Abstract
Purpose: :
To examine the effects of adenovirus-driven c-met proto-oncogene overexpression on corneal epithelial wound healing, and the patterns of corneal diabetic markers and signaling molecules.
Methods: :
Organ-cultured autopsy human diabetic corneas were transduced with adenovirus harboring c-met gene under the cytomegalovirus promoter (1.2x108 plaque forming units of adenovirus per cornea in culture medium for 72 hr). The other cornea from each donor received control virus harboring β-galactosidase gene or vector alone. After another 4-6 days, corneas were harvested for immunohistochemical and Western blot analyses, or 5-mm epithelial wounds were created with n-heptanol, and healing was monitored microscopically. Expression of phosphorylated forms of protein kinases involved in c-met signaling, ERK, Akt, and p38 mitogen-activated protein kinase (p38MAPK), was examined using Western blot, phosphokinase antibody arrays and immunohistochemistry.
Results: :
C-met transduction resulted in its overexpression in corneal epithelium including total, extracellular and phosphorylated protein. Basement membrane and integrin diabetic markers had more normal staining patterns when compared to control vector-transduced fellow corneas. Patterns of tight junction components, ZO-1 and claudin-1, suggested no change in corneal barrier function upon c-met transduction. The epithelial healing rate after c-met transduction accelerated 2-fold compared to control corneas and became similar to normal ones. Data obtained by several methods suggested the involvement of p38MAPK activation in c-met effects.
Conclusions: :
Adenoviral c-met transduction into diabetic corneas appears to restore HGF signaling and leads to normalization of marker patterns and wound healing rate. C-met gene therapy may be useful for correcting diabetic corneal alterations.
Keywords: cornea: epithelium • gene transfer/gene therapy • diabetes