• Proceedings of the PSK Conference
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• 2002.10a
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• pp.257.2-257.2
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• 2002

This research was performed to investigate the protective effect of Yangguksanwha-tang(YST) agaist ischemic damage in PC 12 cells. To elucidate the mechanism of the protective effect of YST on ischemic insult. cell viability and changes in activities of Superoxide dismutase. Glutathione Peroxidase. Catalase. capase 3 and the production of Malondialdehyde were observed after treating PC12 cells with YSt which was metabolized by rat liver homogenate. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.1
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• pp.57-64
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• 2013

Cells can resist and even recover from stress induced by acute hypoxia, whereas chronic hypoxia often leads to irreversible damage and eventually death. Although little is known about the response(s) to acute hypoxia in neuronal cells, alterations in ion channel activity could be preferential. This study aimed to elucidate which channel type is involved in the response to acute hypoxia in rat pheochromocytomal (PC12) cells as a neuronal cell model. Using perfusing solution saturated with 95% $N_2$ and 5% $CO_2$, induction of cell hypoxia was confirmed based on increased intracellular $Ca^{2+}$ with diminished oxygen content in the perfusate. During acute hypoxia, one channel type with a conductance of about 30 pS (2.5 pA at -80 mV) was activated within the first 2~3 min following onset of hypoxia and was long-lived for more than 300 ms with high open probability ($P_o$, up to 0.8). This channel was permeable to $Na^+$ ions, but not to $K^+$, $Ca^+$, and $Cl^-$ ions, and was sensitively blocked by amiloride (200 nM). These characteristics and behaviors were quite similar to those of epithelial sodium channel (ENaC). RT-PCR and Western blot analyses confirmed that ENaC channel was endogenously expressed in PC12 cells. Taken together, a 30-pS ENaC-like channel was activated in response to acute hypoxia in PC12 cells. This is the first evidence of an acute hypoxia-activated $Na^+$ channel that can contribute to depolarization of the cell.

• Biomedical Science Letters
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• v.12 no.2
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• pp.81-89
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• 2006

The ischemia-responsive 94 gene (irp94) encoding a 94 kDa endoplasmic reticulum resident protein was investigated its molecular properties associated with unfoled protein responses. First, the expression of irp94 mRNA was tested after the reperfusion of the transient forebrain ischemia induction at the central nervous system in three Mongolian gerbils. Second, irp94 expression in PC12 cells, which are derived from transplantable rat pheochromocytoma cultured in the DMEM media, was tested at transcriptional and translational levels. The half life of irp94 mRNA was also determined In PC12 cells. Last, the changes of irp94 mRNA expression were investigated by the addition of various ER stress inducible chemicals (A23187, BFA, tunicamycin, DTT and $H_2O_2$) and proteasome inhibitors, and heat shock. High level expression of irp94 mRNA was detected after 3 hours reperfusion in the both sites of the cerebral cortex and hippocampus of the gerbil brain. The main regulation of irp94 mRNA expression in PC 12 cells was determined at the transcriptional level. The half life of irp94 mRNA in PC12 cells was approximately 5 hours after the initial translation. The remarkable expression of irp94 mRNA was detected by the treatment of tunicamycin, which blocks glycosylation of newly synthesized polypeptides, and $H_2O_2$, which induces apoptosis. When PC12 cells were treated with the cytosol proteasome inhibitors such as ALLN (N-acetyl-leucyl-norleucinal) and MG 132 (methylguanidine), irp94 mRNA expression was increased. These results indicate that expression of irp94 was induced by ER stress including oxidation condition and glycosylation blocking in proteins. Expression of irp94 was increased when the cells were chased after heat shock, suggesting that irp94 may be involved in recovery rather than protection against ER stresses. In addition, irp94 expression was remarkably increased when cytosol proteasomes were inhibited by ALLN and MG 132, suggesting that irp94 plays an important role for maintaining the ERAD (endoplasmic reticulum associated degradation) function.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1111-1119
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• 2004

