• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1311-1319
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• 2016

Alternaria brassicicola (Schwein.) invades Brassicaceae and causes black spot disease, significantly lowering productivity. Mitogen-activated protein kinases (MAPKs) and their upstream kinases, including MAPK kinases (MAPKKs) and MAPKK kinases (MAPKKK), comprise one of the most important signaling pathways determining the pathogenicity of diverse plant pathogens. The AbSte7 gene in the genome of A. brassicicola was predicted to be a homolog of yeast Ste7, a MAPKK; therefore, the function was characterized by generating null mutant strains with a gene replacement method. AbSte7 replacement mutants (RMs) had a slower growth rate and altered colony morphology compared with the wild-type strain. Disruption of the AbSte7 gene resulted in defects in conidiation and melanin accumulation. AbSte7 was also involved in the resistance pathways in salt and oxidative stress, working to negatively regulate salt tolerance and positively regulate oxidative stress. Pathogenicity assays revealed that AbSte7 RMs could not infect intact cabbage leaves, but only formed very small lesions in wounded leaves, whereas typical lesions appeared on both intact and wounded leaves inoculated with the wild-type strain. As the first studied MAPKK in A. brassicicola, these data strongly suggest that the AbSte7 gene is an essential element for the growth, development, and pathogenicity of A. brassicicola.

• Journal of Ginseng Research
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• 제42권1호
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• pp.75-80
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• 2018

Background: The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells. Methods: LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay. Results: Reduction in cell viability by $60{\mu}M$ FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 ($10{\mu}M$ and $50{\mu}M$). Conclusion: The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

• Biodesign
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• 제6권4호
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• pp.79-83
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• 2018

Mitogen-activated protein kinases (MAPKs) are one of the most important enzymes in various cellular activities, and the MAPK signaling pathway is implicated in many disorders. MAPK phosphatases (MKPs) are regulators that contain a MAPK-binding domain (MBD) for MAPK recognition, and a catalytic domain (CD), for dephosphorylation and inactivation of MAPKs. Due to their crucial role in regulating the MAPK pathway, MKPs are regarded as a potential drug target in various diseases. Attempts have also been made to regulate the MAPK pathway by reducing the MKP activity. For drug development, it is important to understand the key features of MAPK-MKP complex formation. This review summarizes the studies on MAPK-MKP complexes, mainly focusing on their selective recognition and catalytic activation.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.80.1-80.1
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• 2003

Intestinal epithelial cells can produce cytokines and chemokines that play an important role in the mucosal immune response. Regulation of this production is important to prevent inflammatory tissue damage. Glycyrrhiza glabra has been shown to inhibit inflammation. The aim of this study was to examine the inhibitory effect of 18- beta-glycyrrhetinic acid, a triterpenoid saponin of Glycyrrhiza glabra, on IL-S production via mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-kB) in TNF-alpha-stimulated human colon epithelial cells. (omitted)

• 생약학회지
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• 제53권4호
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• pp.181-191
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• 2022

As the incidence of skin cancer increases every year, non-surgical treatment methods for cancer are being sought. Esculetin, a natural dihydroxy coumarin, is attracting attention as a therapeutic agent for certain diseases, such as cancer, based on its broad pharmacological activity. In this study, the anticancer ability of esculetin was evaluated using the epidermoid carcinoma cell line A431. As a result of evaluating the apoptosis ability of esculetin by MTT assay, apoptosis was observed in a time-concentration-dependent manner regardless of the presence or absence of FBS. As a result of quantitative real-time PCR, esculetin reduced cyclin D1 mRNA in a time-concentration-dependent manner. In addition, as a result of western blotting, esculetin significantly inhibited phosphorylation of ERK, JNK, and p38 in a concentration-dependent manner. The results of this study suggest that esculetin has the potential to be used as an effective natural medicine for the treatment of skin cancer.

• 한방안이비인후피부과학회지
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• 제36권1호
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• pp.40-49
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• 2023

Objectives : This study was conducted to confirm the skin anti-aging effect of Chungpyesagan-tang(CPSGT) extract. Methods : We performed MMT assay to confirm the cytotoxicity of CPSGT. After inducing matrix metalloproteinase-1(MMP-1) with tumor necrosis factor-α(TNF-α), we investigated mRNA expression and protein secretion of MMP-1 by real-time RT-PCR and ELISA. In addition, we measured the protein expression of mitogen-activated protein kinases(MAPKs) and transcription factors by western blot. Results : CPSGT was not cytotoxic at 25-800㎍/㎖. The mRNA expression and protein secretion of MMP-1 decreased when treated with CPSGT. The protein expression of p-ERK, p-JNK, p-p38 was decreased by CPSGT. In addition, the protein expression of p-c-jun and p-NF-κB, which are transcription factors, were also decreased. Conclusion : This suggests that CPSGT can inhibit MMP-1 and thus be a potential anti-aging substance.

