• BMB Reports
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• v.49 no.7
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• pp.382-387
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• 2016

Reactive oxygen species generated under oxidative stress are involved in neuronal diseases, including ischemia. Glutathione S-transferase pi (GSTpi) is a member of the GST family and is known to play important roles in cell survival. We investigated the effect of GSTpi against oxidative stress-induced hippocampal HT-22 cell death, and its effects in an animal model of ischemic injury, using a cell-permeable PEP-1-GSTpi protein. PEP-1-GSTpi was transduced into HT-22 cells and significantly protected against H2O2-treated cell death by reducing the intracellular toxicity and regulating the signal pathways, including MAPK, Akt, Bax, and Bcl-2. PEP-1-GSTpi transduced into the hippocampus in animal brains, and markedly protected against neuronal cell death in an ischemic injury animal model. These results indicate that PEP-1-GSTpi acts as a regulator or an antioxidant to protect against oxidative stress-induced cell death. Our study suggests that PEP-1-GSTpi may have potential as a therapeutic agent for the treatment of ischemia and a variety of oxidative stress-related neuronal diseases.

• Molecules and Cells
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• v.38 no.2
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• pp.138-144
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• 2015

Raloxifene is a selective estrogen receptor modulator (SERM) that binds to the estrogen receptor (ER), and exhibits potent anti-tumor and autophagy-inducing effects in breast cancer cells. However, the mechanism of raloxifene-induced cell death and autophagy is not well-established. So, we analyzed mechanism underlying death and autophagy induced by raloxifene in MCF-7 breast cancer cells. Treatment with raloxifene significantly induced death in MCF-7 cells. Raloxifene accumulated GFP-LC3 puncta and increased the level of autophagic marker proteins, such as LC3-II, BECN1, and ATG12-ATG5 conjugates, indicating activated autophagy. Raloxifene also increased autophagic flux indicators, the cleavage of GFP from GFP-LC3 and only red fluorescence-positive puncta in mRFP-GFP-LC3-expressing cells. An autophagy inhibitor, 3-methyladenine (3-MA), suppressed the level of LC3-II and blocked the formation of GFP-LC3 puncta. Moreover, siRNA targeting BECN1 markedly reversed cell death and the level of LC3-II increased by raloxifene. Besides, raloxifene-induced cell death was not related to cleavage of caspases-7, -9, and PARP. These results indicate that raloxifene activates autophagy-dependent cell death but not apoptosis. Interestingly, raloxifene decreased the level of intracellular adenosine triphosphate (ATP) and activated the AMPK/ULK1 pathway. However it was not suppressed the AKT/mTOR pathway. Addition of ATP decreased the phosphorylation of AMPK as well as the accumulation of LC3-II, finally attenuating raloxifene-induced cell death. Our current study demonstrates that raloxifene induces autophagy via the activation of AMPK by sensing decreases in ATP, and that the overactivation of autophagy promotes cell death and thereby mediates the anti-cancer effects of raloxifene in breast cancer cells.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.425-433
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• 2023

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7435-7439
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• 2015

A failure of a cell to self destruct has long been associated with cancer progression and development. The fact that tumour cells may not instigate cell arrest or activate cell death mechanisms upon cancer drug delivery is a major concern. Autophagy is a mechanism whereby cell material can be engulfed and digested while apoptosis is a self-killing mechanism, both capable of hindering multiplication after cell injury. In particular situations, autophagy and apoptosis seem to co-exist simultaneously or interdependently with the aid of mutual proteins. This review covers roles of microRNAs and chemopreventive agents and makes an attempt at outlining possible partnerships in maximizing cancer cell death with minimal normal cell damage.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1059-1064
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• 2001

Objective : 6R-Tetrahydrobiopterin(BH4) is a cofactor for the aromatic amino acid hydroxylases which is essential for the biosynthesis of catecholamines and serotonin. It also acts as a cofactor for nitric oxide synthase, and stimulates the release of some neurotransmitters such as dopamine, serotonin, acetylcholine and glutamate. Recently, it has been reported that BH4 could induce cellular proliferation and enhance neuronal survival. This study was performed to investigate the antioxidative effect of BH4 on the various oxidative insults in mouse cerebral cortical cell cultures. Methods : Iron ion(FeCl2), zinc ion(ZnCl2), sodium nitroprusside(SNP) and buthionine sulfoximine(BSO, a glutathione depletor) were used as oxidants. Cell death was assessed by measurement of lactate dehydrogenase efflux to bathing media at the end of exposure. Result : All 4 oxidants induced neuronal cell death associated with cell body swelling, which was markedly inhibited by trolox($100{\mu}M$), a vitamin E analog. BH4($10-100{\mu}M$) markedly inhibited the neuronal cell death induced by all 4 oxidants($20{\mu}M\;Cu^{2+}$, $20{\mu}M\;Zn^{2+}$, $1{\mu}M$ SNP or 1mM BSO). However, BH4 failed to inhibit the neuronal cell death induced by 24hr exposure to $20{\mu}M$ NMDA. Conculsion : These results suggest that BH4 has antioxidative action independently of any actions of enzyme cofactor.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.79.2-79.2
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• 2003

