Tissue apoptosis in mice infected with Leptospira interrogans serovar Icterohaemorrhagiae

Background: this investigation aimed to evaluate the occurrence of some apoptotic features induced by leptospira interrogans serovar icterohaemorrhagiae infection in young balb/c mice during 2,4,7,10,14 and 21 days post-infection (dpi). methods: the animals were euthanized and lung,liver and kidneys were harvested to histopathology analysis and immunohistochemistry to caspase-3 antigen detection was performed. results: chromatin condensation in kidney and liver tissues,but not in lung tissue,was observed. caspase-3 reactive cells,mainly characterized as renal epithelial cells,were detected in the days 14 and 21 at high levels when compared to days 2,4 and 7 (p = 0.025; p < 0.05). lung sections revealed caspase-3 labeled alveolar cells in 10 and 14 days post-infection was higher than observed at 7 days (p = 0.0497; p < 0.05). liver sections demonstrated reactive cells at a highest level at 14 and 21 days post-infection when comparison to 2,4,7 and 10 days (p = 0.0069; p < 0.05). conclusions: our results suggest that infection of l. interrogans induce in kidney,liver and lung an activation of apoptosis mediated by caspase-3 dependent pathway in later phases of infectious process. © 2015 marinho et al.