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Tryptophan dilates preconstricted chorionic arteries and endothelial indoleamine 2,3-dioxygenase-1 is deficient in intrauterine growth restriction and preeclampsia
A46
Abstracts / Placenta 36 (2015) A1eA60
P2.27. TRYPTOPHAN DILATES PRECONSTRICTED CHORIONIC ARTERIES AND ENDOTHELIAL INDOLEAMINE 2,3-DIOXYGENASE-1 IS DEFICIENT IN INTRAUTERINE GROWTH RESTRICTION AND PREECLAMPSIA Pablo Zardoya Laguardia, Astrid Blaschitz, Sasa Frank, Ingrid LangOlip, Martin Gauster, Martin Haeusler, Mila Cervar-Zivkovic, Eva Karpf, Peter Sedlmayr. Medical University of Graz, Graz, Styria, Austria Objectives: The establishment of an adequate feto-placental circulation is required for successful pregnancy. Indoleamine 2,3-dioxygenase-1 (IDO1), a tryptophan (Trp)-degrading enzyme, may be involved in the regulation of placental blood flow which is impaired in pregnancy complications such as intrauterine growth restriction (IUGR) or preeclampsia (PE). Methods: IDO1 protein expression was assessed by Western blotting in IUGR, pre-eclamptic and praevia placentae (the latter were chosen as controls due to a comparable gestational age), and also in placental arterial endothelial cells (PLAEC) isolated from normal term placentae (passages 3 e 5). Localisation of IDO1 protein was done by immunohistochemistry (IHC). IDO1 mRNA levels were assessed by quantitative PCR. Vasorelaxation of pre-constricted placental arteries as a measure of IDO1 activity was assayed by myography upon exposure of vessels to Trp. Results: Trp induced vasorelaxation of pre-constricted placental arteries. A significant decrease in IDO1 protein expression was found by Western blotting in IUGR (n ¼ 5, gestational age (GA) 35.9 + 1.3 weeks) and PE (n ¼ 13, GA 33.9 + 2.1 weeks) in comparison with control placentae (n ¼ 5, GA 33.6 + 1.8 weeks), whereas on the level of mRNA we did not detect significant differences between these groups. Constitutive IDO1 protein and mRNA expression was observed in PLAEC from normal term placentae. IHC revealed that in some cases (three in the PE group, one in the control placentae) IDO1 protein expression in the chorion was not restricted to the vascular endothelium but also present in macrophages in regions affected by chronic villitis and intervillositis.. Conclusion: Trp metabolism by IDO1 is likely to contribute to the regulation of the vascular tone of chorionic vessels. Expression of IDO1 is down-regulated at the protein level in IUGR and PE placentae. Further studies are warranted to elucidate a possible causal relationship between deficient vascular endothelial IDO1 and placental diseases.
P2.28. INHIBITION OF COLLAGEN EXPRESSION BY CORTISOL IN HUMAN AMNION FIBROBLASTS: A NOVEL ROLE OF LOCAL REGENERATION OF CORTISOL IN THE RUPTURE OF FETAL MEMBRANES Gang Sun, Chao Liu. Center for Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China Objectives: One of the leading causes for preterm labor is premature rupture of the fetal membranes. The underlying mechanisms remain largely unknown. Collagen types I and III of the amnion compact layer forms the main fibrous skeleton of the fetal membranes. Previously we have demonstrated that there exists a feed-forward regeneration of cortisol from biologically-inactive cortisone by 11b-HSD1 towards the end of gestation in the fetal membranes. Since topical glucocorticoid treatment is known to cause cutaneous atrophy mostly by inhibition of collagen synthesis, we propose that this local regeneration of cortisol might be related to collagen synthesis thereby influencing the tensile strength of fetal membranes leading to the rupture of membranes. Methods: The effects of cortisol and cortisone with or without CBX, the inhibitor of 11b-HSD1, on collagen I and III mRNA and protein levels were studied in cultured primary human amnion fibroblasts, the collagen source for the compact layer. Results: Cortisol (0.01e1 mM) decreased collagen I and III mRNA and protein levels in a dose-dependent manner, which was attenuated by glucocorticoid receptor antagonist RU486. Cortisone (5, 10 mM) also reduced collagen I and III mRNA and protein levels, which was blocked by CBX, the inhibitor of 11b-HSD1 which converts biologically-inactive cortisone to active cortisol.
