Pathway and Network Analysis in Primary Open Angle Glaucoma

Glaucoma, a group of multifactor ocular diseases, is the second leading cause of blindness worldwide. Primary open angle (POA) is the most common type of glaucoma, characterized by progressive optic nerve degeneration. Numerous genes and proteins have been revealed to be associated with POAG, but the pathologic mechanisms of the disease are still poorly understood. Proteomics, the collective study of proteins in an organism at a given condition, has extensively been used for the high-throughput identification of proteins related to POAG. A significant obstacle in proteomics studies is the data variability which makes it hard to interpret the results. Pathway analysis and network topological information can help address the challenge and provide a greater appreciation of the disease mechanism and progression. The purpose of this paper is to determine POAG biological and network information to further understand the mechanisms associated with POAG. PANTHER classification system was used, including classification with gene ontology, protein class and pathway. 474 gene/protein IDs were extracted from previous proteomic studies. Among pathways found by PANTHER classification, apoptosis signaling pathway was the most significant pathway (with the p-value of 5.54E-12). Other PANTHER categories results demonstrated that developmental processes, receptor binding, extracellular region and extracellular matrix proteins were the most significant biological process, molecular function, cellular component and protein class respectively. Pathway analysis aids to find probable mechanisms involved in POAG. A network analysis on proteins was also performed using STRING database and cytoscape software. From network analysis, candidate biomarkers for the disease were introduced.