INTEGRIN INVOLVEMENT IN KERATOCYTE LOCOMOTION

Citation
E. Debeus et K. Jacobson, INTEGRIN INVOLVEMENT IN KERATOCYTE LOCOMOTION, Cell motility and the cytoskeleton, 41(2), 1998, pp. 126-137
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell Biology",Biology
Journal title
ISSN journal
0886-1544
Volume
41
Issue
2
Year of publication
1998
Pages
126 - 137
Database
ISI
SICI code
0886-1544(1998)41:2<126:IIIKL>2.0.ZU;2-W
Abstract
Keratocytes are useful in the study of locomotion because they move ra pidly (up to 1 micron/second) while maintaining an almost uniform shap e, speed and direction. The smooth gliding motion of the keratocyte re quires a precise coordination between adhesion, contractility, and ret raction. To ask what role integrins play in keratocyte adhesion and lo comotion, either RGD peptides or an anti-Pi integrin mAb that binds to an ectodomain epitope and inhibits adhesion formation was added to th e culture media of moving keratocytes. The response to these reagents depended on three interrelated factors: the dose of RGD/mAb, the appar ent adhesion strength of the keratocyte to the substratum and the cell speed. High doses cause keratocytes to quickly and irreversibly round up. At intermediate RGD/mAb doses, keratocytes reestablish adhesion a fter treatment and briefly resume locomotion until partial detachment recurs. At the lowest doses, disruption of pi integrin-mediated adhesi on formation destabilizes the lamella, temporarily preventing lamellar extension and forward movement of the cell. With increasing culture t ime, there is an increase in apparent adhesion and a corresponding mar ked decrease in locomotory velocity. Under these conditions, high dose s of RGD/mAb do not cause keratocytes to detach or even produce detect able lamellar instabilities. We postulate that RGD/mAb competitively i nhibits new pi integrin mediated adhesion formation that is required t o support the rates of lamellar extension necessary for rapid locomoti on. Cell Motil. Cytoskeleton 41:126-137, 1998. (C) 1998 Wiley-Liss, In c.