Conclusion: These results indicate that cortisol regenerated from cortisone by 11b-HSD1 in the fetal membranes could reduce collagen I and III synthesis by amnion fibroblasts. Decreased levels of collagen I and III may therefore weaken the tensile strength of the fetal membranes resulting in the rupture of the membranes. Premature activation of this feedforward mechanism may thus lead to premature rupture of the fetal membranes. This study provides evidence for a novel role of local feedforward regeneration of cortisol in the rupture of fetal membranes.
P2.29. SERIAL CHANGE IN CERVICAL LENGTH AND THE RISK OF EMERGENT CESAREAN DELIVERY IN PLACENTA PREVIA Sae Kyung Choi, Jae Eun Shin, Sa Jin Kim. The Catholic university of Korea, Seoul, Republic of Korea Objective: To evaluate whether serial cervical length measurements can be predictors for emergent cesarean section in women with placenta previa Methods: This was retrospective cohort study including 93 women with placenta previa. Cervical lengths were measured transvaginal ultrasound from early gestation until delivery. We compared clinical characteristics, serial change of cervical length, and outcomes between emergent cesarean delivery group (case group) and elective cesarean delivery group (control group). Predictive value of cervical change in predicting emergent cesarean delivery was evaluated. Results: A total of 93 women were analyzed; 31 women had emergent cesarean delivery due to massive vaginal bleeding. Emergent cesarean delivery group had abrupt cervical change during early third trimester compared with control group. On univariate analysis, hospitalization, cervical change between 2nd and third trimester, and nullipartiy were significantly associated with emergent cesarean delivery. On multivariate analysis after adjusted by maternal age, hospitalization, placenta totalis, ant placenta, cervical change, nulligravidity, nulliparity, previous cesarean delivery, previous preterm delivery, only hospitalization, cervical change remained significantly associated with emergent cesarean delivery. Analyses of the ROC curve showed that cervical change could be the predictor of emergent cesarean delivery (area under the curve 0.676, p ¼ 0.041) with optimal cutoff for predicting emergent cesarean delivery of 1.40. Conclusions: Tranvaginal sonography for CL measurement can be helpful for predicting emergent cesarean delivery.
P2.30. EXOGENOUS MYOSTATIN AND VARIED OXYGEN TENSIONS ALTER THE RELEASE OF INTERLEUKIN-2 FROM FIRST TRIMESTER PLACENTAL EXPLANTS. Hassendrini Peiris 1, Carlos Salomon 1, Kanchan Vaswani 1, Gregory Duncombe 2, Gregory Rice 1, Murray Mitchell 1. 1 The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia; 2 Royal Brisbane and Women’s Hospital, Department of Obstetrics and Gynaecology, Brisbane, Queensland, Australia Objectives: Placental cytokines play a critical role in establishment of pregnancy. A shift in the balance of T-helper 1 (Th1) and T-helper 2 (Th2) cytokines occurs in normal pregnancies. In pregnancies complicated by preeclampsia and intrauterine growth restriction the Th1/Th2 cytokine balance may be altered (as indicated by elevated IL-2 and TNF-a expression in these conditions). In non-gestational tissues, myostatin (a member of the TGFb superfamily) has been implicated in the regulation of cytokine expression, however, its role in regulating placental cytokine production is yet to be described. Thus, the aim of this study was to establish the effect of exogenous myostatin on the release of IL-2 from first trimester placental explants incubated in vitro. Methods: The Human Research Ethics Committees of the Royal Brisbane and Women’s Hospital, and the University of Queensland approved the collection of first trimester placental tissues from women undergoing terminations of pregnancy for psychosocial reasons. Placental explants (10 weeks gestation) were maintained at oxygen tensions of 1% (hypoxic) 3%
Abstracts / Placenta 36 (2015) A1eA60
