Serum- and Glucocorticoid-Regulated Kinase Isoform-1 and Epithelial Sodium Channel Subunits in Human Ocular Ciliary Epithelium

• DOI: 10.1167/iovs.02-0514
• Publication Date: 2003-03-25T19:04:59Z
• Authors: Saaeha Rauz; Elizabeth A. Walker; Susan V. Hughes; Miguel Coca-Prados; Martin Hewison; Philip I. Murray; Paul M. Stewart
• Keywords: Epithelial sodium channel; SGK1; Antiglucocorticoid; Amiloride

purpose. In peripheral sodium-transporting tissues, the serum- and glucocorticoid-regulated kinase (SGK) isoform-1 is an early corticosteroid target gene in activation of epithelial sodium channels (ENaCs). Sodium transport across human ocular nonpigmented pigmented ciliary bilayer (NPE-PE) essential for aqueous humor production, but expression SGK1 ENaC subunits remain to be defined. methods. were evaluated by situ hybridization RT-PCR analysis on NPE-PE sections NPE cell line (ODM-2). Northern blot analyses conducted ODM-2 cells incubated with dexamethasone (DEX) or aldosterone (ALDO) RU38486 (a glucocorticoid receptor [GR] antagonist) RU26752 mineralocorticoid [MR] both inhibitors. The affinity GRs MRs DEX ALDO was assessed radioligand-binding assays. results. Expression confirmed tissues cells. Dose-dependent induction mRNA demonstrated after incubation ALDO. While response not inhibited RU26752, there a moderate reduction presence that completely abolished Specific binding 3[H]DEX 3[H]ALDO established, revealing greater than MRs. conclusions. ENaCs within regulation through GR MR, indicate this mechanism may feature epithelium.