• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.205-211
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• 2022

Probiotics can effectively modulate host immune responses and prevent gastrointestinal diseases. The objective of this study was to investigate the probiotic characteristics of Lactobacillus brevis KU15152 isolated from kimchi and its protective potential against intestinal inflammation induced by Staphylococcus aureus lipoteichoic acid (aLTA). L. brevis KU15152 exhibited a high survival rate in artificial gastric and bile environments. Additionally, the adhesion capability of the strain to HT-29 cells was higher than that of L. rhamnosus GG. L. brevis KU15152 did not produce harmful enzymes, such as β-glucuronidase, indicating that it could be used as a potential probiotic. The anti-inflammatory potential of L. brevis KU15152 was determined in HT-29 cells. Treatment with L. brevis KU15152 suppressed the production of interleukin-8 without inducing significant cytotoxicity. The downregulatory effects of L. brevis KU15152 were involved in the suppression of nuclear factor-kappa B activation mediated by the extracellular signal-regulated kinase and Akt signaling pathways. Collectively, these data suggest that L. brevis KU15152 can be used in developing therapeutic and prophylactic products to manage and treat aLTA-induced intestinal damage.

• BMB Reports
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• 제57권5호
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• pp.238-243
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• 2024

Bone marrow-derived mesenchymal stem cells (BM-MSCs) can differentiate into endothelial cells in an inflammatory microenvironment. However, the regulatory mechanisms underlying this process are not entirely understood. Here, we found that TIE2 in BM-MSCs was upregulated at the transcriptional level after stimulation with tumor necrosis factor-alpha (TNFα), a major pro-inflammatory cytokine. Additionally, the STAT-binding sequence within the proximal region of TIE2 was necessary for TNFα-induced TIE2 promoter activation. TIE2 and STAT3 knockdown reduced TNFα-induced endothelial tube formation in BM-MSCs. Among the major TNFα-activated MAP kinases (ERK1/2, JNK1/2, and p38 MAPK) in BM-MSCs, only inhibition of the p38 kinase abrogated TNFα-induced TIE2 upregulation by inhibiting the JAK-STAT signaling pathway. These findings suggest that p38 MAP contributes to the endothelial differentiation of BM-MSCs by activating the JAK-STAT-TIE2 signaling axis in the inflammatory microenvironment.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.319-328
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• 2024

Lysophosphatidic acid receptor 1 (LPA₁) plays a critical role in brain injury following a transient brain ischemic stroke. However, its role in permanent brain ischemic stroke remains unknown. To address this, we investigated whether LPA₁ could contribute to brain injury of mice challenged by permanent middle cerebral artery occlusion (pMCAO). A selective LPA₁ antagonist (AM152) was used as a pharmacological tool for this investigation. When AM152 was given to pMCAO-challenged mice one hour after occlusion, pMCAO-induced brain damage such as brain infarction, functional neurological deficits, apoptosis, and blood-brain barrier disruption was significantly attenuated. Histological analyses demonstrated that AM152 administration attenuated microglial activation and proliferation in injured brain after pMCAO challenge. AM152 administration also attenuated abnormal neuroinflammatory responses by decreasing expression levels of pro-inflammatory cytokines while increasing expression levels of anti-inflammatory cytokines in the injured brain. As underlying effector pathways, NF-κB, MAPKs (ERK1/2, p38, and JNKs), and PI3K/Akt were found to be involved in LPA₁-dependent pathogenesis. Collectively, these results demonstrate that LPA₁ can contribute to brain injury by permanent ischemic stroke, along with relevant pathogenic events in an injured brain.

