The cytokine regulation of SPARC production by rabbit corneal epithelial cells and fibroblasts in vitro.
OBJECTIVE
SPARC (osteonectin/BM40) is detected in the corneal stroma during the wound-healing process. To understand the metabolism of SPARC in the cornea, we investigated the effects of cytokines and growth factors on SPARC synthesis by rabbit corneal epithelial cells and fibroblasts.


METHODS
Rabbit corneal epithelial cells or fibroblasts were cultured for 3 days with serum-containing minimal essential medium (MEM), then subcultured for 3 days on serum-free MEM with epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta), or interleukin-1beta (IL-1beta). SPARC concentration in the medium was measured by the ELISA method using anti-SPARC monoclonal antibody.


RESULTS
The concentration of SPARC in the conditioned medium of the epithelial cells depended on either cell numbers or cultivation periods. When EGF was added to the medium, the amount of SPARC in the medium decreased. The addition of IL-1beta, PDGF, or TGF-beta did not affect SPARC synthesis by the epithelial cells. The production of SPARC by rabbit corneal fibroblasts was low compared with that by epithelial cells. However, the synthesis of SPARC by corneal fibroblasts was significantly enhanced by the addition of TGF-beta. The addition of IL-1beta, PDGF, or EGF slightly increased SPARC synthesis by corneal fibroblasts.


CONCLUSIONS
Cytokines and growth factors modulate SPARC synthesis by rabbit corneal epithelial cells and fibroblasts. These results suggest that cytokines and growth factors modulate cell-matrix interaction in corneal wound healing, possibly by regulating SPARC synthesis.
Abe
Kosuke
K
Department of Ophthalmology, Kinki University School of Medicine, Osaka-Sayama City, Osaka, 589-8511, Japan. abe@ganka.med.kindai.ac.jp
Hibino
Tsuyoshi
T
Mishima
Hiroshi
H
Shimomura
Yoshikazu
Y
D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002452:Cell Count; D002478:Cells, Cultured; D003319:Corneal Stroma / Q000166:cytology; D017077:Culture Media, Conditioned; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology*; D015676:Osteonectin / Q000096:biosynthesis*; D011817:Rabbits
D000911:Antibodies, Monoclonal; D017077:Culture Media, Conditioned; D006133:Growth Substances; D015676:Osteonectin