Expression of Human Cu-Zn Superoxide Dismutase Gene in Transgenic Mice: Model for Gene Dosage Effect in Down Syndrome

It was suggested that increased Cu-Zn superoxide dismutase (SOD-I) might be involved in the various biological abnormalities found in Down's syndrome (DS) such as premature aging and Alzheimer-type neurological lesions. As a model system for testing this hypothesis we have developed two strains of transgenic mice carrying only one copy of the human SOD-I gene. In the first strain (TGI). no expression has been found by northern blot analysis. The second strain (TG2) exhibited human SOD-I mRNA and increased SOD-l activity in the brain (1.93 fold), in the heart (I.69 fold), thymus (I.49 fold) and to a lesser extent in muscle (1.25 fold), liver (1.19 fold), kidney (1.18 fold), spleen (1.35 fold), lung (1.26 fold) and erythrocytes (1.09 fold). In this strain, increased SOD-1 activity in the brain did not induce modifications in the seleno-dependent glutathione peroxidase. glutathione reductase and glutathione S-transferase activities. In brain homogenates, we have focused our studies on Tau proteins which are known to be the major antigenic components of paired helical filaments (P11F). both in DS and Alzheimer's disease. Our results suggested that, in our experimental conditions, the overexpression of SOD-I did not induce the modifications of Tau proteins similar to those seen during neurofibrillary degeneration.     

Altered element concentrations in tissues of Dahl salt-sensitive rats

It is recognized that the development of hypertension in Dahl salt-sensitive (DS) rats as compared to Dahl salt-resistant (DR) rats is dependent on the addition of a high percentage of sodium chloride, often 8% to the diet. In this work, blood systolic pressure and the concentrations of many elements in different tissues of DS and DR rats were measured. However, to distinguish the modifications linked to the strain from the modifications owing to excess of sodium intake, no additional Na was included in the diet in all our experiments. Without any addition of sodium chloride to the diet, a statistically significant increase of the systolic blood pressure of DS rats (152±10 mmHg) in comparison to DR rats (131 +/? 3 mmHg) was observed. The analysis of the concentrations of many elements in different tissues showed no major modifications of sodium concentrations in DS rats as compared to DR rats, but a decrease of calcium in plasma (?9%), brain (?20%), and heart (?7%) and of magnesium in plasma (?13%), kidney (?11%), and bone (?7%). In conclusion, an increased intake of Na is not necessary to obtain a higher systolic blood pressure in DS rats compared to DR rats. Since we did not find noticeable modifications of Na concentration in tissues but modifications of Ca and Mg, we suggest that an alteration of the homeostasis of these two elements may be involved in the development of the hypertension in DS rats.     

PINCH in the Cellular Stress Response to Tau-Hyperphosphorylation

Particularly interesting new cysteine- histidine- rich protein (PINCH) is an adaptor protein that our data have shown is required for neurite extension under stressful conditions. Our previous studies also report that PINCH is recalled by neurons showing decreased levels of synaptodendritic signaling proteins such as MAP2 or synaptophysin in the brains of human immunodeficiency virus (HIV) patients. The current study addressed potential role(s) for PINCH in neurodegenerative diseases. Mass spectrometry predicted the interaction of PINCH with Tau and with members of the heat shock response. Our in vitro data confirmed that PINCH binds to hyperphosphorylated (hp) Tau and to E3 ubiquitin ligase, carboxy-terminus of heat shock-70 interacting protein. Silencing PINCH prior to induction of hp-Tau resulted in more efficient clearance of accumulating hp-Tau, suggesting that PINCH may play a role in stabilizing hp-Tau. Accumulation of hp-Tau is implicated in more than 20 neuropathological diseases including Alzheimer''s disease (AD), frontotemporal dementia (FTD), and human immunodeficiency virus encephalitis (HIVE). Analyses of brain tissues from HIVE, AD and FTD patients showed that PINCH is increased and binds to hp-Tau. These studies address a new mechanism by which AD and HIV may intersect and identify PINCH as a contributing factor to the accumulation of hyperphosphorylated Tau.     

