• The Korean Journal of Physiology and Pharmacology
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• v.10 no.4
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• pp.207-212
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• 2006

Mitochondrial permeability transition has been shown to be involved in neuronal cell death. Mitochondrial monoamine oxidase (MAO)-B is considered to play a part in the progress of nigrostriatal cell death. The present study examined the effect of MAO inhibitors against the toxicity of 1-methyl-4-phenylpyridinium $(MPP^+)$ in relation to the mitochondrial permeability transition. Chlorgyline (a selective inhibitor of MAO-A), deprenyl (a selective inhibitor of MAO-B) and tranylcypromine (nonselective inhibitor of MAO) all prevented cell viability loss, cytochrome c release, caspase-3 activation, formation of reactive oxygen species and depletion of GSH in differentiated PC12 cells treated with $500\;{\mu}M$$MPP^+$. The MAO inhibitors at $10\;{\mu}M$ revealed a maximal inhibitory effect and beyond this concentration the inhibitory effect declined. On the basis of concentration, the inhibitory potency was tranylcypromine, deprenyl and chlorgyline order. The results suggest that chlorgyline, deprenyl and tranylcypromine attenuate the toxicity of $MPP^+$ against PC12 cells by suppressing the mitochondrial permeability transition that seems to be mediated by oxidative stress.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.150-151
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• 2003

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the progressive deterioration of cognition and memory in association with widespread neuronal loss. AD is supposed to be very often associated with missense mutation located on homologous protein Presenilin (PS1) and (PS2). Up to now, the molecular mechanisms underlying the role of the gene mutation in AD still remain unclear. (omitted)

• International Journal of Oral Biology
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• v.45 no.2
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• pp.33-41
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• 2020

Neuroinflammation is known as the main mechanism implicated in the advancement of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. The main feature of neuroinflammation is associated with the activation of microglia. The activated microglia increase proinflammatory cytokine production and induce progressive neuronal cell death. Citrus flavonoids show neuroprotective effects that are associated with the anti-inflammatory action of flavonoids in neurodegenerative diseases. Among these citrus flavonoids, kaempferol, naringin, and nobiletin show inhibitory effects on nuclear factor-κB and mitogen-activated protein kinase signaling pathways that can modulate inflammatory conditions in microglial cells. In the present review, we present the anti-inflammatory activities of citrus flavonoids and therapeutic potential of flavonoids as neuroprotective agents.

• BMB Reports
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• v.35 no.6
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• pp.537-546
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• 2002

NF-${\kappa}B$/Rel transcription factor family participates in diverse biological processes including embryo development, hematopoiesis, immune regulation, as well as neuronal functions. In this review, the NF-${\kappa}B$/Rel signal transduction pathways and their important roles in the regulation of immune system will be discussed. NF-${\kappa}B$/Rel members execute distinct functions in multiple immune cell types via the regulation of target genes essential for cell proliferation, survival, effector functions, cell trafficking and communication, as well as the formation of lymphoid architecture. Consequently, proper activation of NF-${\kappa}B$/Rel during immune responses to allergens, auto-antigens, allo-antigens, and pathogenic infection is crucial for the integrity of host innate and adaptive immunity.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.73-74
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• 2003

Familial form of Alzheimer's disease (FAD) is caused by mutations in presenilin-1 and presenilin-2 (PS2). PS1 and PS2 mutation are known to similar effects on the production of amyloid $\beta$ peptide (A$\beta$) and cause of cell death in the Alzheimer's brain. The importance of the alternation of calcium homeostasis in the neuronal cell death by PS1 mutation in a variety of experimental system has been demonstrated. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.389-396
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• 2001

Neuroprotective properties of lithium were investigated by using in vivo NMDA excitotoxicity model. The appearance of TUNEL positive cells was prominent within 24 h of NMDA (70 mg/kg, i.p.) injection in the regions of the cortex, hippocampal formation, and thalamus of mouse cerebrum. NMDA treatment resulted in the extensive enhancement of Bax immunoreactivity in the cortical and hippocampal regions. NMDA also increased the immunoreactivity of caspase 8 in the similar regions of the mouse cerebrum. However, the increased immunoreactivity of Bax and caspase 8 were dramatically attenuated by chronic lithium pretreatment (lithium chloride, 300 mg/kg/d, i.p. for $7{\sim}10$ days). At the same time, lithium ion blocked the appearance of TUNEL positive cells, and the morphological assessment indicated an effective neuroprotection by lithium against NMDA excitotoxicity. Although the exact action mechanism of lithium is not straightforward at this time, we propose that the inhibition of Bax and caspase cascade is involved in the neuroprotective action of lithium.

• Animal cells and systems
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• v.5 no.3
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• pp.247-251
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• 2001

Differentiating HiB5 cells, a rat hippocampal cell line, expressed neuregulins and showed constitutive activation of a neuregulin receptor, ErbB2, suggesting development of a neuregulin autocrine loop. RT-PCR analyses indicated that HiB5 cells produced SMDF and NDF, but not GGF, during the differentiation. None of neuregulin isoforms were detected in proliferating HiB5 cells. The neuregulins in HiBS cells, at least in part, are the $\beta$-isoforms of which the most of neuronal neuregulin isoforms are. The expression of SMDF and NDF was enhanced by PDGF and bFGF that promote cell survival and differentiation, suggesting a close relationship between the synthesis of neuregulins and the differentiation process. HiB5 cells have ErbB2 and ErbB4, but not ErbB3 receptors. Constitutive tyrosine phosphorylation of ErbB2 was detected in HiB5 cells that had not been exposed to exogenous GGF.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.425-430
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• 2011

In this study, we found that Forsythiae fructus (FF) and one of its main compounds, arctigenin, significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Arctigenin also suppressed the expression of inducible nitric oxide synthase and cyclooxygenase-2, and inhibited the activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38. Moreover, it also reduced levels of proinflammatory cytokines, interleukin $1{\beta}$, tumor necrosis factor ${\alpha}$ and prostaglandin E2, and inhibited neuronal death in LPS-treated organotypic hippocampal cultures. Therefore, we suggest that arctigenin may confer a neuroprotective effect via the inhibition of neuroinflammation.

• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.63-72
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• 2003

Functional MRI (fMRI) provides an indirect mapping of cerebral activity, based on the detection of the local blood flow and oxygenation changes following neuronal activity (Blood Oxygenation Level Dependent). fMRI allows us to study noninvasively the normal and pathological aspects of functional cortical organization. Each fMRI study compares two different states of activity. Echo-Planar Imaging is the technique that makes it possible to study the whole brain at a rapid pace. Activation maps are calculated from a statistical analysis of the local signal changes. fMRI is now becoming an essential tool in the neurofunctional evaluation of normal volunteers and many neurological patients as well as the reference method to image normal or pathologic functional brain organization.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.108-111
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• 2003

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by a progressive loss of dopaminergic neurons in the substantia nigra. While its precise etiology is unknown, such factors as oxidative stress, impairment of mitochondrial respiration, excitotoxicity and inflammation may play roles in its pathogenesis. Although the role of apoptosis in the process of dopaminergic neuronal death has been highlighted in studies using postmortem brains and experimental models of PD, other evidence implicates both apoptosis and non-apoptotic death in PD. (omitted)