• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.374-379
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• 2018

In this study, we investigated the effects of pelargonidin, an anthocyanidin found in many fruits and vegetables, on endothelium-independent vascular contractility to determine the underlying mechanism of relaxation. Isometric contractions of denuded aortic muscles from male rats were recorded, and the data were combined with those obtained in western blot analysis. Pelargonidin significantly inhibited fluoride-, thromboxane A2-, and phorbol ester-induced vascular contractions, regardless of the presence or absence of endothelium, suggesting a direct effect of the compound on vascular smooth muscles via a different pathway. Pelargonidin significantly inhibited the fluoride-dependent increase in the level of myosin phosphatase target subunit 1 (MYPT1) phosphorylation at Thr-855 and the phorbol 12,13-dibutyrate-dependent increase in the level of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation at Thr202/Tyr204, suggesting the inhibition of Rho-kinase and mitogen-activated protein kinase kinase (MEK) activities and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxation effect of pelargonidin on agonist-dependent vascular contractions includes inhibition of Rho-kinase and MEK activities, independent of the endothelial function.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.161-176
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• 2018

Fungal ${\beta}$-glucan, known to have immunostimulatory and antitumor activities, can be recognized by host immune cells as one of the pathogen-associated molecular patterns (PAMPs). Although there are several reports on the diverse immunostimulatory activities of ${\beta}$-glucan, little is known about the intracellular signal transduction of ${\beta}$-glucan. Stimulation of RAW264.7 macrophage cells with ${\beta}$-glucan from Ganoderma lucidum induced the expressions of dectin-1, toll-like receptor 2 (TLR2), TLR4, and TLR6 at the transcription stage. Treatment with ${\beta}$-glucan also induced inflammatory mediators such as macrophage inflammatory proteins (MIP)-$1{\alpha}$, MIP-$1{\beta}$, MIP-$1{\gamma}$, interleukin (IL)-$1{\beta}$, and tumor necrosis factor (TNF)-${\alpha}$. Treatment of the cells with polymyxin B, an inhibitor of lipopolysaccharides (LPS), blocked the induction of inflammatory mediators in LPS- or ${\beta}$-glucan-stimulated systems. Pretreatment of the cells in our cell culture system with LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, or U0126, a mitogen-activated protein kinase/extracellular-signal-regulated kinase (MAPK/ERK) kinase (MEK)1/MEK2 inhibitor, led to a reduction in the induction of inflammatory mediators in a concentration-dependent manner. These results show that stimulation of the macrophage cells by ${\beta}$-glucan induced the expressions of both dectin-1 and TLRs. We also found that the PI3K/Akt and MEK pathways were involved in the induction of inflammatory mediators in macrophage cells during intracellular signal transduction of ${\beta}$-glucan.

• Journal of Ginseng Research
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• v.45 no.6
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• pp.617-630
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• 2021

Chemotherapy-induced side effects affect the quality of life and efficacy of treatment of cancer patients. Current approaches for treating the side effects of chemotherapy are poorly effective and may cause numerous harmful side effects. Therefore, developing new and effective drugs derived from natural nontoxic compounds for the treatment of chemotherapy-induced side effects is necessary. Experiments in vivo and in vitro indicate that Panax ginseng (PG) and its ginsenosides are undoubtedly non-toxic and effective options for the treatment of chemotherapy-induced side effects, such as nephrotoxicity, hepatotoxicity, cardiotoxicity, immunotoxicity, and hematopoietic inhibition. The mechanism focus on anti-oxidation, anti-inflammation, and anti-apoptosis, as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (Nrf2)/heme oxygenase-1 (HO-1), P62/keap1/Nrf2, c-jun Nterminal kinase (JNK)/P53/caspase 3, mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinases (ERK), AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase kinase 4 (MKK4)/JNK, and phosphatidylinositol 3-kinase (PI3K)/AKT. Since a systemic review of the effect and mechanism of PG and its ginsenosides on chemotherapy-induced side effects has not yet been published, we provide a comprehensive summarization with this aim and shed light on the future research of PG.

