Low doses of ultraviolet A radiation stimulate adhesion of human dermal fibroblasts by integrins in a protein kinase C-dependent pathway.
In this work, we have studied the modulation of fibroblast-extracellular matrix interactions by physiological doses of ultraviolet A (UV-A) radiation using an adhesion assay on collagen. We have shown that low doses of UV-A (20 kJ/m2) stimulate fibroblast adhesion while higher doses (100 and 200 kJ/m2) inhibit it. By measurement of the thiobarbituric acid reactive substances (TBARS) and use of the chain-breaking antioxidant vitamin E, no role of lipid peroxidation can be detected in these effects. By incubating fibroblasts with a specific protein kinase C (PKC) inhibitor, GF109203X, we have demonstrated that the stimulation of the adhesion by low doses of UV-A involves, at least in part, a PKC-dependent mechanism. In addition, using function-blocking antibodies of alpha 1, alpha 2 or alpha 5 integrin chains involved in extracellular matrix anchorage, we have shown that they decrease the stimulation of adhesion following low doses of UV-A radiation, demonstrating the involvement of these three integrin chains in this UV-A effect. In parallel, 20 kJ/M2 of UV-A are found to rapidly stimulate membrane expression of alpha 1, alpha 2 and alpha 5 integrin chains. This work, which underlines the involvement of integrins in UV-A effects, contributes to the evaluation of the mechanisms by which cell-matrix interactions modulate cell behaviour.
Tupet
A
A
Institut de Recherche sur la Peau, INSERM U. 312, Hôpital Saint Louis, Paris, France.
Lebreton-De Coster
C
C
Dubertret
L
L
Coulomb
B
B
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D002448:Cell Adhesion / Q000528:radiation effects*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D039423:Integrin alpha1; D039421:Integrin alpha2; D039482:Integrin alpha5; D016023:Integrins / Q000378:metabolism*; D015227:Lipid Peroxidation; D008875:Middle Aged; D011493:Protein Kinase C / Q000378:metabolism*; D014466:Ultraviolet Rays
D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D039423:Integrin alpha1; D039421:Integrin alpha2; D039482:Integrin alpha5; D016023:Integrins; D003094:Collagen; D011493:Protein Kinase C