Dexamethasone induces specific proteins in human trabecular meshwork cells.
Previous studies have demonstrated the presence of high-affinity, glucocorticoid-specific receptors in explants of human outflow tissue and in cultured trabecular meshwork. Glucocorticoid-induced responses of scleral fibroblasts and trabecular meshwork cells were evaluated in this study. Incubation of human trabecular meshwork (HTM) and scleral fibroblast (HS) cells with 10(-7) M dexamethasone (DEX) results in a 60% inhibition of prostaglandin production. The effects of glucocorticoid treatment on cellular and secreted proteins using [35S] methionine incorporation were evaluated. Treatment of HTM cells cultured from two normal individuals with DEX induced the expression of [35S] methionine-labelled cellular proteins of 35, 65 and 70 kD, and secreted proteins of 40, 90 and 100 kD. Under the same experimental conditions, a 70 kD molecular weight cellular protein was induced in the HS cells. There were no apparent DEX-induced alterations in HS-secreted proteins. Since a functional common response to glucocorticoid treatment in both HS and HTM cells was inhibition of prostaglandin production, the dexamethasone-induced expression of the 70 kD protein in these cells may be related to this effect. Further studies are required to elucidate specific roles of the steroid-induced proteins in the effects of glucocorticoids on HTM and HS cells.
Partridge
C A
CA
Department of Physiology, New York Medical College, Valhalla 10595.
Weinstein
B I
BI
Southren
A L
AL
Gerritsen
M E
ME
D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D015180:Electrophoresis, Gel, Two-Dimensional; D005136:Eye Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D011458:Prostaglandins E / Q000378:metabolism; D011460:Prostaglandins F / Q000378:metabolism; D011863:Radioimmunoassay; D012590:Sclera / Q000187:drug effects; D013997:Time Factors; D014129:Trabecular Meshwork / Q000187:drug effects* / Q000378:metabolism
D005136:Eye Proteins; D011458:Prostaglandins E; D011460:Prostaglandins F; D003907:Dexamethasone