In this study, we investigated that the effects of corynoxeine on the apoptosis by inducible CT105 in PC 12 cells and neuronpathogenic agent as CT105 confirmed with apoptosis, DNA fragmentation, neurite outgrowth and immunocytochemistry analysis This study examines whether corynoxeine have an anti-alzhmeimer agent by inhibition of apoptosis by CT105 and induces neurite outgrowth. Cytotoxicity was assessed in PC12 cell cultures by DNA fragmentation and measuring lactate dehydrogenase (LDH) in the culture media. The treatment of corynoxeine in exposure of cultures to CT105 and provided complete protection against cytotoxicity. CT105-induced cytotoxicity was blocked by apoptotsis, repaired by DNA fragmentation, neurite outgrowth and exposure to CT105 expression and regenerated with neurite outgrowth and immunocytochemistry by corynoxeine. These results indicate that in neuronal cell cultures, damage of T105, repaired excitotoxicity by corynoxeine and CT105-induced cytotoxicity is blocked primarily by the activation of anti-apoptosis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.394-403
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• 2006

This research investigated the effect of the CMT and MCMT on Alzheimer's disease. The effects of the CMT and MCMT extract on expression of proinflammatory cytokine($IL-1{\beta}$, IL-6, $TNF-{\alpha}$) in the THP-1 cell; amyloid precursor proteins(APP), acetylcholinesterase(AChE) mRNA of PC-12 cells treated with CT105; the AChE activity and the APP production of PC-12 cell lysate treated with CT105 were investigated. The CMT and MCMT extract suppressed overexpression of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ in the THP-1 cell treated by LPS; the expression of APP, AChE mRNA in PC-12 cells treated with CT105; the AChE activity and the production of APP in PC-12 cell lysate treated with CT105 significantly. This study suggest that CMT and MCMT may be effective for the prevention and treatment of Alzheimer's disease.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.138-148
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• 2006

This research investigated the effect of the CMT and SCMT on Alzheimer's disease. The effects of the CMT and SCMT extract on expression of proinflammatory cytokine(IL-$1{\beta}$, IL-6, TNF-$\alpha$) in the THP-1 cell; amyloid precursor proteins(APP), acetylcholinesterase(AChE) mRNA of PC-12 cells treated with CT105; the AChE activity and the APP production of PC-12 cell lysate treated with CT105 were investigated. The CMT and SCMT extract suppressed overexpression of IL-$1{\beta}$, IL-6, TNF-$\alpha$ in the THP-1 cell treated dy LPS; the expression of APP, AChE mRNA in PC-12 cells treated with CT105; the AChE activity and the production of APP in PC-12 cell Iysate treated with CT105 significantly. This study suggest that CMT and SCMT may be effective for the prevention and treatment of Alzheimer's disease.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.228-232
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• 2008

In the present study, we investigated the glutathione S-transferase (GST) induction of medicinal plants using a cultured PC12 cells. The methanol extracts of Dendrobium nobile Lindley, Schizonepeta tenuifolia Briquet, Glycyrrhiza uralensis Fischer, Paenoia lactiflora Pall were tested. As the result, exposure of PC12 cells to G. uralensis resulted in the significant induction of GST. On the continuous experiment, G. uralensis was extracted with methanol, ethanol, and acetone. Among these extracts, methanol extracts showed the highest GST induction. The methanol extracts were further fractionated with hexane, diethyl ether, ethyl acetate, and water layer according to the degree of polarity. The diethyl ether layer showed the highest exhibited GST induction on PC12 cells. Based on these results suggest that the extracts of G. uralensis can be applicable for the development of a new antioxidant agent.

