Shiga toxin 1 and 2 induce apoptosis in the amniotic cell line WISH.

OBJECTIVE: The aim of this study was to evaluate the toxicity of Shiga toxin (Stx) 1 and 2 on amniotic cells in vitro. METHODS: WISH cells, which were derived from human amniotic cells, and Vero cells were cultured with or without Stxs. After 24 hours of culture, cell viability was measured by Cell Counting Kit-8, and extracted DNA was electrophoresed on a 1% agarose gel. The morphologic changes were observed by Papanicolaou staining, and the apoptotic index (percentage of apoptotic nuclei per total nuclei) was calculated. Quantification of apoptotic cells was also measured by an enzyme-linked immunosorbent assay. RESULTS: The viability of WISH cells decreased in proportion to the concentrations of Stxs. Cellular ladder formation was observed by DNA electrophoresis of Stx-treated WISH cells, and the typical morphologic changes were observed by Papanicolaou staining. The proportion of apoptotic cells increased in response to Stxs. CONCLUSIONS: Stxs injured WISH cells directly and induced apoptosis in vitro. WISH cells were as sensitive as Vero cells to Stxs and cell death occurred by apoptosis.