Regulation of human corneal epithelial cell proliferation and apoptosis by dexamethasone.
OBJECTIVE
To investigate whether human corneal epithelial cells express the glucocorticoid receptor (GR) and to assess the influence of dexamethasone (DEX) on these cells.


METHODS
Human corneal epithelial cells were cultured in medium supplemented with various concentrations of DEX (ranging from 10(-10) to 10(-4) M). Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfop henyl) -2H-tetrazolium inner salt (MTS) assay at 2, 4, and 6 days of culture. Apoptosis was studied by nucleus labeling using a fluorescent dye and immunostaining by APO 2.7 at 6 days of culture. GR mRNA was detected in corneal epithelium and cultured corneal epithelial cells by means of reverse transcription-polymerase chain reaction (RT-PCR). Immunocytochemical staining of the epithelial cells was performed with a monoclonal anti-human GR.


RESULTS
RT-PCR and immunocytochemistry showed the expression of GR (mRNA and protein) in corneal epithelial cells. DEX significantly increased corneal epithelial cell proliferation with concentrations ranging from 10(-10) to 10(-6) M, with a maximum effect at 10(-7) M (P < 0.005). However, DEX also induced apoptosis of cultured corneal epithelial cells at any concentration used.


CONCLUSIONS
These results indicate that human corneal epithelial cells express the GR and proliferate in response to DEX stimulation which also induces corneal epithelial cell apoptosis.
Bourcier
T
T
Cornea Bank, AP-HP, Paris VI University, the. Institut National de la Santé et de la Recherche Médicale (U33g), Saint-Antoine Hospital, Paris, France. bourcier@quinze-vingts.fr
Forgez
P
P
Borderie
V
V
Scheer
S
S
Rostène
W
W
Laroche
L
L
D017209:Apoptosis / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D003907:Dexamethasone / Q000494:pharmacology*; D019573:Epithelium, Corneal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008773:Methylphenazonium Methosulfate / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
D017931:DNA Primers; D005938:Glucocorticoids; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D013778:Tetrazolium Salts; D013844:Thiazoles; C070380:3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; D008773:Methylphenazonium Methosulfate; D003907:Dexamethasone