Involvement of Neutrophil Elastase in the effects Induced by Shiga Toxin Type 2 in vitro and in vivo.

FERNANDO NICOLÁS SOSA; ALAN MAURO BERNAL; FLORENCIA SABBIONE; 1ROMINA JIMENA FERNÁNDEZ-BRANDO; ANALÍA SILVINA TREVANI; MARINA SANDRA PALERMO; MARÍA VICTORIA RAMOS

Conferencia; Reunión Anual de Sociedades de Biociencias; 2022

Hemolytic Uremic Syndrome (HUS), a vascular disease that results in renal failureis caused by Shiga toxin (Stx)-producing E. coli. Besides Stx, inflammation causedby neutrophils (PMN) is needed for HUS. PMN release Neutrophil ExtracellularTraps (NETs), involved in many diseases. We have shown that Stx2 inducesNETosis in PMN and an increase of circulating free DNA in mice. Our aim was tostudy if neutrophil elastase (NE), an enzyme associated to NETs, is involved inNETosis and inflammation triggered by Stx2 in PMN; and to evaluate if there is anincrease in NE in a murine model of HUS as a first approach to studying itsinvolvement in the disease. PMN were incubated with medium (Basal), Stx2 (0.1μg/mL) alone or with an NE inhibitor, Sivelestat (Siv, 10 μM). After 4 h, DNAcontent and NE activity were measured by fluorescence and absorbancerespectively. IL-8 secretion, an inflammatory cytokine, was measured by ELISA.For in vivo assays, BALB/c mice inoculated with saline (Basal), Stx2 (1 ng/kg) orStx+DNAse (300 U) were bled at day 3. After incubation with Stx2, we sawelevated levels of DNA (μg/mL) (Median(IQR)= Basal:0.12(0.09-0.16);Stx:0.27(0.22-0.43)*; Stx+Siv:0.14(0.13-0.16); *p