LAUSR

Introduction During normal trophoblast invasion, integrin α6β4 are downregulated and α1β1 are upregulated in invasive cytotrophoblast cells. In preeclampsia, both interstitial and endovascular invasion are shallow and cytotrophoblast fail to upregulate α1β1 and downregulate α6β4. Objective This study aims to investigate role of integrin α1β1 and integrin α6β4 during trophoblast integration into endothelial cellular networks in vitro. Methods Red fluorescent-labeled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel to form endothelial networks. Green fluorescent-labeled trophoblast HTR-8/SVneo cells pre-incubated with 20 μg/ml of neutralizing antibodies (anti-α1, β1, α6, β4, α1β1 or α6β4) for 1 h were then co-cultured with the endothelial networks with the neutralizing antibody for 24 h. Fluorescent images were captured and quantified by image J. Free soluble fms-like tyrosine kinase-1 (sFlt-1), placenta growth factor (PlGF), matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) from conditioned media were measured by ELISA. Cells were retrieved to examine mRNA expression of invasion markers of tissue inhibitor of metalloproteinase-1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) by quantitative PCR. Results The integration of trophoblast cells into endothelial cellular networks was significantly inhibited by anti-β1 (72 ± 3%, p  Discussion We have shown that anti-integrin β1, not anti-integrin a1 inhibited and anti-integrin a6, not anti-integrin β4 increased endothelial-trophoblast cellular integration in vitro. The matrix degradation enzymes (MMP-2 and MMP-9) and their associated inhibitors (TIMP-1 and PAI-1) may involve in this process.