SHIGA TOXIN TYPE 2 IMPAIRS TROPHOBLAST CELL MIGRATION BUT NOT CELL VIABILITY

M.LUJAN SCALISE; FLAVIA SACERDOTI; CRISTINA IBARRA

Mar del plata

Congreso; LXI Reuinion cientifica anual de la Sociedad Argentina de Investigación Clínica; 2016

Shiga toxin type 2 (Stx2) is the main virulence factor of Shiga toxin producing Escherichia coli (STEC). STEC are pathogens involved in food-borne diseases and are responsible for Hemolytic Uremic Syndrome (HUS) development. We have previously demonstrated that Stx2 induce miscarriage and premature delivery in rats. We propose that STEC infections during early pregnancy may cause damage in the development of placenta mediated by Stx2. The aim of this study was to evaluate the effects of Stx2, alone or in combination with lipopolysaccharide (LPS), on human first trimester trofoblast cells. In order to analyze if viability or cell migration could be affected by Stx2, citotoxicity and wound-healing assays were performed. HTR-8 and Swan 71 first trimester trofoblast cells were exposed to different concentrations of pure Stx2 (1 ng to 1 µg/ml), with or without LPS (5 µg/ml). Cell viability was analyzed by neutral red uptake at 72 hs after treatment. On the other hand, HTR-8 cells were seed in 24 well plates and pre-incubated for 24 h in arrested conditions with the different concentrations of Stx2 (1-10 ng/ml) with or without LPS to estimate the effect of Stx2 on extent of cell migration. After that cells were washed with PBS and a vertical scratch was made in the center of each well. Photos of the scratch were taken at regular times (0, 5, 24 h). Images were analyzed by TScratch software version 1.0 to estimate the percentage of bound closure. Stx2 did not affect HTR-8 or Swan 71 cell viability even in combination with LPS. However Stx2 impaired HTR-8 cell migration after 24 hs of treatment with Stx2 alone or in combination with LPS. These results suggest that Stx2 can alter in vitro cell trofoblast migration. These data suggest that Stx2 may affect trofoblast invasion and early placentation. Although nowadays there are not reports indicating that Stx2 may affect early pregnancy in humans this data suggest a possible direct effect of Stx2 in human trofoblast migration.