Shiga toxin type 2 (Stx2) inhibits migration, invasion and tubes formation in trophoblast cells of the first trimester (Swan 71 cell line). Possible role of inducible nitric oxide synthase (iNOS) in the damage produced by Stx2

SCALISE M.LUJAN; IBARRA CRISTINA; SACERDOTI FLAVIA

Mar del Plata

Congreso; LXIII Reunión de la Sociedad Argentina de Investigación Clínica (SAIC).; 2018

SAIC

Successful placentation involves migration, invasion and remodeling of uterine arteries by trophoblast cells. Failures in these processes are related to serious obstetric complications, as placental dysfunction or miscarriage. We propose was that Stx2, the main virulence factor of Shiga toxin producing Escherichia coli, can cause feto-placental damages through a misbalance of nitric oxide production by inducible nitric oxide synthase (iNOS). Our aim was to evaluate the effects of Stx2 on migration, invasion and tube formation of first trimester trophoblast cells and to analyze if aminoguanidine (AG), a selective inhibitor of iNOS can modulate Stx2 effects. Swan 71 cell line was used as first trimester model. The effect of Stx2 on cell migration was determined by the wound-healing assay. Percentage of wound closure was analyzed with o whitout Stx2 (0.1 μg/ml) after 24 h. Impairment of the invasive capacity of Swan 71 by Stx2 was evaluated seeding cells on transwell coated with Matrigel for 24 h, and then the number of invading cells was counted and Stx2 treatment was compared with control. Finally, Stx2 effect on tube formation was analyzed by tubulogenesis assay. The number of extremities and branch formation was evaluated. Stx2 significantly decreased cell migration (27.5 ± 6.9%* vs 64.80± 3.1%, *p< 0.05), the number of invading cells (41.5±6.9* vs 107.3±19.5, *p< 0.05) and tube formation: numbers of extremities ( 304.0 ± 27.6* vs 538 ± 57.8, *p< 0.05 ) and number of branch ( 138.7± 4.04 vs 335.3 ± 40.9) compared to control in each case. AG partially reverted the Stx2 effects on migration and invasion compared to control (AG+ Stx2 vs Control, n.s, n=3 p >0.05). These results support that Stx2 could impair placenta formation and may be responsible for human feto-placental damages.