• Journal of Life Science
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• 제27권8호
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• pp.951-957
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• 2017

To understand the cytotoxic activity of Machilus thunbergii, which has been used as a traditional oriental medicine, the mechanism underlying the cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of M. thunbergii was evaporated, dissolved in, and then extracted by water. The water-extracted active substance was designated MTWE. When Jurkat T cells were treated with MTWE at concentrations of 0, 25, 50, and $100{\mu}g/ml$, the apoptotic phenomenon of cells accompanying several subsequent biochemical reactions, such as mitochondrial cytochrome c release, activation of caspase-3, and ICAD degradation, was detected in the Jurkat T cells. Moverover. the expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release pathway, was reduced in the Jurkat T cells. As DUSP6, a growth suppressor of cancer cells, ranged from 0, 25, 50, $100{\mu}g/ml$ of MTWE, the expression level was elevated in the Jurkat T cells. The apoptotic morphological change of the nuclei was observed by DAPI staining. Although the potential involvement of the other factors and DUSP6 is currently being investigated in more detail, these findings support the notion that MTWE is able to achieve the apoptosis of Jurkat T cells, and it seems that MTWE is useful as a method of evaluating a chemotherapeutic agent or tonic materials for human acute leukemia.

• Journal of Life Science
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• 제29권12호
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• pp.1329-1336
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• 2019

Subventricular zone (SVZ) in the brain contains neural stem cells (NSCs) which self-renew and differentiate to neurons and glial cells during postnatal period and throughout adulthood. Since fate decision to either proliferation or differentiation has to respond to intracellular and extracellular conditions, many intrinsic and extrinsic factors are involved. Among them, mitochondria have been reported to participate in fate decision of NSCs. In our previous report, we showed that long-term treatment of a mitochondrial inhibitor rotenone greatly inhibited neurogenesis. In this study, we examined the effects of short-term treatment of rotenone on SVZ NSCs. We found that (1) even one-day treatment of rotenone significantly reduced neurogenesis and earlier time points seemed to be more sensitive to rotenone, (2) a number of Mash1+ transit amplifying cells was decreased by one-day treatment of rotenone, (3) short-term treatment of rotenone eliminated most of the differentiated Tuj1+ neurons and Olig2+ oligodendrocytes, while glial fibrillary acidic protein (GFAP)+ astrocytes were not affected, and (4) sulfiredoxin 1 (Srxn1) gene expression was increased after one-day treatment of rotenone, indicating activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. All these results confirm that functional mitochondria are necessary during differentiation to neurons or oligodendrocytes as well as maintenance of neurons after differentiation. Also, these data suggest that temporary exposure to mitochondrial inhibitor such as rotenone might have long-term effects on neurogenic potential of NSCs.

• Applied Microscopy
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• 제33권2호
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• pp.155-168
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• 2003

The purpose of this study was to evaluate the effect the radiation-resistance of chitosan on the mice. A healthy male ICR mice were used for experiment. The SOD and MDA activity was measured from the liver of mice at 48 and 72 hours after the irradiation. The ultrastructural changes of the liver by irradiation was observed at 24, 48 and 72 hours after irradiation. The experimental groups were divided into three groups. Group 1 was the control group which was not treated with chitosanoligosaccharide before or after iradiation. Group 2 was the prefeeding group which chitosanoligosaccharide solution was supplied by feeding ad libitum for 30 days before irradiation. Group 3 was the postfeeding group which chitosanoligosaccharide solution was supplied by feeding after irradiation. In all groups 10 mice were used. The results were as follow: The SOD and MDA activity of the prefeeding group was decreased significantly (P<0.01). Control group - The nuclei were condensed. The mitochondria and rough endoplasmic reticulum (rER) were extended and the ribosome was dropped from the rER. Prefeeding group - The nuclei were rounded. The mitochondria was elongated. And the rER attached ribosomes. Postfeeding group - The nuclei were slightly condensed. The mitochondria and the rER were extended and the ribosome was dropped from the rER. It was concluded that the chitosanoligosaccharide was effective in the radiation-protection. So, chitosan would have the potential as the radiation-protection materials.

