• Title/Summary/Keyword: Rat Brain

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Large Scale Gene Expression Analysis in Rat Models of 4-Vessel Occlusion Ischemia (4-Vessel Occlusion 허혈동물모델에서의 대규모 유전자 발현 연구)

  • Kang, Bong-Joo;Hong, Seong-Gil;Kim, Yun-Taik;Kim, Young-Ok;Cho, Dong-Wuk
    • Korean Journal of Oriental Medicine
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    • v.6 no.1
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    • pp.89-98
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    • 2000
  • Cerebral ischemia, the most prevalent form of clinical stroke, is a medical problem of the first magnitude. Substantial efforts are being made to develop drugs which will protect the brain from the neurodegeneration followed by an ischemic stroke. A key factor in this process is the development of animal models that mimic the neuropathological consequences of stroke. Recently, there is increasing an evidence that free radical is involved in the mechanisms of ischemic brain damage. We investigated the macro scale gene expression analysis on the global ischemia induced by 4-vessel occlusion in Wister rats. The recent availability of microarrays provides an attractive strategy for elaborating an unbiased molecular profile of large number of genes during ischemic injury. This experimental approach offers the potential to identify molecules or cellular pathways not previously associated with ischemia. Ischemia was induced by 4-vessel occlusion for 10 minutes and reperfused again. RNA from sham control brain and time-dependent ischemed brain were hybridized to microarrays containing 4,000 rat genes. 589 genes were found to be at least 2 fold regulated at one or more time points. These survey data provide the foundation studies that should provide convincing proof for ischemia and oxidative stress on gene expression.

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Neuroprotective Effects of Ginkgo biloba extract, GBB, in the Transient Ischemic Rat Model

  • Oh, Jin-Kyung;Jung, Ji-Wook;Oh, Hye-Rim;Han, Yong-Nam;Ryu, Jong-Hoon
    • Biomolecules & Therapeutics
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    • v.15 no.3
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    • pp.169-174
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    • 2007
  • In the present study, we investigated the neuroprotective effects of standardized Ginkgo biloba extract (GBB) (total terpene trilactones, 13 ${\pm}$ 3%; biflavone, 4.5 ${\pm}$ 1.5%; flavonol glycoside, < 8%; proanthocyanidine, under detection limit) on ischemia-reperfusion-induced brain injury in the rats. Ischemia was induced by the intraluminal occlusion of the right middle cerebral artery for 2 h and reperfusion was continued for 22 h. GBB was orally administered, promptly prior to reperfusion and 2 h after. Total infarction volume in the ipsilateral hemispheres of ischemia-reperfusion rats were significantly reduced by treatment with GBB in a dose-dependent manner (P<0.05). The therapeutic time window of GBB was 3 h in this ischemia-reperfusion rat model. Furthermore, GBB also significantly inhibited increased neutrophil infiltration of ischemic brain tissue, as estimated by myeloperoxidase activity. These findings suggest that GBB plays a crucial protective role in ischemia-induced brain injury, in part, via inhibition of neutrophil infiltration, and suggest that this GBB could serve as a neuroprotective agent following transient focal ischemic brain injury.

Attenuation of Brain Injury by Water Extract of Goat's-beard (Aruncus dioicus) and Its Ethyl Acetate Fraction in a Rat Model of Ischemia-Reperfusion

  • Han, Hyung-Soo;Lee, Jong-Won
    • Preventive Nutrition and Food Science
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    • v.16 no.3
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    • pp.217-223
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    • 2011
  • Ischemic stroke constitutes about 80% of all stroke incidences. It is characterized by brain cell death in a region where cerebral arteries supplying blood are occluded. Under these ischemic conditions, apoptosis is responsible for the cell death, at least in part. Goat's-beard (Aruncus dioicus var. kamtschaticus) is a perennial plant that grows naturally in the alpine regions of Korea. In the present study, we first determined whether water extract of goat's-beard (HY1646) and some of its fractions prepared by partitioning with organic solvents could improve the viability of human hepatocellular carcinoma cells (HepG2) cultured under hypoxic condition by blocking apoptotic pathways. Based on the in vitro findings, we subsequently investigated whether HY1646 and the ethyl acetate fraction (EA) selected from cell culture-based screening could attenuate brain injury in a rat middle cerebral artery occlusion (MCAO) model of ischemia (2 hr), followed by 22 hours of reperfusion. The cell number was sustained close to that initially plated in the presence of HY1646 even after 24 hr of cell culture under hypoxic condition (3% $O_2$), at which time the cell number reached almost zero in the absence of HY1646. This improvement in cell viability was attributed to the delay in apoptosis, identified by the formation of DNA ladder in gel electrophoresis. Of fractions soluble in hexane, ethyl acetate (EA) and butanol, EA was chosen for the animal experiments because EA demonstrated the best cell viability at the lowest concentration (10 ${\mu}g$/mL). HY1646 (200 mg/kg) and EA (10 and 20 mg/kg) significantly reduced infarct size, an index of brain injury, by 16.6, 40.0 and 61.0%, respectively, as assessed by 2,3,5-triphenyl tetrazolium chloride staining. The findings suggest that prophylactic intake of goat's beard might be beneficial for preventing ischemic stroke.

