GFAP and Hyperglycemia: However, macroglia stimulated by hyperglycemia increases ROS production and amplifies AGEs formation and becomes dysfunctional due to increase glial fibrillary acidic protein (GFAP) expression, NO production, and glutamate synthesis (as a function of glutamate transporter disruption), and in consequence Müller cells contribute indirectly with retinal neurons excitotoxicity to the diabetic retina [166].