All issues > Volume 42(5); 1999

Original Article

J Korean Pediatr Soc. 1999;42(5):686-696. Published online May 15, 1999.

Effects of Thioredoxin on Oxidative Neuronal Cell Injury

Hyunmi Hm Kim¹, Gyoung Hee GH Kim², Yoon Song YS Lee³

¹Department of Pediatrics, Ulsan University, College of Medicine, Ulsan, Korea
²Department of Pediatrics, Ewha Womans University, College of Medicine, Seoul, Korea
³Department of Pharmacology†, Sungkunkwan University, College of Medicine, Seoul, Korea

Correspondence Hyunmi Hm Kim ,Email: 1

Abstract

Purpose
: Thioredoxin is an endogenous antioxidant which directly scavenges reactive oxygen species(ROS) and regenerates oxidatively damaged protein by reducing potential at the redox active disulfide(-Cys-Gly-Pro-Cys-) site. Under oxidative stress, thiredoxin plays a protective and adaptative role by inducing expressions. The aim of this study was to clarify the role of thioredoxin on oxidative neuronal cell injury. We investigated the protective effects of E. coli thioredoxin, also acting as a substrate for mammalian thioredoxin reductase, against oxidative neuronal cell injury under oxidative stresses such as hydrogen peroxide and diamide.
Methods
: PC 12 cells were cultured in RPMI 1640 media containing 10% fetal calf serum and subcultured in 96-well plates. Each well contained 30,000 cells. Cells were treated with hydrogen peroxide or diamide 30 minutes after thioredoxin treatment and then incubated for 24 hours. Cytotoxicity and cellular viability were assessed by measuring of lactate dehydrogenase(LDH) release and MTT reduction.
Results
: Thioredoxin not only decreased the cytotoxicity of PC 12 cell treated with hydrogen peroxide by decreasing LDH release and preventing the decrease of MTT reduction but also thioredoxin showed greater protective effects when simultaneously treated with hydrogen peroxide. Also, thioredoxin decreased cytotoxicity by decreasing LDH release from PC 12 cells damaged by diamide. Thioredoxin did not prevent the decrease of MTT reduction on PC 12 cells damaged by diamide.
Conclusion
: Thioredoxin protected PC 12 cells under oxidative stresses by directly scavenging and inhibiting oxidants such as hydrogen peroxide and diamide.

Keywords :Thioredoxin, Oxidative stress, Hydrogen peroxide, Diamide