• 한국축산식품학회지
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• 제43권1호
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• pp.101-112
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• 2023

This study aimed to assess whether genomic DNA (gDNA) extracted from Pediococcus acidilactici inhibits Porphyromonas gingivalis lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells. Pretreatment with gDNA of P. acidilactici K10 or P. acidilactici HW01 for 15 h effectively inhibited P. gingivalis LPS-induced mRNA expression of interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein (MCP)-1. Although both gDNAs did not dose-dependently inhibit P. gingivalis LPS-induced mRNA expression of IL-6 and MCP-1, they inhibited IL-1β mRNA expression in a dose-dependent manner. Moreover, pretreatment with both gDNAs inhibited the secretion of IL-1β, IL-6, and MCP-1. When RAW 264.7 cells were stimulated with P. gingivalis LPS alone, the phosphorylation of mitogen-activated protein kinases (MAPKs) was increased. However, the phosphorylation of MAPKs was reduced in the presence of gDNAs. Furthermore, both gDNAs restored IκBα degradation induced by P. gingivalis LPS, indicating that both gDNAs suppressed the activation of nuclear factor-κB (NF-κB). In summary, P. acidilactici gDNA could inhibit P. gingivalis LPS-induced inflammatory responses through the suppression of MAPKs and NF-κB, suggesting that P. acidilactici gDNA could be effective in preventing periodontitis.

• International Journal of Oral Biology
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• 제34권2호
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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.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.19-25
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• 2011

Tocopherols belong to the plant-derived poly phenolic compounds known for antioxidant functions in plants and animals. Activation of mitogen-activated protein kinases (MAPK) is a common reaction of plant cells in defense-related signal transduction pathways. We report a novel non-antioxidant function of ${\alpha}$-tocopherol in higher plants linking the physiological role of tocopherol with stress signalling pathways. Pre-incubation of a low concentration of $50{\mu}M$ ${\alpha}$-tocopherol negatively interferes with MAPK activation in elicitor-treated tobacco BY2 suspension culture cells and wounded tobacco leaves, whereas pre-incubated BY2 cells with ${\alpha}$-tocopherol phosphate did not show the inhibitory effect on stimuli-induced MAPK activation. The decreased MAPK activity was neither due to a direct inhibitory effect of ${\alpha}$-tocopherol nor due to the induction of an inhibitory or inactivating activity directly affecting MAPK activity. The data support that the target of ${\alpha}$-tocopherol negatively regulates an upstream component of the signaling pathways that leads to stress dependent MAPK activation.

• 대한의생명과학회지
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• 제23권4호
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• pp.310-320
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• 2017

Ginseng has been widely used for traditional medicine in eastern Asia and is known to have inhibitory effects on cardiovascular disease (CVD) such as thrombosis, atherosclerosis, and myocardial infarction. Because, platelet is a crucial mediator of CVD, many studies are focusing on inhibitory mechanism of platelet functions. Among platelet activating molecules, thromboxane $A_2$ ($TXA_2$) and P-selectin play a central role in CVD. $TXA_2$ leads to intracellular signaling cascades and P-selectin plays an important role in platelet-neutrophil and platelet-monocyte interactions leading to the inflammatory response. In this study, we investigated the inhibitory mechanisms of total saponin fraction from Korean red ginseng (KRG-TS) on $TXA_2$ production and P-selectin expression. Thrombin-elevated $TXA_2$ production and arachidonic acid release were decreased by KRG-TS dose (25 to $150{\mu}g/mL$)-dependently via down regulation of microsomal cyclooxygenase-1 (COX-1), $TXA_2$ synthase (TXAS) activity and dephosphorylation of cytosolic phospholipase $A_2$ ($cPLA_2$). In addition, KRG-TS suppressed thrombin-activated P-selectin expression, an indicator of granule release via dephosphorylation of mitogen-activated protein kinases (MAPK). Taken together, we revealed that KRG-TS is a beneficial novel compound inhibiting $TXA_2$ production and P-selectin expression, which may prevent platelet aggregation-mediated thrombotic disease.