• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.65-71
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• 2003

Bax, a mammalian pro-apoptotic member of the Bcl-2 family, induces cell death when expressed in yeast. To investigate whether Bax expression can induce cell death in plant, we produced transgenic Arabidopsis plants that contained murine Bax cDNA under control of a glucocorticoid-inducible promoter. Transgenic plants treated with dexamethasone, a strong synthetic glucocorticoid, induced Bax accumulation and cell death, suggesting that some elements of cell death mechanism by Bax may be conserved among various organisms. Therefore, we developed novel yeast genetic system, and cloned several Plant Bax Inhibitors (PBIs). Here, we report the function of two PBIs in detail. PBI1 is ascorbate peroxidase (sAPX). Fluorescence method of dihydrorho-damine 123 oxidation revealed that expression of Bax in yeast cells generated reactive oxygen species (ROS), and which was greatly reduced by co-expression with sAPX. These results suggest that sAPX inhibits the generation of ROS by Bax, which in turn suppresses Baxinduced cell death in yeast. PBI2 encodes nucleoside diphosphate kinase (NDPK). ROS stress strongly induces the expression of the NDPK2 gene in Arabidopsis thaliana (AtNDPK2). Transgenic plants overexpressing AtNDPK2 have lower levels of ROS than wildtype plants. Mutants lacking AtNDPK2 had higher levels of ROS than wildtype. $H_2O_2$ treatment induced the phosphorylation of two endogenous proteins whose molecular weights suggested they are AtMPK3 and AtMPK6. In the absence of $H_2O_2$ treatment, phosphorylation of these proteins was slightly elevated in plants overexpressing AtNDPK2 but markedly decreased in the AtNDPK2 deletion mutant. Yeast two-hybrid and in vitro protein pull-down assays revealed that AtNDPK2 specifically interacts with AtMPK3 and AtMPK6. Furthermore, AtNDPK2 also enhances the MBP phosphorylation activity of AtMPK3 in vitro. Finally, constitutive overexpression of AtNDPK2 in Arabidopsis plants conferred an enhanced tolerance to multiple environmental stresses that elicit ROS accumulation in situ. Thus, AtNDPK2 appears to play a novel regulatory role in $H_2O_2$-mediated MAPK signaling in plants.

• Journal of Life Science
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• v.20 no.9
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• pp.1409-1414
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• 2010

The aim of this study was to investigate the effects of exercise on intrinsic and extrinsic apoptosis signaling pathways in skeletal muscle. ICR-type white male mice were divided into a control group (CON: n=10) and an exercise training group (EX: n=10) after a 1 week adaptation period. EX performed treadmill running at 16.4 m/min with a 4% incline, 40 min/day and 5 days/week for 8 weeks. Cervical dislocation was performed at 48 hours after the last bout of exercise, after which gastrocnemius skeletal muscles were immediately collected. The results of verifying the intrinsic apoptosis pathway showed that there were no significant differences in Bcl-2, Bax, or the ratio of Bax/Bcl-2 proteins between EX and CON. On the other hand, the results of verifying the extrinsic apoptosis pathway showed that caspase-8 proteins were significantly lower in EX than in CON (p<0.05). Apoptosis suppressing protein HSP70 was higher in EX than in CON. In addition, caspase-3, which is the final factor for apoptosis, was not activated. These results indicate that apoptosis did not develop since caspase-3 is non-cleaved by the effects of caspase-8 and HSP70 extrinsic pathways rather than Bcl-2 and Bax intrinsic pathways among signal pathways for apoptosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.338-346
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• 2015

This study was performed to elucidate the anti-proliferative and apoptotic mechanism of flavonoids in HT-29 human colon cancer cells. We investigated the anti-proliferative activity of flavonoids in HT-29 human colon cancer cells via cell viability assay (MTT assay), caspase-3 activity, RT-PCR, and western blotting. We cultured HT-29 cells in the presence of various flavonoids (apigenin, rutin, naringenin, and myricetin) at a concentration of $100{\mu}M$. In the MTT assay, naringenin showed the strongest effect on cell viability in HT-29 colon cancer cells. Caspase-3 activity, a marker of apoptosis, significantly increased upon naringenin treatment. For RT-PCR, myricetin significantly increased Bax protein levels, naringenin increased p53 protein levels, and rutin reduced expression of the anti-apoptotic protein Bcl-2. Western blotting of HT-29 colon cancer cells showed that myricetin increased cleaved caspase-3 protein levels, naringenin significantly increased poly (ADP-ribose) polymerase protein levels, and rutin increased E-cadherin protein levels. These results indicate that flavonoid exerts anticancer effects on human colon HT-29 cells through a caspase-dependent apoptotic pathway.