• International Journal of Molecular Medicine
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• 제44권5호
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• pp.1979-1987
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• 2019

Sargassum thunbergii is a brown alga from which various bioactive compounds can be extracted. Among these, the activities of indole derivatives, particularly as potential inhibitors of matrix metalloproteinases (MMPs), and their underlying mechanisms have been rarely investigated. Therefore, we evaluated the inhibitory effects of indole-6-carboxaldehyde (I6CA) on MMP-9 by gelatin zymography and western blot anlaysis. We used phorbol 12-myristate 13-acetate (PMA), which is known to induce MMP-9 expression and secretion, to stimulate HT1080 cells. Our results revealed that I6CA significantly inhibited MMP-9 expression and secretion, without significantly affecting the viability of PMA-stimulated HT1080 cells. Our mechanistic studies indicated that I6CA suppressed the phosphorylation and activation of two mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK). Furthermore, I6CA inhibited the phosphorylation of inhibitor of κBα (IκBα) in response to PMA stimulation, which suppressed nuclear factor-κB (NF-κB) p65 subunit nuclear translocation. Collectively, I6CA was determined to suppress MMP-9 expression and secretion, and effects were proposed to be mediated via the inhibition of the MAPK and NF-κB p65 pathways. Therefore, we suggested I6CA to be a potential therapeutic agent for MMP-9-related processes, including tumor invasion and metastasis; however, further investigation is required.

• 한국식품영양과학회지
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• 제43권2호
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• pp.224-230
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• 2014

항암, 항염증 및 비만억제 등의 생리활성을 지닌 해조류는 최근 건강기능 식품, 기능성 화장품 그리고 의약품 산업 분야에서 미용과 건강식품 소재로 각광받고 있다. 본 연구에서는 10종의 갈조류 메탄올 추출물을 이용하여 1,1-diphenyl-2-picrylhydrazyl(DPPH) 라디칼 소거능과 아밀로이드 베타 단백질($A{\beta}$)의 신경독성에 대한 HT-22 신경세포 보호효과를 조사함으로써 천연물로부터 안전하고 새로운 신경세포 보호소재를 개발해내고자 한다. DPPH 라디칼 소거능의 경우 미역쇠를 포함한 8종의 갈조류에서는 비교적 낮은 활성산소 소거능을 보인 반면, 감태와 패에서 강력한 활성산소 소거능이 나왔다. $A{\beta}$의 신경독성에 대해 10종의 갈조류 추출물이 갖는 HT-22 신경세포 보호효과를 검증하기 위해 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) 분석과 APP, BACE1, iNOS 단백질의 발현양상 및 ERK1/2, p38, JNK1/2 단백질의 활성화 양상을 분석했다. MTT 분석 결과, $A{\beta}$의 신경독성으로부터 미역쇠가 $25{\mu}g/mL$의 농도에서 가장 효과적으로 세포를 보호하고 있는 것으로 나타났고, 알쏭이모자반, 불레기말, 바위수염, 짝잎모자반도 세포 보호효과가 있는 것으로 나타났다. 세포 보호효과가 있는 것으로 밝혀진 5종의 갈조류를 가지고 수행한 단백질 발현분석 결과, 미역쇠는 $A{\beta}$의 신경독성에 의해 HT-22 신경세포에서 발현되는 단백질인 BACE1과 iNOS의 발현을 저해하였다. 이는 미역쇠의 세포보호효과가 $A{\beta}$의 신경독성으로부터 일어난 ERK와 p38의 활성화에 연관된 세포신호전달 경로를 억제하는 것으로 보인다. 그러므로 특히 식용 갈조류인 미역쇠는 $A{\beta}$에 의해 유도된 신경독성에 대해서 신경세포 보호효과를 갖는 건강기능 식품 소재로서의 가치가 충분한 것으로 사료된다.