Histone deacetylase-6 modulates Tau function in Alzheimer's disease

Alzheimer's disease (AD), one of the major tauopathies, is multifactorial with a massive demand for disease-modifying treatments rather than symptom management. An AD-affected neuron shows Tau depositions generated due to overload on the proteostasis machinery of the cell and/or abnormal post-translational modifications on Tau protein. Loss of memory or dementia is the most significant concern in AD, occurring due to the loss of neurons and the connections between them. In a healthy brain, neurons interact with the environment and each other through extensions and migratory structures. It can thus be safe to assume that Tau depositions affect these growth structures in neurons. A Histone Deacetylase, HDAC6, has shown elevated levels in AD while also demonstrating direct interaction with the Tau protein. HDAC6 interacts with multiple proteins in the cell and is possibly involved in various signalling pathways. Its deacetylase activity has been a point of controversy in AD; however other functional domains remain unexplored. This review highlights the beneficial potential of HDAC6 in AD in mediating both Tau proteostasis and cytoskeletal rewiring for the neuritic extensions through its Ubiquitin Binding domain (HDAC6 ZnF UBP).     

Pin1 in Alzheimer's disease: multiple substrates, one regulatory mechanism?

Presence of neuritic plaques and neurofibrillary tangles in the brain are two neuropathological hallmarks of Alzheimer's disease (AD), although the molecular basis of their coexistence remains elusive. The neurofibrillary tangles are composed of microtubule binding protein Tau, whereas neuritic plaques consist of amyloid-beta peptides derived from amyloid precursor protein (APP). Recently, the peptidyl-prolyl cis/trans isomerase Pin1 has been identified to regulate the function of certain proteins after phosphorylation and to play an important role in cell cycle regulation and cancer development. New data indicate that Pin1 also regulates the function and processing of Tau and APP, respectively, and is important for protecting against age-dependent neurodegeneration. Furthermore, Pin1 is the only gene known so far that, when deleted in mice, can cause both Tau and Abeta-related pathologies in an age-dependent manner, resembling many aspects of human Alzheimer's disease. Moreover, in the human AD brain Pin1 is downregulated or inhibited by oxidative modifications and/or genetic changes. These results suggest that Pin1 deregulation may provide a link between formation of tangles and plaques in AD.     

Increased lipid peroxidation in Down's syndrome mouse models

Elevated oxidative stress has been suggested to be associated with the features of Down's syndrome (DS). We previously reported increased oxidative stress in cultured cells from the embryonic brain of Ts1Cje, a mouse genetic DS model. However, since in vivo evidence for increased oxidative stress is lacking, we here examined lipid peroxidation, a typical marker of oxidative stress, in the brains of Ts1Cje and another DS mouse model Ts2Cje with an overlapping but larger trisomic segment. Accumulations of proteins modified with the lipid peroxidation-derived products, 13-hydroperoxy-9Z,11E-octadecadienoic acid and 4-hydroxy-2-nonenal were markedly increased in Ts1Cje and Ts2Cje brains. Analysis with oxidation-sensitive fluorescent probe also showed that reactive oxygen species themselves were increased in Ts1Cje brain. However, electron spin resonance analysis of microdialysate from the hippocampus of Ts1Cje showed that antioxidant activity remained unaffected, suggesting that the reactive oxygen species production was accelerated in Ts1Cje. Proteomics approaches with mass spectrometry identified the proteins modified with 13-hydroperoxy-9Z,11E-octadecadienoic acid and/or 4-hydroxy-2-nonenal to be involved in either ATP generation, the neuronal cytoskeleton or antioxidant activity. Structural or functional impairments of these proteins by such modifications may contribute to the DS features such as cognitive impairment that are present in the Ts1Cje mouse.     

综述:Tau蛋白过度磷酸化机制及其在阿尔茨海默病神经元变性中的作用

Tau蛋白是神经元中含量最高的微管相关蛋白,其经典生物学功能是促进微管组装和维持微管的稳定性．在阿尔茨海默病(Alzheimer's disease,AD)患者,异常过度磷酸化的Tau蛋白以配对螺旋丝结构形成神经原纤维缠结并在神经元内聚积．大量研究提示,Tau蛋白异常在AD患者神经变性和学习记忆障碍的发生发展中起重要作用．本课题组对Tau蛋白异常磷酸化的机制及其对细胞的影响进行了系列研究,发现Tau蛋白表达和磷酸化具有调节细胞生存命运的新功能,并由此对AD神经细胞变性的本质提出了新见解．本文主要综述作者实验室有关Tau蛋白的部分研究结果．     

