• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1029-1030
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• 2010

• BMB Reports
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• v.49 no.6
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• pp.337-343
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• 2016

Understanding of trafficking, processing, and degradation mechanisms of amyloid precursor protein (APP) is important because APP can be processed to produce β-amyloid (Aβ), a key pathogenic molecule in Alzheimer's disease (AD). Here, we found that APP contains KFERQ motif at its C-terminus, a consensus sequence for chaperone-mediated autophagy (CMA) or microautophagy which are another types of autophagy for degradation of pathogenic molecules in neurodegenerative diseases. Deletion of KFERQ in APP increased C-terminal fragments (CTFs) and secreted N-terminal fragments of APP and kept it away from lysosomes. KFERQ deletion did not abolish the interaction of APP or its cleaved products with heat shock cognate protein 70 (Hsc70), a protein necessary for CMA or microautophagy. These findings suggest that KFERQ motif is important for normal processing and degradation of APP to preclude the accumulation of APP-CTFs although it may not be important for CMA or microautophagy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.53-57
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• 2004

In order to evaluate the neuroprotective effects of Kamisinsunbulo-dan(KSM), the cytotoxicity of amyloid β and the recovering effect of KSM were checked at first. Then the viability of C6 cells was tested in comparison with each concentration of KSM. The cytotoxicity of amyloid β(31-35) showed from 5 μM higher to 100 μM. And the recovering effect by KSM showed significantly at 100㎍/㎖. concentration. And the cell viability was shown significantly over 200 ㎍/㎖ of KSM. This is thought that the viability has some relation to length of culturing duration, 6 to 12 hrs. Lastly in the western blotting of APP, the amount of low molecule's APP was decreased. So the APP form ratio(APPr) changed to increase, and it meant that KSM can be used to lower the toxic APP, and can be a candidate for Alzheimer's disease.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.139-140
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• 2003

Inflammatory as well as oxidative tissue damage has been implicated in pathophysiology of Alzheimer's disease (AD), and non-steroidal anti-inflammatory drugs have been reported to have beneficial effects in the treatment or prevention of AD. In the present study, we investigated the effect of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on inflammatory cell death induced by beta-amyloid, a neurotoxic peptide associated with senile plaques formed in the brains of patients with AD.(omitted)

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.447-450
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• 2006

Cerebral amyloid angiopathy[CAA] is characterized by the deposition of amyloid ${\beta}-protein$ in the walls of small to medium-sized arteries of the leptomeninges and cerebral cortex. While often asymptomatic, CAA can develop into intracerebral hemorrhage facilitated by arterial hypertension. We report the case of a 52-year-old man with CAA and arterial hypertension who developed recurrent cerebral hemorrhages on three different occasions and in multiple non-overlapping loci over a period of nine years. Based on our findings, we recommend brain biopsies for all patients undergoing evacuation of multiple recurrence or atypical pattern intracerebral hemorrhages.

• Journal of the Korean Magnetic Resonance Society
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• v.26 no.1
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• pp.17-20
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• 2022

High-pressure (HP) NMR is a versatile tool to investigate diverse features of proteins. This technique has been particularly powerful to elucidate structural dynamics that only populates sufficiently in a pressurized condition. Amyloidogenic proteins, which are prone to aggregate and form amyloid fibrils, often maintains highly dynamic states in its native or aggregation-prone states, and HP NMR contributed much to advance our understandings of the dynamic behaviors of amyloidogenic proteins and the molecular mechanisms of their aggregation. In this mini review, we therefore summarize recent HP NMR studies on amyloid-beta (Aβ), the representative amyloidogenic intrinsically disordered protein (IDP).

