Gene Expression and miR Profiles of Human Corneal Fibroblasts in Response to Dexamethasone

Abstract

Dexamethasone (DEX) is commonly used as a therapeutic agent for various ocular inflammatory diseases; however, its effect on resident naive cells is unknown. In this study, genome microarray and microRNA (miR) analyses were used to evaluate the global gene and miR expression of human corneal fibroblasts (HKFs) in response to treatment with DEX. Primary HKFs from three donors were treated with DEX for 16 hours. Treated and untreated cells were snap frozen for microarray and miR array analyses. Genes with a more than threefold change were classified into gene families using the DAVID web-based classification database, and six of these genes were validated using quantitative real-time PCR. Five miRs were also validated using miR-detection assays. Of the 41,093 genes examined, 261 were upregulated and 123 were downregulated greater than threefold after DEX treatment. Real-time PCR confirmed upregulation of six genes, including oculocutaneous albinism II (OCA2), angiopoietin-like 7 (ANGPTL7), neuron navigator 2 (NAV2), neurofilament light chain polypeptide (NEFL), solute carrier family 16/member 12 (SLC16A12), and serum amyloid A1 (SAA1). Expression of several miR including miR-16, -21, and -29C were upregulated, whereas miR-100 was downregulated in fibroblasts by DEX. DEX can greatly change the global gene and miR profile of HKFs. DEX not only downregulates inflammatory genes, but can also induce expression of angiogenic and inflammatory genes. In addition, DEX may exert posttranscriptional gene regulation through miRs. These data support a complex role for DEX-induced changes in resident cells that may have implications in the clinical management of corneal inflammation with topical glucocorticoids.