Alternagin-C binding to 21 integrin controls matrix metalloprotease-9 and matrix metalloprotease-2 in breast tumor cells and endothelial cells

Background Matrix metalloproteinases (MMPs) are key players in tumor progression, helping tumor cells to modify their microenvironment, which allows cell migration to secondary sites. The role of integrins, adhesion receptors that connect cells to the extracellular matrix, in MMP expression and activity has been previously suggested. However, the mechanisms by which integrins control MMP expression are not completely understood. Particularly, the role of 21 integrin, one of the major collagen I receptors, in MMP activity and expression has not been studied. Alternagin-C (ALT-C), a glutamate-cysteine-aspartate-disintegrin from Bothrops alternatus venom, has high affinity for an 21 integrin. Herein, we used ALT-C as a 21 integrin ligand to study the effect of ALT-C on MMP-9 and MMP-2 expression as well as on tumor cells, fibroblats and endothelial cell migration. Methods ALT-C was purified by two steps of gel filtration followed by anion exchange chromatography. The 21, integrin binding properties of ALT-C, its dissociation constant (Kd) relative to this integrin and to collagen I (Col I) were determined by surface plasmon resonance. The effects of ALT-C (10, 40, 100 and 1000 nM) in migration assays were studied using three human cell lines: human fibroblasts, breast tumor cell line MDA-MB-231, and microvascular endothelial cells HMEC-1, considering cells found in the tumor microenvironment. ALT-C effects on MMP-9 and MMP-2 expression and activity were analyzed by quantitative PCR and gelatin zymography, respectively. Focal adhesion kinase activation was determined by western blotting. Results Our data demonstrate that ALT-C, after binding to 21 integrin...(AU)

Alternagin-C binding to 21 integrin controls matrix metalloprotease-9 and matrix metalloprotease-2 in breast tumor cells and endothelial cells

Background Matrix metalloproteinases (MMPs) are key players in tumor progression, helping tumor cells to modify their microenvironment, which allows cell migration to secondary sites. The role of integrins, adhesion receptors that connect cells to the extracellular matrix, in MMP expression and activity has been previously suggested. However, the mechanisms by which integrins control MMP expression are not completely understood. Particularly, the role of 21 integrin, one of the major collagen I receptors, in MMP activity and expression has not been studied. Alternagin-C (ALT-C), a glutamate-cysteine-aspartate-disintegrin from Bothrops alternatus venom, has high affinity for an 21 integrin. Herein, we used ALT-C as a 21 integrin ligand to study the effect of ALT-C on MMP-9 and MMP-2 expression as well as on tumor cells, fibroblats and endothelial cell migration. Methods ALT-C was purified by two steps of gel filtration followed by anion exchange chromatography. The 21, integrin binding properties of ALT-C, its dissociation constant (Kd) relative to this integrin and to collagen I (Col I) were determined by surface plasmon resonance. The effects of ALT-C (10, 40, 100 and 1000 nM) in migration assays were studied using three human cell lines: human fibroblasts, breast tumor cell line MDA-MB-231, and microvascular endothelial cells HMEC-1, considering cells found in the tumor microenvironment. ALT-C effects on MMP-9 and MMP-2 expression and activity were analyzed by quantitative PCR and gelatin zymography, respectively. Focal adhesion kinase activation was determined by western blotting. Results Our data demonstrate that ALT-C, after binding to 21 integrin...

Effects of blocking av b3 integrin by a recombinant RGD disintegrin on remodeling of wound healing after induction of incisional hernia in rats

PURPOSE: To investigate the changes induced by DisBa-01 on repair of wound healing after induced incisional hernia (IH) in rats. METHODS: Thirty two male albino rats were submitted to IH and divided into four experimental groups: G1, placebo control; G2, DisBa-01-treated; G3, anti-αv β3 antibodies-treated and G4, anti-α2 antibodies-treated. Histological, biochemical and extracellular matrix remodeling analysis of abdominal wall were evaluated. RESULTS: After 14 days, 100% of the G2 did not present hernia, and the hernia ring was closed by a thin membrane. In contrast, all groups maintained incisional hernia. DisBa-01 also increased the number macrophages and fibroblasts and induced the formation of new vessels. Additionally, MMP-2 was strongly activated only in G2 (p<0.05). Anti- αv β3 -integrin antibodies produced similar results than DisBa-01 but not anti-α2 integrin blocking antibodies. CONCLUSION: DisBa-01 has an important role in the control of wound healing and the blocking of this integrin may be an interesting therapeutically strategy in incisional hernia.(AU)

Effects of Blocking avb3 integrin by a recombinant RGD disintegrin on remodeling of wound healing after induction of incisional hernia in rats

Incisional hernia (IH) is characterized by defective wound healing process. Disba-01, a αvb3 integrin blocker has shown to control the rate of wound repair and therefore it could be a target for new wound healing therapies.The objective of the study was to determine the changes induced by Disba-01 on repair of wound healing after induced IH in rats. Thirty two male albino rats were submitted to IH and divided into 4 experimental groups: G1, placebo control; G2, DisBa-01-treated; G3, anti-αvβ3 antibodies-treated and G4, anti-α2 antibodies-treated. Histological. biochemical and extracellular matrix remodeling analysis of abdominal wall were evaluated. After 14 days, 100% of the G2 did not present hernia, and the hernia ring was closed by a thin membrane. In contrast, all groups maintained incisional hernia. DisBa-01 also increased the number macrophages and fibroblasts and induced the formation of new vessels. Additionally, MMP-2 was strongly activated only in G2 (P<0.05). Anti- αvβ3-integrin antibodies produced similar results than Disba-01 but not anti-α2 integrin blocking antibodies. These results strongly indicate that Disba-01 has an important role in the control of wound healing and the blocking of this integrin may be an interesting therapeutical strategy in IH.(AU)