• 생명과학회지
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• 제30권2호
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• pp.211-220
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• 2020

CAR의 활성은 리간드 결합 뿐만 아니라, 세포외신호전달 경로를 통한 관련 조절인자들의 인산화, 전사 조절인자들과의 상호작용, 그리고 coactivators 및 corepressors의 동원, 분해 및 발현 등에 의해 조절되며, 이러한 CAR의 활성 조절은 또한 외인성 화학물질과 에너지 대사, 세포의 증식 및 사멸을 포함한 다양한 생리적 항상성 조절에 영향을 미친다. CAR는 ERK1/2의 신호전달경로에 의해 인산화되어 Hsp-90/CCRP와 복합체를 형성하여 세포질 내에 잔류하는 반면, PB는 ERK1/2를 억제하여 downstream 신호전달 조절인자들의 탈인산화를 유발하고, 활성화된 RACK-1/PP2A를 동원하여 CAR를 탈인산화 함으로써 핵 이동 및 전사 활성을 유도한다. CAR의 활성은 FoxO1 및 PGC-1α와의 cross-talk을 통하여 각각 전사 활성 억제와 ubiquitination을 통한 단백질 분해를 유도하여 당합성과정에 관여하는 PEPCK 및 G6Pase 유전자의 발현을 억제한다. CAR에 의한 지방의 합성과 산화 조절은 각각 PPARγ 및 PPARα와의 cross-talk에 의한 PGC-1α의 분해와 CPT-1의 발현 억제 또는 PGC-1α와의 결합을 통해 지방 합성 유전자의 발현 억제와 조직 특이적 산화 억제 또는 촉진으로 이루어진다. CAR는 FoxO1의 억제를 통한 p21의 발현 억제와 cyclin D1의 발현을 유도하여 세포 증식을 촉진하는 반면, GADD45B의 발현을 통한 MKK7과 JNK1의 활성을 억제하여 세포 사멸을 억제한다. 결론적으로, CAR는 세포외신호전달 경로와 세포내 조절인자들과의 다양한 상호작용을 통하여 외인성 화학물질의 대사뿐만 아니라 에너지 대사 및 세포의 성장과 사멸의 조절을 통한 항상성 유지에 관여한다.

• 생명과학회지
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• 제24권6호
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• pp.664-670
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• 2014

비브리오균(Vibrio vulnificus)은 심각하고 치명적인 감염을 일으킬 수 있는 호염성의 식중독균이지만, 숙주세포 내에서 염증반응을 일으키는 분자적 기작은 아직 잘 알려지지 않았다. 본 연구에서는 오염된 식품 섭취를 통해 유입되는 비브리오균의 소장 특이적 염증 반응 위치와 기작을 알아보기 위해, 7주령의 수컷 마우스에 비브리오균($1{\times}10^9CFU$)을 16시간 동안 경구 투여하였다. 그 결과 비브리오균은 주로 회장(ileum) 부위에서 비브리오균(WT) 수가 가장 많이 증가하였고, 공장(Jejunum), 근위부대장(proximal colon), 원위부 대장(distal colon)에도 유의적으로 군집현성이 이루어짐을 알 수 있었지만, 십이지장(duodenum)과 비장(spleen), 그리고 간(liver) 조직들에서는 관찰되지 않았다. 특히 비브리오균의 표적기관인 회장상피조직에서는 비브리오균(WT)이 침입 시 융모 안으로 다량의 염증세포들이 유입되었고, 융포의 폭이 넓어지고 길이가 짧아지는 전형적인 조직학적 염증 반응을 보여주었다. 비브리오균이 유도한 조직 특이적 염증반응기작을 알아보기 위해, 비브리오에 감염된 회장상피조직으로부터 단백질과 mRNA를 분리하였다. 비브리오균은 숙주세포의 중추적 신호전달 단백질인 protein kinase C (PKC)의 인산화 및 $PKC{\alpha}$의 세포막이동을 촉진시켰고, mitogen-activated protein kinase (MAPK) 중 extracellular signal-regulated kinases (ERK)와 c-Jun N-terminal kinases (JNK)의 인산화를 유도하였지만, p38 MAPK 인산화에는 영향을 미치지 않았다. 특히 비브리오균은 inhibitory factor-kappa B (I-${\kappa}B$)의 활성을 촉진시킴으로써 nuclear factor-kappa B (NF-${\kappa}B$)의 인산화를 유도하였다. 마지막으로 비브리오균(WT)에 감염된 회장의 경우, 정상마우스에 비해 염증성 cytokine인 interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-${\alpha}$의 mRNA 수준이 유의적으로 증가되었다. 염증매개 수용체인 toll like receptor (TLR)-4, TLR-5, TLR-9의 mRNA의 발현 또한 비브리오균 처리에 의해 증가되어 있음이 관찰되었다. 종합적으로 오염된 식품 섭취를 통해 유입되는 비브리오균은 회장상피세포를 표적으로 염증반응을 일으키며, 그 기작은 PKC, ERK1/2, 그리고 JNK의 인산화를 통한 NF-${\kappa}B$ 활성의 촉진이며, 이로 인한 다양한 염증 매개 단백질 발현의 증가를 통해 이루어진다고 할 수 있다.

