Lysophosphatidic Acid Triggers Angiogenesis Through LPA3 Receptor in Human First Trimester Trophoblast

BELTRAME, JS; SORDELLI, MS; CAÑUMIL, VA; RIBEIRO MARÍA LAURA

Orlando - Florida

Congreso; 64th Annual Meeting of the Society for Reproductive Investigation (SRI); 2017

Introduction: The coordination ofvascular processes at the maternal?fetal interface involves extravillous trophoblast differentiation intoendovascular trophoblast, facilitating spiral artery remodeling. Lysophosphatidic acid (LPA) is a lipid mediator thatregulates female reproductive functions and plays an important role duringangiogenesis. Angiogenesis implies the sprouting of existing blood vessels andrequires endothelial cells proliferation, migration and tube formation.Objective: Using in vitro and in vivomodels we investigated the action of LPA in angiogenesis at the maternal?fetalinterface.Methods: Human first trimestertrophoblast cells (HTR-8/SVneo)were seeded on a reduced growth factor membrane matrix (Geltrex®),incubated with LPA (10-6M) in the presence of a non-selective LPA3 antagonist(8 Br-LPA 5x10-6 M), a selective LPA3 antagonist (DGPP 10-4 M) or a selectiveLPA1 antagonist (BMT 10-5 M), and assayed for tube formation during 6h. Tubulelength and the number of branches were calculated. MTT Cell Proliferation assay was employedto test trophoblast proliferation ability. Cells were incubated with LPA(10-6M) for 48h. Then, MTT was added for 4h and solubilised formazan was measured spectrophotometrically (540 nm).To test trophoblast migration we employedthe wound healing assay. After incubating the cells with LPA (10-6M) for 18h wedetermined the percentage of wound closure.For the in vivo treatment, female rats inday 5 of gestation received an intra-uterine dose of DGPP. Blood vesselscircumference at the implantation site as well as in the placentas, weredetermined at days 8 and 15 respectively.Results: LPA stimulates trophoblastcapillary response through LPA3 (p<0.05). Also, HTR-8/SVneocells incubated with LPA significantly increase cell migration andproliferation compared to control (p<0.05).The pharmacological ablation of LPA3augmented embryo resorption (60%). DGPP reduced the vessel density in theimplantation sites and in the placentas from the resorpted units. Furthermore,these vessels showed a larger perimeter (p<0.05).Conclusion: Collectively our results showthat LPA increases angiogenesis through the activation of LPA3 expressed at thematernal-fetal interface. Extravillous trophoblast cells are crucial in uterinevascular remodeling. Deficient LPA-driven angiogenesis may contribute toobstetric complications such as implantation failure, and preeclampsia.