Effect of anti-inflammatory drugs on human neutrophils in endothelial cell damage induced by shiga toxin-1

LANDONI V.I; D ATRI P; RAMOS M.V; FERNANDEZ G.C; REARTE B; LABORDE E; PALERMO M.S; SCHATTNER M; ISTURIZ M.A

Ginebra Suiza

Congreso; XIX Congress of ISTH; 2007

Hemolytic Uremic Syndrome (HUS), characterized by hemolytic anemia, thrombocytopenia and acute renal failure, results in renal endothelial damage and is generally caused by E. coli producing Shiga toxins. We had previously demonstrated that the maximal activity of shiga toxin-1 (Stx1) is observed in the presence of inflammatory agents and polymorphonuclear leukocytes (PMN). This may explains the correlation between poor prognosis in HUS and neutrophilia. In this work, we studied the effect of antiinflammatory substances on endothelial cells damage induced by Stx1, inflammatory agents such us lypolysaccharide (LPS) and PMN. Human umbilical vein endothelial cells (HUVEC) were preincubated with different anti-inflammatory substances and then LPS and/or Stx1 was added. Then, PMN treated with the same antiinflammatory drug were coincubated with the endothelial monolayer. The cytotoxic effect was evaluated by optical microscopy after crystal violet staining. Results are expressed as percentage of damage ± SD and p<0.05 was considered statistically different (one way ANOVA, Bonferroni post test). The damage of HUVEC induced by LPS and Stx1 (HUVEC+Stx+LPS: 49±2%) was significantly diminished by preincubation of the cells with IL-10 (HUVEC+IL10+Stx+LPS: 28±3%, p<0.05, n=3). Similar results were observed with other antiinflammatory cytokines IL-13 and TGFb (n=3). When PMN were added, the increased cytotoxicity percentage (HUVEC+LPS+Stx+PMN: 90±3%) was reduced when HUVEC and PMN were pretreated not only with IL-10 (HUVEC+IL10+LPS+Stx+PMN: 34±9%, p<0.05, n=5) but also with IL-13 and TGFb (n=4). Antiinflammatory drugs also inhibit the maximal damage induced by Stx1+LPS+PMN (dexamethasone: 50±6%; N-acetylcysteine: 41±6%; ibuprofeno 48±8% and methylthiourea: 49±5%, p<0.05, n=5). In conclusion, our results show that control of inflammatory mechanisms could be used as a tool to reduce the cytotoxicity induced by Stx1.