Abstract
Purpose :
We investigate a genomic basis of the gene expression in the trabecular meshwork/extracellular matrix of the eye and its potential association with primary open-angle glaucoma , a blinding eye disease involving the degeneration of retinal ganglion cells and the optic nerve.
Methods :
Microsurgical tissue samples (~ 0.1 mm block or less of extracellular/trabecular meshwork (TM-ECM)) were collected from 28 patients undergoing a trabeculectomy to reduce intraocular pressure (IOP) for primary open-angle glaucoma (POAG). Using a multiplex high-throughput microfluidic real-time RT-qPCR system, we examined the individual RNA isolates from these samples for the expression of 48 genes known to be associated with the trabecular meshwork/extracellular matrix and elevated IOP. For each gene, we determined its transcriptional range of expression (threshold cycles, Ct ) and the frequency distribution for the gene detection across all the samples (expression heterogeneity).
Results :
Profiles of RNA transcripts exhibited a high efficiency/sensitivity (mean efficiency > 95.0%, ΔCt ~9-35) and specificity (coefficient of variation<0.05, amplicon peak location for melting curve). The data showed a very high level of RNA transcript heterogeneity for various genes across the individual samples (32.1 + 12.7 %). Genes such as optineurin (OPTN) and myocilin (MYOC), previously associated with glaucoma from genome-wide association (GWA) and genetic linkage studies, were among those transcripts having the highest range of expression (differ by ΔCt> 25) and expression heterogeneity (~50% ).
Conclusions :
This study reveals the presence of potentially useful biological/molecular information in the discarded microsurgical tissue removed during a trabeculectomy for the treatment of glaucoma. Transcription readouts from primary tissue may provide a genomic "snaphot" for the dynamic progression of the disease.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.