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A novel tryptophan-based mechanism regulating the placental vascular tone – potential contribution to intrauterine growth restriction and preeclampsia
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Abstracts / Placenta 57 (2017) 225e335
P1.66. A NOVEL TRYPTOPHAN-BASED MECHANISM REGULATING THE PLACENTAL VASCULAR TONE e POTENTIAL CONTRIBUTION TO INTRAUTERINE GROWTH RESTRICTION AND PREECLAMPSIA Pablo Zardoya-Laguardia 1, Astrid Blaschitz 1, Birgit Hirschmugl 2, Ingrid Lang 1, Sereina Herzog 3, Liudmila Nikitina 1, Martin Gauster 1, Martin €usler 2, Mila Cervar-Zivkovic 1, Eva Karpf 4, Ghassan Maghzal 5,6, Chris Ha Stanley 5, Roland Stocker 5,6, Christian Wadsack 2, Sasa Frank 7, Peter Sedlmayr 1. 1 Medical University of Graz, Institute of Cell Biology, Histology and Embryology, Graz, Styria, Austria; 2 Medical University of Graz, Department of Obstetrics and Gynaecology, Graz, Styria, Austria; 3 Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz, Styria, Austria; 4 Medical University of Graz, Institute of Pathology, Graz, Styria, Austria; 5 Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; 6 University of New South Wales, School of Medical Sciences, Sydney, New South Wales, Australia; 7 Medical University of Graz, Institute of Molecular Biology and Biochemistry, Graz, Styria, Austria Objectives: The establishment and maintenance of an adequate fetoplacental circulation is required for successful pregnancy. We asked the questions whether indoleamine 2,3-dioxygenase-1 (IDO1), a tryptophan (Trp)-degrading enzyme which is constitutively expressed in the chorionic endothelium, may be involved in the regulation of placental blood flow, this way contributing to the control of placental and fetal growth, and whether this mechanism is impaired in intrauterine growth restriction (IUGR) and preeclampsia (PE). Methods: Vasorelaxation to Trp of in vitro pre-constricted arteries from the chorionic plate in the presence and absence of IFNg and TNFa as an approach to upregulate IDO1 was assayed by myography. The arteriovenous pressure in normal and preconstricted placental cotyledons was monitored by ex-vivo perfusion during administration of Trp. IDO1 protein expression was assessed by Western blotting in IUGR, pre-eclampsia, term and gestational age-matched pre-term controls, and also in placental arterial endothelial cells (PLAECs) isolated from normal term placentas. IDO1 mRNA levels were assessed by RT-qPCR. Localization of IDO1 protein was done by immunohistochemistry (IHC). IDO activity was measured by LC/MS. Results: Constitutive expression of IDO1 was found in PLAECs on the level of mRNA but only partly on the protein level, exhibiting an upregulation of IDO1 following IFNg/TNFa stimulation. Trp induced vasorelaxation of preconstricted perfused placental cotyledons and cytokine-stimulated preconstricted placental arteries, effect that was partially blocked by using an IDO1 competitive inhibitor. Removal of the endothelium did not abolish the vasorelaxing effect of Trp. Whereas no differences were found on the level of mRNA, a decrease in IDO1 protein expression, as well as in IDO activity were found in IUGR and PE in comparison with pre-term controls. Conclusion: IDO1-mediated metabolism of Trp contributes to the regulation of the placental vascular tone. The pregnancy complications IUGR and PE are associated with a deficiency in chorionic IDO1. http://dx.doi.org/10.1016/j.placenta.2017.07.154
P1.67. PLACENTAL CHORIONIC VASCULAR ANGIOGENESIS IS ALTERED IN PREECLAMPSIA AND FETAL GROWTH RESTRICTION INDEPENDENT OF GESTATIONAL AGE Elizabeth Klimowicz 1, Ruchit Shah 2, Theresa Girardi 2, Sanford Lederman 1, Beata Dygulska 1, Pramod Narula 1, Carolyn Salafia 1, 2. 1 New York Presbyterian-Broo0klyn Methodist Hospital, Brooklyn, NY, USA; 2 Placental Analytics LLC, New Rochelle, NY, USA Fetoplacental vasculogenesis begins in early pregnancy and angiogenesis continues in the terminal villi until term. Maternal malperfusion is considered the hallmark of pre-eclampsia (PE) and of many cases of fetal growth restriction (FGR), but distal fetal villous capillary networks have also been shown to be abnormal in these two conditions. No study has
