Disintegrin causes proteolysis of beta-catenin and apoptosis of endothelial cells. Involvement of cell-cell and cell-ECM interactions in regulating cell viability.
Disintegrins, the snake venom-derived arginine-glycine-aspartic acid-containing peptides, have been demonstrated to inhibit angiogenesis through induction of endothelial cell apoptosis. However, it is not clear how a disintegrin causes endothelial apoptosis. In this study, we elucidated the action mechanism of disintegrin in causing endothelial apoptosis by using rhodostomin as a tool. We showed that cell detachment was observed at the early stage of rhodostomin treatment. It was initiated through the blockade by integrin alphanubeta3 and was accelerated by a mechanical stretch from neighboring cells. Both rhodostomin and poly(HEME) induced a higher percentage of cells at G2-M phase, the cleavage of beta-catenin and poly(ADP-ribose) polymerase during apoptosis, indicating that cell detachment is a prerequisite for rhodostomin-induced apoptosis. Moreover, pp125(FAK) phosphorylation and actin cytoskeleton were affected upon rhodostomin treatment. The activation of caspase-3 but not that of caspase-9 was detected after rhodostomin treatment. In addition, general caspase inhibitors inhibited the cleavage of beta-catenin and poly(ADP-ribose) polymerase, and DNA fragmentation, whereas they did not prevent cell shape change or detachment. According to these results, we concluded that disintegrin-induced endothelial apoptosis is a complex process, not merely caused by a blockade of endothelial integrin alphanubeta3 but also by an accompanied shape change and mechanical stretches among cells.
Department of Pharmacology, College of Medicine, National Taiwan University, No. 1 Sec. 1 Jen-Ai Road, Taipei, Taiwan.
Wen-Bin
WB
Wu
Hui-Chin
HC
Peng
Tur-Fu
TF
Huang
D000199:Actins / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002448:Cell Adhesion; D002453:Cell Cycle / Q000502:physiology; D002460:Cell Line; D048429:Cell Size; D002470:Cell Survival; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D053938:DNA Fragmentation; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D004789:Enzyme Activation; D005434:Flow Cytometry; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D010766:Phosphorylation; D010975:Platelet Aggregation Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D051176:beta Catenin
D000199:Actins; C495270:CTNNB1 protein, human; D061945:Caspase Inhibitors; D003598:Cytoskeletal Proteins; D039302:Integrin alphaVbeta3; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D011506:Proteins; D015534:Trans-Activators; D051176:beta Catenin; C072026:rhodostomin; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D020169:Caspases