• Journal of Nutrition and Health
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• v.38 no.10
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• pp.807-816
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• 2005

The objective of the study was to observe the effect of n-3 PUFA on cell proliferation and apoptosis by determining mRNA and protein of COX-2 and eicosanoid product and the mRNA and protein of Bu and Bcl-2 related to apoptosis in colon carcinogenesis of 1,2- dimethylhydrazine (DMH)-treated rats. Ninety male Sprague Dawley rats weighing about 170g were divided into 3 groups, control and n-3 PUFA supplemented groups (FO group: 6.2 mmoles n-3 PUFA; 2FO group: 12.4 mmoles n-3 PUFA) and fed experimental diet for 14 weeks. All rats were intramuscularly injected with DMH 15 mg/kg twice a week for 6 weeks to deliver total dose of 180 mg/kg body weight. Compared with the control group, 6.2 mmoles n-3 PUFA significantly reduced the levels of mRNA and protein expression of COX-2 and 2-series eicosanoids ($TXB_{2}$ and $PGE_{2}$) and decreased cell proliferation in colonic mucosa. However, high levels of n-3 PUFA supplementation significantly increased the levels of mRNA and protein expression of COX-2, TXB2 and PGE2. and increased cell proliferation which was similar level to that of control group. Compared with the control group, n-3 PUFA, regardless of the amount, significantly increased apoptotic index in colonic mucosa. Western blot and RT-PCR analyses showed that the levels of mRNA and protein expression of Bax were significantly increased by 6.2 mmoles n-3 PUFA, but decreased by 12.4 mmoles n-3 PUFA. The analyses also showed the levels of mRNA and protein expression of Bcl-2 were significantly reduced by 6.2 mmoles n-3 PUFA, but increased by 12.4 mmoles n-3 PUFA. The ratio of Bcl-2/Bax in mRNA and protein was significantly reduced by 6.2 mmoles n-3 PUFA but increased by 12.4 mmoles n-3 PUFA. Overall, these results indicate that n-3 PUFA could be effective in preventing colon carcinogenesis by reducing cell proliferation with lower level of COX-2 and 2-series eicosanoid, and increasing apoptosis by inducing pro-apoptotic gene, Bax and inhibiting anti-apoptotic gene, Bcl-2 in the colonic mucosa of DMH-treated rats. However, high level of n-3 PUFA supplementation could stimulate colon carcinogenesis by increasing cell proliferation and inhibiting apoptosis. (Korean J Nutrition 38(10): 807$\sim$816,2005)

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.989-995
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• 2003

Purpose : Dexamethasone is frequently administered to prevent or treat chronic lung disease in human neonates who are also prone to hypoxic-ischemic(HI) insults. Recently, meta-analysis of the follow-up studies reveals a significantly increased odd ratio for the occurrence of cerebral palsy or an abnormal neurologic outcome, and there is conflicting evidence regarding the impact of dexamethasone exposure on HI brain injury. This study was conducted to explore the effect of post-HI dexamethasone administration on neuronal injury in neonatal rats. Methods : HI was produced in seven-day-old rats by right carotid artery ligation followed by two hours of 8% oxygen exposure. At the end of HI, the animals were injected intraperitoneally either with dexamethasone(0.5 mg/kg) or saline. Neuronal injury was assessed seven days after the HI by the area of infarction, TUNEL reactivity, Bcl-2 and Bax expression in brain. Results : Post-insult dexamethasone administration resulted in reduction of weight gain and a higher mortality rate during seven days after HI. Dexamethasone treatment revealed no effect on the size of brain infarction induced by HI. Bax protein expression increased in dexamethasone treated brain but Bcl-2 protein expression and TUNEL reactivity revealed no significant differences between dexamethasone treated and non treated brain. Increased Bax protein expression suggest upregulation of the apoptosis by dexamethasone. Conclusion : The result suggests the adverse role of Post-HI administration of dexamethasone in neonatal HI.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.37-42
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• 2011

The plant-homologue of Bax Inhibitor, a gene described to suppress the cell death induced by Bax gene expression in yeast, was isolated from rice (Oryza sativa L.). Nucleic acid sequence and amino acid sequence were 741 bp and 247 bp, respectively. The amino acid sequence of the predicted protein was well conserved in plant (84 % in amino acids) and contained five membrane-spanning segments.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.3
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• pp.159-167
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• 2016

Prostate cancer is one of the most common non-skin cancers in men. Armeniacae Amarum Semen has traditionally been used for the treatment of inflammation diseases, leprosy, leucoderma, and tumors. Apoptosis, which is also known as programmed cell death, is an important mechanism in cancer treatment.Objectives : We observed whether an aqueous extract of Armeniacae Amarum Semen induces apoptotic cell death in human DU145 prostate cancer cells.Methods : We treated DU145 cells with Armeniacae Amarum Semen extract and investigated characteristics of apoptosis. And investigated whether treated with Armeniacae Amarum Semen extract increased Bax mRNA expression, Bcl-2 mRNA expression, caspase-3 enzyme activity and their protein level.Results : We have shown that Armeniacae Amarum Semen extract can induce apoptotic cell death in human DU145 prostate cancer cells by caspase-3 activation through the down-regulation on Bcl-2 expression and the up-regulation on Bax expression.Conclusions : It can be expected that an aqueous extract of Armeniacae Amarum Semen may offer a valuable means for the treatment of prostate cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8617-8622
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• 2014