evaluated the chorionic surface vascular network in PE or FGR pregnancy, vessels that have been shown to be to a large degree determined by 11-14 weeks gestation. Methods: Digital photographs were obtained of cleaned and dried chorionic surfaces. Networks were traced and analyzed according to a published protocol and algorithm. ANOVA, Mann-Whitney U-test and Pearson’s correlations considered p<0.05 significant. Results: In 46 non-PE and 17 PE-FGR vascular networks, birthweight (BW), gestational age and placental weight (PW) showed similar relationships. In PE-FGR pregnancies, there were significantly greater numbers of chorionic surface branch points (64+/-24 v. 52+/- 18, p¼0.036), and a significantly shorter mean segment arc length (p¼0.005), and significantly reduced distance between chorionic arteries and veins on the placental surface (p¼0.001). These relationships were independent of gestational age. Conclusions: We observed in PE-FGR an unexpected finding of increased chorionic surface branch points, indicating a more “lush” placental surface vasculature than in normal controls. We had previously found that increased branch points were typical of preterm placentas, but our results were independent of GA. These data suggest that PE-FGR placentas may manifest chorionic surface vascular changes in early gestation that one may suggest would improve placental ability to compensate for a compromised maternal vascular perfusion environment. We can objectively measure the impact of PE-FGR on the vasculature of the placenta. We predict that such analyses will allow better understanding of the etiologies of pregnancy complication associated with PE-FGR. http://dx.doi.org/10.1016/j.placenta.2017.07.155
P1.68. PLACENTAL CHORIONIC VASCULAR ANGIOGENESIS IS ALTERED IN MATERNAL DIABETES MELLITUS Cadesa Ramharrack 1, Ruchit Shah 2, Theresa Girardi 2, Sanford Lederman 1, Pramod Narule 1, Carolyn Salafia 1, 2. 1 New York PresbyterianBrooklyn Methodist Hospital, Brooklyn, NY, USA; 2 Placental Analytics, LLC, New Rochelle, NY, USA Background: Placental development is essential to fetal development and well being. Patterns of distal villous angiogenesis have been shown to be abnormal in pregestational and gestational diabetes (DM). No study has evaluated the chorionic surface vascular network in DM pregnancy. Methods: Digital photographs of cleaned and dried chorionic surfaces were traced and analyzed according to a published protocol and algorithm. Principal components analysis (PCA) reduced the novel vascular variables to 3 factors in the non-DM controls; these equations were then applied to the DM vascular networks. ANOVA and Pearson’s correlations considered p<0.05 significant. Results: In 38 non-DM pregnancies, birthweight and gestational age (r¼0.89, p¼0.0001), and birthweight and placental weight correlated with (r¼0.87, p¼0.0001); in 11 DM pregnancies, birthweight was related to GA (r¼0.67, p¼0.024) but not PW (p¼0.99). The 3 PCA factors accounted for 75% of variance of vascular variables in non-DM. In non-DM, factor 1 was strongly related to BW (p¼0.44), PW (p¼0.005) and GA (p¼0.044), and factor 3 was related to BW (p¼0.053) and PW (p¼0.025). No factor was associated with BW, GA or PW in DM networks. In non-DM networks, the average segment arc length was associated with BW (p¼0.045) and the distance at which vessels ceased extending to the perimeter was related to GA (p¼0.035) and BW (p¼0.002). Neither was related to BW GA or PW in DM networks. Conclusions: DM results in striking differences in the most basic relationships in pregnancy, of placental vasculature to BW, to PW, and PW to GA. We can objectively measure the impact of DM on placental vasculature. We predict that such analyses will allow better understanding of the etiologies of pregnancy complication associated with DM. http://dx.doi.org/10.1016/j.placenta.2017.07.156
