- Correlation Between Neuronal Apoptosis and Expression of Inducible Nitric Oxide Synthase after Transient Focal Cerebral Ischemia.
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Byoung Yuk Yi, Sung Kyoo Hwang, Ku Seong Kang, Hong Hua Quan, Young Mi Lee, Jung Wan Kim, Eun Kyoung Kwak, Ji Young Park, Yoon Kyung Sohn
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Korean J Pathol. 2004;38(6):364-371.
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 Abstract
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- BACKGROUND
Neuronal death in acute-phase cerebral ischemic injury is caused by necrosis. However, neuronal injury after reperfusion can be associated with apoptosis.
METHODS
We used Sprague-Dawley rats whose brains were reperfused after middle cerebral artery occlusion for either 30 min or 2 h. We examined a relationship between apoptosis and the expression of inducible nitric oxide synthase (iNOS) in the brain tissue from 3 h to 14 days after reperfusion in both groups.
RESULTS
TUNEL and iNOS positivity were closely related in both groups. The 2-h ischemia group exhibited increases in the amount of TUNEL and iNOS-positive cells for up to 3 days after reperfusion, at which the TUNEL and iNOS-positive cells decreased. The 30-min ischemia group exhibited peak positivity 24 h after reperfusion, followed by a similar decrease. iNOS mRNA expression peaked 3 h after reperfusion in the 30-min ischemia group, at which time it decreased. In the 2-h ischemia group, iNOS mRNA increased 3 h after reperfusion, peaked 24 h after reperfusion, and then decreased.
CONCLUSION
These results indicated the occurrence of delayed apoptosis in transient cerebral ischemia. Increased expression of iNOS is closely associated with this apoptosis, and oxygen free radical-producing materials, such as nitric oxide, may play an important role in the induction of this apoptosis.
- Expression of Tumor Necrosis Factor-alpha, Interleukin-1beta and Inducible Nitric Oxide Synthase after Stereotaxic Injection of Lipopolysaccharide in Rat Hippocampus.
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Hoon Kyu Oh, Ku Seong Kang, Ji Yeon Kim, Eun Kyoung Kwak, Jung Wan Kim, Ji Young Park, Yoon Kyung Sohn
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Korean J Pathol. 2004;38(3):157-164.
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Abstract
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- BACKGROUND
Brain inducible nitric oxide synthase (iNOS) might be detectable in several pathologic conditions, and it is thought to play an important role in their pathophysiology. Tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta are believed to be essential factors of iNOS induction of the brain.
METHODS
After intrahippocampal stereotaxic injection of lipopoly-saccharide (LPS), the rat brains were removed at 6, 12 and 24 h. The rat brain tissues were examined to clarify the expression patterns of TNF-alpha, IL-1beta and iNOS.
RESULTS
The inflammatory cells which were stained with anti-TNF-alpha antibody, appeared in 6 h and increased for 24 h after LPS injection. The iNOS positive cells appeared after 12 h of LPS injection. A semiquantitative analysis of reverse transcription-polymerase chain reaction (RT-PCR) revealed that the TNF-alpha and IL-1beta mRNA arose at 1 h, peaked at 6 h and then declined until 48 h after LPS injection. The iNOS mRNA arose after 6 h, peaked at 12 h, and declined until 48 h after LPS injection.
CONCLUSIONS
We conclude that the induction of inflammatory events by intrahippocampal injection of LPS activates TNF-alpha and IL-1beta secretion, and this is followed by an induction of iNOS expression. TNF-alpha and IL-1beta seem to be related with iNOS expression in brain inflammation.
- The Effects of Ginsenoside Rb1 on the Apoptosis and the Production of Nitric Oxide in Rat C6 Glioma Cells.
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Joo Hyeon Park, Yoon Hee Lee, Ku Seong Kang, Soo Kyoung Lee, Sun Zoo Kim, Ji Young Park, Eun Kyoung Kwak, Yoon Kyung Sohn
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Korean J Pathol. 2004;38(1):1-7.
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Abstract
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- BACKGROUND
Ginsenosides, the extract of Panax ginseng, exert various pharmacological effects such as anticancer activity by the mechanism that is not yet defined. In this study, we proposed that the anticancer effect of ginsenoside Rb1 is related to tumor cell apoptosis and ginsenoside Rb1 induces the tumor cell apoptosis via the nitric oxide (NO) production.
METHODS
Rat C6 glioma cells were activated by treating with lipopolysaccharide (LPS), interferon (IFN)-gamma , and tumor necrosis factor (TNF)-alpha on the culture medium to investigate the effects of ginsenoside Rb1.
RESULTS
Compared with C6 glioma cells treated with LPS/IFN-gamma/TNF-alpha, C6 glioma cells treated with LPS/IFN-gamma/TNF-alpha/ginsenoside Rb1 showed marked increase in the NO production and apoptosis. Ginsenoside Rb1 induces the NO production in C6 glioma cells in dose-dependent manner. When C6 glioma cells treated with LPS/IFN-gamma/TNF-alpha/ginsenoside Rb1 were incubated with the specific inhibitor of iNOS, S-Methyl-2-thiopseudoureasulfate (SMT), both NO production and apoptosis in C6 glioma cells was significantly decreased. Ginsenoside Rb1 induced the expression of iNOS mRNA and iNOS protein in C6 glioma cells.
