Effects of shiga toxin 2 on cellular regeneration mechanisms in primary and three-dimensional cultures of human renal tubular epithelial cells

MÁRQUEZ LAURA B; IBARRA FERNANDO R; REPETTO HORACIO A; ARÁOZ A; SILBERSTEIN CLAUDIA

MICROBIAL PATHOGENESIS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 99 p. 67 - 94

0882-4010

Shiga toxin (Stx)-producing Escherichia coli (STEC) causes post-diarrheal Hemolytic Uremic Syndrome(HUS), which is one of the most common causes of acute renal failure in children in Argentine. The aim ofthe present work was to study the effects of Shiga toxin type 2 (Stx2) on regenerative mechanisms ofprimary cultures of human cortical renal tubular epithelial cells (HRTEC) and three-dimensional (3D)cultures of HRTEC. Primary cultures of HRTEC were able to develop tubular structures when grown inmatrigel, which showed epithelial cells surrounding a central lumen resembling the original renal tubules.Exposure to Stx2 inhibited tubulogenesis in 3D-HRTEC cultures. Moreover, a significant increase inapoptosis, and decrease in cell proliferation was observed in tubular structures of 3D-HRTEC exposed toStx2. A significant reduction in cell migration and vimentin expression levels was observed in HRTECprimary cultures exposed to Stx2, demonstrating that the holotoxin affected HRTEC dedifferentiation.Furthermore, a decreased number of cells expressing CD133 progenitor marker was found in HRTECcultures treated with Stx2. The CD133 positive cells also expressed the Stx receptor globotriaosylceramide,which may explain their sensitivity to Stx2. In conclusion, Stx2 affects the regenerative processesof human renal tubular epithelial cells in vitro, by inhibiting cell dedifferentiation mechanisms, as well astubules restoration. The development of 3D-HRTEC cultures that resemble original human renal proximaltubules is a novel in vitro model to study renal epithelial repair mechanisms after injury.