Abstracts / Placenta 57 (2017) 225e335
P1.66. A NOVEL TRYPTOPHAN-BASED MECHANISM REGULATING THE PLACENTAL VASCULAR TONE e POTENTIAL CONTRIBUTION TO INTRAUTERINE GROWTH RESTRICTION AND PREECLAMPSIA Pablo Zardoya-Laguardia 1, Astrid Blaschitz 1, Birgit Hirschmugl 2, Ingrid Lang 1, Sereina Herzog 3, Liudmila Nikitina 1, Martin Gauster 1, Martin €usler 2, Mila Cervar-Zivkovic 1, Eva Karpf 4, Ghassan Maghzal 5,6, Chris Ha Stanley 5, Roland Stocker 5,6, Christian Wadsack 2, Sasa Frank 7, Peter Sedlmayr 1. 1 Medical University of Graz, Institute of Cell Biology, Histology and Embryology, Graz, Styria, Austria; 2 Medical University of Graz, Department of Obstetrics and Gynaecology, Graz, Styria, Austria; 3 Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz, Styria, Austria; 4 Medical University of Graz, Institute of Pathology, Graz, Styria, Austria; 5 Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; 6 University of New South Wales, School of Medical Sciences, Sydney, New South Wales, Australia; 7 Medical University of Graz, Institute of Molecular Biology and Biochemistry, Graz, Styria, Austria Objectives: The establishment and maintenance of an adequate fetoplacental circulation is required for successful pregnancy. We asked the questions whether indoleamine 2,3-dioxygenase-1 (IDO1), a tryptophan (Trp)-degrading enzyme which is constitutively expressed in the chorionic endothelium, may be involved in the regulation of placental blood flow, this way contributing to the control of placental and fetal growth, and whether this mechanism is impaired in intrauterine growth restriction (IUGR) and preeclampsia (PE). Methods: Vasorelaxation to Trp of in vitro pre-constricted arteries from the chorionic plate in the presence and absence of IFNg and TNFa as an approach to upregulate IDO1 was assayed by myography. The arteriovenous pressure in normal and preconstricted placental cotyledons was monitored by ex-vivo perfusion during administration of Trp. IDO1 protein expression was assessed by Western blotting in IUGR, pre-eclampsia, term and gestational age-matched pre-term controls, and also in placental arterial endothelial cells (PLAECs) isolated from normal term placentas. IDO1 mRNA levels were assessed by RT-qPCR. Localization of IDO1 protein was done by immunohistochemistry (IHC). IDO activity was measured by LC/MS. Results: Constitutive expression of IDO1 was found in PLAECs on the level of mRNA but only partly on the protein level, exhibiting an upregulation of IDO1 following IFNg/TNFa stimulation. Trp induced vasorelaxation of preconstricted perfused placental cotyledons and cytokine-stimulated preconstricted placental arteries, effect that was partially blocked by using an IDO1 competitive inhibitor. Removal of the endothelium did not abolish the vasorelaxing effect of Trp. Whereas no differences were found on the level of mRNA, a decrease in IDO1 protein expression, as well as in IDO activity were found in IUGR and PE in comparison with pre-term controls. Conclusion: IDO1-mediated metabolism of Trp contributes to the regulation of the placental vascular tone. The pregnancy complications IUGR and PE are associated with a deficiency in chorionic IDO1. http://dx.doi.org/10.1016/j.placenta.2017.07.154
P1.67. PLACENTAL CHORIONIC VASCULAR ANGIOGENESIS IS ALTERED IN PREECLAMPSIA AND FETAL GROWTH RESTRICTION INDEPENDENT OF GESTATIONAL AGE Elizabeth Klimowicz 1, Ruchit Shah 2, Theresa Girardi 2, Sanford Lederman 1, Beata Dygulska 1, Pramod Narula 1, Carolyn Salafia 1, 2. 1 New York Presbyterian-Broo0klyn Methodist Hospital, Brooklyn, NY, USA; 2 Placental Analytics LLC, New Rochelle, NY, USA Fetoplacental vasculogenesis begins in early pregnancy and angiogenesis continues in the terminal villi until term. Maternal malperfusion is considered the hallmark of pre-eclampsia (PE) and of many cases of fetal growth restriction (FGR), but distal fetal villous capillary networks have also been shown to be abnormal in these two conditions. No study has