• Biomolecules & Therapeutics
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• 제24권5호
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• pp.529-535
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• 2016

Atopic dermatitis (AD) results from gene and environment interactions that lead to a range of immunological abnormalities and breakdown of the skin barrier. Protease-activated receptor 2 (PAR2) belongs to a family of G-protein coupled receptors and is expressed in suprabasal layers of the epidermis. PAR2 is activated by both trypsin and a specific agonist peptide, SLIGKV-$NH_2$ and is involved in both epidermal permeability barrier homeostasis and epithelial inflammation. In this study, we investigated the effect of lobaric acid on inflammation, keratinocyte differentiation, and recovery of the skin barrier in hairless mice. Lobaric acid blocked trypsin-induced and SLIGKV-$NH_2$-induced PAR2 activation resulting in decreased mobilization of intracellular $Ca^{2+}$ in HaCaT keratinocytes. Lobaric acid reduced expression of interleukin-8 induced by SLIGKV-$NH_2$ and thymus and activation regulated chemokine (TARC) induced by tumor necrosis factor-a (TNF-${\alpha}$) and IFN-${\gamma}$ in HaCaT keratinocytes. Lobaric acid also blocked SLIGKV-$NH_2$-induced activation of ERK, which is a downstream signal of PAR2 in normal human keratinocytes (NHEKs). Treatment with SLIGKV-$NH_2$ downregulated expression of involucrin, a differentiation marker protein in HaCaT keratinocytes, and upregulated expression of involucrin, transglutamase1 and filaggrin in NHEKs. However, lobaric acid antagonized the effect of SLIGKV-$NH_2$ in HaCaT keratinocytes and NHEKs. Topical application of lobaric acid accelerated barrier recovery kinetics in a SKH-1 hairless mouse model. These results suggested that lobaric acid is a PAR2 antagonist and could be a possible therapeutic agent for atopic dermatitis.

• Molecules and Cells
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• 제37권12호
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• pp.899-906
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• 2014

Prostaglandin $E_2$ ($PGE_2$) promotes tumor-persistent inflammation, frequently resulting in cancer. Curcumin is a diphenolic turmeric that inhibits carcinogenesis and induces apoptosis. $PGE_2$ inhibits curcumin-induced apoptosis; however, the underlying inhibitory mechanisms in colon cancer cells remain unknown. The aim of the present study is to investigate the survival role of $PGE_2$ and whether addition of exogenous $PGE_2$ affects curcumininduced cell death. HCT-15 cells were treated with curcumin and $PGE_2$, and protein expression levels were investigated via Western blot. Reactive oxygen species (ROS) generation, lipid peroxidation, and intracellular glutathione (GSH) levels were confirmed using specific dyes. The nuclear factor-kappa B ($NF-{\kappa}B$) DNA-binding was measured by electrophoretic mobility shift assay (EMSA). $PGE_2$ inhibited curcumin-induced apoptosis by suppressing oxidative stress and degradation of PARP and lamin B. However, exposure of cells to the EP2 receptor antagonist, AH6809, and the PKA inhibitor, H89, before treatment with $PGE_2$ or curcumin abolished the protective effect of $PGE_2$ and enhanced curcumin-induced cell death. $PGE_2$ activates PKA, which is required for cAMP-mediated transcriptional activation of CREB. $PGE_2$ also activated the Ras/Raf/Erk pathway, and pretreatment with PD98059 abolished the protective effect of $PGE_2$. Furthermore, curcumin treatment greatly reduced phosphorylation of CREB, followed by a concomitant reduction of $NF-{\kappa}B$ (p50 and p65) subunit activation. $PGE_2$ markedly activated nuclear translocation of $NF-{\kappa}B$. EMSA confirmed the DNA-binding activities of $NF-{\kappa}B$ subunits. These results suggest that inhibition of curcumin-induced apoptosis by $PGE_2$ through activation of PKA, Ras, and $NF-{\kappa}B$ signaling pathways may provide a molecular basis for the reversal of curcumin-induced colon carcinoma cell death.

