title: Differential response and withdrawal profile of glucocorticoid-treated human trabecular meshwork cells.
abstract: The goal of the study was to examine secreted protein response and withdrawal profiles from cultured human trabecular meshwork (HTM) cells following short- and long-term glucocorticoid treatment. Primary cultures of five human HTM cell strains isolated from 5 different individual donor eyes were tested. Confluent HTM cells were differentiated in culture media containing 1% FBS for at least one week, and then treated with Dexamethasone (Dex, 100 nM) 3 times/week for 1 or 4 weeks. Cell culture supernatants were collected 3 times per week for 8 weeks. Secretion profiles of myocilin (MYOC), matrix metalloproteinase-2 (MMP2) and fibronectin (FN) were determined by Western blot analysis and MMP2 activity by zymography. Dex treatment reduced MMP2 expression and activity, returning to normal levels shortly after Dex withdrawal in 5 HTM cell strains. All five cell strains significantly upregulated MYOC in response to Dex treatment by an average of 17-fold, but recovery to basal levels after Dex withdrawal took vastly different periods of time depending on cell strain and treatment duration. Dex treatment significantly increased FN secretion in all strains but one, which decreased FN secretion in the presence of Dex. Interestingly, secretion of FN and MYOC negatively correlated during a 4 week recovery period following 4 weeks of Dex treatment. Taken together, the time course and magnitude of response and recovery for three different secreted, extracellular matrix-associated proteins varied greatly between HTM cell strains, which may underlie susceptibility to glucocorticoid-induced ocular hypertension.
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC, United States.
authors.forename: Guorong
authors.initials: G
authors.lastname: Li
authors.affiliation: University of North Carolina at Chapel Hill, Collaborative Studies Coordinating Center, United States.
authors.forename: Gang
authors.initials: G
authors.lastname: Cui
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC, United States.
authors.forename: W Michael
authors.initials: WM
authors.lastname: Dismuke
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC, United States.
authors.forename: Iris
authors.initials: I
authors.lastname: Navarro
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC, United States.
authors.forename: Kristin
authors.initials: K
authors.lastname: Perkumas
authors.affiliation: Department of Bioengineering, Imperial College London, UK.
authors.forename: David F
authors.initials: DF
authors.lastname: Woodward
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC, United States. Electronic address: dan.stamer@duke.edu.
authors.forename: W Daniel
authors.initials: WD
authors.lastname: Stamer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005938:Glucocorticoids / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007223:Infant; D009798:Ocular Hypertension / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014019:Tissue Donors; D014129:Trabecular Meshwork / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D000099179:Myocilin
chemical_list: D003598:Cytoskeletal Proteins; D003907:Dexamethasone; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D005938:Glucocorticoids; D006023:Glycoproteins; D000099179:Myocilin
keywords: Conventional outflow; Dexamethasone; Extracellular matrix; Glaucoma; Ocular hypertension