396회 Impaired Synaptic and Memory by Neuron specific Peroxiredoxin II …

396회  

일시: 2006. 11. 02

연사: 이동석, 강원대학교 동물생명과학대학 동물생명공학과

제목: Impaired Synaptic and Memory by Neuron specific Peroxiredoxin II KO.

Abstract

It has been known well that Reactive oxygen species (ROS) generation by oxidative stress is implicated in various pathological conditions of the brain, such as epilepsy, ischemia/reperfusion, metal toxicity , trauma, neurodegenerative diseases including Parkinson’s disease, and Alzheimer’s disease, amyotrophic lateral sclerosis, and immunologic inflammatory disorders such as multiple sclerosis. Oxidative stress can result in damage to the cell through the oxidation of cellular components such as membrane lipids, proteins and DNA. Relationship between Reactive oxygen species (ROS) and synaptic plasticity (long-term potentiation; LTP) as an underline of mammalian learning and memory is concerned by Neurophysiology study. Although these studies were reported about relationship between ROS and LTP, the role of ROS in LTP has been not known well yet.

Peroxiredoxins (Prxs), previously referred to as NKEF (for natural killer enhancing factor) , TSA (for thiol-specific antioxidant) , Tpx (for thioredoxin peroxidase) , and PRP (for protective protein) are a novel family of antioxidant enzymes that have recently been characterized and control cytokine-induced peroxide levels which mediate signal transduction in mammalian cells has also been reported. The Prxs, consisted of six different members in mammalian, are widely distributed in most of tissues, but few informative results were reported in brain tissues.

Recently, in our study, the mapping of the distribution of the all Prx subtype proteins in the mammalian brain by immunohistochemistry study results may be indicative of the specific roles in their preferential neural cell types (Neuroscience letters (2005) Vol.381 pp252-257). In particular, Prx II immunoreactivity was mainly found in neurons such as hippocampus, cerebral cortex, etc. This indicates that Prx II may be associated with a regulatory role in signal transduction in specific neurons in addition to antioxidant activity. To determine the role of Prx2 in the brain, in this study, we investigated the functions of Prx2 about memory and learning using Prx II KO mice. We examined the ability of learning and memory in the PrxII KO mice. First, we performed recordings of long-term potentiation (LTP) on CA1 of the mice hippocampal slices for the ability of learning and memory in the PrxII KO mice. Maximal population spike amplitude was significantly different in old mice (from 6 months old ) between wild type and PrxII KO mice. And then, in the Morris water maze as spatial learning test, 12 months old PrxII KO mice showed significantly decrease compare to wild type mice. These results lead us to the possibility that Prx II is related to loss of LTP, learning and memory by aging.