In-vitro effects of dexamethasone on cellular proliferation, apoptosis, and Na+-K+-ATPase activity of bovine corneal endothelial cells.
OBJECTIVE
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.
Chen
Wei-Li
WL
Department of Ophthalmology and Graduate Institute of Clinical Medicine, National Taipei University Hospital, Taipei, Taiwan.
Lin
Chung-Tien
CT
Yao
Chung-Chen
CC
Huang
Yu-Hua
YH
Chou
Yu-Bin
YB
Yin
Hsiang-Shu
HS
Hu
Fung-Rong
FR
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D005938:Glucocorticoids / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D015735:Mifepristone / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D005938:Glucocorticoids; D006727:Hormone Antagonists; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D015735:Mifepristone; D003907:Dexamethasone; D000254:Sodium-Potassium-Exchanging ATPase