Hypothermia Effect on Apoptotic Neuronal Death in Traumatic Brain Injury Model

  • Yoo, Do-Sung;Lee, Soon-Kyu;Huh, Pil-Woo;Han, Young-Min;Rha, Hyung-Kyun;Kim, Dal-Soo
    • Journal of Korean Neurosurgical Society
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    • v.38 no.3
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    • pp.215-220
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    • 2005
  • Objective : Many researchers believe that the hypothermia shows neuro-protective effect on brain injury. To understand the molecular mechanism of the hypothermic treatment, this study investigated its effects on the expression of cell death or survival related proteins such as p53, Bcl-2 and Bax in the rat traumatic brain injury[TBI] model. Methods : Twenty rats [Spraque Dawley, $200{\sim}250g$] were subjected to the brain injury of moderate severity [$2.4{\sim}2.6atm$] using the fluid percussion injury device and five rats were received only same surgery as controls. During 30minutes after the brain injury, the hypothermia group was maintained the body temperature around $34^{\circ}C$ while the control group were maintained that of $36^{\circ}C$. Five rats in each group were sacrificed 12h or 24h after brain injury and their brain sections was analyzed for physical damages by H-E stains and the extent of apoptosis by TUNEL assay and immunohistochemical stains. The tissue damage after TBI was mainly observed in the ipsilateral cortex and partly in the hippocampus. Results : Apoptosis was observed by TUNEL assay and the Bax protein was detected in both sample which harvested 12h and 24h after TBI. In the hypothermia treatment group, tissue damage and apoptosis were reduced in HE stains and TUNEL assay. In hypothermia treatment group rat shows more expression of the Bcl-2 protein and shows less expression of the Bax protein, at both 12h and 24h after TBI. Conclusion : These results show that the hypothermia treatment is an effective treatment after TBI, by reducing the apoptotic process. Therefore, it could be suggested that hypothermia has a high therapeutic value for treating tissue damages after TBI.

Imperatorin is Transported through Blood-Brain Barrier by Carrier-Mediated Transporters

  • Tun, Temdara;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.25 no.4
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    • pp.441-451
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    • 2017
  • Imperatorin, a major bioactive furanocoumarin with multifunctions, can be used for treating neurodegenerative diseases. In this study, we investigated the characteristics of imperatorin transport in the brain. Experiments of the present study were designed to study imperatorin transport across the blood-brain barrier both in vivo and in vitro. In vivo study was performed in rats using single intravenous injection and in situ carotid artery perfusion technique. Conditionally immortalized rat brain capillary endothelial cells were as an in vitro model of blood-brain barrier to examine the transport mechanism of imperatorin. Brain distribution volume of imperatorin was about 6 fold greater than that of sucrose, suggesting that the transport of imperatorin was through the blood-brain barrier in physiological state. Both in vivo and in vitro imperatorin transport studies demonstrated that imperatorin could be transported in a concentration-dependent manner with high affinity. Imperatorin uptake was dependent on proton gradient in an opposite direction. It was significantly reduced by pretreatment with sodium azide. However, its uptake was not inhibited by replacing extracellular sodium with potassium or N-methylglucamine. The uptake of imperatorin was inhibited by various cationic compounds, but not inhibited by TEA, choline and organic anion substances. Transfection of plasma membrane monoamine transporter, organic cation transporter 2 and organic cation/carnitine transporter 2/1 siRNA failed to alter imperatorin transport in brain capillary endothelial cells. Especially, tramadol, clonidine and pyrilamine inhibited the uptake of [$^3H$]imperatorin competitively. Therefore, imperatorin is actively transported from blood to brain across the blood-brain barrier by passive and carrier-mediated transporter.

Differential Expression of Chemokine MCP-1, MIP-1α, MIP-2 in Lipopolysaccharide-stimulated Neonatal and Adult Rat Brain (LPS 유도에 의한 신생쥐에서 chemokine의 단계별 발현)

