Abstract
Purpose: :
Previous investigations in non-corneal wound models have demonstrated that TGF-β3 stimulates a reduction in scarring after wounding. We have demonstrated in a 3-D culture model that TGF-β3 stimulates assembly of a non-fibrotic matrix. In the current investigation, we examined if TGF-β3 would promote scar-free healing in a corneal wound model.
Methods: :
Immediately after performing 3-mm keratectomy wounds on Sprague-Dawley rat corneas in vivo, TGF-β3 (0, 10 or 50 ng/ml) drops were applied to the cornea for 10 minutes. The eyes were allowed to heal for 1 week, at which time, the animals were euthanized and the eyes were frozen for indirect-immunofluorescence microscopy. Antibody against α-smooth mucle actin (SMA) was examined as a marker of myofibroblasts, as well as anti-thrombospondin-1 (TSP-1) as a marker of fibrotic matrix. Slit-lamp examinations were also performed to assay overall healing.
Results: :
SMA localization was present in the anterior stroma within the original wound area in the corneas that received 0ng/ml TGF-β3 drops (control); however, with the addition of a 50ng/ml drop of TGF-β3, few, if any SMA-positive cells were observed. TSP-1 levels also appeared to be decreased in the 50ng/ml TGF-β3-treated corneas. The 10ng/ml TGF-β3 drops gave similar results as the control. No obvious differences were observed in healing rates or quality of overall healing in the TGF-β3 treated corneas.
Conclusions: :
A single application of TGF-β3 immediately after wounding appeared to blunt the generation of myofibroblasts following a keratectomy wound in rat corneas. No obvious adverse affect on healing rates or healing quality were observed. TGF-β3 may potentially be useful in stimulating corneal healing with reduced levels of scarring.
Keywords: wound healing • growth factors/growth factor receptors • cornea: stroma and keratocytes