In-vitro effects of dexamethasone on cellular proliferation, apoptosis, and Na+-K+-ATPase activity of bovine corneal endothelial cells.

PURPOSE

To assess the in-vitro effects of dexamethasone (DEX) on the proliferation, apoptosis, and Na+-K+-ATPase activity of bovine corneal endothelial cells.

METHODS

Bovine corneal endothelial cells were cultured with DEX ranging from 10-10 to 10-3 M. The effect of DEX on the proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay. Apoptosis and necrosis were detected by staining with fluorescein-conjugated annexin V and propidium iodide, followed by flow cytometry. The effect of DEX on Na+-K+-ATPase activity was evaluated using non-isotopic methods.

RESULTS

DEX did not affect cellular proliferation or induce apoptosis/necrosis from 10-10 to 10-5 M. At 10-4 and 10-3 M, DEX significantly decreased proliferation and increased apoptosis and/or necrosis. DEX significantly increased the Na+-K+-ATPase activity from 10-8 to 10-6 M, with the maximal effect at 10-6 M (p < 0.01); this effect was inhibited by RU38486, an antiglucocorticoid molecule.

CONCLUSIONS

Bovine corneal endothelial cells express glucocorticoid receptor (GR) mRNA and protein. DEX decreases cell proliferation and induces cellular apoptosis and/or necrosis at high concentrations. DEX also increases the Na+-K+-ATPase activity at certain concentrations.