Abstract
Purpose:
Prostaglandin analogs lower intraocular pressure (IOP) by modulating the trabecular outflow pathway and are used as first line drugs for treating ocular hypertension. However, the mechanism of action of these drugs is largely unknown. The current study was undertaken to identify differential gene expression patterns in human Schlemm’s canal cells following treatment with latanoprost, bimatoprost and PGF2α.
Methods:
Three confluent primary human Schlemm’s canal cell lines (provided by Dr. Dan Stamer, Duke University) were incubated with DMEM containing latanoprost-free acid (100nM), bimatoprost-free acid (1 µM), and PGF2α (100nM). DMEM containing vehicle (ethanol) was used as the control. Following 2, 6 and 12 hour incubations, total RNA was isolated from each cell line. Total RNA (100 ng) was reverse transcribed, column purified, and in vitro transcribed generating biotin-labeled cRNA. The in vitro transcribed products were fragmented and used to probe Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays. A total of 54 Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays were probed. Following normalization, differentially regulated gene sequences that had >1.5-fold change in gene expression were considered significant. Real-time PCR was used to verify accuracy of the microarrays.
Results:
A total of 15 genes were upregulated and 2 genes were downregulated at all timepoints, in all cell lines, and under all treatments. Among the upregulated genes, NR4A3 and RCAN1 were elevated greater than 4.5-fold. Many of the differentially regulated genes are associated with metabolic pathways and ion transport systems suggesting that treatment with the prostaglandin analogs may result in increased metabolic functions and overall better cell health.
Conclusions:
Treatment with PGF2α and its analogs cause differential expression of gene targets involved in functionally concentric pathways suggesting that common signaling mechanisms are utilized by all three drugs in human Schlemm’s canal cells.
Keywords: 735 trabecular meshwork •
533 gene/expression