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Abstract #13728 Published in IGR 8-2
Gene expression profile of human trabecular meshwork cells in response to long-term dexamethasone exposure
Rozsa FW; Reed DM; Scott KM; Pawar H; Moroi SE; Kijek TG; Krafchak CM; Othman MI; Vollrath D; Elner VMMolecular Vision 2006; 12: 125-141
PURPOSE: Topical use of dexamethasone has long been associated with steroid induced-glaucoma, although the mechanism is unknown. We applied a strict filtering of comparative microarray data to more than 18,000 genes to evaluate global gene expression of cultured human trabecular meshwork cells in response to treatment with dexamethasone. METHODS: Three human trabecular meshwork cell primary cultures from nonglaucomatous donors were incubated with and without dexamethasone for 21 days. Relative gene expression was evaluated by analysis of U133A GeneChip and the results validated using quantitative polymerase chain reaction (PCR). RESULTS: Application of strict filtering to include only genes with statistically significant differences in gene expression across all three trabecular meshwork cell cultures produced a list of 1,260 genes. Significant changes in signal level were observed, including 23 upregulated and 18 downregulated genes that changed greater than threefold in each of three cell cultures. Using quantitative PCR we found changes greater than a thousandfold for two genes (SLP1 and SAA2) and changes greater than a hundredfold for another five genes (ANGPTL7, MYOC, SAA1, SERPINA3, and ZBTB16). CONCLUSIONS: Expression changes in trabecular meshwork cells in response to dexamethasone treatment indicate that a group of actins and actin-associated proteins are involved in the development of cross-linked actin networks that form in response to dexamethasone. A trend was identified toward decreased expression of protease genes accompanied by an increased expression of protease inhibitors. Such a trend in nonproteasomal proteolysis conceivably affects gene product levels above the level of transcription. Only two genes, MYOC and IGFBP2, showed significantly elevated expression after dexamethasone treatment in our study and the other three previously published reports of primary culture trabecular meshwork cell gene expression.
Dr. J.E. Richards, Department of Epidemiology, The University of Michigan, Ann Arbor, MI, USA
Classification:
3.5 Molecular biology incl. SiRNA (Part of: 3 Laboratory methods)
3.6 Cellular biology (Part of: 3 Laboratory methods)