• BMB Reports
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• v.49 no.8
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• pp.437-442
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• 2016

We aimed to study the role of protein L-isoaspartyl methyltransferase (PIMT) in neuronal differentiation using basic fibroblast growth factor (bFGF)-induced neuronal differentiation, characterized by cell-body shrinkage, long neurite outgrowth, and expression of neuronal differentiation markers light and medium neurofilaments (NF). The bFGF-mediated neuronal differentiation of PC12 cells was induced through activation of mitogen-activated protein kinase (MAPK) signaling molecules [MAPK kinase 1/2 (MEK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), and p90RSK], and phosphatidylinositide 3-kinase (PI3K)/Akt signaling molecules PI3Kp110β, PI3Kp110γ, Akt, and mTOR. Inhibitors (adenosine dialdehyde and S-adenosylhomocysteine) of protein methylation suppressed bFGF-mediated neuronal differentiation of PC12 cells. PIMT-eficiency caused by PIMT-specific siRNA inhibited neuronal differentiation of PC12 cells by suppressing phosphorylation of MEK1/2 and ERK1/2 in the MAPK signaling pathway and Akt and mTOR in the PI3K/Akt signaling pathway. Therefore, these results suggested that PIMT was critical for bFGF-mediated neuronal differentiation of PC12 cells and regulated the MAPK and Akt signaling pathways.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.473-481
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• 2021

Background: Mitochondrial dysfunction is one of the significant reasons for Alzheimer's disease (AD). Ginsenosides, natural molecules extracted from Panax ginseng, have been demonstrated to exert essential neuroprotective functions, which can ascribe to its anti-oxidative effect, enhancing central metabolism and improving mitochondrial function. However, a comprehensive analysis of cellular mitochondrial bioenergetics after ginsenoside treatment under Aβ-oxidative stress is missing. Methods: The antioxidant activities of ginsenoside Rb₁, Rd, Re, Rg₁ were compared by measuring the cell survival and reactive oxygen species (ROS) formation. Next, the protective effects of ginsenosides of mitochondrial bioenergetics were examined by measuring oxygen consumption rate (OCR) in PC12 cells under Aβ-oxidative stress with an extracellular flux analyzer. Meanwhile, mitochondrial membrane potential (MMP) and mitochondrial dynamics were evaluated by confocal laser scanning microscopy. Results: Ginsenoside Rg₁ possessed the strongest anti-oxidative property, and which therefore provided the best protective function to PC12 cells under the Aβ oxidative stress by increasing ATP production to 3 folds, spare capacity to 2 folds, maximal respiration to 2 folds and non-mitochondrial respiration to 1.5 folds, as compared to Aβ cell model. Furthermore, ginsenoside Rg1 enhanced MMP and mitochondrial interconnectivity, and simultaneously reduced mitochondrial circularity. Conclusion: In the present study, these results demonstrated that ginsenoside Rg₁ could be the best natural compound, as compared with other ginsenosides, by modulating the OCR of cultured PC12 cells during oxidative phosphorylation, in regulating MMP and in improving mitochondria dynamics under Aβ-induced oxidative stress.

• Herbal Formula Science
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• v.31 no.1
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• pp.29-39
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• 2023

Objective : Gardeniae Fructus (GF) is the ripe fruit of Gardenia jasminoides Ellisa with a bitter taste and cold properties. Ingredient compounds including geniposide are known to have anti-inflammatory, antioxidant, and neuroprotective effects. The purpose of this study was to investigate the neuroprotective effect of GF on tBHP-induced PC12 cells. Methods : Cell viability was measured by the MTT assay, and apoptosis was determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The expression level of each protein was monitored by Western blot analysis, and reactive oxygen species (ROS) were analyzed using DCFH-DA. Results : In PC12 cells, tBHP induced cell death through apoptosis with caspase activation and PARP inactivation. Cells treated with tBHP showed an increase in intracellular ROS and depletion of GSH. Pretreatment with GF prevented tBHP-induced apoptosis, reduced ROS, and increased GSH. GF also maintained increased Nrf2 expression in the presence of tBHP. Phosphorylation of JNK and p38 MAPK was increased by tBHP, whereas phosphorylation of ERK was decreased. GF restored changes in ERK and p38 phosphorylation, but not JNK phosphorylation. Conclusion : These results indicate that GF has neuroprotective effects through anti-apoptotic and antioxidant effects mediated by regulation of Nrf2 expression and phosphorylation of ERK and p38. It also demonstrates the potential use of GF as a source of antioxidant and neuroprotective substances.