• Journal of Life Science
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• 제27권11호
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• pp.1349-1356
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• 2017

Potassium channel openers (KCOs) produce physiological and pharmacological defense mechanisms against cell injuries caused by oxidative stress of diverse origins. Openings of mitochondrial and plasmalemmal $K^+$ channels are involved in the defense mechanisms. This study tested whether NS 1619, an opener of large-conductance BK channels, has a similar beneficial influence on the pigment epithelial cells of retinas. The human retinal pigment epithelial cell line ARPE-19 was exposed to $H_2O_2$-induced oxidative stress in the absence and presence of NS 1619. The degrees of the cells' injuries were assessed by analyzing the cells' trypan-blue exclusion abilities and TUNEL staining. NS 1619 produced remarkable protections against cell injuries caused by $H_2O_2$. It prevented apoptotic and necrotic cell deaths. The protective effect of NS 1619 was significantly diminished when the cells were treated with NS 1619 in combination with the BK channel-blocker paxilline. NS 1619 significantly ameliorated cellular ATP deprivations in $H_2O_2$-treated cells. It helped mitochondria preserve their functional integrity, which was estimated by their MTT reduction abilities and mitochondrial membrane potential. In conclusion, it was suggested that NS 1619 had a beneficial effect on mitochondria in regards to preserving their functional integrity under oxidative stress, and it produces defense mechanisms against oxidant-induced cell injuries in ARPE-19 cells.

• International Journal of Stem Cells
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• 제16권2호
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• pp.123-134
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• 2023

Objective: The heart contains a pool of c-kit⁺ progenitor cells which is believed to be able to regenerate. The differentiation of these progenitor cells is reliant on different physiological cues. Unraveling the underlying signals to direct differentiation of progenitor cells will be beneficial in controlling progenitor cell fate. In this regard, the role of the mitochondria in mediating cardiac progenitor cell fate remains unclear. Specifically, the association between changes in mitochondrial morphology with the differentiation status of c-kit⁺ CPCs remains elusive. In this study, we investigated the relationship between mitochondrial morphology and the differentiation status of c-kit⁺ progenitor cells. Methods and Results: c-kit⁺ CPCs were isolated from 2-month-old male wild-type FVB mice. To activate differentiation, CPCs were incubated in α-minimal essential medium containing 10 nM dexamethasone for up to 7 days. To inhibit Drp1-mediated mitochondrial fragmentation, either 10 μM or 50 μM mdivi-1 was administered once at Day 0 and again at Day 2 of differentiation. To inhibit calcineurin, either 1 μM or 5 μM ciclosporin-A (CsA) was administered once at Day 0 and again at Day 2 of differentiation. Dexamethasone-induced differentiation of c-kit⁺ progenitor cells is aligned with fragmentation of the mitochondria via a calcineurin-Drp1 pathway. Pharmacologically inhibiting mitochondrial fragmentation retains the undifferentiated state of the c-kit⁺ progenitor cells. Conclusions: The findings from this study provide an alternative view of the role of mitochondrial fusion-fission in the differentiation of cardiac progenitor cells and the potential of pharmacologically manipulating the mitochondria to direct progenitor cell fate.