The goal of this study was to establish paclitaxel resistant MCF-7 cells, as in vitro model, to identify the molecular mechanisms leading to acquired chemoresistance in breast cancer cells. Resistant cells were developed by stepwise increasing exposure to paclitaxel. Gene expression levels of Bax and Bcl-2 along with protein levels of caspase-8 and caspase-9 were evaluated in two resistant cell lines (MCF-7/Pac64 and MCF-7/Pac5 nM). Morphological modifications in paclitaxel resistance cells were examined by light microscopy and fluorescence activated cell sorting (FACS). As an important indicator of resistance to chemotheraputic agents, the Bcl-2/Bax ratio showed a significant increase in both MCF-7/Pac5nM and MCF-7/Pac 64nM cells (p<0.001), while caspase-9 levels were decreased (p<0.001) and caspase-8 was increased (p<0.001). FACS analysis demonstrated that MCF-7/Pac64 cells were smaller than MCF-7 cells with no difference in their granularity. Our results support the idea that paclitaxel induces apoptosis in a mitochondrial-dependent manner. Identifying breast cancer patients with a higher Bcl-2/Bax ratio and caspase 9 level and then inhibiting the activity of these proteins may improve the efficacy of chemotheraputic agents.

• The Journal of Korean Medicine
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• v.30 no.4
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• pp.79-92
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• 2009

Objectives: The aim of the present study was to explore the neuroprotective effect and the possible mechanism of the PD-1 extracts on 1-methyl-4-phenyl-1,2,3,6-tetrahydrophridine (MPTP)-lesioned C57BL/6 mouse model of Parkinson's disease (PD). Methods: The mice were supplemented (or not) with 50 or 100 mg/kg/day of PD-1 for 2 weeks, after which MPTP was injected intraperitoneally. We observed that daily administration of PD-1 prevented MPTP-induced depletion of striatal DA, and maintained striatal and nigral tyrosine hydroxylase (TH) protein levels. Results: Our results demonstrated that mice treated with PD-1 prior to MPTP administration showed more abundant TH-immunopositive (TH-ir) fibers and neurons than mice given only MPTP, indicating that PD-1 protects dopaminergic striatal fibers and nigral neurons from MPTP insults. Possible neuroprotective effect of PD-1 was further studied by the detection of antiapoptotic protein (bcl-2) and proapoptotic protein (Bax). In this assay, MPTP elevated the Bax protein and decreased the bcl-2 protein, while these expressions were prevented by PD-1 pre-treatment. Conclusions: The present results suggest that PD-1 is able to protect dopaminergic neurons from MPTP-induced neuronal injury with anti-apoptotic activity being one of the possible mechanisms.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.110-122
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• 2022

The reduction of milk yield caused by heat stress in summer is the main condition restricting the economic benefits of dairy farms. To examine the impact of hyperthermia on bovine mammary epithelial (MAC-T) cells, we incubated the MAC-T cells at thermal-neutral (37℃, CON group) and hyperthermic (42℃, HS group) temperatures for 6 h. Subsequently, the cell viability and apoptotic rate of MAC-T cells, apoptosis-related genes expression, casein and amino acid transporter genes, and the expression of the apoptosis-related proteins were examined. Compared with the CON group, hyperthermia significantly decreased the cell viability (p < 0.05) and elevated the apoptotic rate (p < 0.05) of MAC-T cells. Moreover, the expression of heat shock protein (HSP)70, HSP90B1, Bcl-2-associated X protein (BAX), Caspase-9, and Caspase-3 genes was upregulated (p < 0.05). The expression of HSP70 and BAX (pro-apoptotic) proteins was upregulated (p < 0.05) while that of B-cell lymphoma (BCL)2 (antiapoptotic) protein was downregulated (p < 0.05) by hyperthermia. Decreased mRNA expression of mechanistic target of rapamycin (mTOR) signaling pathway-related genes, amino acid transporter genes (SLC7A5, SLC38A3, SLC38A2, and SLC38A9), and casein genes (CSNS1, CSN2, and CSN3) was found in the heat stress (HS) group (p < 0.05) in contrast with the CON group. These findings illustrated that hyperthermia promoted cell apoptosis and reduced the transport of amino acids into cells, which inhibited the milk proteins synthesis in MAC-T cells.