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PURPOSE: To assess in vitro myocilin (MYOC) expression in trabecular meshwork (TM) cells exposed to BOL-303242-X, a selective glucocorticoid receptor (GR) agonist (SEGRA), in comparison with dexamethasone (DEX), and prednisolone acetate (PA). METHODS: After drug treatment of monkey TM cultures, MYOC protein in conditioned media (CM) was measured by Western blot and densitometry. MYOC mRNA levels were analyzed by qRT-PCR. RU-486 was tested for antagonism of MYOC protein expression induced by DEX and BOL-303242-X. RESULTS: Baseline MYOC protein released into CM and MYOC mRNA were detected. DEX or PA elicited dose-dependent increases in MYOC in CM and also in MYOC mRNA. BOL-303242-X effects typified partial agonism, with significantly reduced MYOC protein and mRNA, compared with DEX. Maximum efficacy for BOL-303242-X was 53% of that for DEX. Mean EC(50) across all strains tested was lower, but not significantly different, for BOL-303242-X versus DEX. Compared with DEX, MYOC mRNA levels were significantly lower in BOL-303242-X-treated TM cells at the highest doses tested. EC(50)s for PA were higher than DEX, for both myocilin protein and mRNA. RU-486 displayed a dose-dependent antagonism to drug-induced increases in myocilin levels. CONCLUSIONS: In vitro quantitative assays of myocilin expression in TM cells can be used for characterizing anti-inflammatory drugs that are GR ligands. The results suggest that, compared with traditional ocular steroids, therapeutic doses of BOL-303242-X elicit a reduced myocilin expression profile in TM cells by virtue of the partial agonist properties of this compound.
Preclinical Pharmacology Department, Pharmaceutical Research and Development, Bausch & Lomb, Inc, Rochester, New York 14609, USA. bruce_pfeffer@bausch.com
5.2 Primates (Part of: 5 Experimental glaucoma; animal models)
3.5 Molecular biology incl. SiRNA (Part of: 3 Laboratory methods)
9.4.1 Steroid-induced glaucoma (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders)
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)