Studies of cell viability and proliferation in Vero cells treated with Shiga toxin type 2 in the presence of L-NAME.

FISHER SIGEL LILIANA KARINA; SILBERSTEIN CLAUDIA; IBARRA CRISTINA; SANCHEZ DIANA

Mar del Plata

Congreso; LXVI Reunión Annual de la Sociedad Argentina de Inmunología, Reunión Anual de la Sociedad Argentina de Fisiología.; 2018

Sociedad Argentina de Investigación Clínica, Sociedad Argentina de Fisiología, Sociedad de Inmunología

Post-diarrhea Hemolytic Uremic Syndrome (HUS) due to Shiga toxin-producing Escherichia Coli (STEC) is a common cause of acute renal failure in children in Argentina. It was reported that the inhibition of nitric oxide (NO) by Stx2 enhanced renal damage in mice and baboon models of Stx-mediated HUS. Furthermore, it was foundthat Stx reduced the NO synthesis, and therefore, increased Stx effects in human renal mesangial and endothelial cells. Therefore, the aim of the present work was to evaluate whether the inhibition of NO synthesis potentiates the cytotoxic effect of Stx2 in renal epithelial cells. Hence, the direct effect of L-NAME (N(G)-Nitro-L-argininemethyl ester), was evaluated in Vero cells, used as model of renal tubular epithelial cells. Cell viability was measured by neutral red uptake, 24 h after pre-treatment with different doses of L-NAME (1μM-1mM) followed by co-treatment with L-NAME and Stx2 (10 ng/ml) for 48 h. Cell proliferation was evaluated by bromodeoxyuridine uptake using the same experimental protocol. The treatment of Vero cells with L-NAME did not significantly modify the cell viability (N=4, n.s.) and the cell proliferation (N=3, n.s.), indicating that L-NAME was not toxic at any dose assayed. Incubation of Vero cells with Stx2 significantly inhibited cell viability (p