J. Wu et al., Vitronectin adsorption to chrysotile asbestos increases fiber phagocytosisand toxicity for mesothelial cells, AM J P-LUNG, 279(5), 2000, pp. L916-L923
Citations number
41
Categorie Soggetti
da verificare
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY
Biological modification of asbestos fibers can alter their interaction with
target cells. We have shown that vitronectin (VN), a major adhesive protei
n in serum, adsorbs to crocidolite asbestos and increases fiber phagocytosi
s by mesothelial cells via integrins. Because chrysotile asbestos differs s
ignificantly from crocidolite in charge and shape, we asked whether VN woul
d also adsorb to chrysotile asbestos and increase its toxicity for mesothel
ial cells. We found that VN, either from purified solutions or from serum,
adsorbed to chrysotile but at a lower amount per surface area than to croci
dolite. Nevertheless, VN coating increased the phagocytosis of chrysotile a
s well as of crocidolite asbestos. VN coating of both chrysotile and crocid
olite, but not of glass beads, increased intracellular oxidation and apopto
sis of mesothelial cells. The additional apoptosis could be blocked by inte
grin-ligand blockade with arginine-glycine-aspartic acid peptides, confirmi
ng a role for integrins in the fiber-induced toxicity. We conclude that VN
increases the phagocytosis of chrysotile as well as of crocidolite asbestos
and that phagocytosis is important in fiber-induced toxicity for mesotheli
al cells.