P2.27. TRYPTOPHAN DILATES PRECONSTRICTED CHORIONIC ARTERIES AND ENDOTHELIAL INDOLEAMINE 2,3-DIOXYGENASE-1 IS DEFICIENT IN INTRAUTERINE GROWTH RESTRICTION AND PREECLAMPSIA Pablo Zardoya Laguardia, Astrid Blaschitz, Sasa Frank, Ingrid LangOlip, Martin Gauster, Martin Haeusler, Mila Cervar-Zivkovic, Eva Karpf, Peter Sedlmayr. Medical University of Graz, Graz, Styria, Austria Objectives: The establishment of an adequate feto-placental circulation is required for successful pregnancy. Indoleamine 2,3-dioxygenase-1 (IDO1), a tryptophan (Trp)-degrading enzyme, may be involved in the regulation of placental blood flow which is impaired in pregnancy complications such as intrauterine growth restriction (IUGR) or preeclampsia (PE). Methods: IDO1 protein expression was assessed by Western blotting in IUGR, pre-eclamptic and praevia placentae (the latter were chosen as controls due to a comparable gestational age), and also in placental arterial endothelial cells (PLAEC) isolated from normal term placentae (passages 3 e 5). Localisation of IDO1 protein was done by immunohistochemistry (IHC). IDO1 mRNA levels were assessed by quantitative PCR. Vasorelaxation of pre-constricted placental arteries as a measure of IDO1 activity was assayed by myography upon exposure of vessels to Trp. Results: Trp induced vasorelaxation of pre-constricted placental arteries. A significant decrease in IDO1 protein expression was found by Western blotting in IUGR (n ¼ 5, gestational age (GA) 35.9 + 1.3 weeks) and PE (n ¼ 13, GA 33.9 + 2.1 weeks) in comparison with control placentae (n ¼ 5, GA 33.6 + 1.8 weeks), whereas on the level of mRNA we did not detect significant differences between these groups. Constitutive IDO1 protein and mRNA expression was observed in PLAEC from normal term placentae. IHC revealed that in some cases (three in the PE group, one in the control placentae) IDO1 protein expression in the chorion was not restricted to the vascular endothelium but also present in macrophages in regions affected by chronic villitis and intervillositis.. Conclusion: Trp metabolism by IDO1 is likely to contribute to the regulation of the vascular tone of chorionic vessels. Expression of IDO1 is down-regulated at the protein level in IUGR and PE placentae. Further studies are warranted to elucidate a possible causal relationship between deficient vascular endothelial IDO1 and placental diseases.
P2.28. INHIBITION OF COLLAGEN EXPRESSION BY CORTISOL IN HUMAN AMNION FIBROBLASTS: A NOVEL ROLE OF LOCAL REGENERATION OF CORTISOL IN THE RUPTURE OF FETAL MEMBRANES Gang Sun, Chao Liu. Center for Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China Objectives: One of the leading causes for preterm labor is premature rupture of the fetal membranes. The underlying mechanisms remain largely unknown. Collagen types I and III of the amnion compact layer forms the main fibrous skeleton of the fetal membranes. Previously we have demonstrated that there exists a feed-forward regeneration of cortisol from biologically-inactive cortisone by 11b-HSD1 towards the end of gestation in the fetal membranes. Since topical glucocorticoid treatment is known to cause cutaneous atrophy mostly by inhibition of collagen synthesis, we propose that this local regeneration of cortisol might be related to collagen synthesis thereby influencing the tensile strength of fetal membranes leading to the rupture of membranes. Methods: The effects of cortisol and cortisone with or without CBX, the inhibitor of 11b-HSD1, on collagen I and III mRNA and protein levels were studied in cultured primary human amnion fibroblasts, the collagen source for the compact layer. Results: Cortisol (0.01e1 mM) decreased collagen I and III mRNA and protein levels in a dose-dependent manner, which was attenuated by glucocorticoid receptor antagonist RU486. Cortisone (5, 10 mM) also reduced collagen I and III mRNA and protein levels, which was blocked by CBX, the inhibitor of 11b-HSD1 which converts biologically-inactive cortisone to active cortisol.