Minocycline is known to protect neurons from microglia-mediated cell death in many experimental models of brain diseases including ischemic stroke, Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), traumatic brain injury, multiple sclerosis, and Parkinson's disease. Activation of caspase-2, 3, 8, and 9 was evident within 2-8 hr following oxidative insult with 0.5 mM hydrogen peroxide in PC12 cells. Minocycline significantly attenuated activation of these caspases up to 18 hr, resulting a significant increase in cell viability as assessed by MTT assay. (omitted)

• The Journal of Korean Medicine
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• v.29 no.2
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• pp.21-31
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• 2008

Backgrounds: Singihwan is used "to strengthen inborn energy" and we suspected a protective effect on brain neuron cells. Objectives: The aim of this study was to evaluate the effects of Singihwan (SGH) on traumatic brain injury-induced delayed apoptosis in rat hippocampal dentate gyrus. Methods: For a surgical induction of traumatic brain injury (TBI), a 5 mm diameter stainless rod was used to make traumatic attack from the surface of the brain used by an impactor. The protective effect of the aqueous extract of SGH against TBI in the rat hippocampal dentate gyrus was investigated by using step-down avoidance task, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, Bax immunohistochemistry, and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. Results: The aqueous extract of SGH suppressed the TBI-induced increase in apoptosis and cell proliferation in the hippocampal dentate gyrus. Conclusions: It is possible that the aqueous extract of SGH has a neuroprotective effect on TBI-induced neuronal cell death.

• The Korea Journal of Herbology
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• v.28 no.2
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• pp.45-53
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• 2013

Objectives : The purpose of the study is to determine the neuroprotective effects of the water and 80% EtOH extract of some herbal medicine plant on ischemia reperfusion-induced cell death in SK-N-SH human brain neuronal cells. Methods : SK-N-SH cells were treated with 3mM sodium azide and 10 mM 2-deoxy-D-glucose for 45 min, ptior to the addition of different concentrations of herbal medicine plant extract (0, 10, 25, 50, 100, 250, 500, 1000 ${\mu}g/ml$) for 2 hr and then reperfused with growth medium, incubated for 24 h. Cell viability was determined by WST-1 assay, and ATP/ADP levels were measured by ADP/ATP ratio assay kit. Results : Herbal medicine plant extract significantly inhibited decreasing the cell viability in ischemia-induced SK-N-SH cells. Also increased the ratio of ADP/ATP in ischemia-induced neuronal cells. Conclusions : Our results suggest that herbal medicine plant extract has a neuroprotective property via increasing the energy levels in neuronal cells, suggesting that extract may has a therapeutic potential in the treatment of ischemic brain injury. The exact component and mechanism remains for the future study.

• International Journal of Oral Biology
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• v.46 no.1
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• pp.15-22
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• 2021

Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and Bcl-xL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.21-21
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• 2003

Male germ cell apoptosis has been extensively explored in rodent. In contrast, very little is known about their susceptibility to apoptosis stimuli of developing germ cell stages at the time when germ cell depletion after busulfan treatment occurs. Furthermore, it is still unanswered how spermatogonial stem cells are resistant to busulfan treatment. We examined the change of gene expression in detail using cDNA microarray analysis of mouse testis treated with busulfan. A subtoxic dose of busulfan (40mg/kg of body weight) transiently increased 228 mRNA levels among of the 8000 genes analyzed. TagMan analysis confirmed that the mRNA levels such as defensive protein, support protein, enzymatic protein, transport protein, and hormonal protein were rapidly increased. These results were re-confirmed by real-time PCR analysis. However, the expression levels of these genes induced by busulfan treatment were significantly reduced in control testis, indicating that both of male germ cells and somatic cells after busulfan treatment induces self-defense mechanism for protection of testicular cell death. Among them, we conclude that defense proteins play a key role in testis injury induced by busulfan.