cDNA microarray analysis of gene expression changes induced by dexamethasone in cultured human trabecular meshwork cells.
OBJECTIVE
To profile gene expression changes induced by dexamethasone in cultured human trabecular meshwork (TM) cells and identify genes related to the occurrence of steroid-induced glaucoma.


METHODS
At confluence, dexamethasone (final concentration 10(-7) M in 0.1% ethanol) or vehicle alone (control, 0.1% ethanol) was applied to cultured human TM cells from eyes of four normal subjects. After 7 days of application, a labeled cDNA probe was synthesized from extracted total RNA and hybridized to a human cDNA microarray containing 2400 genes. After hybridization, the tyramide signal was amplified, and the fluorescent signals on each microarray were scanned and analyzed.


RESULTS
In dexamethasone-treated TM cells, simultaneous analysis of 2400 human genes indicated a more than twofold increase in 30 genes. Five of them, myocilin (MYOC), decorin, insulin-like growth factor binding protein 2, ferritin L chain, and fibulin-1C, were the most upregulated genes with higher-than-control expression levels in all four experiments. Their upregulation was further confirmed by semiquantitative RT-PCR. Downregulation, with fluorescent signals decreased to less than a half, was found in 34 genes. The dexamethasone-induced expression changes in most of these TM cell genes have not been reported previously.


CONCLUSIONS
cDNA microarray is a useful tool for gene expression analysis that confirms previous reports of upregulated mRNA expression of MYOC after treatment with dexamethasone in human TM cells. Changes in other genes subsequent to the treatment with dexamethasone may also reduce outflow facility, providing new insights into the pathogenesis of steroid-induced glaucoma.
Ishibashi
Takeshi
T
Departments of Ophthalmology, Kyoto Prefectural University of Medicine, Japan. tishibas@ophth.kpu-m.ac.jp
Takagi
Yasutaka
Y
Mori
Kazuhiko
K
Naruse
Shigeta
S
Nishino
Hoyoku
H
Yue
Beatrice Y J T
BY
Kinoshita
Shigeru
S
D000293:Adolescent; D000328:Adult; D002135:Calcium-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured; D002648:Child; D003598:Cytoskeletal Proteins; D058575:Decorin; D003907:Dexamethasone / Q000494:pharmacology*; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins / Q000096:biosynthesis* / Q000235:genetics; D005293:Ferritins / Q000096:biosynthesis / Q000235:genetics; D020869:Gene Expression Profiling; D005938:Glucocorticoids / Q000494:pharmacology*; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D011509:Proteoglycans / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014129:Trabecular Meshwork / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015854:Up-Regulation; D000099179:Myocilin
D002135:Calcium-Binding Proteins; D003598:Cytoskeletal Proteins; D058575:Decorin; D003907:Dexamethasone; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D005293:Ferritins; D005938:Glucocorticoids; D006023:Glycoproteins; D018971:Insulin-Like Growth Factor Binding Protein 2; D011509:Proteoglycans; D012333:RNA, Messenger; D000099179:Myocilin; C546878:DCN protein, human; C060820:fibulin