• 대한한방소아과학회지
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• 제30권3호
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• pp.1-30
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• 2016

Objectives Previous studies have found out that Forsythiae Fructus (FF) extracts have anti-atopic activities by in vitro experiment. In order to understand more about FF extracts' benefit, we subdivided FF extracts depending on systematic fractionation method by using Methylene chloride (MC), Ethyl acetate (EtOAc), n-BuOH and n-hexane (n-Hx). This study is designed to examine the effect of FF fractions on the PMA- ionomycin-induced activation of RBL-2H3 mast cell lines in vitro and on the DNCB-induced activation of NC/Nga mice in vivo. Methods For this study, we examined IL-4, IL-13 production by ELISA analysis, IL-4, IL-13, IL-31, IL-31RA and TNF-${\alpha}$ mRNA expression by real-time PCR and manifestations of AP-1 and MAPKs transcription factors by western blotting in vitro. Through in vitro experiment, we selected FF n-BuOH fraction that seems the best effective in atopic dermatitis then induced it on NC/Nga mice by DNCB. We measured mice's WBC, eosinophil and neutrophil in heart blood, IL-4, IL-5, IFN-${\gamma}$ in the spleenocyte culture supernatant, the absolute cell numbers of CD4+, CD8+, B220+CD23+, CD3+CD69+ and Gr-1+CD11b+ in the PBMCs, ALN and dorsal skin, IL-5, IL-13, IL-31, IL-31RA in the dorsal skin by real-time PCR and the distribution of immune cells by H&E on dorsal skin and ANL and toluidine blue staining on dorsal skin. Results FF n-BuOH fraction suppressed IL-4, IL-13 production and mRNA expression of IL-4, IL-13, IL-31, IL-31RA and TNF-${\alpha}$. Results from the western blot analysis showed that FF n-BuOH fraction reduced the activation of the mast cell specific transduction factors involved in AP-1 by suppressing JNK and ERK phosphorylation. In the gross, atopic dermatitis induced by DNCB in NC/Nga mice were improved by oral administration of FF n-BuOH fraction. Oral FF n-BuOH fraction also decreased the level of IgE in mice's serum and the level of IL-4 and IL-5 in the spleenocyte culture supernatant, cell numbers of CD8+, B220+CD23+ in the PBMCs, CD4+ in the ALN and CD4+, Gr-1+CD11b+ in the dorsal skin and suppressed mRNA expression of IL-5, IL-13, IL-31, IL-31RA in the dorsal skin. Histological examination showed that infiltration levels of immune cells in atopic dermatitis induced NC/Nga mice were improved by FF n-BuOH fraction. Conclusions FF n-BuOH fraction can reduce pruritus by suppressing IL-31, IL-31RA secretion and modulate molecular mediators and immune cells associated with atopic dermatitis induced in NC/Nga mice which may have played a significant role in recovering atopic dermatitis symptoms.