• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1132-1143
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• 2022

Insects are a valuable natural source that can produce a variety of bioactive compounds due to their increasing species diversity. CopA3 is an antimicrobial peptide derived from Copris tripartitus (i.e., the dung beetle). It is known to increase the proliferation of colonic epithelial and neuronal stem cells by regulating cell cycle. This research hypothesized that CopA3 can promote the proliferation of porcine muscle satellite cells (MSCs). The effects of CopA3 on porcine MSCs, which are important for muscle growth and regeneration, remain unclear. Here, we investigated the effects of CopA3 on porcine MSCs. According to viability results, we designed four groups: control (without CopA3) and three treatment groups (treated with 5,10, and 25 ㎍/mL of CopA3). At a CopA3 concentration of 5 ㎍/mL and 10 ㎍/mL, the proliferation of MSCs increased more than that observed in the control group. Furthermore, compared to that in the control, CopA3 treatment increased the S phase but decreased the G0/G1 phase ratio. Additionally, early and late apoptotic cells were found to be decreased in the 5 ㎍/mL group. The expressions of the myogenesis-related transcription factor PAX7 and MYOD proteins were significantly upregulated in the 5 ㎍/mL and 10 ㎍/mL groups, whereas the MYOG protein remained undetected in all group. This study suggested that CopA3 promotes muscle cell proliferation by regulating the cell cycle of MSCs and can regulate the activity of MSCs by increasing the expressions of PAX7 and MYOD.

• Journal of Ginseng Research
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• v.32 no.1
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• pp.62-66
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• 2008

Non-saponin gingseng fraction components (NSRG) have been known to have a variety of biological activity. However, the effects of these components on the function of brain cell have not been characterized in detail. In this study, we investigated the preventive effect of non-saponin red ginseng components on acrylamide (ACR)-induced suppression of neural cell adhesion molecule (NCAM), which is highly expressed in neuronal cells. The data showed that NSRG blocked the suppression of NCAM expression by ACR in neuroblastoma cells (SK-N-SH). In addition, NSRG significantly increased NCAM expression in ACR-nontreated neuroblastoma cells. NSRG treatment resulted in the increase of cell proliferation in a concentration-dependent manner. We also examined whether NSRG could modulate the NO production of astrocytes. When glioma cells (C6) were treated with various concentrations of NSRG (100-300 ug/ml) in the presence or absence of $IFN-{\gamma}$ for 24 hours, NO production was suppressed in $IFN-{\gamma}-$stimulated C6 cells. Taken together, these results demonstrate that treatment of brain cells with NSRG results in the enhancement of proliferation, the suppression of NO production and the protective effect on NCAM expression impaired by ACR. Thus, the present data suggest that NSRG has proliferative and neuroprotective effects and these effects could be useful in neuronal diseases.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.163-170
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• 2020

Objective : Milk fat globule-epidermal growth factor VIII (MFG-E8) may play a key role in inflammatory responses and has the potential to function as a neuroprotective agent for ameliorating brain injury in cerebral infarction. This study aimed to determine the role of MFG-E8 in brain injury in the subacute phase of cerebral ischemia in a rat model. Methods : Focal cerebral ischemia was induced in rats by occluding the middle cerebral artery with the modified intraluminal filament technique. Twenty-four hours after ischemia induction, rats were randomly assigned to two groups and treated with either recombinant human MFG-E8 or saline. Functional outcomes were assessed using the modified Neurological Severity Score (mNSS), and infarct volumes were evaluated using histology. Anti-inflammation, angiogenesis, and neurogenesis were assessed using immunohistochemistry with antibodies against ionized calcium-binding adapter molecule 1 (Iba-1), rat endothelial cell antigen-1 (RECA-1), and bromodeoxyuridine (BrdU)/doublecortin (DCX), respectively. Results : Our results showed that intravenous MFG-E8 treatment did not reduce the infarct volume; however, the mNSS test revealed that neurobehavioral deficits were significantly improved in the MFG-E8-treated group than in the vehicle group. Immunofluorescence staining revealed a significantly lower number of Iba-1-positive cells and higher number of RECA-1 in the periinfarcted brain region, and significantly higher numbers of BrdU- and DCX-positive cells in the subventricular zone in the MFG-E8-treated group than in the vehicle group. Conclusion : Our findings suggest that MFG-E8 improves neurological function by suppressing inflammation and enhancing angiogenesis and neuronal proliferation in the subacute phase of cerebral infarction.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.41-51
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• 2016