Amyloidogenesis of Tau protein

The role of microtubule‐associated protein Tau in neurodegeneration has been extensively investigated since the discovery of Tau amyloid aggregates in the brains of patients with Alzheimer's disease (AD). The process of formation of amyloid fibrils is known as amyloidogenesis and attracts much attention as a potential target in the prevention and treatment of neurodegenerative conditions linked to protein aggregation. Cerebral deposition of amyloid aggregates of Tau is observed not only in AD but also in numerous other tauopathies and prion diseases. Amyloidogenesis of intrinsically unstructured monomers of Tau can be triggered by mutations in the Tau gene, post‐translational modifications, or interactions with polyanionic molecules and aggregation‐prone proteins/peptides. The self‐assembly of amyloid fibrils of Tau shares a number of characteristic features with amyloidogenesis of other proteins involved in neurodegenerative diseases. For example, in vitro experiments have demonstrated that the nucleation phase, which is the rate‐limiting stage of Tau amyloidogenesis, is shortened in the presence of fragmented preformed Tau fibrils acting as aggregation templates (“seeds”). Accordingly, Tau aggregates released by tauopathy‐affected neurons can spread the neurodegenerative process in the brain through a prion‐like mechanism, originally described for the pathogenic form of prion protein. Moreover, Tau has been shown to form amyloid strains—structurally diverse self‐propagating aggregates of potentially various pathological effects, resembling in this respect prion strains. Here, we review the current literature on Tau aggregation and discuss mechanisms of propagation of Tau amyloid in the light of the prion‐like paradigm.     

Oxidative damage increases with age in a canine model of human brain aging

We assayed levels of lipid peroxidation, protein carbonyl formation, glutamine synthetase (GS) activity and both oxidized and reduced glutathione to study the link between oxidative damage, aging and beta-amyloid (Abeta) in the canine brain. The aged canine brain, a model of human brain aging, naturally develops extensive diffuse deposits of human-type Abeta. Abeta was measured in immunostained prefrontal cortex from 19 beagle dogs (4-15 years). Increased malondialdehyde (MDA), which indicates increased lipid peroxidation, was observed in the prefrontal cortex and serum but not in cerebrospinal fluid (CSF). Oxidative damage to proteins (carbonyl formation) also increased in brain. An age-dependent decline in GS activity, an enzyme vulnerable to oxidative damage, and in the level of glutathione (GSH) was observed in the prefrontal cortex. MDA level in serum correlated with MDA accumulation in the prefrontal cortex. Although 11/19 animals exhibited Abeta, the extent of deposition did not correlate with any of the oxidative damage measures, suggesting that each form of neuropathology accumulates in parallel with age. This evidence of widespread oxidative damage and Abeta deposition is further justification for using the canine model for studying human brain aging and neurodegenerative diseases.     

Qualitative and quantitative comparison of brain proteins in Alzheimer's disease

In human brain extracts, most proteins of pathological interest in Alzheimer's disease are insoluble and their analysis is often performed on denatured and reduced samples by immunoblotting after electrophoresis on polyacrylamide gel in presence of sodium dodecyl sulfate. Because we needed to accurately compare the concentration of several proteins in brain extracts to investigate the etiology of the disease, the quantitative aspect of immunoblotting was assessed and the results compared for a soluble component with those obtained by electroimmunoassay. Glial fibrillary acidic protein (GFAP) and Tau proteins were analysed by immunoblotting in brain homogenates treated with the Laemmli sample buffer from 10 control and 25 Alzheimer's disease brains. The linearity of densitometric measures of dilutions for one given sample was demonstrated. A 8 to 16-fold GFAP increase in Alzheimer brain was established. With regard to Tau proteins it was possible to show the presence of two pathological Tau variants (Tau 64 and 69) in all the Alzheimer brain homogenates, furthermore, the amount of Tau 64 and 69 was proportional to the presence of neurofibrillary degeneration. As far as alpha 1-antichymotrypsin is concerned, we showed, in a second set of brain samples (14 control and 12 Alzheimer brains), discrepancies between the results obtained by immunoblotting and by electroimmunoassay while for a given sample linearity of immunoblotting measures of dilutions of this sample was demonstrated. Quantitation by immunoblotting of such components which can be quantified using other procedures is uncertain whereas the interest of immunoblotting is undoubted for the insoluble proteins in the brain extracts.     

