Reduced myocilin expression in cultured monkey trabecular meshwork cells induced by a selective glucocorticoid receptor agonist: comparison with steroids.
OBJECTIVE
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.
Pfeffer
Bruce A
BA
Preclinical Pharmacology Department, Pharmaceutical Research and Development, Bausch & Lomb, Inc, Rochester, New York 14609, USA. bruce_pfeffer@bausch.com
DeWitt
Charu A
CA
Salvador-Silva
Mercedes
M
Cavet
Megan E
ME
López
Francisco J
FJ
Ward
Keith W
KW
D000818:Animals; D001572:Benzofurans / Q000494:pharmacology*; D015153:Blotting, Western; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005938:Glucocorticoids / Q000494:pharmacology*; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D006727:Hormone Antagonists / Q000494:pharmacology; D008253:Macaca mulatta; D015735:Mifepristone / Q000494:pharmacology; D000439:Pentanols / Q000494:pharmacology*; D011239:Prednisolone / Q000031:analogs & derivatives / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000819:agonists*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014129:Trabecular Meshwork / Q000187:drug effects* / Q000378:metabolism; D000099179:Myocilin
D001572:Benzofurans; D003598:Cytoskeletal Proteins; D003907:Dexamethasone; D005136:Eye Proteins; D005938:Glucocorticoids; D006023:Glycoproteins; D006727:Hormone Antagonists; D015735:Mifepristone; D000439:Pentanols; D011239:Prednisolone; D011804:Quinolines; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D000099179:Myocilin; C546413:R-1,1,1-trifluoro-4-(5-fluoro-2,3-dihydrobenzofuran-7-yl)-4-methyl-2-(((2-methyl-5-quinolyl)amino)methyl)pentan-2-ol; C009935:prednisolone acetate