Adult hippocampal dentate granule neurons are generated from neural stem cells (NSCs) in the mammalian brain, and the fate specification of adult NSCs is precisely controlled by the local niches and environment, such as the subventricular zone (SVZ), dentate gyrus (DG), and Toll-like receptors (TLRs). Epigallocatechin-3-gallate (EGCG) is the main polyphenolic flavonoid in green tea that has neuroprotective activities, but there is no clear understanding of the role of EGCG in adult neurogenesis in the DG after neuroinflammation. Here, we investigate the effect and the mechanism of EGCG on adult neurogenesis impaired by lipopolysaccharides (LPS). LPS-induced neuroinflammation inhibited adult neurogenesis by suppressing the proliferation and differentiation of neural stem cells in the DG, which was indicated by the decreased number of Bromodeoxyuridine (BrdU)-, Doublecortin (DCX)- and Neuronal Nuclei (NeuN)-positive cells. In addition, microglia were recruited with activating TLR4-NF-${\kappa}B$ signaling in the adult hippocampus by LPS injection. Treating LPS-injured mice with EGCG restored the proliferation and differentiation of NSCs in the DG, which were decreased by LPS, and EGCG treatment also ameliorated the apoptosis of NSCs. Moreover, pro-inflammatory cytokine production induced by LPS was attenuated by EGCG treatment through modulating the TLR4-NF-${\kappa}B$ pathway. These results illustrate that EGCG has a beneficial effect on impaired adult neurogenesis caused by LPS-induced neuroinflammation, and it may be applicable as a therapeutic agent against neurodegenerative disorders caused by inflammation.

• Molecules and Cells
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• v.26 no.1
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• pp.12-17
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• 2008

The TrkA tyrosine kinase is activated by autophosphorylation in response to NGF, and plays an important role in cell survival, differentiation, and apoptosis. To investigate its role in cell fate determination, we produced stable TrkA-inducible SK-N-MC and U2OS cell lines using the Tet-On system. Interestingly, TrkA overexpression induced substantial cell death even in the absence of NGF, by stimulating ERK phosphorylation and caspase-7 activation leading to PARP cleavage. TrkA-mediated cell death was shown by the annexin-V binding assay to be, at least in part, apoptotic in both SK-N-MC and U2OS cells. Furthermore, the truncated form (p18) of Bax accumulated in the TrkA-induced cells, suggesting that TrkA induces mitochondria-mediated apoptosis. NGF treatment augmented the cell death induced by TrkA overexpression. This TrkA-induced cell death was blocked by the tyrosine kinase inhibitors, K-252a and GW441756. Moreover, TrkA overexpression inhibited long-term proliferation of both the neuronal SK-N-MC cells and the non-neuronal U2OS cells, suggesting a potential role of TrkA as a tumor suppressor.

• BMB Reports
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• v.43 no.2
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• pp.122-126
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• 2010

Homozygous staggerer ($RORa^{sg/sg}$) mice showed a severe ataxia caused by cerebellum degeneration. Decreased and dysfunctional Rora is a main cause of this neurologic phenotype. The phenotype of staggerer mice has been well known in cerebellum. However, there has been rarely reported about cerebrum even though of staggerer is expressed in merely cerebellum but hippocampus, thalamus, cortex, and olfactory bulb. The expressions of Ki67, doublecortin (DCX), and NeuN, which are cell proliferation, neuronal differentiation and mature neuron markers, respectively, were measured with immunohistechemistry in dentate gyrus in staggerer mice in order to uncover whether staggerer can affect the change in dentate gyrus. The immunoreactivities of DCX and NeuN were significantly reduced in the dentate gyrus of staggerer mice than normal control, while Ki67 were rarely unchanged in staggerer mice. These results suggest that staggerer mutation has an influence on the neuronal differentiation and development not only in cerebellum but also in dentate gyrus.

• BMB Reports
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• v.35 no.3
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• pp.267-272
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• 2002

TNF-$\alpha$ elicits various responses including apoptosis, proliferation, and differentiation according to cell type. In neuronal PC12 cells, TNF-$\alpha$ induces moderate apoptosis while lipopolysarccaharide or trophic factor deprivation can potentiate apoptosis that is induced by TNF-$\alpha$. TNF-$\alpha$ initiates various signal transduction pathways leading to the activation of the caspase family, NF-${\kappa}B$, Jun N-terminal kinase, and p38 MAPK via the death domain that contains the TNF-$\alpha$ receptor. Inhibition of translation using cycloheximide greatly enhanced the apoptotic effect of TNF-$\alpha$. This implies that the induction of anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic Bcl-2 family member, was highly expressed in response to TNF-$\alpha$. In this study, we examined the anti-apoptotic role of p38 MAPK that is activated by TNF-$\alpha$ in neuronal PC12 cells. The phosphorylation of p38 MAPK in response to TNF-$\alpha$ slowly increased and lasted several hours in the PC12 cell and DRG neuron. This specific inhibitor of p38 MAPK, SB202190, significantly enhanced the apoptosis that was induced by TNF-$\alpha$ in PC12 cells. This indicates that the activation of p38 MAPK could protect PC12 cells from apoptosis since there is no known role of p38 MAPK in resoonse to TNF-$\alpha$ in neuron. This discovery could be evidence for the neuroprotective role of the p38 MAPK.