• Clinical and Experimental Pediatrics
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• 제52권4호
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• pp.471-475
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• 2009

Purpose : Mitochondrial disorders are a clinical entity characterized by diverse symptoms and signs of involvement of various systems. Furthermore, the disorders are known to show ophthalmologic manifestations as well as neurological findings. Visually evoked potential is a sensitive measure to check the integrity of the visual pathway. In this study, we have investigated the value of visually evoked potential in mitochondrial disorders with respiratory chain defects. Methods : Nineteen patients diagnosed with mitochondrial respiratory chain complex I defect as confirmed by spectrophotometric enzyme assay in muscle samples were enrolled for this study. The patients underwent a visually evoked potential study. We classified the results into four groups and compared these with clinical ophthalmologic findings. Results : Among the 19 patients, 14 showed abnormal visually evoked potential findings. Seven patients showed abnormal clinical ophthalmologic findings. All patients with abnormal ophthalmologic findings showed abnormal visually evoked potential findings. Among the 12 patients with normal ophthalmologic findings, seven showed abnormal results in visually evoked potential. Conclusion : Visually evoked potential study could be used as an effective screening tool for mitochondrial disorders to detect ophthalmologic and neurological abnormalities.

• Journal of Life Science
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• 제19권5호
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• pp.598-606
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• 2009

Oxidative stress by free radicals is a major cause of neuronal cell death. Excitotoxicity in hypoxia/ischemia causes an increase in reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP), resulting in dysfunction of the mitochondria and cell death. Pinelliae Rhizoma (PR) is a traditional medicine for incipient stroke. We investigated the effects of PR Water-Extract on the modulation of ROS and MMP in a hypoxic model using cultured rat cortical cells. PR Water-Extract was added to the culture medium at various concentrations (0.25${\sim}$5, 5.0 ${\mu}g/ml$) on day in vitro 12(DIV12), given a hypoxic shock (2% $O_2$/5% $CO_2$, $37^{\circ}C$, 3 hr), and cell viability was assessed on DIV15 by Lactate Dehydrogenase Assay (LDH assays). PR Water-Extract showed a statistically significant effect on neuroprotection (10${\sim}$15% increase in viability; p<0.01) at 1.0 and 2.5 ${\mu}g/ml$ in normoxia and hypoxia. Measurement of ROS production by $H_2DCF-DA$ stainings showed that PR Water-Extract efficiently reduced the number and intensity of ROS-producing neurons, especially at 1 hr post shock and DIV15. When MMP was measured by JC-1 stainings, PR Water-Extract efficiently maintained high-energy charged mitochondria. These results indicate that PR Water-Extract protects neurons in hypoxia by preventing ROS production and preserving the cellular energy level.

• The Journal of Internal Korean Medicine
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• 제27권2호
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• pp.379-393
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• 2006

Objectives: We are aimed to identify anti-tumor effects of Curcuma aromatics on some kinds of cancer cells through molecular biologic methods. Materials & Methods: We used 4 kinds of cancer cell lines such as lung cancer cells(AS49), cervical cancer cells(HeLa), glioma cancer cells(A172) and prostate cancer cells(PC3). We treated the boiled extract of Curcuma aromatica $5{\mu}g,\;10{\mu}g$ to cultural media(ml) for 24 hours. We measured the cytotoxicitv on 4 kinds of cancer cells through tryphan blue exclusion test and the suppressive effect on viability of 4 kinds of cancer cells via MTT assay. We measured change of mitochondria membrane potential via flow cytometry. The quantitative RT-PCR was used to examine the effect on the revelation of Bcl-2 and Bax which are genes related to apoptosis. We examined the effect on the revelation of Bcl-2 Protein and Bar protein by western blot analysis. Results : In the experiment of tryphan blue exclusion test, the extract of Curcuma aromatica showed more significant killing effect on AS49, HeLa than the control group with density dependent manner, which was statistically significant. In the experiment of MTT assay the extract of Curcuma aromatica showed more suppressive effect on viability of A549, HeLa than the control group with density dependent manner, which was statistically significant. Curcuma aromatica induced apoptosis by decreasing the membrane potential of mitochondria in A549, HeLa. In the experiment of the revelation of genes related to apoptosis, the revelation of Bcl-2 decreased and the revelation of Bax increased in A549, HeLa treated with Curcuma aromatica with dose dependent manner. In the experiment of the revelation of protein related to apoptosis, the protein levels of Bcl-2 decreased and the protein levels of Bax increased in AS49, HeLa treated with Curcuma aromatica with dose dependent manner. Conclusions: From this study, we can infer that Curcuma aromatica has anti-tumor effect on lung cancer cells and uterine carcinoma cells but not on glioma cells and prostate cancer cells.