The reduction of NADH ubiquinone oxidoreductase 24- and 75-kDa subunits in brains of patients with Down syndrome and Alzheimer's disease

NADH: ubiquinone oxidoreductase (complex I), one of the most complicated multi-protein enzyme complexes, is important for energy metabolism because it is the initial enzyme of the mitochondrial respiratory chain. Deficiency of complex I is frequently found in various tissues of patients with neurodegenerative disease. Here we studied the protein levels of complex I 24- and 75-kDa subunits in several brain regions from patients with Down syndrome (DS) and Alzheimer's disease (AD). We determined protein levels of complex I 24-, 75-kDa subunits and mitochondrial marker proteins mitochondrial matrix protein P1 (hsp60) and aconitate hydratase from seven brain regions of patients with DS, AD and controls. Proteins were separated by two-dimensional (2-D) gel electrophoresis and identified by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Complex I 24-kDa subunit was significantly reduced in occipital cortex and thalamus in patients with DS and temporal and occipital cortices in patients with AD. Complex I 75-kDa subunit was significantly reduced in brain regions from patients with DS (temporal, occipital and caudate nucleus) and AD (parietal cortex). Reductions of two subunits of complex I may lead to the impairment of energy metabolism and result in neuronal cell death (apoptosis), a hallmark of both neurodegenerative disorders.     

Intracellular Clusterin Interacts with Brain Isoforms of the Bridging Integrator 1 and with the Microtubule-Associated Protein Tau in Alzheimer's Disease

Sporadic or late-onset Alzheimer''s disease (AD) is expected to affect 50% of individuals reaching 85 years of age. The most significant genetic risk factor for late-onset AD is the e4 allele of APOE gene encoding apolipoprotein E, a lipid carrier shown to modulate brain amyloid burden. Recent genome-wide association studies have uncovered additional single nucleotide polymorphisms (SNPs) linked to AD susceptibility, including those in the CLU and BIN1 genes encoding for clusterin (CLU) and the bridging integrator 1 (BIN1) proteins, respectively. Because CLU has been implicated in brain amyloid-β (Aβ) clearance in mouse models of amyloid deposition, we sought to investigate whether an AD-linked SNP in the CLU gene altered Aβ42 biomarker levels in the cerebrospinal fluid (CSF). Instead, we found that the CLU rs11136000 SNP modified CSF levels of the microtubule-associated protein Tau in AD patients. We also found that an intracellular form of CLU (iCLU) was upregulated in the brain of Tau overexpressing Tg4510 mice, but not in Tg2576 amyloid mouse model. By overexpressing iCLU and Tau in cell culture systems we discovered that iCLU was a Tau-interacting protein and that iCLU associated with brain-specific isoforms of BIN1, also recently identified as a Tau-binding protein. Through expression analysis of CLU and BIN1 variants, we found that CLU and BIN1 interacted via their coiled-coil motifs. In co-immunoprecipitation studies using human brain tissue, we showed that iCLU and the major BIN1 isoform expressed in neurons were associated with modified Tau species found in AD. Finally, we showed that expression of certain coding CLU variants linked to AD risk led to increased levels of iCLU. Together, our findings suggest that iCLU and BIN1 interaction might impact Tau function in neurons and uncover potential new mechanisms underlying the etiology of Tau pathology in AD.     

Alzheimer's disease: study of the distribution of tau proteins constituting helical filament pairs in human central nervous tissue

Tau proteins are the major components of Paired Helical Filaments (PHF) of Alzheimer's disease. Using the immunoblot technique and an antiserum against PHF, we have studied the distribution of Tau proteins in the different areas of normal human brains and Alzheimer brains. Tau proteins were clearly present in cortical grey matter but were difficult to detect in the white matter. In Alzheimer brains, we observed two differences: first, there is an important background due to the partial dissociation of the lesions containing Tau aggregates. Second, the profile of Tau proteins is modified, due to abnormal phosphorylation. Thus, Tau proteins are found in large amounts in the grey matter of the cortical areas and are not exclusively distributed in the axonal domain. The normal cortical distribution of Tau in the human brain correlates well with the distribution of histological lesions that contain PHF (neurofibrillary tangles and neuritic plaques) in the Alzheimer cortex.     

