ELAM-1 and interleukin-1α mRNA expression in trabecular meshwork cells

Purpose. Previous immunohistochemical experiments in this lab have shown that ELAM-1 is not expressed on normal trabecular meshwork (TM) cells but is significantly expressed on glaucomatous TM cells and normal TM cells stimulated with IL-la and IL-l. This study attempts to detect the presence of mRNA for ELAM-1 and IL-la in normal, stimulated normal, and glaucomatous TM cells. Methods. Normal and glaucomatous human cadaver eyes were obtained from NDRI and New England Eye Bank. TM cells were isolated and cultured until confluent. Normal TM cells were incubated with medium containing 10 ng/ml IL-1 a for 3 hours. Normal non-stimulated and glaucomatous TM cells remained in culture media and were placed in the same culture conditions. After incubation, total UNA was extracted, purified, and analyzed by Northern Blot Analysis using ELAM-1 and IL-la probes. ReguJtSt Glaucomatous TM cells were positive for the presence of ELAM-1 mRNA. Normal TM cells showed no ELAM-1 mRNA synthesis, but upregulated ELAM-1 mRNA synthesis when stimulated with IL-1 a. Glaucomatous TM cells also showed the presence of ILla mRNA, as did normal TM cells stimulated with IL-la. In contrast, no detectable levels of IL-la message was found in normal TM cells. Conclusions. Our results indicate that glaucomatous but not normal TM cells express ELAM-1, and produce mRNA for both ELAM-1 and IL-1 .Stimulation of normal TM cells causes production of ELAM-1 mRNA; normal TM can therefore be induced to produce this molecule. The possible role of ELAM-1 in aqueous outflow requires further investigation.