• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.04a
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• pp.125-144
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• 2007

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.718-724
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• 2017

The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.2
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• pp.73-88
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• 2009

Objectives : Neuronal changes that result from treadmill exercise for patients with Parkinson's disease(PD) have not been well documented, although some clinical and laboratory reports suggest that regular exercise may produce a neuroprotective effect and restore dopaminergic and motor functions. However, it is not clear if the improvements are due to neuronal alterations within the affected nigrostriatal region or result from a more general effect of exercise on affect areas and motivation. In this study, we demonstrate that motorized treadmill exercise improves the neuronal outcomes in rodent models of PD. Methods : We used a chronic mouse model of parkinsonism, which was induced by injecting male C57BL/6 mice with 10 doses(Every 12 hour) of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (30 mg/kg) and probenecid (20 mg/kg) over 5 days. These mice were able to sustain an exercise training program on a motorized rodent treadmill at a speed of 18 m/min, $0^{\circ}$ of inclination, 40 min/day, 5 days/week for 4 weeks. At the end of exercise training, we extracted the brain and compared their neuronal and neurochemical changes with the control(saline and sedentary) mice groups. Synphilin protein is the substance that manifestly reacts with ${\alpha}$-synuclein. In this study, we used Synphilin as a manifest sign of recovery from neurodegeneration. We analyze the brain stems of the substantia nigra and striatum region using the western blotting technique. Results : There were no expression of synphilin in the saline-induced groups. The addition of MPTP(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) greatly accelerated synphilin expression which meant an aggregation of ${\alpha}$-synuclein. But, the MPTP-induced treadmill exercise group showed significantly lower expression than the MPTP-induced sedentary group. This means treadmill exercise has a definite effect on the decrease of ${\alpha}$-synuclein aggregation. Conclusions : In this study, our results suggest that treadmill exercise promoted the removal of the aggregation of ${\alpha}$-synuclein, resulting in protection against disease development and blocks the apoptotic process in the chronic parkinsonian mice brain with severe neurodegeneration.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.625-632
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• 2017

Familial Parkinson's disease (PD) has been linked to point mutations and duplication of the ${\alpha}$-synuclein (${\alpha}$-syn) gene. Mutant ${\alpha}$-syn expression increases the vulnerability of neurons to exogenous insults. In this study, we developed a new PD model in the transgenic mice expressing mutant hemizygous (hemi) or homozygous (homo) A53T ${\alpha}$-synuclein (${\alpha}$-syn Tg) and their wildtype (WT) littermates by treatment with sub-toxic (10 mg/kg, i.p., daily for 5 days) or toxic (30 mg/kg, i.p., daily for 5 days) dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Tyrosine hydroxylase and Bcl-2 levels were reduced in the ${\alpha}$-syn Tg but not WT mice by sub-toxic MPTP injection. In the adhesive removal test, time to remove paper was significantly increased only in the homo ${\alpha}$-syn Tg mice. In the challenging beam test, the hemi and homo ${\alpha}$-syn Tg mice spent significantly longer time to traverse as compared to that of WT group. In order to find out responsible proteins related with vulnerability of mutant ${\alpha}$-syn expressed neurons, DJ-1 and ubiquitin enzyme expressions were examined. In the SN, DJ-1 and ubiquitin conjugating enzyme, UBE2N, levels were significantly decreased in the ${\alpha}$-syn Tg mice. Moreover, A53T ${\alpha}$-syn overexpression decreased DJ-1 expression in SH-SY5Y cells. These findings suggest that the vulnerability to oxidative injury such as MPTP of A53T ${\alpha}$-syn mice can be explained by downregulation of DJ-1.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.665-668
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• 2013

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.848-854
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• 2012

We have studied the oligomerization of a fibril-forming segment of ${\alpha}$-Synulcein using a replica exchange molecular dynamics (REMD) simulation. The simulation was performed with trimers and tetramers of a 12 amino acid residue stretch (residues 71-82) of ${\alpha}$-Synulcein. From extensive REMD simulations, we observed the spontaneous formation of both trimer and tetramer, demonstrating the self-aggregating and fibril-forming properties of the peptides. Secondary structure profile and clustering analysis illustrated that antiparallel ${\beta}$-sheet structures are major species corresponding to the global free energy minimum. As the size of the oligomer increases from a dimer to a tetramer, conformational stability is increased. We examined the evolution of simple order parameters and their free energy profiles to identify the process of aggregation. It was found that the degree of aggregation increased as time passed. Tetramer formation was slower than trimer formation and a transition in order parameters was observed, indicating the full development of tetramer conformation which is more stable than that of the trimer. The shape of free energy surface and change of order parameter distributions indicate that the oligomer formation follows a dock-and-lock process.