• The Journal of Internal Korean Medicine
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• 제27권2호
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• pp.429-443
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• 2006

Objectives : The Purpose of this study was to identify anti-tumor effects of Curcuma longa L. on some kinds of cancer cells through molecular biologic methods. Materials & Methods : We used 4 kinds of cancer cell lines such as glioma cells(A172), cervical cancer cells(HeLa), Prostate cancer cells(PC3), lung cancer cells(A549). We injected the boiled extract of Curcuma longa L. $5{\mu}g,\;10{\mu}g$ to culture media(ml) for 24 hours. We measured the cytotoxic effect on 4 kinds of cancer cells through trypan blue exclusion test and the suppressive effect on viability of 4 kinds of cancer cells via MTT assay. We measured the change of mitochondria membrane potential via flow cytometry. The quantitative RT-PCR was used to examine the effect on the revelation of Bcl-2 and Bax which genes are related to apoptosis. We examined the effect on the revelation of Bcl-2 protein and Bax protein by western blot analysis. Results: 1. Extract of Curcuma longa L. showed significant cytotoxic effect on A172, HeLa, PC3 compared to the control group with density dependent manner. 2. Extract of Curcuma longs L. showed significant suppressive effect on viability of A172, HeLa, PC3 compared to the control group with density dependent manner. 3. Curcuma longs L. induced apoptosis by decreasing the membrane potential of mitochondria in A172, HeLa, PC3. 4. In the test about the revelation of genes related to apoptosis, the revelation of Bcl-2 decreased and the revelation of Bax increased in A172. HeLa, PC3 treated with Curcuma longa L. with density dependent manner. 5. In the test about the revelation of protein related to apoptosis, the protein levels of Bcl-2 decreased and the protein levels of Bax increased in A172, HeLa, PC3 treated with Curcuma longa L. Conclusions: This experiment shewed that Curcuma longs L. has anti-tumor effect on glioma, cervical, Prostate cancer cells except on lung cancer. We hope that anti-tumor effects of Curcuma longa L. will be more Practically identified.

• Nuclear Medicine and Molecular Imaging
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• 제41권6호
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• pp.561-565
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• 2007

Purpose: Lipophilic cations including tetraphenylphosphonium (TPP) salts penetrate the hydrophobic barriers of the plasma and mitochondrial membranes, resulting in accumulation in mitochondria in response to the negative inner transmembrane potentials. The development of radiolabeled phosphonium cations as a noninvasive imaging agent may serve as a new molecular "voltage sensor" probe to investigate the role of mitochondria in the pathophysiology and diagnosis of cancer. Materials and Methods: We have synthesized a reference compound (4-fluorophenyl)triphenylphosphonium (TPP) and a labeled compound $[^{18}F]$TPP via two step nucleophilic substitution of no-carrier-added $[^{18}F]$fluoride with the precursor, 4-iodophenyltrimethylammonium iodide, in the presence of Kryptofix-2.2.2 and $K_2CO_3$. Result: The reference compound (4-fluorophenyl)triphenylphosphonium (TPP) was synthesized in 60% yield. The radiolabeled compound $[^{18}F]$TPP was synthesized in $10\sim15%$ yield. The radiochemical purity of the $[^{18}F]$TPP was $95.57{\pm}0.51%$ (n=11). Conclusion: $[^{18}F]$TPP was successfully synthesized that might have a potential to be utilized as a novel myocardial or cancer imaging agent for PET. However, it is required to improve the radiochemical yield to apply $[^{18}F]$TPP in preclinical or clinical researches.