Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia

Background/objectivesPreeclampsia is a life-threatening hypertensive disease affecting 3–5% of pregnancies. While the pathogenesis of preeclampsia remains unclear, it is known that placenta-derived factors trigger the disease by activating maternal endothelial cells prior to the onset of clinical sy...

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Main Authors: Mancy Tong, Qi Chen, Joanna L. James, Peter R. Stone, Lawrence W. Chamley
Format: Article
Language:English
Published: Frontiers Media S.A. 2017-07-01
Series:Frontiers in Endocrinology
Subjects:
Online Access:http://journal.frontiersin.org/article/10.3389/fendo.2017.00174/full
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author Mancy Tong
Qi Chen
Joanna L. James
Peter R. Stone
Lawrence W. Chamley
author_facet Mancy Tong
Qi Chen
Joanna L. James
Peter R. Stone
Lawrence W. Chamley
author_sort Mancy Tong
collection DOAJ
description Background/objectivesPreeclampsia is a life-threatening hypertensive disease affecting 3–5% of pregnancies. While the pathogenesis of preeclampsia remains unclear, it is known that placenta-derived factors trigger the disease by activating maternal endothelial cells prior to the onset of clinical symptoms. Extracellular vesicles (EVs) of different sizes extruded by the placenta may be one factor. The truncated/secreted form of Flt-1 (sFlt-1) has also been implicated in the pathogenesis of preeclampsia. We investigated whether placental EV production is altered in preeclampsia such that they induce endothelial cell activation, and whether (s)Flt-1 is involved.MethodsMacro-, micro-, and nano-vesicles were collected from normal and preeclamptic (PE) placental explants, and separated by differential centrifugation. The number and size of micro- and nano-vesicles was measured by nanoparticle tracking analysis and their ability to activate endothelial cells was quantified by endothelial cell intercellular adhesion molecule 1 expression and monocyte adhesion. The levels of Flt-1 were measured by western blots and ELISA.ResultsPE placentae extruded significantly more micro- and nano-vesicles than control placentae and the extruded micro-vesicles were larger than those from control placentae. Micro- and nano-vesicles from both first trimester and term human placentae carried Flt-1 and levels were significantly increased in EVs from severe, but not mild, PE compared to normotensive placentae. All fractions of EVs from PE placentae activated endothelial cells, and for micro- and nano-vesicles, activation was reduced in the presence of exogenous vascular endothelial growth factor (VEGF), a Flt-1 neutralizing antibody, or by pre-treatment with VEGF. While EV-bound VEGF constituted over 20% of the total detected VEGF secreted by PE and normotensive placentae, EV-bound Flt-1 did not significantly contribute to the total level of sFlt-1/Flt-1 released by human third trimester placentae.DiscussionMicro- and nano-vesicles extruded by human placentae carry Flt-1 across gestation and in severe preeclampsia, the levels of vesicle-bound Flt-1 are upregulated. All fractions of PE placental EVs activated endothelial cells and for micro- and nano-vesicles, this was in part due to the ability of EV-bound Flt-1 to sequester VEGF. That placental EVs can activate endothelial cells supports the contention that EVs are one placental toxin contributing to the pathogenesis of preeclampsia.
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spelling doaj.art-2a36e79cd82b4b50b0d06ea0116c42b72022-12-22T03:08:26ZengFrontiers Media S.A.Frontiers in Endocrinology1664-23922017-07-01810.3389/fendo.2017.00174277108Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe PreeclampsiaMancy Tong0Qi Chen1Joanna L. James2Peter R. Stone3Lawrence W. Chamley4Department of Obstetrics and Gynaecology, School of Medicine, The University of Auckland, Auckland, New ZealandDepartment of Obstetrics and Gynaecology, School of Medicine, The University of Auckland, Auckland, New ZealandDepartment of Obstetrics and Gynaecology, School of Medicine, The University of Auckland, Auckland, New ZealandDepartment of Obstetrics and Gynaecology, School of Medicine, The University of Auckland, Auckland, New ZealandDepartment of Obstetrics and Gynaecology, School of Medicine, The University of Auckland, Auckland, New ZealandBackground/objectivesPreeclampsia is a life-threatening hypertensive disease affecting 3–5% of pregnancies. While the pathogenesis of preeclampsia remains unclear, it is known that placenta-derived factors trigger the disease by activating maternal endothelial cells prior to the onset of clinical symptoms. Extracellular vesicles (EVs) of different sizes extruded by the placenta may be one factor. The truncated/secreted form of Flt-1 (sFlt-1) has also been implicated in the pathogenesis of preeclampsia. We investigated whether placental EV production is altered in preeclampsia such that they induce endothelial cell activation, and whether (s)Flt-1 is involved.MethodsMacro-, micro-, and nano-vesicles were collected from normal and preeclamptic (PE) placental explants, and separated by differential centrifugation. The number and size of micro- and nano-vesicles was measured by nanoparticle tracking analysis and their ability to activate endothelial cells was quantified by endothelial cell intercellular adhesion molecule 1 expression and monocyte adhesion. The levels of Flt-1 were measured by western blots and ELISA.ResultsPE placentae extruded significantly more micro- and nano-vesicles than control placentae and the extruded micro-vesicles were larger than those from control placentae. Micro- and nano-vesicles from both first trimester and term human placentae carried Flt-1 and levels were significantly increased in EVs from severe, but not mild, PE compared to normotensive placentae. All fractions of EVs from PE placentae activated endothelial cells, and for micro- and nano-vesicles, activation was reduced in the presence of exogenous vascular endothelial growth factor (VEGF), a Flt-1 neutralizing antibody, or by pre-treatment with VEGF. While EV-bound VEGF constituted over 20% of the total detected VEGF secreted by PE and normotensive placentae, EV-bound Flt-1 did not significantly contribute to the total level of sFlt-1/Flt-1 released by human third trimester placentae.DiscussionMicro- and nano-vesicles extruded by human placentae carry Flt-1 across gestation and in severe preeclampsia, the levels of vesicle-bound Flt-1 are upregulated. All fractions of PE placental EVs activated endothelial cells and for micro- and nano-vesicles, this was in part due to the ability of EV-bound Flt-1 to sequester VEGF. That placental EVs can activate endothelial cells supports the contention that EVs are one placental toxin contributing to the pathogenesis of preeclampsia.http://journal.frontiersin.org/article/10.3389/fendo.2017.00174/fullpreeclampsiatrophoblastparticleexosomevesiclevascular endothelial growth factor
spellingShingle Mancy Tong
Qi Chen
Joanna L. James
Peter R. Stone
Lawrence W. Chamley
Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
Frontiers in Endocrinology
preeclampsia
trophoblast
particle
exosome
vesicle
vascular endothelial growth factor
title Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
title_full Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
title_fullStr Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
title_full_unstemmed Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
title_short Micro- and Nano-vesicles from First Trimester Human Placentae Carry Flt-1 and Levels Are Increased in Severe Preeclampsia
title_sort micro and nano vesicles from first trimester human placentae carry flt 1 and levels are increased in severe preeclampsia
topic preeclampsia
trophoblast
particle
exosome
vesicle
vascular endothelial growth factor
url http://journal.frontiersin.org/article/10.3389/fendo.2017.00174/full
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