I1PP2A affects tau phosphorylation via association with the catalytic subunit of protein phosphatase 2A

In Alzheimer disease (AD) brain, the level of I (1)(PP2A), a 249-amino acid long endogenous inhibitor of protein phosphatase 2A (PP2A), is increased, the activity of the phosphatase is decreased, and the microtubule-associated protein Tau is abnormally hyperphosphorylated. However, little is known about the detailed regulatory mechanism by which PP2A activity is inhibited by I (1)(PP2A) and the consequent events in mammalian cells. In this study, we found that both I (1)(PP2A) and its N-terminal half I (1)(PP2A(1-120)), but neither I (1)(PP2A(1-163)) nor I (1)(PP2A(164-249)), inhibited PP2A activity in vitro, suggesting an autoinhibition by amino acid residues 121-163 and its neutralization by the C-terminal region. Furthermore, transfection of NIH3T3 cells produced a dose-dependent inhibition of PP2A activity by I (1)(PP2A)(1). I (PP2A) and PP2A were found to colocalize in PC12 cells. I (1)(PP2A) could only interact with the catalytic subunit of PP2A (PP2Ac) and had no interaction with the regulatory subunits of PP2A (PP2A-A or PP2A-B) using a glutathione S-transferase-pulldown assay. The interaction was further confirmed by coimmunoprecipitation of I (1)(PP2A) and PP2Ac from lysates of transiently transfected NIH3T3 cells. The N-terminal isotype specific region of I (1)(PP2A) was required for its association with PP2Ac as well as PP2A inhibition. In addition, the phosphorylation of Tau was significantly increased in PC12/Tau441 cells transiently transfected with full-length I (1)(PP2A) and with PP2Ac-interacting I (1)(PP2A) deletion mutant 1-120 (I (1)(PP2A)DeltaC2). Double immunofluorescence staining showed that I (1)(PP2A) and I (1)(PP2A)DeltaC2 increased Tau phosphorylation and impaired the microtubule network and neurite outgrowth in PC12 cells treated with nerve growth factor.     

Age-related changes in antioxidant enzymes and lipid peroxidation in brains of control and transgenic mice overexpressing copper-zinc superoxide dismutase.

The aim of our study was first to obtain a comprehensive profile of the brain antioxidant defense potential and peroxidative damage during aging. We investigated copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), seleno-dependent glutathione peroxidase (GSH-PX), glutathione reductase (GSSG-R) activities, endogenous and in vitro stimulated lipid peroxidation in 40 brains of control mice divided into 3 age groups: 2 months (young), 12 months (middle-aged) and 28 months (old). We found a positive correlation between age and activities of CuZnSOD (r = 0.47; P < 0.01) and GSH-PX (r = 0.72; P < 0.0001). CuZnSOD and GSH-PX activities are independently regulated during brain aging since temporal changes of these two enzymes do not correlate. No modification in MnSOD activity and basal lipid peroxidation was observed as a function of age. Nevertheless, stimulated lipid peroxidation was significantly higher at 12 months (6.53 +/- 0.71 mumole MDA/g tissue) than at 2 months (5.69 +/- 0.90) and significantly lower at 28 months (5.13 +/- 0.33) than at 12 months. Second, we used genetic manipulations to construct transgenic mice that specifically overexpress CuZnSOD to understand the role of CuZnSOD in neuronal aging. The human CuZnSOD transgene expression was stable during aging. The increased CuZnSOD activity in the brain (1.9-fold) of transgenic mice resulted in an enhanced rate of basal lipid peroxidation and in increased MnSOD activity in the 3 age groups. Other antioxidant enzymes did not exhibit modifications indicating the independence of the regulation between CuZnSOD and glutathione-related enzymes probably due to their different cellular localization in the brain.     

Modulation of In Vivo Striatal Transmitter Release by Nitric Oxide and Cyclic GMP

Abstract: The effects of nitric oxide (NO) and cyclic GMP on in vivo transmitter release in the rat striatum were investigated using microdialysis sampling in urethane-anaesthetised animals. The NO release-inducing substances S -nitrosoacetylpenicillamine (SNAP), S -nitrosoglutathione (SNOG), and sodium nitroprusside (SNP) increased extracellular concentrations of aspartate (Asp), glutamate (Glu), γ-aminobutyric acid (GABA), taurine (Tau), acetylcholine (ACh), and serotonin (5-HT). Dopamine (DA) concentrations were decreased by SNAP but were increased by SNOG and SNP. An NO scavenger, haemoglobin, blocked or reduced the effects of SNAP on transmitter release. However, the control carrier compounds for SNAP, SNOG, and SNP (penicillamine, glutathione, and potassium ferricyanide, respectively, which do not induce release of NO) also increased GABA, Tau, DA, and 5-HT concentrations. When NO gas was given directly by dissolving it in degassed Ringer's solution, DA concentrations decreased significantly, and those of Asp, Glu, GABA, Tau, ACh, and 5-HT increased. These effects of NO gas were all inhibited by coadministration of haemoglobin and for GABA, Tau, ACh, and DA showed some calcium dependency. The cyclic GMP agonists 8-bromo-cyclic GMP and dibutryl-cyclic GMP stimulated dose-dependent increases in Asp, Glu, GABA, Tau, ACh, DA, and 5-HT concentrations. Increased striatal transmitter release in response to NO may therefore be mediated by its stimulatory action on cyclic GMP formation. NO inhibition of DA release may be mediated indirectly through its stimulation of local cholinergic and GABAergic neurones.     

