Stimulation of integrin receptors using a magnetic drag force device induces an intracellular free calcium response.
Mechanical loading of cells is of fundamental relevance in physiological processes and induces several functional responses in cells. Integrins, a family of adhesion receptors, which are responsible for the interaction with the extracellular matrix, may play a role in transmission of mechanical signals into cells. The osteogenic cell line U-2 OS expresses different integrin subunits which are uniformly distributed over the cell surface. We applied defined physical forces on individual integrin receptor subunits using paramagnetic microbeads coated with anti-integrin antibodies. Application of an inhomogeneous magnetic field consequently leads to a mechanical stress on the receptor. Intracellular Ca2+ increased when the alpha 2 or the beta 1 integrin subunits were stressed, whereas mechanical loading of the transferrin receptor had a significantly lower effect. This result indicates that forces specifically exerted to individual integrin receptors induce signal transduction pathways.
Pommerenke
H
H
Department of Internal Medicine, University of Rostock, Germany.
Schreiber
E
E
Dürr
F
F
Nebe
B
B
Hahnel
C
C
Möller
W
W
Rychly
J
J
D002118:Calcium / Q000378:metabolism*; D006801:Humans; D016023:Integrins / Q000737:chemistry*; D008280:Magnetics; D008863:Microspheres; D010006:Osteoblasts / Q000378:metabolism*; D012516:Osteosarcoma / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry*; D013314:Stress, Mechanical; D014407:Tumor Cells, Cultured
D016023:Integrins; D010446:Peptide Fragments; D002118:Calcium