  • Lee, Jong-Hwan
    • Journal of Life Science
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    • v.16 no.5
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    • pp.840-849
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    • 2006
  • Severe brain injuries induced by toxin pose one of the most important problems on our health care because of their high morbidity and mortality, are implicated to leucocyte infiltration more premature or immature brain than mature brain. Chemokines are the induction meditators for infiltration of inflammatory cells to the inflammation sites. In order to study the mechanism of leucocyte infiltration, the expression of several chemokines, MCP-1, $MIP-1{\alpha}$ and MIP-2 was studied in lipopolysaccharide(LPS)-stimulated neonatal and adult brain. One week old Sprague-Dawley rats or adult male rats weighing 300-350 g were used for the experiment. After anesthetization, $1\;{\mu}l$ LPS (0.5 mg/ml) subsequently was injected in the right caudate nucleus of the brain with stereotaxic frame. Animals were sacrificed at 6 hours, 24 hours, and 72 hours after injection. The present study was carried out using RT-PCR for the mRNA and immunohistochemistry for the expression of the proteins. In the neonatal rat brain, prominent interstitial edema with significant accumulation of leukocytes was detected at 24 and 72 hours after LPS injection. A semiquantitative analysis of RT-PCR revealed that the MCP-1, $MIP-1{\alpha}$, and MIP-2 mRNA expression peaked at 24 hours in neonatal and adult rat brain. Neonatal rats showed about 2.6, 1.4, and 1.2 times more expression of the MCP-1, $MIP-1{\alpha}$, and MIP-2 than that of the adult rats in the brain tissue. Immunohistochemical analysis also showed that MCP-1 immunoreactivity was paralleled with the RT-PCR results. MCP-1 protein was significantly detected at 24 and 72 hours in the brain parenchyma. $MIP-1{\alpha}$protein was highly expressed at 24 hours. The results of leukocyte infiltration in H&E stain was parallelled with that of the immunohistochemistry. Chemokine proteins were markedly detected at 24 hours after injection of LPS and neutrophil influx into intraparenchymal was prominent at 24 hours. These results suggest that the leukocyte infiltration in the intracranial infection may be controlled by mechanisms influenced by chemokine producing cells in the central nervous system such as microglia, astrocyte and endothelial cell.

Nucleotide Sequence of Rat Transketolase and Liver-Specific Pretranslational Activation During Postnatal Development

  • Kim, Sung-Min F.;Kim, Byung-Moon;Jeng, Jingjau;Soh, Yun-Jo;Bak, Choong-Il;Huh, Jae-Wook;Song, Byoung-J.
    • BMB Reports
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    • v.29 no.2
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    • pp.146-150
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    • 1996
  • A 2.1 kb cDNA clone for rat transketolase was isolated from rat liver ${\lambda}gt11$ cDNA library and its sequence was determined. The predicted rat transketolase (655 amino acids with $M_r$ 71,186) is highly similar (92%) to that of the human enzyme except that it contains an extra 32 amino acids at its N-terminus. Although it is less similar (<27%) to transketolases from non-mammalian species, the functional motifs such as the catalytic sites and thiamine binding domain are well conserved in the rat enzyme. Southern blot analysis of genomic DNA verified that transketolase appears to be derived from a single gene. Immunoblot and Northern blot analyses suggested that hepatic transketolase was activated pretranslationally by a 2.1-fold while little change was observed in brain enzyme, indicating a tissue-specific pretranslational activation during postnatal development.

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Circadian Expression of Clock Genes in the Rat Eye and Brain

  • Park, Kyungbae;Kang, Hae Mook
    • Molecules and Cells
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    • v.22 no.3
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    • pp.285-290
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    • 2006
  • The light sensing system in the eye directly affects the circadian oscillator in the mammalian suprachiasmatic nucleus (SCN). To investigate this relationship in the rat, we examined the circadian expression of clock genes in the SCN and eye tissue during a 24 h day/night cycle. In the SCN, rPer1 and rPer2 mRNAs were expressed in a clear circadian rhythm like rCry1 and rCry2 mRNAs, whereas the level of BMAL1 and CLOCK mRNAs decreased during the day and increased during the night with a relatively low amplitude. It seems that the clock genes of the SCN may function in response to a master clock oscillation in the rat. In the eye, the rCry1 and rCry2 were expressed in a circadian rhythm with an increase during subjective day and a decrease during subjective night. However, the expression of Opn4 mRNA did not exhibit a clear circadian pattern, although its expression was higher in daytime than at night. This suggests that cryptochromes located in the eye, rather than melanopsin, are the major photoreceptive system for synchronizing the circadian rhythm of the SCN in the rat.

Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes

  • Jeong, Yeon-Hui;Park, Jin-Sun;Kim, Dong-Hyun;Kim, Hee-Sun
    • Biomolecules & Therapeutics
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    • v.22 no.6
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    • pp.497-502
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    • 2014
  • In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.

PREVENTIVE EFFECT OF MUSHROOM PHELLINUS LINTEUS ON THE INHIBITION OF GAP JUNCTIONAL INTERCELLULAR COMMUNICATION BY $H_2O_2$ IS INVOLVED IN THE UP-REGULATION OF ERK2 AND p38

  • Kang, Kyung-Sun;Cho, Jong-Ho;Cho, Sung-Dae;Kim, Kyung-Bae;Lee, Ji-Hae;Ahn, Nam-Shik;Jung, Ji-Won;Yang, Se-Ran;Park, Joon-Suk;Yoon, Byung-Su;Kim, Sung-Hoon;Lee, Yong-Soon
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.159-160
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    • 2001
  • Gap junctional intercellular communication (GJIC) is a cellular event underlying the tumor promotion process and that treatment to prevent the down-regulation or to up-regulate GJIC is important in preventing tumor promotion. We evaluated the potential preventive effect of Mushroom Phellinus Linteus (PL) against the promoting action of hydrogen peroxide ($H_2O$$_2$) in WB-F344 rat liver epithelial cells.(omitted)

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