Hypothermia Inhibits Endothelium-Independent Vascular Contractility via Rho-kinase Inhibition

The present study was undertaken to investigate the influence of hypothermia on endothelium-independent vascular smooth muscle contractility and to determine the mechanism underlying the relaxation. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Hypothermia significantly inhibited fluoride-, thromboxane A2-, phenylephrine-, and phorbol ester-induced vascular contractions regardless of endothelial nitric oxide synthesis, suggesting that another pathway had a direct effect on vascular smooth muscle. Hypothermia significantly inhibited the fluoride-induced increase in pMYPT1 level and phorbol ester-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxing effect of moderate hypothermia on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activities.

US28, a Virally-Encoded GPCR as an Antiviral Target for Human Cytomegalovirus Infection

Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.

Extremely Low Frequency Magnetic Field Modulates the Level of Neurotransmitters

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and gamma -aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.

Growth Hormone-Releaser Diet Attenuates Cognitive Dysfunction in Klotho Mutant Mice via Insulin-Like Growth Factor-1 Receptor Activation in a Genetic Aging Model

BACKGROUND: It has been recognized that a defect in klotho gene expression accelerates the degeneration of multiple age-sensitive traits. Accumulating evidence indicates that aging is associated with declines in cognitive function and the activity of growth hormone (GH)/insulin-like growth factor-1 (IGF-1). METHODS: In this study, we examined whether a GH-releaser diet could be effective in protecting against cognitive impairment in klotho mutant mice. RESULTS: The GH-releaser diet significantly induced the expression of IGF-1 and IGF-1 receptors in the hippocampus of klotho mutant mice. Klotho mutant mice showed significant memory impairments as compared with wild-type mice. In addition, the klotho mutation significantly decreased the expression of cell survival/antiapoptotic factors, including phospho-Akt (p-Akt)/phospho-glycogen synthase kinase3beta (p-GSK3beta), phospho-extracellular signal-related kinase (p-ERK), and Bcl-2, but significantly increased those of cell death/proapoptotic factors, such as phospho-c-jun N-terminal kinase (p-JNK), Bax, and cleaved caspase-3 in the hippocampus. Treatment with GH-releaser diet significantly attenuated both decreases in the expression of cell survival/antiapoptotic factors and increases in the expression of cell death/proapoptotic factors in the hippocampus of klotho mutant mice. In addition, klotho mutation-induced oxidative stress was significantly attenuated by the GH-releaser diet. Consequently, a GH-releaser diet significantly improved memory function in the klotho mutant mice. GH-releaser diet-mediated actions were significantly reversed by JB-1, an IGF-1 receptor antagonist. CONCLUSION: The results suggest that a GH-releaser diet attenuates oxidative stress, proapoptotic changes and consequent dysfunction in klotho mutant mice by promoting IGF-1 expression and IGF-1 receptor activation.

Protective Effect of Phosphatidylcholine on Lipopolysaccharide-Induced Acute Inflammation in Multiple Organ Injury

Soybean polyunsaturated phosphatidylcholine (PC) is thought to exert anti-inflammatory activities and has potent effects in attenuating acute renal failure and liver dysfunction. The aim of this study was to investigate the effects of PC in protecting multiple organ injury (MOI) from lipopolysaccharide (LPS). Six groups of rats (N=8) were used in this study. Three groups acted as controls and received only saline, hydrocortisone (HC, 6 mg/kg, i.v.) or PC (600 mg/kg, i.p.) without LPS (15 mg/kg, i.p.) injections. Other 3 groups, as the test groups, were administered saline, HC or PC in the presence of LPS. Six hours after the LPS injection, blood and organs (lung, liver and kidney) were collected from each group to measure inflammatory cytokines and perform histopathology and myeloperoxidase (MPO) assessment. Serum cytokines (TNF-alpha, IL-6 and IL-10) and MPO activities were significantly increased, and significant histopathological changes in the organs were observed by LPS challenge. These findings were significantly attenuated by PC or HC. The treatment with PC or HC resulted in a significant attenuation on the increase in serum levels of TNF-alpha and IL-6, pro-inflammatory cytokines, while neither PC nor HC significantly attenuated serum levels of IL-10, anti-inflammatory cytokine. In the organs, the enhanced infiltration of neutrophils and expression of ED2 positive macrophage were attenuated by PC or HC. Inductions of MPO activity were also significantly attenuated by PC or HC. From the findings, we suggest that PC may be a functional material for its use as an anti-inflammatory agent.