Conclusion: These results indicate that cortisol regenerated from cortisone by 11b-HSD1 in the fetal membranes could reduce collagen I and III synthesis by amnion fibroblasts. Decreased levels of collagen I and III may therefore weaken the tensile strength of the fetal membranes resulting in the rupture of the membranes. Premature activation of this feedforward mechanism may thus lead to premature rupture of the fetal membranes. This study provides evidence for a novel role of local feedforward regeneration of cortisol in the rupture of fetal membranes.
P2.29. SERIAL CHANGE IN CERVICAL LENGTH AND THE RISK OF EMERGENT CESAREAN DELIVERY IN PLACENTA PREVIA Sae Kyung Choi, Jae Eun Shin, Sa Jin Kim. The Catholic university of Korea, Seoul, Republic of Korea Objective: To evaluate whether serial cervical length measurements can be predictors for emergent cesarean section in women with placenta previa Methods: This was retrospective cohort study including 93 women with placenta previa. Cervical lengths were measured transvaginal ultrasound from early gestation until delivery. We compared clinical characteristics, serial change of cervical length, and outcomes between emergent cesarean delivery group (case group) and elective cesarean delivery group (control group). Predictive value of cervical change in predicting emergent cesarean delivery was evaluated. Results: A total of 93 women were analyzed; 31 women had emergent cesarean delivery due to massive vaginal bleeding. Emergent cesarean delivery group had abrupt cervical change during early third trimester compared with control group. On univariate analysis, hospitalization, cervical change between 2nd and third trimester, and nullipartiy were significantly associated with emergent cesarean delivery. On multivariate analysis after adjusted by maternal age, hospitalization, placenta totalis, ant placenta, cervical change, nulligravidity, nulliparity, previous cesarean delivery, previous preterm delivery, only hospitalization, cervical change remained significantly associated with emergent cesarean delivery. Analyses of the ROC curve showed that cervical change could be the predictor of emergent cesarean delivery (area under the curve 0.676, p ¼ 0.041) with optimal cutoff for predicting emergent cesarean delivery of 1.40. Conclusions: Tranvaginal sonography for CL measurement can be helpful for predicting emergent cesarean delivery.
P2.30. EXOGENOUS MYOSTATIN AND VARIED OXYGEN TENSIONS ALTER THE RELEASE OF INTERLEUKIN-2 FROM FIRST TRIMESTER PLACENTAL EXPLANTS. Hassendrini Peiris 1, Carlos Salomon 1, Kanchan Vaswani 1, Gregory Duncombe 2, Gregory Rice 1, Murray Mitchell 1. 1 The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia; 2 Royal Brisbane and Women’s Hospital, Department of Obstetrics and Gynaecology, Brisbane, Queensland, Australia Objectives: Placental cytokines play a critical role in establishment of pregnancy. A shift in the balance of T-helper 1 (Th1) and T-helper 2 (Th2) cytokines occurs in normal pregnancies. In pregnancies complicated by preeclampsia and intrauterine growth restriction the Th1/Th2 cytokine balance may be altered (as indicated by elevated IL-2 and TNF-a expression in these conditions). In non-gestational tissues, myostatin (a member of the TGFb superfamily) has been implicated in the regulation of cytokine expression, however, its role in regulating placental cytokine production is yet to be described. Thus, the aim of this study was to establish the effect of exogenous myostatin on the release of IL-2 from first trimester placental explants incubated in vitro. Methods: The Human Research Ethics Committees of the Royal Brisbane and Women’s Hospital, and the University of Queensland approved the collection of first trimester placental tissues from women undergoing terminations of pregnancy for psychosocial reasons. Placental explants (10 weeks gestation) were maintained at oxygen tensions of 1% (hypoxic) 3%