ETX1 is over-expressed in the glaucomatous trabecular meshwork

Purpose: To determine whether exon-trapped X chromosome clone 1 (ETX1) is overexpressed in the trabecular meshwork (TM) of glaucomatous human eyes compared to controls. Methods: Immunohistochemical, western blot, and enzyme-linked immunosorbent assay analysis were used with human tissues and TM protein extracts. Reverse transcription-PCR was performed on isolated mRNA-derived cDNA preparations. Results: Elevated expression levels of ETX1 were detected in glaucomatous compared to control TM tissue. This corroborates previous detection of ETX1 in glaucomatous TM by proteomic analysis. ETX1 mRNA is present in TM tissue, suggesting ETX1 protein is locally produced within TM cells. Conclusions: This is the first report demonstrating overexpression of ETX1 in glaucomatous TM. ETX1 expression may regulate TM protein interactions involved in cell adhesion, and its aberrant overexpression may be part of the pathophysiological pathway in the development of glaucoma.