Differential effects of transforming growth factors on localization of adhesion complex proteins following corneal epithelial cell wounding.
OBJECTIVE
The differential effects of transforming growth factor (TGF) alpha, beta 1 and beta 2 on the de novo localization of heparan sulfate proteoglycan, collagen type VII and laminin-1 to the adhesion complex were analyzed using an in vitro model of corneal epithelial cell wound healing.


METHODS
Bovine corneal explants were maintained in culture media containing either no growth factor or 1, 5, or 10 ng/ml TGF alpha, TGF beta 1 or TGF beta 2. After 24 or 48 hours in culture, cryostat sections of explants were processed for immunofluorescence microscopy using antibodies directed against heparan sulfate proteoglycan, collagen type VII or laminin-1.


RESULTS
A comparison of antibody labeling patterns and relative fluorescence intensity of antibody labeling to controls suggested that TGF alpha inhibits the spatial polarization of proteins into the reforming adhesion complex during early stages of wound healing. Both TGF beta 1 and beta 2 enhanced the linear localization of the three proteins to the site of the reforming adhesion complex. However, in our model TGF beta isoforms did not have identical functions. TGF beta 2 accelerated the temporal localization of collagen type VII to the adhesion complex, an effect which was not observed with TGF beta 1.


CONCLUSIONS
TGF beta, but not TGF alpha, may play an important role in corneal epithelial cell wound healing by accelerating the reformation of the adhesion complex and subsequent epithelial cell-extracellular matrix adhesion.
Gassner
H L
HL
Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
Esco
M
M
Smithson
M W
MW
Kurpakus
M A
MA
D000818:Animals; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000378:metabolism* / Q000473:pathology; D065306:Corneal Injuries; D046508:Culture Techniques; D004848:Epithelium / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000378:metabolism*; D007797:Laminin / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism*; D014018:Tissue Distribution; D015291:Transforming Growth Factors / Q000494:pharmacology*
D015815:Cell Adhesion Molecules; D003094:Collagen; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D007797:Laminin; D011509:Proteoglycans; D015291:Transforming Growth Factors