HLA-DRB1 Study of DNA from Ancient Human Skeleton by Sequence-based Typing / 체질인류학회지

The analysis of ancient human DNA is increasingly used recently in the study of anthropology and human evolution. Although mitochondrial DNA and Y chromosomal DNA has commonly been the target in the field of human DNA study, HLA analysis of ancient human DNA is extremely rare. This study aimed to develop the PCR method of ancient human DNA for analyzing the sequence of HLA. Authors established a new method for HLA-DRB1 analysis by sequence-based typing. Alleles of HLA-DRB1 were analyzed and typed by sequencing with DNA of ancient human skeletons from Korea and Mongolia 3000-500 years ago. The types of HLA-DRB1 were determined by comparing the sequences with those of HLA database (http://www. ebi.ac.uk/Tools/blast2/nucleotide.html). The alleles of HLA-DRB1 of ancient human DNA from Korea and Mongolia were classified by types. The frequencies of HLA-DRB1 types of Mongolia were also presented according to the geography such as West, Central, East, and North. In summary, our method was successful in the analyzing the type of HLA-DRB1 from DNA of ancient human bones. Authors anticipate that many researchers could do their research in a better way to get the genetic information for the kinship analysis between individuals or communities from ancient human bones.

Immunohistochemical study on the expression of calcium binding proteins (calbindin-D28k, calretinin, and parvalbumin) in the cerebellum of the nNOS knock-out(-/-) mice / 대한해부학회지

Nitric Oxide (NO) actively participates in the regulation of neuronal intracellular Ca2+ levels by modulating the activity of various channels and receptors. To test the possibility that modulation of Ca2+ buffer protein expression level by NO participates in this regulatory effect, we examined expression of calbindin-D28k, calretinin, and parvalbumin in the cerebellum of neuronal NO synthase knock-out (nNOS(-/-)) mice using immunohistochemistry. We observed that in the cerebellar cortex of the nNOS(-/-) mice, expression of calbindin-D28k and parvalbumin were significantly increased while expression of calretinin was significantly decreased. These results suggest another mechanism by which NO can participate in the regulation of Ca2+ homeostasis.

A Kinship Analysis of Ancient Human Bones and Teeth from Mongolia / 체질인류학회지

The kinship was analyzed genetically on the three 2000 year old ancient human bones and teeth excavated in Mongolia. The samples were processed in a clean room to prevent the contamination from modern human DNA. The DNA extraction and purification was done with ion-exchange column kit (Qiagen G-tip 20G, USA). The PCR was done with purified DNAs from ancient human bones for paternal Y-SNP haplogroup, maternal mtDNA haplogroup, and autosomal short tandem repeats (STR). Two samples belonged to the maternal D major haplogroup, which is one of the most frequent types in the present North East Asia. One of them, showing male genotype, belonged to the paternal C major haplogroup, which is also one of the most frequent types in the present North East Asia. The remaining one belonged to the paternal R major haplogroup, frequent in the present Europe, and the maternal U haplogroup, frequent in the present Europe and East Mediterranean. The repeated results were consistent in the autosomal STR PCR. The STR data were analyzed with DNA-VIEW program (http://www.dna-view.com), which showed no close kinship among the three ancient humans. Our method was successful in the analyzing kinship among ancient human bones, which has been possible in few restricted laboratories in the World. Authors anticipate that many researchers could do their research in a better way to get the genetic information from ancient human bones.

Protective Effect of HSP90 on Neuronal Cell Death-induced by beta-Amyloid Peptide / 체질인류학회지

In the present study, we determined the protective mechanism of HSP90 against neuronal cell death induced by Abeta. For the evaluation of protective role of HSP90, we used human neuroblastoma SK-N-SH cell lines, examined AlamarBlue assay, Western blot analysis and immunofluorescence assay. Incubation of SK-N-SH cells with Abeta significantly induced neuronal cell death. However, HSP90 induced by mild heat shock could attenuate neuronal apoptosis in Abeta treated condition. To identify the role of HSP90, we determined localization of HSP90 in SK-N-SH cells. Interestingly, HSP90 was increased and localized in mitochondria as treatment of mild heat shock. Also, treatment or increase of HSP90 largely elevated level of Bcl-2 expression, whereas inhibition of HSP90 with HSP90 antisense oligonucleotide significantly decreased Bcl-2 expression. In contrast to Bcl-2, Bax expression was regulated independently by HSP90. Moreover, increase of HSP90 could attenuate collapse of mitochondrial membrane potential induced by Abeta. However, HSP90 antisense oligonucleotide largely increase breakdown of mitochondrial membrane potential induced by Abeta. These data suggest that HSP90 as chaperone protein significantly attenuates neuronal damage and protects neuroanl cells from neurotoxin such as Abeta.

Immunohistochemical Study on the Distribution of Canonical Transient Receptor Potential Channels in Rat Cerebellum / 체질인류학회지

Channels formed by the transient receptor potential (TRP) family of proteins have a variety of physiological functions. In the present study, we examined the localization of canonical transient receptor potential channels (TRPCs) in rat cerebellum. Twelve adult (4~6 month old) Sprague-Dawley rats were examined in this study. We performed immunohistochemistry using specific antibodies against TRPCs to investigate the detailed and comparative distribution of six TRPCs in rat cerebellum. There was a high density of TRPC1, TRPC3, TRPC4, TRPC5 and TRPC7, with a much lower density of TRPC6 in the rat cerebellar cortex. The somatodendritic Purkinje cell areas were intensely stained with antiTRPC3, TRPC4, TRPC5 or TRPC7 antibodies, whereas the staining intensity of TRPC6 was relatively low in the Purkinje cell bodies. In the cerebellar nuclei, the cell bodies of cerebellar output neurons showed moderate TRPC1, TRPC3, TRPC5 and TRPC7 immunoreactivities, while TRPC6 immunoreactivity was observed in the surrounding neuropil. This study showing the differential localizations of TRPC channels in the cerebellum may provide useful data for the future investigations on the structural and functional properties of TRPCs.

Immunohistochemical Study on the Distribution of Insulin-like Growth Factor Binding Protein 7 (IGFBP7) in the Central Nervous System of Adult Rats / 체질인류학회지

In the present study, we performed immunohistochemical studies to investigate the detailed distribution of insulin-like growth factor binding protein 7 (IGFBP7) in the central nervous system of adult rats. Twelve adult (4~6 month old) Sprague-Dawley rats were examined in this study. Immunohistochemistry using specific antibodies against IGFBP7 was performed in accordance with the free-floating method. In the present study, IGFBP7 immunoreactivity was observed in the cerebral cortex, hippocampus, brainstem, cerebellum and spinal cord. In the cerebral cortex, heavily stained neurons were seen in layers II-VI. In the hippocampus, pyramidal cells in CA1-3 region were strongly immunoreactive for IGFBP7. Strong immunoreactive neurons were also found in the supraoptic nucleus, paraventricular nucleus, periaqueductal gray and oculomotor nucleus. In the cerebellum, IGFBP7 immunoreactivity was prominent in the Purkinje cells and cerebellar output neurons. IGFBP7-immunoreactive neurons were prominent in the superior vestibular nucleus, cochlear nucleus, trigeminal motor nucleus, nucleus of the trapezoid, and facial nucleus. IGFBP7-immunoreactive neurons were also observed mainly in the anterior horn of the spinal cord. The first demonstration of IGFBP7 localization in the whole brain may provide useful data for the future investigations on the structural and functional properties of IGFBP7.

Immunohistochemical Study on the Distribution of Kv1.2 in Aged Rat Brain / 체질인류학회지

In the present study, we demonstrated age-related changes in Kv1.2 immunoreactivity in the rat brain for the first time. Twelve adult (4~6 month old) and 15 aged (20~29 month old) Sprague-Dawley rats were examined in this study. Immunohistochemistry was performed in accordance with the free-floating method, and densitometric measurement using a NIH image program (Scion Image) determined the staining density. In the cerebral cortex of aged rats, there was a significant increase in the number of Kv1.2-immunoreactive neurons in the cingulate cortex, infralimbic cortex and piriform cortex, compare to adult rats. In the hippocampal CA1-3 regions, moderate Kv1.2 immunoreactivity was found in the cell bodies and processes of some medium to large-sized neurons in aged rats. The intensity was increased in the cell bodies of Kv1.2-positive neurons in the amygdala of aged rats, whereas the number of immunoreactive neurons was not significantly increased. It was noteworthy that age-related changes in Kv1.2-immunoreactive neurons were prominent in the facial nuclei, raphe magnus nuclei, and pontine and medullary reticular formation. Although the present study has not addressed multiple mechanisms contributing to neuronal degeneration during aging, the first demonstration of age-related changes in Kv1.2 immnuoreactivity may offer a comprehensive understanding of the pathophysiology of aging and age-related neurodegenerative diseases such as Alzheimer's disease.

Differential Expression of Neuronal Death-related Factors in Aged Rat Cerebellum / 체질인류학회지

In the present study, we investigated the expression of apoptosis-associated proteins in the cerebellum of aged rats: IGF-I receptor (IGF-IR), nitrotyrosine (NT), p53, key pro-apoptotic gene ICH-1 (caspase-2), c-Fos and Bcl-2 family members (Bcl-2 and Bax). Twelve adult (4~6 month old) and 15 aged (24~29 month old) Sprague-Dawley rats were examined in this study. We performed immunohistochemical staining, in situ hybridization and densitometric measurement using a NIH image program (Scion Image) to determine the staining density. In adult rats, there were no immunoreactivities for insulin-like growth factor-I receptor (IGF-IR), nitrotyrosine (NT) or p53 in any region of cerebellum. However, IGF-IR immunoreactivity was found in some Purkinje cells in aged rat cerebellum. The prominent staining of NT or p53 was also localized in the Purkinje cell layer in aged rats. A high density of ICH-1 (caspase-2) immunoreactivity was observed in the molecular and Purkinje cell layers in aged rats. Immunoreactivity for c-Fos was significantly decreased in the granule cells in aged rats. Positive signal for bcl-2 was significantly decreased in the Purkinje cells and granule cells of aged rats. The most intense staining for Bax was observed in the soma of Purkinje cells of adult rats. However, Bax immunoreactivity was not changed in any layers in the cerebellar cortex of aged rats. In conclusion, this study provides the first morphological data concerning the differential regulation of apoptosisrelated genes in rat cerebellum during aging.

Reactive Astrocytes Expressing Intense Estrogen Receptor-alpha Immunoreactivities Have Much Elongated Cytoplasmic Processes: An Autopsy Case of Human Cerebellar Tissue with Multiple Genitourinary and Gastrointestinal Anomalies

We performed an immunohistochemical study on the estrogen receptor alpha (ER-alpha) distribution in the cerebellum of a human neonate with multiple congenital anomalies, that had been acquired during autopsy. Although the exact pathology in the brain was not clearly elucidated in this study, an unidentified stressful condition might have induced the astrocytes into reactive states. In this immunohistochemical study on the neonatal cerebellum with multiple congenital anomalies, intense ER-alpha immunoreactivities (IRs) were localized mainly within the white matter even though ER-alpha IRs were known to be mainly localized in neurons. Double immunohistochemical staining showed that ER-alpha IR cells were reactive astrocytes, but not neurons. Interestingly, there were differences in the process length among the reactive astrocytes showing ER-alpha IRs. Our quantitative data confirmed that among the glial fibrillary acidic protein (GFAP)-expressing reactive astrocytes, the cells exhibiting intense ER-alpha IRs have much longer cytoplasmic processes and relatively weaker GFAP IRs. Taken together, the elongated processes of reactive astrocytes might be due to decreased expression of GFAP, which might be induced by elevated expression of ER-alpha even though the elucidation of the exact mechanism needs further studies.

Changes of Tight Junction and Epithelial Cells after Treatment of Cadmium / 체질인류학회지

Cadmium (Cd) affects cell proliferation, differentiation, apoptosis and other cellular activities and can cause numerous molecular lesions that would be relevant to carcinogenesis. The mechanism of adverse effects of Cd has been poorly understood and, especially on the tight junction. Since there is rare information about the effect of Cd on tight junction protein, we here investigated whether Cd can alter the localization of the proteins. This study examined Cd effects on of tight junction (occludin, ZO-1, and ZO-2) using MDCK cell culture. The change of MDCK cell and tight junction was investigated after treatment of cadmium with phase contrast microscopy, TEER, cell viability, Transmission electron microscopy and confocal laser microscopy. After treatment of cadmium, transendothelial electrical resistance decreased with time and concentration dependent manner. AlamarBlue assay revealed that decreased cell viability also decreased with time and concentration dependent manner. The tight junction moved down between intercellular spaces with decreased density and the cellular thickness around cell junctions decreased with increasing concentration and exposure time of CdCl2. The MDCK cells eventually showed cell death with. Confocal laser microscopy revealed that immunofluorescent reaction of occludin, ZO-1 and ZO-2 decreased. Occludin, ZO-1 and ZO-2 were disrupted at tight junction. These data suggest that after treatment of Cd, increased permeability of MDCK cell monolayer increased. This might be accompanied with disruption of occludin, ZO-1 and ZO-2.

Immunohistochemical Study on the Distribution of Glycogen Synthase Kinase (GSK) 3beta in the Central Nervous System of SOD1G93A Transgenic Mice / 체질인류학회지

In the present study, we investigated influences of glycogen synthase kinase (GSK) 3beta on the development and/or progression of amyotrophic lateral sclerosis (ALS). We used transgenic mice expressing a human Cu/Zn superoxide dismutase mutant (SOD1G93A) as an in vivo model of ALS and examined expressional changes of GSK3beta immunohistochemically in the spinal cord, brain stem and cerebellum. With these experiments we demonstrate that the neurons in these regions of symptomatic SOD1G93A transgenic mice showed increased GSK3beta immunoreactivities compared with wild-type SOD1 transgenic mice. In contrast to symptomatic SOD1G93A transgenic mice, few GSK3beta immunoreactivity changes were detected in 8w- and 13w-old presymptomatic SOD1G93A transgenic mice. These data suggest the possibility that GSK3 functions as a modulating factor of apoptosis-related alterations in ALS and that GSK3beta exert differential functions in the development and/or progression of ALS. But the exact functional significances of these changes require further elucidation.

Alpha-tocopherol Prevents H2O2-induced Tight Junction Occludin Disruption in Blood-Brain Barrier / 체질인류학회지

Vitamin E is the most important lipid-soluble antioxidant in humans. Although alpha-tocopherol is suggested that it has protective effect from many diseases, little is known about the prevention of occludin alteration in tight junction of blood-brain barrier (BBB) under pathologic insults producing reactive oxygen species (ROSs). In this study, the effects of alpha-tocopherol on H2O2-induced tight junction occludin were studied. Primary culture of rat brain microvessel endothelial cells was investigated with confocal microscopy, Western blot, and cell viability assay. Alpha-tocopherol had no apparent cytotoxicity up to 2.8 mM. The preincubation with alpha-tocopherol suppressed the H2O2-induced cytotoxicity in Alamar Blue assay and phase contrast microscopy. In confocal laser microscopy and Western blot, H2O2-induced loss of occludin was suppressed by preincubation with alpha-tocopherol. The present findings provide evidence that alpha-tocopherol may be beneficial for cellular protection from pathologic insults. Since alpha-tocopherol was demonstrated to have far fewer adverse effects, it would become a noteworthy nutrient or drug for the treatment of neurodegenerative diseases.

