Salmosin, a disintegrin purified from a Korean snake (Agkistrodon halys brevicaudus) venom, interacts with integrin αvβ3 and inhibits the proliferation of bovine capillary endothelial (BCE) cells induced by basic fibroblast growth factor (bFGF) [1,2]. We investigated salmosin's mechanism of inhibition of BCE cell proliferation by examining changes in the cytoskeleton and activation of integrin-mediated signaling molecules. Salmosin disassembled cortical actins at focal adhesions and induced cells to be rounded and detached, but it did not alter microtubule structures in the early stage of cells being rounded. Immunolocalization of paxillin also demonstrated that focal adhesions were disassembled by salmosin. In salmosin-treated BCE cells, focal adhesion kinase (FAK) was dephosphorylated and expression of paxillin and p130CAS was decreased, but PI3 kinase, ILK, and β-catenin were not expressed in decreased amounts or modified, suggesting that salmosin inactivated FAK-dependent integrin signaling pathways. While BCE cells proliferated normally on plates coated with salmosin, cells treated with salmosin eventually underwent apoptosis. These observations strongly suggest that salmosin disorganizes focal contacts to detach cells by competing with the extracellular matrix (ECM) for direct binding to integrin αvβ3 on the cell surface, eventually leading to apoptosis.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2003 Mar 14|
Bibliographical noteFunding Information:
The authors thank H.-S. Hwang for the technical support on microscopic image preparation. This work was supported by Grant 00-G-08-01-A-04 and by the 21st Century Frontier for Functional Analysis of Human Genome (#HGM0200112) from the Korea Institute of Science and Technology Evaluation and Planning (KISTEP), Korea.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology