Abstract
Purpose: :
To examine the effects of varying substratum compliance (relative stiffness) on Transforming Growth Factor beta-1 (TGF-β1)-induced differentiation of corneal myofibroblasts.
Methods: :
Substrates with compliances of 30 kPa and 100 kPa were generated using polyacrylamide hydrogels by altering crosslinker density. Standard tissue culture plastic polystyrene (TCP), which possesses GPa-range compliance, served as a control. Primary rabbit corneal fibroblasts were seeded in 6-well plates on substrates and cultured with media containing 0-10 ng/ml TGF-β1 at 37 °C for 72 hrs. RNA and protein were harvested from all cells for quantitative real-time PCR and Western analyses of the myofibroblast phenotypic marker α-smooth muscle actin (α-SMA).
Results: :
α-SMA RNA and protein levels were increased in cells cultured on stiffer substrates, and the level expressed was modulated by the concentration of TGF-β1 in a dose-dependent manner.
Conclusions: :
The presentation of biophysical cues is an important component in the genesis of the myofibroblast phenotype. We have previously reported that the presentation of biomimetic topographic cues decreases the expression of α-SMA. We propose that the native biophysical attributes of the microenvironment of corneal stromal cells participate in stabilizing the corneal stromal cell phenotype. Furthermore, alterations in stromal topography and compliance would occur throughout stromal wound healing and would participate in the genesis of myofibroblasts.
Keywords: cornea: basic science • cornea: stroma and keratocytes • differentiation