evaluated the chorionic surface vascular network in PE or FGR pregnancy, vessels that have been shown to be to a large degree determined by 11-14 weeks gestation. Methods: Digital photographs were obtained of cleaned and dried chorionic surfaces. Networks were traced and analyzed according to a published protocol and algorithm. ANOVA, Mann-Whitney U-test and Pearson’s correlations considered p<0.05 significant. Results: In 46 non-PE and 17 PE-FGR vascular networks, birthweight (BW), gestational age and placental weight (PW) showed similar relationships. In PE-FGR pregnancies, there were significantly greater numbers of chorionic surface branch points (64+/-24 v. 52+/- 18, p¼0.036), and a significantly shorter mean segment arc length (p¼0.005), and significantly reduced distance between chorionic arteries and veins on the placental surface (p¼0.001). These relationships were independent of gestational age. Conclusions: We observed in PE-FGR an unexpected finding of increased chorionic surface branch points, indicating a more “lush” placental surface vasculature than in normal controls. We had previously found that increased branch points were typical of preterm placentas, but our results were independent of GA. These data suggest that PE-FGR placentas may manifest chorionic surface vascular changes in early gestation that one may suggest would improve placental ability to compensate for a compromised maternal vascular perfusion environment. We can objectively measure the impact of PE-FGR on the vasculature of the placenta. We predict that such analyses will allow better understanding of the etiologies of pregnancy complication associated with PE-FGR. http://dx.doi.org/10.1016/j.placenta.2017.07.155
P1.68. PLACENTAL CHORIONIC VASCULAR ANGIOGENESIS IS ALTERED IN MATERNAL DIABETES MELLITUS Cadesa Ramharrack 1, Ruchit Shah 2, Theresa Girardi 2, Sanford Lederman 1, Pramod Narule 1, Carolyn Salafia 1, 2. 1 New York PresbyterianBrooklyn Methodist Hospital, Brooklyn, NY, USA; 2 Placental Analytics, LLC, New Rochelle, NY, USA Background: Placental development is essential to fetal development and well being. Patterns of distal villous angiogenesis have been shown to be abnormal in pregestational and gestational diabetes (DM). No study has evaluated the chorionic surface vascular network in DM pregnancy. Methods: Digital photographs of cleaned and dried chorionic surfaces were traced and analyzed according to a published protocol and algorithm. Principal components analysis (PCA) reduced the novel vascular variables to 3 factors in the non-DM controls; these equations were then applied to the DM vascular networks. ANOVA and Pearson’s correlations considered p<0.05 significant. Results: In 38 non-DM pregnancies, birthweight and gestational age (r¼0.89, p¼0.0001), and birthweight and placental weight correlated with (r¼0.87, p¼0.0001); in 11 DM pregnancies, birthweight was related to GA (r¼0.67, p¼0.024) but not PW (p¼0.99). The 3 PCA factors accounted for 75% of variance of vascular variables in non-DM. In non-DM, factor 1 was strongly related to BW (p¼0.44), PW (p¼0.005) and GA (p¼0.044), and factor 3 was related to BW (p¼0.053) and PW (p¼0.025). No factor was associated with BW, GA or PW in DM networks. In non-DM networks, the average segment arc length was associated with BW (p¼0.045) and the distance at which vessels ceased extending to the perimeter was related to GA (p¼0.035) and BW (p¼0.002). Neither was related to BW GA or PW in DM networks. Conclusions: DM results in striking differences in the most basic relationships in pregnancy, of placental vasculature to BW, to PW, and PW to GA. We can objectively measure the impact of DM on placental vasculature. We predict that such analyses will allow better understanding of the etiologies of pregnancy complication associated with DM. http://dx.doi.org/10.1016/j.placenta.2017.07.156