Abstract
Purpose: :
The fibulins are a family of extracellular matrix (ECM) molecules, which regulate the organ shape besides other growth factors and stromal cells. We report here the in vitro expression of ECM proteins fibulin–1 and fibulin–2 by corneal fibroblasts. The ability of fibulin–1 to modulate cell motility was investigated.
Methods: :
The pattern of fibulin–1, fibulin–2 mRNA and proteins expression in human corneal fibroblast cell line and primo–culture cells were analyzed respectively by gene array, RT– PCR and immunocytochemistry. The motility and adhesion of the cells transfected with fibulin–1 si–RNA were analyzed on tissue culture polystyrene coated with ECM secreted by those fibroblasts.
Results: :
1) The microarray analysis shows the expression of fibulin–1, fibulin–2 and their protein ligands i.e. fibronectin, nidogen–1, aggregan, fibrilin–1, endostatin and laminin alpha–2 chain. Interestingly, ADAMTS–1, a fibulin–1 cofactor for this matrix metalloprotease, was also detected in corneal fibroblasts. 2) The synthesis of fibulins by corneal fibroblasts was also confirmed by RT–PCR. By immunocytochemistry, using specific antibodies, fibulins were detected in corneal cells and in the surrounding cell matrix. 3) Transfection of corneal fibroblasts by fibulin–1 si–RNA has no effect on cell adhesion but increases cell migration as compared with that of the control cells. This observation suggests a crucial role of fibulin–1 on cell motility.
Conclusions: :
The expression of fibulins and that of their ligands by corneal fibroblasts indicate the important role of these proteins in the organization of supra molecular ECM structures of cornea. The variation of their expression and the structural changes of fibulins remain to be determined in corneal pathology.
Keywords: cornea: stroma and keratocytes • extracellular matrix • gene microarray