoblast cell line SGHPL4 with the elastin-derived matrikine VGVAPG (1 μg/ml) significantly increased total elastase activity, promoted migration in a wound healing assay and increased invasion through Matrigel-coated transwells compared with vehicle control (0.1% DMSO) or the scrambled sequence VVGPGA. Furthermore, treatment of first-trimester placental villous explants with this EDP significantly increased both the area of trophoblast outgrowth and distance of migration away from the villous tips. Primary first-trimester cytotrophoblast exposed to VGVAPG (1 μg/ml) for 30 min showed increased phosphorylation of endothelial nitric oxide synthase and activation of the mitogen activated protein kinase pathway, events also associated with tumour cell migration and invasion. These in vitro observations suggest liberation of bioactive EDP during induction of elastolysis in the uterine Spiral arteries may orchestrate a positive feedback loop that promotes EVT invasion and further elastin breakdown, contributing to the process of vascular remodelling.
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uterine natural killer cells initiate Spiral Artery remodeling in human pregnancy
The FASEB Journal, 2012Co-Authors: Andrew Robson, Lynda K. Harris, Philip N. Baker, John D. Aplin, Stephen C Robson, Barbara A Innes, Gendie E Lash, Mais M Aljunaidy, J N BulmerAbstract:Uterine Spiral Artery remodeling is required for successful human pregnancy; impaired remodeling is associated with pregnancy complications, including late miscarriage, preeclampsia, and fetal growth restriction. The molecular triggers of remodeling are not known, but it is now clear that there are "trophoblast-independent" and "trophoblast-dependent" stages. Uterine natural killer (uNK) cells are abundant in decidualized endometrium in early pregnancy; they surround Spiral arteries and secrete a range of angiogenic growth factors. We hypothesized that uNK cells mediate the initial stages of Spiral Artery remodeling. uNK cells and extravillous trophoblast (EVT) cells were isolated from early pregnancy decidua and placenta. Chorionic plate arteries from full-term placentas and Spiral arteries from nonpregnant myometrium were cultured with angiogenic growth factors or conditioned medium (CM) from uNK cells or EVT or uNK cell/EVT cocultures. In both vessel models, uNK cell CM induced disruption of vascular smooth muscle cells (VSMCs) and breakdown of extracellular matrix components. Angiopoietin (Ang)-1, Ang-2, interferon-γ, and VEGF-C also disrupted VSMC integrity with an Ang-2 inhibitor abrogating the effect of uNK cell CM. These results provide compelling evidence that uNK cells contribute to the early stages of Spiral Artery remodeling; failure of this process could contribute to pregnancy pathology.
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uterine natural killer cells initiate Spiral Artery remodeling in human pregnancy
The FASEB Journal, 2012Co-Authors: Andrew Robson, Lynda K. Harris, Philip N. Baker, John D. Aplin, Stephen C Robson, Barbara A Innes, Gendie E Lash, Mais M Aljunaidy, J N BulmerAbstract:Uterine Spiral Artery remodeling is required for successful human pregnancy; impaired remodeling is associated with pregnancy complications, including late miscarriage, preeclampsia, and fetal growth restriction. The molecular triggers of remodeling are not known, but it is now clear that there are “trophoblast-independent” and “trophoblast-dependent” stages. Uterine natural killer (uNK) cells are abundant in decidualized endometrium in early pregnancy; they surround Spiral arteries and secrete a range of angiogenic growth factors. We hypothesized that uNK cells mediate the initial stages of Spiral Artery remodeling. uNK cells and extravillous trophoblast (EVT) cells were isolated from early pregnancy decidua and placenta. Chorionic plate arteries from full-term placentas and Spiral arteries from nonpregnant myometrium were cultured with angiogenic growth factors or conditioned medium (CM) from uNK cells or EVT or uNK cell/EVT cocultures. In both vessel models, uNK cell CM induced disruption of vascular s...
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Trophoblast- and Vascular Smooth Muscle Cell-Derived MMP-12 Mediates Elastolysis during Uterine Spiral Artery Remodeling
The American journal of pathology, 2010Co-Authors: Lynda K. Harris, Judith E Cartwright, Guy St J Whitley, Samantha D. Smith, Rosemary J. Keogh, Rebecca L. Jones, Philip N. Baker, Martin Knöfler, John D. AplinAbstract:During the first trimester of pregnancy, the uterine Spiral arteries are remodeled, creating heavily dilated conduits that lack maternal vasomotor control but allow the placenta to meet an increasing requirement for nutrients and oxygen. To effect permanent vasodilatation, the internal elastic lamina and medial elastin fibers must be degraded. In this study, we sought to identify the elastolytic proteases involved in this process. Primary first-trimester cytotrophoblasts (CTBs) derived from the placenta exhibited intracellular and membrane-associated elastase activity; membrane-associated activity was primarily attributable to matrix metalloproteinases (MMP). Indeed, Affymetrix microarray analysis and immunocytochemistry implicated MMP-12 (macrophage metalloelastase) as a key mediator of elastolysis. Cultured human aortic smooth muscle cells (HASMCs) exhibited constitutive membrane-associated elastase activity and inducible intracellular elastase activity; these cells also expressed MMP-12 protein. Moreover, a specific inhibitor of MMP-12 significantly reduced CTB- and HASMC-mediated elastolysis in vitro, to 31.7 ± 10.9% and 23.3 ± 8.7% of control levels, respectively. MMP-12 is expressed by both interstitial and endovascular trophoblasts in the first-trimester placental bed and by vascular SMCs (VSMCs) in remodeling Spiral arteries. Perfusion of isolated Spiral Artery segments with CTB-conditioned medium stimulated MMP-12 expression in medial VSMCs. Our data support a model in which trophoblasts and VSMCs use MMP-12 cooperatively to degrade elastin during vascular remodeling in pregnancy, with the localized release of elastin peptides and CTB-derived factors amplifying elastin catabolism.
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bewo cells stimulate smooth muscle cell apoptosis and elastin breakdown in a model of Spiral Artery transformation
Human Reproduction, 2007Co-Authors: Lynda K. Harris, Judith E Cartwright, Guy St J Whitley, Rosemary J. Keogh, Philip N. Baker, Mark Wareing, John D. AplinAbstract:BACKGROUND During pregnancy, extravillous trophoblast invades the uterine wall and enters the Spiral arteries. Remodelling ensues, with loss of vascular smooth muscle cells (SMCs) to create high flow, low resistance vessels. Pregnancies complicated by pre-eclampsia are characterized by incomplete arterial remodelling. Endovascular trophoblast is not easily accessible for studies to establish the pathogenesis of pre-eclampsia, so we have developed a model appropriate to carry out mechanistic studies of vessel wall transformation. METHODS AND RESULTS Segments of human Spiral Artery were perfused with the choriocarcinoma cell line, BeWo; cells invaded the vessel wall and induced apoptosis of vascular SMC. Perfusion of vessels with BeWo-conditioned medium also induced SMC apoptosis, indicating the presence of a soluble apoptotic factor. BeWo express Fas ligand (FasL) and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Treatment of BeWo-conditioned medium with antibodies against FasL inhibited vascular SMC apoptosis in vitro. Antibodies that blocked TRAIL receptor function had no effect. Extracellular matrix degradation is also a prerequisite for vascular remodelling; BeWo express matrix metalloproteinase-12 (MMP-12) and BeWo-conditioned medium increased MMP-12 expression in Spiral Artery SMC. CONCLUSIONS BeWo induce arterial remodelling via FasL- and MMP-12-dependent mechanisms. BeWo-derived factors up-regulate protease expression in Spiral Artery SMC to facilitate matrix breakdown.