• Nutrition Research and Practice
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• v.14 no.3
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• pp.188-202
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• 2020

BACKGROUND/OBJECTIVES: Brain aging is a major risk factor for severe neurodegenerative diseases. Conversely, L-histidine and L-carnosine are known to exhibit neuroprotective effects. The aim of this study was to examine the potential for L-histidine, L-carnosine, and their combination to mediate anti-brain aging effects in neuronal cells subjected to D-galactose-induced aging. MATERIALS/METHODS: The neuroprotective potential of L-histidine, L-carnosine, and their combination was examined in a retinoic acid-induced neuronal differentiated SH-SY5Y cell line exposed to D-galactose (200 mM) for 48 h. Neuronal cell proliferation, differentiation, and expression of anti-oxidant enzymes and apoptosis markers were subsequently evaluated. RESULTS: Treatment with L-histidine (1 mM), L-carnosine (10 mM), or both for 48 h efficiently improved the proliferation, neurogenesis, and senescence of D-galactose-treated SH-SY5Y cells. In addition, protein expression levels of both neuronal markers (β tubulin-III and neurofilament heavy protein) and anti-oxidant enzymes, glutathione peroxidase-1 and superoxide dismutase-1 were up-regulated. Conversely, protein expression levels of amyloid β (1-42) and cleaved caspase-3 were down-regulated. Levels of mRNA for the pro-inflammatory cytokines, interleukin (IL)-8, IL-1β, and tumor necrosis factor-α were also down-regulated. CONCLUSIONS: To the best of our knowledge, we provide the first evidence that L-histidine, L-carnosine, and their combination mediate anti-aging effects in a neuronal cell line subjected to D-galactose-induced aging. These results suggest the potential benefits of L-histidine and L-carnosine as anti-brain aging agents and they support further research of these amino acid molecules.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.275-281
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• 2014

Autophagy is a series of catabolic process mediating the bulk degradation of intracellular proteins and organelles through formation of a double-membrane vesicle, known as an autophagosome, and fusing with lysosome. Autophagy plays an important role of death-survival decisions in neuronal cells, which may influence to several neurodegenerative disorders including Parkinson's disease. Chebulagic acid, the major constituent of Terminalia chebula and Phyllanthus emblica, is a benzopyran tannin compound with various kinds of beneficial effects. This study was performed to investigate the autophagy enhancing effect of chebulagic acid on human neuroblastoma SH-SY5Y cell lines. We determined the effect of chebulagic acid on expression levels of autophagosome marker proteins such as, DOR/TP53INP2, Golgi-associated ATPase Enhancer of 16 kDa (GATE 16) and Light chain 3 II (LC3 II), as well as those of its upstream pathway proteins, AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and Beclin-1. All of those proteins were modulated by chebulagic acid treatment in a way of enhancing the autophagy. Additionally in our study, chebulagic acid also showed a protective effect against 1-methyl-4-phenylpyridinium ($MPP^+$) - induced cytotoxicity which mimics the pathological symptom of Parkinson's disease. This effect seems partially mediated by enhanced autophagy which increased the degradation of aggregated or misfolded proteins from cells. This study suggests that chebulagic acid is an attractive candidate as an autophagy-enhancing agent and therefore, it may provide a promising strategy to prevent or cure the diseases caused by accumulation of abnormal proteins including Parkinson's disease.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.707-716
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• 2020

Objective : The function of B7H3, a member of the B7 family of proteins, in neuroblastoma (NB) remains poorly characterized. Here we examine the expression pattern of B7H3 in clinical NB specimens and characterize the phenotype of B7H3 knock-down in NB cell line. Methods : Immunohistochemical (IHC) staining was carried out to assess the expression of B7H3 in clinical NB specimens. Survival association was analyzed using five Gene Expression Omnibus (GEO) datasets (GSE85047, GSE45480, GSE62564, GSE16476, GSE49710). Clonogenic survival and flow cytometry were performed after B7H3 knockdown to assess the cellular proliferation and cell survival in vitro. Impact of B7H3 silencing on NB growth was examined in vivo using the SH-SY5Y xenograft model. Results : On IHC staining, B7H3 was widely expressed in clinical NB specimens. Analysis of the transcriptional profiles of five GEO datasets clinically annotated NB specimens revealed that decreased B7H3 expression was associated with improved overall survival. B7H3 knockdown suppressed the proliferation of the SH-SY5Y NB model in vitro and in vivo. Cell cycle analysis revealed that B7H3 silencing induced G1/S arrest. This arrest was associated with the suppression of E2F1 expression and induction of Rb expression. Conclusion : Our results demonstrate that B7H3 expression correlate with clinical survival in NB patients. Preliminary studies suggest that B7H3 may mediate the G1/S transition.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.1-7
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• 2017

