Abstract
Purpose: :
Examination of SV–40 transfected HCECs, two morphologically distinct subclones of this cell line, as well as primary HCECs in terms of orientation and migratory behavior on a patterned collagen matrix with a parallel fiber structure. Furthermore, a possible correlation between alpha–2–integrin expression by these cells and their migratory behavior on the collagen matrix was investigated.
Methods: :
Cultivation of the two clonal cell lines in SFM–medium with bFGF–supplementation and of the primary cells and SV–40 transfected mother cell line in F99 based serum–supplemented medium. Establishing of a self–organizing collagen matrix by addition of collagen I (final concentration 3%) to a KCl–glycine buffer on a freshly cleaved mica surface. For every examined cell type video microscopy was performed in triplicate over the course of 20 h. Quantitative determination of alpha–2–integrin expression in each cell line by Western blotting.
Results: :
All cells align along or in the direction of the collagen fibers, which serve as a "guide rail" for the cells. Cell lines differ in the extent and velocity of migration and some exerted such tractive forces on the matrix that it was completely destroyed within 20h. Primary cells, which exhibited the best alignment but exerted also very strong tractive forces that destroyed the matrix, showed the highest alpha–2–integrin expression. In contrast, the clonal cell line HCEC–B4G12, which displayed poor cell alignment and developed only minor tractive forces, showed the lowest expression of alpha–2–integrin. Immortalized HCECs and the derived subclone HCEC–H9C1 showed medium alignment and directional migration and developed lower tractive forces, which coincided with lower alpha–2–integrin expression.
Conclusions: :
Different HCEC lines align and move directionally on matices containing a parallel array of collagen fibers to a varying degree. Alignment, migration and the development of traction on these matrices appear to be correlated with the expression of alpha–2–integrin, with stronger tractive forces and better cell alignment along the collagen fibers correlating with increased alpha–2–integrin expression. Other cell adhesion proteins, cell cycle status and other characteristics might influence the behavior of the cells on such patterned collagen matrices. Further investigations are necessary.
Keywords: cornea: endothelium • cell membrane/membrane specializations • cornea: basic science