Effect of High Glucose on the Production of Reactive Oxygen Species in Trabecular Meshwork Cells

PURPOSE: To investigate the effect of high glucose concentration on the production of reactive oxygen species in cultured human trabecular meshwork cells (HTMCs). METHODS: Primarily cultured HTMCs were exposed to low glucose (5 mM) and high glucose (22 mM) concentrations, respectively, for seven days. Cellular survival, as well as nitric oxide (NO) and hydrogen peroxide production, were assessed by measured MTT assay, Griess assay, and o-Dianisidine dihydrochloride assay, respectively. Some cells were co-exposed to N-acetyl cysteine (NAC) to assess the effect of this antioxidant. RESULTS: High glucose concentration increased the survival of cultured HTMCs significantly, with no effect from NAC. High glucose concentration increased the production of NO and hydrogen peroxide, which were abolished by co-exposure with NAC. CONCLUSIONS: High glucose concentration increases the production of NO and hydrogen peroxide, which can be abolished by antioxidant in trabecular meshwork cells.

Effect of High Glucose on the Oxidative Stress in Trabecular Meshwork Cells

PURPOSE: To investigate the effect of high glucose (HG) on the oxidative stress in cultured human trabecular meshwork cells (HTMC). METHODS: Primarily cultured HTMC were exposed to low glucose (5 mM) and HG (25 mM) for 7 days. Additionally, 1 mM L-arginine, 5 mM DAHP, 10 microgram/ml insulin, 100 micrometer L-ascorbic acid, 10, and 100 micrometer sepiapterin were co-exposed. The cellular survival and nitric oxide (NO) production were assessed by MTT assay and Griess assay, respectively. Superoxide production was measured by modified cytochrome c assay. RESULTS: HG did not affect the survival of cultured HTMC significantly. HG decreased NO production. Co-exposed DAHP decreased but DAHP and insulin increased NO production. In addition, HG increased superoxide production, which was decreased by insulin, L-ascorbic acid, and sepiapterin. CONCLUSIONS: HG decreased NO production accompanied with increased superoxide production in HTMC. Thus HG induces oxidative stress in HTMC and may cause cellular dysfunction and damage of the trabecular meshwork.