Dynamics of beta1-integrins in living fibroblasts--effect of substratum wettability.
The dynamics of integrin receptors mobility was studied in living human fibroblasts using fluorescence-labeled beta(1)-integrin monoclonal antibodies. Time-lapse image series were obtained by confocal laser scanning microscopy when cells were adhering on model hydrophilic (clean glass) and hydrophobic (octadecyl-silanized; i.e., ODS) surfaces coated with fibronectin. Direct measurements showed approximately twice-higher velocity of integrins on glass compared to ODS, and these velocities varied in different zones of the cells. A kinetic model and algorithm for quantification of images was developed, and the analysis identified three receptor populations on glass: immobilized (82.76% of all), slow (4.16%), and fast (13.08%), while, on ODS, only two were identified: immobilized (83.36%) and fast (16.64%). Fast integrins in the peripheral zone of cells have maximal velocities of 0.353 +/- 0.02 mum/min (n = 48, four cells) on hydrophilic and 0.218 +/- 0.02 mum/min (n = 30, three cells) on hydrophobic substrata. The slow population has a velocity of 0.114 mum/min (n = 48, four cells). Further analyses show that these velocities also differ significantly in the peripheral and middle zones of cells in a substrate-dependent fashion. A well-defined circular motion of receptors around the cell center expressed mainly on hydrophobic substrata was monitored and quantified as well.
Zlatanov
I
I
Institute of Biophysics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Groth
T
T
Lendlein
A
A
Altankov
G
G
D000465:Algorithms; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000737:chemistry* / Q000378:metabolism*; D005353:Fibronectins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019012:Integrin beta1 / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D016023:Integrins / Q000737:chemistry; D007700:Kinetics; D008027:Light; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D012867:Skin / Q000166:cytology
D000911:Antibodies, Monoclonal; D005353:Fibronectins; D005456:Fluorescent Dyes; D019012:Integrin beta1; D016023:Integrins