Parkinson's disease (PD) is an irreversible neurological disorder with related locomotor dysfunction and is characterized by the selective loss of nigral neurons. PD can be experimentally induced by 6-hydroxydopamine (6-OHDA). It has been reported that reactive oxygen species, which deplete endogenous glutathione (GSH) levels, may play important roles in the dopaminergic cell death characteristic of PD. Fucoidan, a sulfated algal polysaccharide, exhibits anti-inflammatory and anti-oxidant actions. In this study, we investigated whether fucoidan can protect against 6-OHDA-mediated cytotoxicity in SH-SY5Y cells. Cytotoxicity was evaluated by using MTT and LDH assays. Fucoidan alleviated cell damage evoked by 6-OHDA dose-dependently. Fucoidan reduced the number of apoptotic nuclei and the extent of annexin-V-associated apoptosis, as revealed by DAPI staining and flow cytometry. Elevation of lipid peroxidation and caspase-3/7 activities induced by 6-OHDA was attenuated by fucoidan, which also protected against cytotoxicity evoked by buthionine-sulfoximine-mediated GSH depletion. Reduction in the glutathione/glutathione disulfide ratio induced by 6-OHDA was reversed by fucoidan, which also inhibited 6-OHDA-induced disruption of mitochondrial membrane potential. The results indicate that fucoidan may have protective action against 6-OHDA-mediated neurotoxicity by modulating oxidative injury and apoptosis through GSH depletion.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1275-1281
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• 2005

The $G_{q/11}$ protein-coupled receptors, such as muscarinic (M1 & M3) receptors, have been shown to regulate the release of a soluble amyloid precursor protein (sAPP$\alpha$) produced from $\alpha$-secretase processing. However, there is no direct evidence for the precise characteristics of G proteins, and the signaling mechanism for the regulation of $G_{q/11}$ protein-coupled receptor mediated sAPP$\alpha$ release is not clearly understood. This study examined whether the muscarinic receptor-mediated release of sAPP$\alpha$ is directly regulated by $G\alpha_{q/11}$ proteins. The HEK293 cells were transiently cotransfected with muscarinic M3 receptors and a dominant-negative minigene construct of the G protein $\alpha$ subunit. The sAPP$\alpha$ release in the media was measured using an antibody specific for sAPP. The sAPP$\alpha$ release enhancement induced by muscarinic receptor stimulation was decreased by a $G_{q/11}$ minigene construct, whereas it was not blocked by a control minigene construct (the G$\alpha$ carboxy peptide in random order, G$\alpha_{q}$R) or $G\alpha_{j}$ constructs. This indicated a direct role of the $G\alpha_{q/11}$ protein in the regulation of muscarinic M3 receptor-mediated sAPP$\alpha$ release. We also investigated whether the transactivation of the epidermal growth factor receptor (EGFR) by a muscarinic agonist could regulate the sAPP$\alpha$ release in SH-SY5Y cells. Pretreatment of a specific EGFR kinase inhibitor, tyrophostin AG1478 (250 nM), blocked the EGF-stimulated sAPP$\alpha$ release, but did not block the oxoM­stimulated sAPP$\alpha$ release. This demonstrated that the transactivation of the EGFR by muscarinic receptor activation was not involved in the muscarinic receptor-mediated sAPP$\alpha$ release.

