Poster Presentation Annual Meetings of the Endocrine Society of Australia and Society for Reproductive Biology and Australia and New Zealand Bone and Mineral Society 2016

Extravillous trophoblast-derived exosomes bioactivity on endothelial cells: possible implication in the uterine spiral arterial remodelling (#473)

Vyjayanthi (Jaya) Kinhal 1 , Carlos Salomon 1 2 , Katherin Scholz-Romero 1 , Greg Duncombe 1 , Gregory E Rice 1 2 , Ramkumar Menon 3 , Sherri Longo 1 , Stephen Fortunato 2
  1. Exosome Biology Laboratory, Centre for Clinical Diagnostics, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
  2. Department of Obstetrics and Gynecology, Ochsner Baptist Hospital, New Orleans, Louisiana, USA
  3. Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, USA

Objectives: Impaired oxygen tension can result in compromised placentation and vascularisation leading to reduced fetal-placental blood flow. Emerging evidence suggests that Extravillous Trophoblast (EVT)-derived exosomes interact with the maternal endothelium and regulate EVT migration and the remodelling of uterine spiral arteries. This project aimed to characterise the protein profile of exosomes isolated from EVT cells cultured under different oxygen tensions to mimic normal and pathological (pre-eclamptic) conditions; and to determine the effect of exosomes on endothelial cell migration and TNFα release.


Methods: The effect of hypoxia on EVT-derived exosomal content was determined through the use of a first-trimester cell line (HTR-8/SVneo). Cells were cultured in RPMI-1640 medium and incubated at 37C and 5% CO2 air atmosphere. Cells were incubated at 1% and 8% O2 in FBS-free RPMI-1640 for 48 hrs. Exosomes were isolated from the EVT-conditioned medium by differential and buoyant density centrifugation. Exosomal content was analysed by mass spectrometry and digested peptides were fractionated using the Agilent 3100 OFFGEL Fractionator.


Results: At 5% FDR, a total of 1115 proteins were identified of which 942 proteins are unique and 173 proteins are conserved across both treatment groups. At hypoxic conditions (1% O2), a total of 573 proteins (400 unique) were identified. In contrast, 542 proteins (369 unique) were identified at 8% O2 tension. Under 1% O2, EVT released ~3-fold more exosomes than when incubated under 8% O2 and the ability of EVT exosomes to induce EC migration was reduced, while exosome-induced TNFα release was greater.


Conclusions: To the best of our knowledge, this is the first study that established that hypoxia changes the protein profile of EVT-derived exosomes. Hypoxia is associated with complications of pregnancy, thus, we suggest that EVT-derived exosomal signalling is altered under pathological conditions and may expand the effect of hypoxia to other cells.