EFFECT OF PLACENTAL GROWTH FACTOR ON TROPHOBLAST INTEGRATION INTO ENDOTHELIAL CELL NETWORKS

K CHAU^1,2,3, B XU¹, A HENNESSY^1,3,4, A MAKRIS^1,5

¹Vascular Immunology Group, Heart Research Institute, Newtown NSW; ²Renal Department, Blacktown Hospital, Blacktown NSW; ³Sydney Medical School University of Sydney, NSW; ⁴School of Medicine, Western Sydney University, Campbelltown NSW; ⁵The Renal Unit, Liverpool Hospital, Liverpool NSW

Aim: To investigate the effect of supplemental placental growth factor (PlGF) on the interaction between a first trimester human trophoblast cell line and capillary-like endothelial cell networks.

Background: PlGF is deficient in early pregnancy in women who subsequently develop preeclampsia. The process of maternal spiral arteriole invasion by trophoblast is vital for normal placentation. The role of PlGF in influencing trophoblast interactions with endothelial cells is not known.

Methods: 24-well tissue culture plates were coated with 300 uL of undiluted Matrigel and allowed to gelatinise at 37^oC for 30 minutes. Fluorescent labelled HTR8/SVNeo cells and uterine myometrial microvascular endothelial cells were co-cultured (1 X 10⁵ per well) for 20 hours at 21% or 2% oxygen (to replicate physiological oxygen conditions in first trimester pregnancy) treated with PlGF 10 ng/mL or 100 ng/mL.  HTR8/SVNeo cells were also cultured singly under the same conditions. Images were captured by fluorescence microscopy and analysed using ImageJ. Experiments were repeated 5 times, data was analysed using SPSS v24.

Results: Integration of HTR8/SVNeo cells into endothelial cell networks expressed as % of control was unaffected by addition of PlGF at both 10 ng/mL and 100 ng/mL concentrations [p = 0.61]. Network formation of trophoblast cells on matrigel was enhanced by addition of PlGF [p = 0.01].

Conclusions: PlGF improves trophoblast network formation but does not affect integration of HTR8/SVNeo cells into uterine endothelial cell networks in vitro.