• International Journal of Oral Biology
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• v.34 no.2
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• pp.115-121
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• 2009

Bone morphogenetic protein (BMP) 2 is a potent osteogenic factor. Although both Smad1/5 and mitogenactivated protein kinases (MAPKs) are activated by BMP2, the hierarchical relationship between them is unclear. In this study, we examined if BMP2-stimulated MAPK activation is regulated by Smad1/5 or vice versa. When C2C12 cells were treated with BMP2, the activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-N-terminal kinase was evident within 5 min. The knockdown of both Smad1 and Smad5 by small interfering RNA did not affect the activation of these MAPKs. In addition, neither the overexpression of Smad1 nor Smad5 induced ERK activation. When ERK activation was induced by constitutively active MEK1 expression, the protein level and activation of Smad1 increased. Furthermore, the inhibition of constitutively active BMP receptor type IB-induced ERK activation significantly suppressed Smad1 activation. These results indicate that Smad1/5 activation is not necessary for BMP2-induced MAPK activation and also that ERK positively regulates Smad1 activation.

• BMB Reports
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• v.54 no.5
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• pp.272-277
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• 2021

RalBP1 associated EPS domain containing 1 (REPS1) is conserved from Drosophila to humans and implicated in the endocytic system. However, an exact role of REPS1 remains largely unknown. Here, we demonstrated that mitogen activated protein kinase kinase (MEK)-p90 ribosomal S6 Kinase (RSK) signaling pathway directly phosphorylated REPS1 at Ser709 upon stimulation by epidermal growth factor (EGF) and amino acid. While REPS2 is known to be involved in the endocytosis of EGF receptor (EGFR), REPS1 knockout (KO) cells did not show any defect in the endocytosis of EGFR. However, in the REPS1 KO cells and the KO cells reconstituted with a non-phosphorylatable REPS1 (REPS1 S709A), the recycling of transferrin receptor (TfR) was attenuated compared to the cells reconstituted with wild type REPS1. Collectively, we suggested that the phosphorylation of REPS1 at S709 by RSK may have a role of the trafficking of TfR.

• Korean Journal of Veterinary Research
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• v.58 no.1
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• pp.1-7
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• 2018

Genus Artemisia occurs as a hardy plant and has a wide range of culinary and medicinal features. In this study, we aimed to describe the melanin inhibitory activity of one Artemisia species, i.e., Artemisia capillaris Thunb. Ethanol extracts of fermented Artemisia capillaris (Art.EtOH.FT) and non-fermented Artemisia capillaris (Art.EtOH.CT) were tested for their ability to inhibit tyrosinase activity and melanin pigmentation. Both extracts showed dose-dependent inhibition against ${\alpha}$-melanocyte stimulating hormone-stimulated melanin formation and tyrosinase activity, without cytotoxicity. At $100{\mu}g/mL$, both extracts showed greater inhibition than kojic acid, the positive control. Protein expressions of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) at the transcriptional level were determined by using real-time and semi-quantitative polymerase chain reaction. To complete the mechanistic study, presences of upstream elements of MITF, the phosphorylated-extracellular signal-regulated kinase (p-ERK), and phosphorylated-mitogen-activated protein kinase kinase (p-MEK) were confirmed by using western blot analysis. Expressions of p-TYR, p-TRP-1 and p-TRP-2, downstream factors for p-ERK and p-MITF, were translationally inhibited by both extracts. Art.EtOH.FT induced more potent effects than Art.EtOH.CT, especially signal transduction effects. In summary, Artemisia capillaris extracts appear to act as potent hypopigmentation agents.

• Advances in Traditional Medicine
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• v.10 no.4
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• pp.254-262
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• 2010

Artemisia capillaris (A. capillaries) is known to play roles in many cellular events, such as cell proliferation, differentiation, and apoptosis. We investigated the antifibrogenic efficacy of A. capillaris in the immortalized human hepatic stellate cell line LX2. Cell proliferation was determined by the MTT assay. Cell cycle was analyzed by the flow cytometry. Apoptotic cells were measured using a cell death detection ELISA. Caspase activity was detected by a colorimetric assay. The mRNA level of Bcl-2 and Bax mRNA were measured by real-time PCR. MEK and ERK protein were detected by Western blot analysis. We provide evidence that A. capillaris induces cell cycle arrest, apoptosis, and potently inhibits the mitogen-activated protein kinase pathway. A. capillaris inhibited cell proliferation of LX2 cells in a dose- and time-dependent manner, increased the apoptosis fraction at cell cycle analysis with an accompanying DNA fragmentation, and resulted in a significant decrease in Bcl-2 mRNA levels and an increase in Bax expression. Exposure of LX2 cells to A. capillaris induced caspase-3 activation, but co-treatment of A. capillaris with the pan-caspase inhibitor Z-VAD-FMK, and the caspase-3 inhibitor Z-DEVE-FMK, blocked apoptosis. A. capillaris down-regulated Mcl-1 protein levels and inhibited phosphorylation of MEK/ERK, suggesting that it mediates cell death in LX2 cells through the down-regulation of Mcl-1 protein via a MEK/ERK-independent pathway.

