Abstract

Maternal uterine spiral arteries (SpA) undergo significant structural changes in early pregnancy, resulting in increased blood flow to the developing fetus. Endothelial cells (EC) and vascular smooth muscle cells (VSMC) are lost from the SpA wall and are replaced by trophoblasts. We have previously shown that matrix metalloproteinase 10 (MMP-10) and Heparin binding-EGF like growth factor (HB-EGF) gene expression is increased in a 3D EC/VSMC co-culture system in response to trophoblast secreted factors. This study investigated trophoblast mediated MMP-10 and HB-EGF expression and determined if there was a relationship between the secretion of MMP-10 and the release of soluble HB-EGF (sHB-EGF) from EC. MMP-10 was widely expressed in first trimester decidual tissue including trophoblast, and EC, but not VSMC. MMP-10 expression was significantly lower in decidual tissue from pregnancies at increased risk of developing pre-eclampsia compared to low-risk pregnancies. In vitro, SGHEC-7 cells, a human EC line, but not SGHVMC-9, a human VSMC cell line, secreted MMP-10 in response to trophoblast conditioned medium (TCM). TCM contains several growth factors and cytokines, but only interleukin-1β (IL1β) significantly stimulated MMP-10 secretion by SGHEC-7 cells. Interleukin-1 receptor antagonist (IL-1Ra) significantly inhibited TCM-induced MMP-10 secretion. Interrogation of intracellular pathways established the involvement of MEK and JNK in TCM and IL-1β stimulated MMP-10 secretion. Although IL-1β also significantly increased sHB-EGF, inhibition of MMP-10 activity using a broad spectrum MMP inhibitor had no effect on sHB-EGF. Western blot analysis indicated that MMP-10 secreted by EC in response to IL-1β stimulation was the enzymatically inactive pro form.