• Journal of Microbiology
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• v.44 no.6
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• pp.665-670
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• 2006

Amyloid $\beta$-peptide (A$\beta$), which is a product of the proteolytic effect of $\beta$-secretase (BACE) on an amyloid precursor protein, is closely associated with Alzheimer's disease (AD) pathogenesis. There is sufficient evidence to suggest that a BACE inhibitor may reduce A$\beta$ levels, thus decreasing the risk of AD. In a previous study, an extract of Clavicorona pyxidata DGUM 29005 mycelia was found to inhibit the production of a soluble $\beta$-amyloid precursor protein (s$\beta$APP), A$\beta$, and BACE in neuronal cell lines. We sought to determine whether this mycelial extract exerts the same effect in human rhabdomyosarcoma A-204 and rat pheochromocytoma PC-12 cells. We found that the production of A$\beta$ decreased in a dose-dependent manner in the presence of the mycelial extract and that the concentration of A$\beta$ never exceeded $50{\mu}g/ml$. The presence of sAPP was detected in every culture medium to which the mycelial extract had been added and its concentration remained the same, regardless of the concentration of the extract used. Endogenous $\beta$-secretase activity in A-204 and PC-12 cellular homogenates also decreased in the presence of this extract. These cells, in culture, were not susceptible to the cytotoxic activity of the mycelial extract.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.195-200
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• 2009

Zinc released from excited glutamatergic neurons accelerates amyloid ${\beta}$ (A ${\beta}$) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A ${\beta}$ concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A ${\beta}$ production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A ${\beta}$ 40 and A ${\beta}$ 42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both ${\beta}$-and ${\alpha}$-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A ${\beta}$ 40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A ${\beta}$ secretion.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.251-258
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• 2008

The neurotoxicity of C-terminal fragments of amyloid precusor protein (CT) is known to play some roles in Alzheimer's disease progression. In this study, we investigated the effects of the recombinant C-terminal 105 amino acid fragment of amyloid precusor protein (CT105) on cholinergic function using CT105-injected rat. To study the effects of CT105 on septohippocampal pathway, choline acetyltransferase (ChAT) positive neurons were examined in the medial septum and in the diagonal band after an injection of CT105 peptide into the lateral ventricle. Immunohistological analysis revealed that the number of ChAT-immunopositive cells decreased significantly in both medial septum and diagonal band. In addition, CT105 decreased ChAT-immunopositive cells in the hippocampal area, particulary in the dentate gyros. To study the effect of amyloid beta peptide ($A{\beta}$) and CT105 on the cholinergic system, each peptide was injected into the left lateral ventricle, and acetylcholine (ACh) levels were monitored in hippocampus. ACh level in the hippocampal area was reduced to 60% of control level in $A{\beta}$-treated group, and the level was reduced to 15% of control level in CT105-treated group, at one week after the injection. ACh level was further reduced to 35% of control in $A{\beta}$-treated group, whereas the level was slightly increased to 30% of control in CT105-treated group at 4 weeks after the injection. Taken together, the results in the present study suggest that CT105 impairs the septohippocampal pathway by reducing acetylcholine synthesis and release, which results in damage of learning and memory.

• Korean Journal of Veterinary Service
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• v.25 no.4
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• pp.377-384
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• 2002

In this study, to assess the diagnostic value for mastitis in dairy cows, change of acute phase proteins(haptoglobin and serum amyloid A) concentrations in milk and sera of dairy cows were measured. 50 dairy cows were used in this experiment and divided into two groups. The first group was the healthy dairy cow group whose milk contained less than 2.0${\times}$10$\^$5/ somatic cell counts(n=5). The second group was the mastitis-dairy cow group whose milk counted higher than 5.0${\times}$10$\^$5/ somatic cell counts(n=45). The concentration of haptoglobin and serum amyloid A in milk and sera from these two groups were determined by Tridelta range haptoglobin kit and serum amyloid A kit. The concentration of haptoglobin in the milk from first group was undetectable value and that of the second group was 124.0$\mu\textrm{g}$/$m\ell$. And the concentration of haptoglobin in serum of the first group was 32.0$\mu\textrm{g}$/$m\ell$ and that of the second group was 214.4$\mu\textrm{g}$/$m\ell$. The concentration of serum amyloid A in the milk from first group was 0.32$\mu\textrm{g}$/$m\ell$ and that of the second group was 17.7$\mu\textrm{g}$/$m\ell$. And the concentration of serum amyloid A in serum of the first group was 5.1$\mu\textrm{g}$/$m\ell$ and that of the second group was 25.8$\mu\textrm{g}$/$m\ell$. It was concluded that concentration of haptoglobin and serum amyoid A in milk and serum may be was to discriminate between normal and mastitic milks.