Caveolin-1 upregulation in senescent neurons alters amyloid precursor protein processing

Lipid rafts provide a platform for regulating cellular functions and participate in the pathogenesis of several diseases. However, the role of caveolin-1 in this process has not been elucidated definitely in neuron. Thus, this study was performed to examine whether caveolin-1 can regulate amyloid precursor protein (APP) processing in neuronal cells and to identify the molecular mechanisms involved in this regulation. Caveolin-1 is up-regulated in all parts of old rat brain, namely hippocampus, cerebral cortex and in elderly human cerebral cortex. Moreover, detergent-insoluble glycolipid (DIG) fractions indicated that caveolin-1 was co-localized with APP in caveolae-like structures. In DIG fractions, bAPP secretion was up-regulated by caveolin-1 over-expression, which was modulated via protein kinase C (PKC) in neuroblastoma cells. From these results we conclude that caveolin-1 is selectively expressed in senescent neurons and that it induces the processing of APP by beta-secretase via PKC downregulation.

Study on the Mitochondrial Dysfunction by p53 Regulation in Ceramide-induced Neuronal Cell Death / 체질인류학회지

Ceramide induces cell death in a dose- and time-dependent manner in neuroblastoma SK-N-SH cells. To investigate the mechanism of SK-N-SH cell death by C2-ceramide, morphological features and Hoechst 33258 staining were analyzed. In these morphlogic study the cell death by ceramide showed typical apoptotic features, nuclear condensation, fragmentation, and membrane blebbing. Ceramide-induced apoptosis was accompanied by nuclear accumulation of p53. Inhibition of p53 expression with p53 antisense oligonucleotides inhibited apoptosis evoked by ceramide. Also, ceramide induced mitochondrial event, collapse of mitochondrial membrane potential (delta psi m) and interestingly, inhibition of p53 attenuated collapse of mitochondrial membrane potential, suggests that ceramide induces mitochondrial dysfunction through upregulation of p53 expression. These results suggest that ceramide-induced apoptosis is dependent upon increase in cellular p53 levels which play a critical role in the regulation of apoptotic cell death and p53 modulates mitochondrial function such as mitochondrial membrane potential level.

Protective Effect of Green Tea Extract on Neuronal Cell Death in Alzheimer Model using beta-amyloid Peptide / 대한해부학회지

In the present study, we determined whether green tea extract, EGCG protected against beta-amyloid induced neurotoxicity and learning impairment in vitro and in vivo models. Incubation of SK-N-SH cells with Abeta induced activation of caspase-3, mitochondrial dysfunction such as collapse of mitochondrial membrane potential (MMP) and release of cytosolic cytochrome c. Interestingly, pre-treatment of EGCG reduced significantly activation of caspase-3 and increase of mitochondrial damage such as the breakdown of MMP and release of cytochrome c, eventually attenuated the cell death induced by Abeta. These results show that EGCG inhibited caspase activity and blocked mitochondrial damage. For in vivo experiment, ICR mice received vehicle or vehicle plus EGCG (10 mg/kg) i.p. for 3 days. Before 2 days of treatment, 5 microliter of PBS containing 8 nmol of Abeta1-42 were injected into the lateral ventricle. On the 14th day of treatment, animals were applied to passive avoidance test, and after behavial test, animals were sacrificed. Then, morphological techniques were used to determine the extent of neuronal degeneration in the hippocampus. Abeta, but not PBS, injections into hippocampus led to neuronal loss and evidence of widespread apoptosis. EGCG treated animals had significant reductions in the amount of neuronal degeneration, and TUNEL positive cells compared with Abeta alone treated animals. These data suggest that EGCG at therapeutically relevant concentrations, might protect against neuronal degeneration induced by Abeta.