Jararhagin is a snake venom metalloproteinase (SVMP) from Bothrops jararaca involved in several hemostatic and inflammatory disorders that occur in human envenomings. In this study, we evaluated the effect of jararhagin on endothelial cells (tEnd). The exposure of tEnd to jararhagin (20 and 40microg/ml) resulted in apoptosis with activation of pro-caspase-3 and alterations in the ratio between Bax/Bcl-xL. We observed that apoptosis was followed by decrease of cell viability and the loss of cell adhesion. Jararhagin induced changes in cell shape with a decrease in cell spreading, rounding up and detachment. This was accompanied by a rearrangement of actin network and a decrease in FAK association to actin and in tyrosine phosphorylated proteins. Morphological alterations and apoptosis were abolished when jararhagin catalytic activity was inhibited, indicating the importance of catalysis. Treatment of murine peritoneal adherent cells or fibroblasts with jararhagin did not result in apoptosis. The data indicate that the pro-apoptotic effect of jararhagin is selective to endothelial cells, interfering with the adhesion mechanisms and inducing anoikis. The present model might be useful for the study of the relationships between the architectural changes in the cytoskeleton and the complex phenomenon named anoikis.

No abstract

No abstract

In the present study, it was investigated which components are responsible for the anti-inflammatory properties of Crotalus durissus terrificus venom (CdtV). The effect of crotoxin, as well as of other CdtV components was evaluated on edema, cell migration and alterations in leukocyte-endothelium interactions induced by carrageenan. Crotoxin (40 microg kg(-1)) was injected at different time periods before or after the injection of carrageenan (15 mg kg(-1)) into the mouse hind paw, peritoneum or scrotum. Results showed that crotoxin, but not other CdtV components, significantly inhibited inflammatory edema and cell migration when administered before or after carrageenan injection in mice. This toxin also prevented the occurrence of alterations in leukocyte-endothelium interactions induced by carrageenan injection, such as the increase in adhered cells. In animals pretreated with Boc2 (a selective antagonist of formyl peptide receptors), crotoxin showed neither inhibitory effects on edema and cell migration, nor prevented alterations in leukocyte-endothelium interactions induced by carrageenan. These findings demonstrate that crotoxin is the component responsible for the long-lasting anti-inflammatory activity of crude C. durissus terrificus venom, and activation of formyl peptide receptors seems to play a major role in this effect.

No abstract