title: Early changes in system [Formula: see text] and glutathione in the retina of diabetic rats.
abstract: Diabetic retinopathy (DR), the main cause of blindness among diabetic patients, affects both neuronal and vascular cells of the retina. Studies show that neuronal cell death begins after 4 weeks of diabetes and could be related with an increase in oxidative stress. System [Formula: see text] is a glutamate/cystine exchanger, formed by a catalytic subunit called xCT and a regulatory subunit 4F2hc, whose activity is crucial to the synthesis of glutathione, which is a key antioxidant molecule for cells. Although some studies have shown that glutamate transport mediated by excitatory amino acid transporters (EAATs) in diabetic rats is downregulated, there are no studies investigating system [Formula: see text] in this context. To evaluate whether system [Formula: see text] is modified by early onset of diabetes, primary retinal cell culture exposed to high glucose and retinas of rats 3 weeks after streptozotocin injection were used. We observed that xCT subunit protein expression both in cultures and in vivo were diminished. Furthermore, system [Formula: see text] activity and GSH levels were also decreased whereas oxidative stress was increased in retinas of diabetic animals. Therefore, this study raises the possibility that alterations in system [Formula: see text] expression and activity could occur during early onset of diabetes. In that way, system [Formula: see text] modifications could be related to increased ROS in diabetic retinopathy.
authors.affiliation: Department of Neurobiology, Neuroscience Program, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Raul
authors.initials: R
authors.lastname: Carpi-Santos
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Marcos José
authors.initials: MJ
authors.lastname: Ferreira
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Annibal Duarte
authors.initials: AD
authors.lastname: Pereira Netto
authors.affiliation: Department of Neurobiology, Neuroscience Program, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Giestal-de-Araujo
authors.affiliation: Department of Neurobiology, Neuroscience Program, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Ana Lucia Marques
authors.initials: ALM
authors.lastname: Ventura
authors.affiliation: Department of Physiology and Pharmacology, Neuroscience Program, Biomedical Institute, Fluminense Federal University, Niterói, RJ, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cossenza
authors.affiliation: Department of Neurobiology, Neuroscience Program, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil. Electronic address: karincalaza@gmail.com.
authors.forename: Karin C
authors.initials: KC
authors.lastname: Calaza
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D016923:Cell Death; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology; D003930:Diabetic Retinopathy / Q000378:metabolism* / Q000473:pathology; D018698:Glutamic Acid / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D018384:Oxidative Stress; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors
chemical_list: D017382:Reactive Oxygen Species; D018698:Glutamic Acid; D005978:Glutathione
keywords: Cysteine; Cystine; Diabetes; Hyperglycemia; Reactive oxygen species (ROS)