• Journal of Acupuncture Research
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• v.18 no.4
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• pp.101-115
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• 2001

Objective : To characterize the antitumorigenic potential of Apamin, one of the major components of bee venom, its effects on cell proliferation and the mitogen-activated protein kinase (MAPK) signal transduction pathway were characterized using the human melanoma cell line SK-MEL-2. Methods & Results : Cell counting analysis for cell death demonstrated that consistent with a previous results, SK-MEL-2 cells treated with $0.5-2.0{\mu}g/ml$ of Apamin showed no recognizable cytotoxic effect whereas detectable induction of cell death was identified at concentrations over $5.0{\mu}g/ml$. [3H]thymidine incorporation assay for cell proliferation demonstrated that DNA replication of SK-MEL-2 cells is inhibited by Apamin in a dose- and time-dependent manner. To explore whether Apamin-induced growth suppression is associated with the MAPK signaling pathway, phosphorylation of Erk, a function mediator of MAPK growth-stimulating signal, was examined Western blot assay using a phospho-specific Erkl/2 antibody. A significant increase of Erkl/2 phosphorylation level was observed in Apamin-treated cells compared with untreated control cells. Qantitative RT-PCR analysis revealed that Apamin inhibit expression of MAPK downstream genes such as c-Jun, c-Fos, and cyclin D1 but not expression of MAPK pathway component genes including Ha-Ras, c-Raf-1, MEK1, and Erk. Conclusion : It is strongly suggested that the antitumorigenic activity of Apamin might result in part from its inhibitory effect on the MAPK signaling pathway in human melanoma cells SK-MEL-2.

• Journal of Genetic Medicine
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• v.16 no.1
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• pp.1-9
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• 2019

Noonan syndrome (NS) and NS-related disorders (cardio-facio-cutaneous syndrome, Costello syndrome, NS with multiple lentigines, or LEOPARD [lentigines, ECG conduction abnormalities, ocular hypertelorism, pulmonic stenosis, abnormal genitalia, retardation of growth and sensory neural deafness] syndrome) are collectively named as RASopathies. Clinical presentations are similar, featured with typical facial features, short stature, intellectual disability, ectodermal abnormalities, congenital heart diseases, chest & skeletal deformity and delayed puberty. During past decades, molecular etiologies of RASopathies have been growingly discovered. The functional perturbations of the RAS-mitogen-activated protein kinase pathway are resulted from the mutation of more than 20 genes (PTPN11, SOS1, RAF1, SHOC2, BRAF, KRAS, NRAS, HRAS, MEK1, MEK2, CBL, SOS2, RIT, RRAS, RASA2, SPRY1, LZTR1, MAP3K8, MYST4, A2ML1, RRAS2). The PTPN11 (40-50%), SOS1 (10-20%), RAF1 (3-17%), and RIT1 (5-9%) mutations are common in NS patients. In this review, the constellation of overlapping clinical features of RASopathies will be described based on genotype as well as their differential diagnostic points and management.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.199-210
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• 2003

Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(II-6) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the release of the inflammatory cytotines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-1 osteoblast cultures with combined $interferon-\gamma(IFN-\gamma)$, lipopolysaccharide (LPS) and tumor necrosis $factor-\alpha(TNF-\alpha)$ induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, $IFN-\gamma,\;LPS,\;and\;TNF-\alpha$ individually induce a non-detectable or small amount of NO and IL-6 in MC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iNOS and IL-6 transcription in the combined agents-stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4-fluorophenyl)-2-(4-metylsulfinylphenyl)-5-(4-metylsulfinylphenyl)-5-(4-pyridyl)imidazole) (SB203580), were significantly diminished. In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p3a MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in $LPS/IFN{\gamma}-or\;TNF-\gamma-treated\;MC3T3E-1$ osteoblasts.