Purpose. To elucidate a possible target of immunosuppressive agents widely used in the treatment of corneal disorders, the authors determined whether corneal cells are capable of expressing and releasing tumor necrosis factor- alpha (TNFα) on lipopolysaccharide (LPS) stimulation, and they investigated whether TNFα production can be modulated by pharmacologic agents. Methods. Trephined central corneas from C57BL/6 mice were kept in culture for 3 days. Release of TNFα after a 24-hour stimulation with LPS (1 μg/ml) into the culture medium was determined both by bioassay and by enzyme-linked immunosorbent assay. Expression of TNFα mRNA after 6-hour stimulation was examined by polymerase chain reaction. Immunofluorescent staining on cryostat sections of cultured corneas was performed to localize TNFα in the tissue. Corneal explants were retreated with immunosuppressive agents (prednisolone, budesonide, cyclosporin A) for 48 hours, followed by 6- or 24-hour stimulation with LPS in the continuous presence of the agents. Results. Lipopolysaccharide stimulated TNF∅ release into the culture medium. The addition of budesonide (10-7M) or prednisolone (10-6 M) significantly inhibited LPS-induced TNFσ release, whereas cyclosporin A (10-7-10-5 M) had no marked effect. levels of TNFα mRNA in corneal explants increased fivefold after stimulation with LPS. Immunohistochemical staining revealed that TNFα was expressed in the epithelia cells. Budesonide markedly decreased mRNA expression and abolished immunostaining of TNFα stimulated by LPS. Conclusions. TNFα is produced and release by the epithelial cells of mouse central cornea in response to LPS. Contrary to cyclosporin A corticosteroids such as prednisolone and budesonide potently inhibit TNFα production.
|Original language||English (US)|
|Number of pages||9|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Jun 1 1996|
- corneal epithelium
- tumor necrosis factor-alpha (TNFα)
ASJC Scopus subject areas