Oxidative Modification of Peroxiredoxin Is Associated with Drug-induced Apoptotic Signaling in Experimental Models of Parkinson Disease

Young Mook Lee,Seong H Park,Dong-Ik Shin,Jee-Yeon Hwang,Bokyung Park,Yun-Jong Park,Tae H Lee,Ho Z Chae,Byung K Jin,Tae H Oh,Young J Oh

doi:10.1074/jbc.m800426200

Abstract

The aim of this study was to investigate changes in protein profiles during the early phase of dopaminergic neuronal death using two-dimensional gel electrophoresis in conjunction with mass spectrometry. Several protein spots were identified whose expression was significantly altered following treatment of MN9D dopaminergic neuronal cells with 6-hydroxydopamine (6-OHDA). In particular, we detected oxidative modification of thioredoxin-dependent peroxidases (peroxiredoxins; PRX) in treated MN9D cells. Oxidative modification of PRX induced by 6-OHDA was blocked in the presence of N-acetylcysteine, suggesting that reactive oxygen species (ROS) generated by 6-OHDA induce oxidation of PRX. These findings were confirmed in primary cultures of mesencephalic neurons and in rat brain injected stereotaxically. Overexpression of PRX1 in MN9D cells (MN9D/PRX1) exerted neuroprotective effects against death induced by 6-OHDA through scavenging of ROS. Consequently, generation of both superoxide anion and hydrogen peroxide following 6-OHDA treatment was decreased in MN9D/PRX1. Furthermore, overexpression of PRX1 protected cells against 6-OHDA-induced activation of p38 MAPK and subsequent activation of caspase-3. In contrast, 6-OHDA-induced apoptotic death signals were enhanced by RNA interference-targeted reduction of PRX1 in MN9D cells. Taken together, our data suggest that the redox state of PRX may be intimately involved in 6-OHDA-induced dopaminergic neuronal cell death and also provide a molecular mechanism by which PRX1 exerts a protective role in experimental models of Parkinson disease.

Highlights

Gic (DA) neurons in the substantia nigra pars compacta [1]
We have proposed that reactive oxygen species (ROS) are one of the initial triggers leading to activation of apoptotic signaling following 6-OHDA treatment, whereas ROS are not involved in MPPϩ-induced cell death in MN9D cells and primary cultures of mesencephalic neurons [20, 21]
We demonstrated that ROS-mediated activation of p38 mitogen-activated protein kinases (MAPKs) and caspase-3 plays an important role in 6-OHDA-induced cell death in MN9D cells and in primary cultures of dopaminergic; gic (DA) neurons [21]

Summary

Introduction

Gic (DA) neurons in the substantia nigra pars compacta [1]. Clinical manifestations, such as resting tremor, slowness of movement, stiffness, and postural instability in patients with PD are consequences of the loss of DA neurons and the resulting depletion of dopamine in the striatum. We found that expression of 17 protein spots was significantly altered following 6-OHDA treatment (at least 4-fold increase/decrease with a p value of less than 0.05) Among these identified proteins, five spots corresponded to thioredoxin-dependent peroxidases (peroxiredoxins; PRX) that belong to an expanding family of antioxidant enzyme present in a large variety of organisms [22, 23]. From subsequent study using cultured models of PD, we found that (i) PRX proteins were oxidatively modified during 6-OHDA- but not 1-methyl-4-phenylpyridinium (MPPϩ)-induced DA neuronal death; (ii) co-treatment of antioxidant blocked 6-OHDA-induced oxidation of PRX; and (iii) overexpression of PRX1 prevented 6-OHDA-induced activation of p38 MAPK and caspase-3 through scavenging of ROS, whereas knockdown of PRX1 enhanced most of these events. Our data indicate that the redox state of PRX may play an important role in regulating 6-OHDAinduced apoptotic signaling

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