• Toxicological Research
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• v.12 no.2
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• pp.203-211
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• 1996

Methanol has been widely used as an industrial solvent and environmental exposure to methanol would be expected to be increasing. In humans, methanol causes metabolic acidosis and damage to ocular system, and can lead to death in severe and untreated case. Clinical symptoms are attributed to accumulation of forrnic acid which is a metabolic product of methanol. In humans and primates, formic acid is accumulated after methanol intake but not in rodents due to the rapid metabolism of methanol. Neverthless, the developmental and reproductive toxicity were reported in rodents. Previous reports showed that perinatal exposure to ethanol produces a variety of damage in human central nervous system by direct neurotoxicity. This suggests that the mechanism of toxic symptoms by methanol in rodents might mimic that of ethanol in human. In the present study I hypothesized that methanol can also induce toxicity in neuronal cells. For the study, primary culture of rat hippocampal neurons and glias were empolyed. Hippocampal cells were prepared from the embryonic day-17 fetuses and maintained up to 7 days. Effect of methanol (10, 100, 500 and 1000 mM) on neurite outgrowth and cell viability was investigated at 0, 18 and 24 hours following methanol treatment. To study the changes in proliferation of glial cells, protein content was measured at 7 days. Neuronal cell viability in culture was not altered during 0-24 hours after methanol treatment. 10 and 100 mM methanol treatment significantly enhanced neurite outgrowth between 18-24 hours. 7-day exposure to 10 or 100 mM methanol significantly increased protein contents but that to 1000 mM methanol decreased in culture. In conclusion, methanol may have a variety of effects on growing and differentiation of neurons and glial cells in hippocampus. Treatment with low concentration of methanol caused that neurite outgrowth was enhanced during 18-24 hours and the numbers of glial cell were increased for 7 days. High concentration of methanol brought about decreased protein contents. At present, the mechanism responsible for the methanol- induced enhancement of neurite outgrowth is not clear. Further studies are required to delineate the mechanism possibly by employing molecular biological techniques.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.475-482
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• 2020

Background: Active natural ingredients, especially small molecules, have recently received wide attention as modifiers used to treat neurodegenerative disease by promoting neurogenic regeneration of neural stem cell (NSC) in situ. 20(S)-protopanaxadiol (PPD), one of the bioactive ingredients in ginseng, possesses neuroprotective properties. However, the effect of PPD on NSC proliferation and differentiation and its mechanism of action are incompletely understood. Methods: In this study, we investigated the impact of PPD on NSC proliferation and neuronal lineage differentiation through activation of the Wnt/glycogen synthase kinase (GSK)-3β/β-catenin pathway. NSC migration and proliferation were investigated by neurosphere assay, Cell Counting Kit-8 assay, and EdU assay. NSC differentiation was analyzed by Western blot and immunofluorescence staining. Involvement of the Wnt/GSK3β/β-catenin pathway was examined by molecular simulation and Western blot and verified using gene transfection. Results: PPD significantly promoted neural migration and induced a significant increase in NSC proliferation in a time- and dose-dependent manner. Furthermore, a remarkable increase in anti-microtubule-associated protein 2 expression and decrease in nestin protein expression were induced by PPD. During the differentiation process, PPD targeted and stimulated the phosphorylation of GSK-3β at Ser9 and the active forms of β-catenin, resulting in activation of the Wnt/GSK-3β/β-catenin pathway. Transfection of NSCs with a constitutively active GSK-3β mutant at S9A significantly hampered the proliferation and neural differentiation mediated by PPD. Conclusion: PPD promotes NSC proliferation and neural differentiation in vitro via activation of the Wnt/GSK-3β/β-catenin pathway by targeting GSK-3β, potentially having great significance for the treatment of neurodegenerative diseases.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.380-388
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• 2018

Neural stem cells (NSCs) have the ability to self-renew and differentiate into multiple nervous system cell types. During embryonic development, the concentrations of soluble biological molecules have a critical role in controlling cell proliferation, migration, differentiation and apoptosis. In an effort to find optimal culture conditions for the generation of desired cell types in vitro, we used a microfluidic chip-generated growth factor gradient system. In the current study, NSCs in the microfluidic device remained healthy during the entire period of cell culture, and proliferated and differentiated in response to the concentration gradient of growth factors (epithermal growth factor and basic fibroblast growth factor). We also showed that overexpression of ASCL1 in NSCs increased neuronal differentiation depending on the concentration gradient of growth factors generated in the microfluidic gradient chip. The microfluidic system allowed us to study concentration-dependent effects of growth factors within a single device, while a traditional system requires multiple independent cultures using fixed growth factor concentrations. Our study suggests that the microfluidic gradient-generating chip is a powerful tool for determining the optimal culture conditions.