• BMB Reports
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• v.50 no.7
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• pp.345-354
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• 2017

Autophagy, a catabolic process necessary for the maintenance of intracellular homeostasis, has recently been the focus of numerous human diseases and conditions, such as aging, cancer, development, immunity, longevity, and neurodegeneration. However, the continued presence of autophagy is essential for cell survival and dysfunctional autophagy is thought to speed up the progression of neurodegeneration. The actual molecular mechanism behind the progression of dysfunctional autophagy is not yet fully understood. Emerging evidence suggests that basal autophagy is necessary for the removal of misfolded, aggregated proteins and damaged cellular organelles through lysosomal mediated degradation. Physiologically, neurodegenerative disorders are related to the accumulation of amyloid ${\beta}$ peptide and ${\alpha}-synuclein$ protein aggregation, as seen in patients with Alzheimer's disease and Parkinson's disease, respectively. Even though autophagy could impact several facets of human biology and disease, it generally functions as a clearance for toxic proteins in the brain, which contributes novel insight into the pathophysiological understanding of neurodegenerative disorders. In particular, several studies demonstrate that natural compounds or small molecule autophagy enhancer stimuli are essential in the clearance of amyloid ${\beta}$ and ${\alpha}-synuclein$ deposits. Therefore, this review briefly deliberates on the recent implications of autophagy in neurodegenerative disorder control, and emphasizes the opportunities and potential therapeutic application of applied autophagy.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.744-754
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• 2020

We investigated the whether endurance exercise and MitoQ intake mediated neuroprotection are associated with mitochondrial function in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine(MPTP) -induced mice model of Parkinson's disease. C57BL/6 male mice were randomly assigned to five groups: Normal Conrol(NC, n=10), MPTP Control(MC, n=10), MPTP +MitoQ(MQ, n=10), MPTP + Exercise(ME, n=10) and MPTP + MitoQ + Exercise(MQE, n=10). Exercise intervention groups performed the treadmill exercise for 5days/week for 5 weeks with gradual increase of intensity. MitoQ intake groups consumed the MitoQ at a concentration of 250μmol by dissolving with water during experiment period. Our data demonstrated that ME and MQE group restored MPTP-induced motor dysfunction. In addition, treatment groups(MQ, ME and MQE) increased tyrosine hydroxylase levels, and suppressed the accumulation of α-synuclein levels. Futhermore, treatment groups modulated the mitochondrial function such as upregulated mitochondrial biogenesis, increased antioxidant enzyme, enhanced a anti-apoptotic protein(e.g., BCL2), and reduced a pro-apoptotic protein(e.g., BAX). Taken together, these results suggested that endurance exercise and MitoQ intake-mediated increase in mitochondrial function contributes to improvement of aggravated dopaminergic neuronal, resulting in attenuation of motor function of Parkinson's disease.

• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.118-125
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• 2011

Free radical scavenging and antioxidants have attracted attention as a way to prevent the progression of Parkinson's disease (PD). This study was carried out to investigate the effects of n-hexane fraction from Laurus nobilis L. (Lauraceae) leaves (HFL) on dopamine (DA)-induced intracellular reactive oxygen species (ROS) production and apoptosis in human neuroblastoma SH-SY5Y cells. Compared with apomorphine (APO, $IC_{50}=18.1\;{\mu}M$) as a positive control, the HFL $IC_{50}$ value for DA-induced apoptosis was $3.0\;{\mu}g/ml$, and two major compounds from HFL, costunolide and dehydrocostus lactone, were $7.3\;{\mu}M$ and $3.6\;{\mu}M$, respectively. HFL and these major compounds significantly inhibited ROS generation in DA-induced SH-SY5Y cells. A rodent 6-hydroxydopamine (6-OHDA) model of PD was employed to investigate the potential neuroprotective effects of HFL in vivo. 6-OHDA was injected into the substantia nigra of young adult rats and an immunohistochemical analysis was conducted to quantitate the tyrosine hydroxylase (TH)-positive neurons. HFL significantly inhibited 6-OHDA-induced TH-positive cell loss in the substantia nigra and also reduced DA induced $\alpha$-synuclein (SYN) formation in SH-SY5Y cells. These results indicate that HFL may have neuroprotective effects against DA-induced in vitro and in vivo models of PD.

• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.615-629
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• 2021

An active compound, triterpene saponin, astersaponin I (AKNS-2) was isolated from Aster koraiensis Nakai (AKNS) and the autophagy activation and neuroprotective effect was investigated on in vitro and in vivo Parkinson's disease (PD) models. The autophagy-regulating effect of AKNS-2 was monitored by analyzing the expression of autophagy-related protein markers in SH-SY5Y cells using Western blot and fluorescent protein quenching assays. The neuroprotection of AKNS-2 was tested by using a 1-methyl-4-phenyl-2,3-dihydropyridium ion (MPP⁺)-induced in vitro PD model in SH-SY5Y cells and an MPTP-induced in vivo PD model in mice. The compound-treated SH-SY5Y cells not only showed enhanced microtubule-associated protein 1A/1B-light chain 3-II (LC3-II) and decreased sequestosome 1 (p62) expression but also showed increased phosphorylated extracellular signal-regulated kinases (p-Erk), phosphorylated AMP-activated protein kinase (p-AMPK) and phosphorylated unc-51-like kinase (p-ULK) and decreased phosphorylated mammalian target of rapamycin (p-mTOR) expression. AKNS-2-activated autophagy could be inhibited by the Erk inhibitor U0126 and by AMPK siRNA. In the MPP⁺-induced in vitro PD model, AKNS-2 reversed the reduced cell viability and tyrosine hydroxylase (TH) levels and reduced the induced α-synuclein level. In an MPTP-induced in vivo PD model, AKNS-2 improved mice behavioral performance, and it restored dopamine synthesis and TH and α-synuclein expression in mouse brain tissues. Consistently, AKNS-2 also modulated the expressions of autophagy related markers in mouse brain tissue. Thus, AKNS-2 upregulates autophagy by activating the Erk/mTOR and AMPK/mTOR pathways. AKNS-2 exerts its neuroprotective effect through autophagy activation and may serve as a potential candidate for PD therapy.