Regulation of neuronal cytoskeleton by lysophosphatidic acid: role of GSK-3

Neurite retraction is a crucial process during nervous system development and neurodegeneration. This process implies reorganization of the neuronal cytoskeleton. Some bioactive lipids such as lysophosphatidic acid (LPA) induce neurite retraction. The reorganization of the actin cytoskeleton during neurite retraction is one of the best-characterized effects of LPA. However, less information is available regarding the reorganization of the microtubule (MT) network in response to LPA in neuronal cells. Here, we first give an overview of the roles of cytoskeleton during neurite outgrowth, and subsequently, we review some of the data from different laboratories concerning LPA-induced cytoskeletal rearrangement in neuronal cells. We also summarize our own recent results about modifications of MTs during LPA-induced neurite retraction. We have shown that LPA induces changes in tubulin pools and increases in the phosphorylation levels of microtubule-associated proteins (MAPs), such as Tau. Tau hyperphosphorylation in response to LPA is mediated by the activation of glycogen synthase kinase-3 (GSK-3). The upregulation of GSK-3 activity by LPA seems to be a general process as it occurs in diverse neuronal cells of different species in correlation with the neurite retraction process.     

Effect of Antioxidant Diets on Mitochondrial Gene Expression in Rat Brain During Aging

Age-related increase of reactive oxygen species (ROS) is particularly detrimental in postmitotic tissues. Calorie restriction (CR) has been shown to exert beneficial effects, consistent with reduced ROS generation by mitochondria. Many antioxidant compounds also mimic such effects. N-acetyl cysteine (NAC) provides thiol groups to glutathione and to mitochondrial respiratory chain proteins; thus, it may counteract both ROS generation and effects. In the present study we investigated, in different rat brain areas during aging (6, 12, and 28 months), the effect of 1-year treatment with CR and dietary supplementation with NAC on the expression of subunit 39 kDa and ND-1 (mitochondrial respiratory complex I), subunit IV (complex IV), subunit α of F₀F₁-ATP synthase (complex V) and of adenine nucleotide translocator, isoform 1 (ANT-1). The observed age-related changes of expression were prevented by the dietary treatments. The present study provides further evidence for the critical role of mitochondria in the aging process.     

Electro-acupuncture potentiates the disulphide-reducing activities of thioredoxin system by increasing thioredoxin expression in ischemia-reperfused rat brains

Reactive oxygen species can directly affect the conformation and activity of sulfhydryl-containing proteins by oxidation of their thiol moiety. During the process of ischemia-reperfusion, the thioredoxin (Trx) system (consisting of thioredoxin reductase (TR), Trx and NADPH) prevents susceptible proteins from this oxidative modification. Oxidative damage is one of the most damaging stress in ischemia. If oxidative stress could be minimized, the damage occurred will be minimized accordingly. We therefore investigated whether electroacupuncture (EA) treatment at Fengchi (GB20) or Zusanli (ST36) acupoints in post-ischemic rats could increase TR-related activities and Trx expression which would translate into maintaining the intact thiol moiety of susceptible proteins in the surrounding. Our results indicated that EA treatment at either acupoint increased the Trx expression in ischemic-reperfused brain tissues. Induced Trx expressed levels gradually increased from post-ischemia day 1 to day 4. Statistical analysis revealed that there was no observable difference in the effect of EA treatment at GB20 and ST36. Sham EA treatment did not induce any Trx expression. EA at either acupoint did not alter TR activities in both non-ischemic and ischemic-reperfused rat brains. Taken overall, our finding suggests that EA treatment at GB20 or ST36 could increase Trx expression which could minimize oxidative modifications of thiol groups of surrounding proteins.