• Journal of Oriental Neuropsychiatry
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• v.30 no.4
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• pp.327-340
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• 2019

Objectives: Alzheimer's disease (AD) is a complex disease accompanied by slow impairment of memory and coordination leading to behavioral changes. To date, the only treatment option is to delay the progress of the disease. The purpose of this study was to investigate the synergistic effects of combination treatment with donepezil and three herbal extracts SIP-3 in the AD mouse model induced by amyloid-β (Aβ). Methods: We tested SIP-3 extracts for the cytotoxicity on Aβ-treated SH-SY5Y cells. Then the synergistic effects of SIP-3 and donepezil were evaluated in the AD mouse model using animal experiments and the next generation sequencing (NGS) study. Results: We found that co-treatment with SIP-3 extracts and donepezil increased the viability in Aβ-treated SH-SY5Y cells. The beneficial effects of the co-treatment were also observed in the Aβ-induced AD mouse model. The NGS study was performed to show that the co-treatment of SIP-3 and donepezil restored the disease phenotype closely to the normal level in the AD mouse model in terms of mRNA expression. However, the phenotypes were only partially restored. Conclusions: This study suggests that the combination treatment has a potential to be used for the treatment of AD. However, longer periods of treatment may be required.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.85-91
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• 2019

Oxidative stress is considered a major contributor in the pathogenesis of diabetic neuropathy and in diabetes complications, such as nephropathy and cardiovascular diseases. Diabetic neuropathy, which is the most frequent complications of diabetes, affect sensory, motor, and autonomic nerves. This study aimed to investigate whether 7,8-dihydroxyflavone (7,8-DHF) protects SH-SY5Y neuronal cells against high glucose-induced toxicity. In the current study, we found that diabetic patients exhibited higher lipid peroxidation caused by oxidative stress than healthy subjects. 7,8-DHF exhibits superoxide anion and hydroxyl radical scavenging activities. High glucose-induced toxicity severely damaged SH-SY5Y neuronal cells, causing mitochondrial depolarization; however, 7,8-DHF recovered mitochondrial polarization. Furthermore, 7,8-DHF effectively modulated the expression of pro-apoptotic protein (Bax) and anti-apoptotic protein (Bcl-2) under high glucose, thus inhibiting the activation of caspase signaling pathways. These results indicate that 7,8-DHF has antioxidant effects and protects cells from apoptotic cell death induced by high glucose. Thus, 7,8-DHF may be developed into a promising candidate for the treatment of diabetic neuropathy.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.865-872
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• 2018

In neuronal cell deaths, oxidative stress is normally implicated with a most of these deaths occurring in neurodegenerative disorders such as the Alzheimer's and Parkinson's diseases. In this study, the neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts on hydrogen peroxide ($H_2O_2$)-induced oxidative stress in neuroblastic cell line were investigated. For an hour, hydrogen peroxide of $100{\mu}M$ concentration, was induced on neuroblastic cells, causing apoptic cell death. For the neuroprotection, a sample of neuroblastic cells had been pre-treated with SC and RF extracts for 24 hours before application of the hydrogen peroxide. No neurotoxic effects were observed in the cells that had been treated by SC and RF. This prove that the treatment of SC and RF extract prevented apoptotic cell death of neuroblastic cell line exposed to oxidative injury. In addition, applying both SC and RF extracts at a 7:3 ratio increased the neuronal cell survival rate, compared to individual treatments of SC and RF extract. This study suggests that SC and RF extracts may be potential therapeutic agents for the prevention of neuronal cell death.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.357-363
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• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.51-58
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• 2021

Oxidative stress-induced neurodegeneration is one of several etiologies underlying neurodegenerative disease. In the present study, we investigated the functional role of histone methyltransferase G9a in oxidative stress-induced degeneration in human SH-SY5Y neuroblastoma cells. Cell viability significantly decreased on H2O2 treatment; however, treatment with the G9a inhibitor BIX01294 partially attenuated this effect. The expression of neuron-specific genes also decreased in H2O2-treated cells; however, it recovered on G9a inhibition. H2O2-treated cells showed high levels of H3K9me2 (histone H3 demethylated at the lysine 9 residue), which is produced by G9a activation; BIX01294 treatment reduced aberrant activation of G9a. H3K9me2 occupancy of the RE-1 site in neuron-specific genes was significantly increased in H2O2-treated cells, whereas it was decreased in BIX01294-treated cells. The differentiation of H2O2-treated cells also recovered on G9a inhibition by BIX01294. Consistent results were observed when used another G9a inhibitor UCN0321. These results demonstrate that oxidative stress induces aberrant activation of G9a, which disturbs the expression of neuron-specific genes and progressively mediates neuronal cell death. Moreover, a G9a inhibitor can lessen aberrant G9a activity and prevent neuronal damage. G9a inhibition may therefore contribute to the prevention of oxidative stress-induced neurodegeneration.