- Lysophosphatidic acid triggers angiogenesis through LPA3 receptor in human first trimester trophoblast

SORDELLI MS; BELTRAME JS; RIBEIRO ML; CAÑUMIL VA

Orlando

Congreso; 64th Annual Scientific Meeting of the Society of Reproductive Investigation; 2017

Society of Reproductive Investigatiob

Introduction:The coordination of vascular processes at the maternal?fetal interface involvesextravillous trophoblast differentiation into endovascular trophoblast,facilitating spiral artery remodeling.  Lysophosphatidic acid (LPA) is a lipidmediator that regulates female reproductive functions and plays an importantrole during angiogenesis. Angiogenesis implies the sprouting of existing blood vesselsand requires endothelial cells proliferation, migration and tube formation.Objective: Usingin vitro and in vivo models we investigated the action of LPA in angiogenesis atthe maternal?fetal interface.Methods: Humanfirst trimester trophoblast cells (HTR-8/SVneo) were seeded on a reduced growthfactor membrane matrix (Geltrex®), incubated with LPA (10-6M) in thepresence of a non-selective LPA3 antagonist (8 Br-LPA 5x10-6 M), aselective LPA3 antagonist (DGPP 10-4 M) or a selective LPA1antagonist (BMT 10-5 M), and assayed for tube formation during 6h. Tubulelength and the number of branches were calculated. MTT Cell Proliferation assay was employed to testtrophoblast proliferation ability. Cells were incubated with LPA (10-6M)for 48h. Then, MTT was added for 4h and solubilised formazan is measuredspectrophotometrically (540 nm).To testtrophoblast migration we employed the wound healing assay. After incubating thecells with LPA (10-6M) for 18h we determined the percentage of woundclosure.For the in vivo treatment, females? rats in day5 of gestation received an intra-uterine dose of DGPP. Blood vessels circumferenceswere determined in the implantation sites from day 8 of pregnancy as well as inthe placentas from day 15.Results: LPAstimulates trophoblast capillary response through LPA3 (p<0.05). Also, HTR-8/SVneocells incubated with LPA significantly increase cell migration and proliferationcompared to control (p<0.05).The pharmacologicalablation of LPA3 augmented embryo resorption (60%). DGPP reduced the vessel densityin the implantation sites, and in the placentas from the resorpted units. Furthermore,these vessels showed a larger perimeter (p<0.05).Conclusion:Collectively our results show that LPA increase angiogenesis through theactivation of LPA3 expressed at the maternal-fetal interface. Extravilloustrophoblast cells are crucial in uterine vascular remodeling. DeficientLPA-driven angiogenesis may contribute to obstetric complications such asimplantation failure, and preeclampsia.