CONCLUSIONS
These results suggest that the induction of iNOS expression and subsequent
- Expression of p53 and Vascular Endothelial Growth Factor mRNA in Angiogenesis of Non-Small Cell Lung Carcinoma.
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Jun Seog Kim, Tae In Park, Myoung Hoon Lee, Eun Kyoung Kwak, Ji Young Park, Jung Sik Kwak, Jong Min Chae
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Korean J Pathol. 2003;37(1):35-40.
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Abstract
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- BACKGROUND
Angiogenesis is one of the most important factors in the progression and me-tastasis of malignancies.
Angiogenesis is a multistep process requiring the interaction of numerous factors able to stimulate the growth and development of new vessels. But, understanding of the mechanism involved in VEGF expression is unclear.
METHODS
Expressions of p53 and VEGF, and neovasculiarization were examined in 19 cases of surgically resected non-small cell carcinoma of the lung by the immunohistochemical staining. Furthermore, VEGF mRNA expressions were quantified in all cases using the real-time quantitative RT-PCR. These results were compared with clinicopathologic parameters such as histologic grade and stage.
RESULTS
Tumors with high aberrant p53 expressions showed significantly higher VEGF mRNA ex-pressions and microvessel counts than those with low p53 expressions. Expressions of p53 as well as VEGF and micovessel counts were closely associated with the tumor stage, but not with the histologic grade and other clinical parameters.
CONCLUSIONS
These results suggest that aberrant p53 expression may play a role in the regulation of VEGF expression and may be involved in controlling angiogenesis in non-small cell carcinoma of the lung.
- Lipopolysaccharide/Interferon-gamma Induced Nitric Oxide Production in C6 Glioma Cells: Modulation by Dexamethasone.
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Jong Heun Shin, Ku Seong Kang, Ji Yeoun Kim, Sun Zoo Kim, Ji Young Park, Eun Kyoung Kwak, Yoon Kyung Sohn
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Korean J Pathol. 2002;36(6):406-411.
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Abstract
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- BACKGROUND
Glial cell-derived nitric oxide (NO), and its regulation has significant implications for central nervous system pathophysiology. The aim of the present study was to see the production of NO in lipopolysaccharide (LPS)/interferon-gamma (IFN-)-treated C6 glioma cells and the effect of dexamethasone on NO production and apoptosis of LPS/IFN--treated C6 glioma cells.
METHODS
The apoptosis of LPS/IFN- treated C6 glioma cell was examined with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method and the production of NO in culture medium was measured. The expression of iNOS mRNA was examined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The effect of the N-monomethyl L-arginine (NMMA) and dexamethasone on the apoptosis and NO production was also examined.
RESULTS
Inducible nitric oxide synthase (iNOS) mRNA and NO production were markedly increased in LPS/IFN--treated C6 glioma cells. The expression of iNOS mRNA arose at 3 hours, peaked at 12 hours, and declined 24 hours after LPS/IFN--treatment. Accumulation of NO derivatives in the culture media was increased at least upto 48 hours after LPS/IFN-. The induction of iNOS expression and NO production in LPS/IFN--treated C6 cells was correlated with apoptotic cell death judged by TUNEL staining. After treatment of NMMA, one of the NOS inhibitors, NO production and apoptosis were markedly decreased. Dexamehasone treatment suppressed the NO production by concentration depenedent manner.
CONCLUSIONS
From the above results it is concluded that the LPS/IFN- induced apoptosis of C6 cells is mediated by iNOS-derived NO and NO production and apoptosis was suppressed by dexamethasone.
- The Effect of Ischemic Preconditioning in Rat Liver: The Expression of Interleukin-1 and Nuclear Factor-B.
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Kum Yoon Seup, Soo Kyoung Lee, Sun zoo Kim, Eun Kyoung Kwak, Ji Young Park, Tae In Park, Han Ik Bae, Yoon Kyung Sohn, In Soo Suh
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Korean J Pathol. 2002;36(4):238-242.
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Abstract
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- BACKGROUND
A short period of ischemia and reperfusion, called ischemic preconditioning, protects various tissues against subsequent sustained ischemic insult. Apoptosis of hepatocytes and sinusoidal endothelial cells are a critical mechanisms of injury in the ischemic liver. Because nuclear factor-B (NF-B) has a significant role in the cell survival, we hypothesized that ischemic preconditioning protects by inhibition of apoptosis through the expression of NF-B, induced by interleukin-1 (IL-1), which is known for enhancement of its transcription and activation.
METHODS
We induced ischemia and reperfusion on rat liver, and performed in situ terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labelling assay and polymerase chain reaction for IL-1 mRNA and NF-B mRNA.
RESULTS
Apoptosis of hepatocytes and sinusoidal endothelial cells, assessed by in situ TUNEL assay, was significantly reduced with preconditioning. The expression of IL-1 mRNA and NF-B mRNA are seen on discrete monoclonal bands around 344 and 356 base pairs, in comparison with normal rat liver, but, there was no significant difference between the ischemia-reperfusion group and the preconditioning group.
CONCLUSIONS
We suggest that ischemic preconditioning confers dramatic protection against prolonged ischemia via inhibition of apotosis through the expression of IL-1 inducing NF-B and its activation. However, we need further study in the activity of NF-B, such as nucleotide shift assay, because the activity of NF-B is regulated by binding of the inhibitory protein, IB.
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