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Chronic hypoxia in ovine pregnancy recapitulates physiological and molecular markers of preeclampsia in the mother, placenta and offspring

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Tong, Wen 
Allison, Beth 
Brain, Kirsty 
Patey, Olga 
Niu, Youguo 

Abstract

Background: Preeclampsia continues to be a prevalent pregnancy complication and underlying mechanisms remain controversial. A common feature of preeclampsia is utero-placenta hypoxia. In contrast to the impact of hypoxia on the placenta and fetus, comparatively little is known on the maternal physiology. Methods: We adopted an integrative approach to investigate the inter-relationship between chronic hypoxia during pregnancy with maternal, placental and fetal outcomes, common in preeclampsia. We exploited a novel technique using isobaric hypoxic chambers and in vivo continuous cardiovascular recording technology for measurement of blood pressure in sheep and studied the placental stress in response to hypoxia at cellular and sub-cellular levels. Results: Chronic hypoxia in ovine pregnancy promoted fetal growth restriction with evidence of fetal brain-sparing, increased placental hypoxia-mediated oxidative damage and activated placental stress response pathways. These changes were linked with dilation of the placental endoplasmic reticulum cisternae and increased placental expression of the antiangiogenic factors sFlt-1 and sEng, combined with a shift towards an angiogenic imbalance in the maternal circulation. Chronic hypoxia further led to an increase in uteroplacental vascular resistance, and the fall in maternal blood pressure with advancing gestation measured in normoxic pregnancy did not occur in hypoxic pregnancy. Conclusions: Therefore, we show in an ovine model of sea level adverse pregnancy that chronic hypoxia recapitulates physiological and molecular features of preeclampsia in the mother, placenta and offspring.

Description

Keywords

endoplasmic reticulum, hypoxia, oxidative stress, placenta, unfolded protein response, Animals, Biomarkers, Female, Humans, Hypoxia, Mothers, Placenta, Placenta Growth Factor, Pre-Eclampsia, Pregnancy, Sheep, Vascular Endothelial Growth Factor Receptor-1

Journal Title

Hypertension

Conference Name

Journal ISSN

0194-911X
1524-4563

Volume Title

Publisher

American Heart Association
Sponsorship
British Heart Foundation (RG/17/8/32924)
British Heart Foundation (None)