Cai, Jingwen; Biomedical Sciences (Augusta University, 2019-10)
      Glaucoma is the leading cause of irreversible blindness worldwide. Primary open angle glaucoma (POAG) is the most common type and its cause remains unclear. The development of POAG is a result of interactions between genetic and environmental factors. Elevated intraocular pressure (IOP) is a major and the only modifiable risk factor for POAG. Schlemm’s canal endothelial (SCE) cells play a significant role in IOP regulation though their mechanism is uncertain. We aimed to study the role of glaucoma-related genes in regulating the function of SCE cells by performing microarray-based expression and pathway analyses, and then to establish and validate an in vitro cellular model from bovine eyes. From primary cultured human glaucomatous SCE cells, we identified 113 differentially expressed genes enriched in cell adhesion, heparin binding, and extracellular matrix. The expression of 18 selected genes was validated and then examined in the cyclically stretched SCE cells that simulated the physiological condition. The pathway analysis of the mechano-responsive glaucoma-related genes identified a significant upstream regulator – TGFβ, which may regulate all these genes. In order to study the signaling pathway in the SCE cells, we established a cellular model using the SCE analogue – angular aqueous plexus (AAP) cells from bovine eyes. The cells were selected based on their drug resistance to puromycin and then validated with cell morphology, contact inhibition, and protein expression of two endothelial markers (von Willebrand factor and vascular endothelial (VE)-cadherin). Upon treatment of varying TGFβ2 concentrations, most of the mechano-responsive glaucoma-related genes had similar response in human SCE cells and bovine AAP cells. This represents the first study of the role of TGFβ2 in SCE cells. In addition, bovine-derived AAP cells provide a validated in vitro cellular model for SCE cell research.