• Journal of Microbiology and Biotechnology
• /
• 제16권3호
• /
• pp.391-398
• /
• 2006

$NF-{\kappa}B$ is a transcription factor involved in the innate immunity against bacterial infection and inflammation. It is also known to render cells resistant to the apoptosis caused by some anticancer drugs. Such a chemoresistance of cancer cells may be related to the activation of $NF-{\kappa}B$ transcription factor; however, the mechanism of activation is not well understood. Here, we demonstrate that a chemotherapeutic agent, etoposide, independently stimulates the $I{\kappa}B{\alpha}$ degradation pathway and PI3-kinase/Akt signaling pathway: The classical $I{\kappa}B{\alpha}$ degradation pathway leads to the nuclear translocation and DNA binding of p65 subunit through $IKK{\beta}$ kinase, whereas the PI3-kinase/Akt pathway plays a distinct role in activating this transcription factor. The PI3-kinase/Akt pathway acts on the p50 subunit of the $NF-{\kappa}B$ transcription factor and enhances the DNA binding affinity of the p50 protein. It may also explain the role of the PI3-kinase/Akt pathway in the anti-apoptotic function of $NF-{\kappa}B$ during chemoresistance of cancer cells.

• Biomolecules & Therapeutics
• /
• 제24권6호
• /
• pp.604-609
• /
• 2016

5-fluorouracil (5-FU) is a chemotherapeutic agent commonly used for treatment of solid tumors, including colorectal cancer. However, chemoresistance against 5-fluorouracil (5-FU) often limits its success for chemotherapy and, therefore, finding out appropriate adjuvant(s) that might overcome chemoresistance against 5-FU bears a significant importance. In the present study, we have found that ${\alpha}$-mangostin can sensitize 5-FU-resistant SNUC5/5-FUR colon cancer cells to apoptosis. Exposure of ${\alpha}$-mangostin induced significant DNA damages and increased the intracellular 8-hydroxyguanosine (8-OH-G) and 4-hydroxynonenal (4-HNE) levels in SNUC5 and SNUC5/5-FUR cells. Western blot analysis illustrated that ${\alpha}$-mangostin-induced apoptosis was mediated by the activation of the extrinsic and intrinsic pathways in SNUC5/5-FUR cells. In particular, we observed that Fas receptor (FasR) level was lower in SNUC5/5-FUR cells, compared with SNUC5 cells and that silencing FasR attenuated ${\alpha}$-mangostin-mediated apoptosis in SNUC5/5-FUR cells. Together, our study illustrates that ${\alpha}$-mangostin might be an efficient apoptosis sensitizer that can overcome chemoresistance against 5-FU by activating apoptosis pathway.

• The Plant Pathology Journal
• /
• 제34권2호
• /
• pp.113-120
• /
• 2018

Chlorella, one single-cell green algae organism that lives autotrophically by photosynthesis, can directly suppress some plant diseases. The objective of this study was to determine whether pre-spraying with Chlorella fusca suspension could induce systemic acquired resistance (SAR) in cucumber plants against anthracnose caused by Colletotrichum orbiculare. In order to illustrate SAR induced by algae, infection structures in host cells were observed under a transmission electron microscope (TEM). Cytological changes as defense responses of host mesophyll cells such as accumulation of vesicles, formation of sheath around penetration hyphae, and thickness of cell wells adjoining with intracellular hyphae were demonstrated in cucumber leaves. Similar defense responses were also found in the plant pre-treated with DL-3-aminobutyric acid, another SAR priming agent. Images showed that defense response of host cells was scarcely observed in untreated leaf tissues. These cytological observations suggest that C. fusca could induce SAR against anthracnose in cucumber plants by activating defense responses of host cells.

• BMB Reports
• /
• 제47권12호
• /
• pp.691-696
• /
• 2014

${\alpha}$-Enolase is a glycolytic enzyme and a surface receptor for plasminogen. ${\alpha}$-Enolase-bound plasminogen promotes tumor cell invasion and cancer metastasis by activating plasmin and consequently degrading the extracellular matrix degradation. Therefore, ${\alpha}$-enolase and plasminogen are novel targets for cancer therapy. We found that the amino acid sequence of a peptide purified from enzymatic hydrolysates of seahorse has striking similarities to that of ${\alpha}$-enolase. In this study, we report that this peptide competes with cellular ${\alpha}$-enolase for plasminogen binding and suppresses urokinase plasminogen activator (uPA)-mediated activation of plasminogen, which results in decreased invasive migration of HT1080 fibrosarcoma cells. In addition, the peptide treatment decreased the expression levels of uPA compared to that of untreated controls. These results provide new insight into the mechanism by which the seahorse-derived peptide suppresses invasive properties of human cancer cells. Our findings suggest that this peptide could emerge as a potential therapeutic agent for cancer.

• Journal of Ginseng Research
• /
• 제44권2호
• /
• pp.194-204
• /
• 2020

The detrimental impact of air pollution as a result of frequent exposure to fine particles posed a global public health risk mainly to the pulmonary disorders in pediatric and geriatric population. Here, we reviewed the current literature regarding the role of ginseng and/or its components as antimicrobials, especially against pathogens that cause respiratory infections in animal and in vitro models. Some of the possible mechanisms for ginseng-mediated viral inhibition suggested are improvements in systemic and mucosa-specific antibody responses, serum hemagglutinin inhibition, lymphocyte proliferation, cell survival rate, and viral clearance in the lungs. In addition, ginseng reduces the expression levels of proinflammatory cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-6, IL-8) and chemokines produced by airway epithelial cells and macrophages, thus preventing weight loss. In case of bacterial infections, ginseng acts by alleviating inflammatory cytokine production, increasing survival rates, and activating phagocytes and natural killer cells. In addition, ginseng inhibits biofilm formation and induces the dispersion and dissolution of mature biofilms. Most clinical trials revealed that ginseng, at various dosages, is a safe and effective method of seasonal prophylaxis, relieving the symptoms and reducing the risk and duration of colds and flu. Taken together, these findings support the efficacy of ginseng as a therapeutic and prophylactic agent for respiratory infections.

• 한국자원식물학회지
• /
• 제35권6호
• /
• pp.704-712
• /
• 2022

Research on whitening materials using natural alternatives is actively being conducted. The aim of this study was to investigate the in vitro inhibitory effects of Ranunculus chinensis Bunge (RCB) on melanogenesis and associated enzymes, such as tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 in B16F10 murine melanoma cells. We found that RCB extract significantly attenuated melanin synthesis and reduced the activity of intracellular tyrosinase, a rate-limiting melanogenic enzyme. Western blot analysis showed that RCB extract decreased the protein expression of tyrosinase and TRP-1. In addition, it significantly decreased the expression of microphthalmia-associated transcription factor (MITF), a key regulator of melanogenesis. Extracellular signal-regulated kinase (ERK) activation has been reported to be involved in the inhibition of melanogenesis. Thus, we investigated whether the hypopigmentary effects of RCB extract were related to the activation of ERK. RCB extract induced ERK phosphorylation in a dose-dependent manner. Furthermore, it markedly inhibited body pigmentation in a zebrafish model. Our results suggest that RCB extract inhibits melanogenesis by activating ERK pathway-mediated suppression of MITF and its downstream target genes, including tyrosinase. Therefore, RCB extract can be used as a whitening agent in the development of functional cosmetics.

• 한국환경과학회:학술대회논문집
• /
• 한국환경과학회 2020년도 정기학술대회 발표논문집
• /
• pp.221-221
• /
• 2020

Curcumin, a hydrophobic polyphenol derived from turmeric, has been used a food additive and as a herbal medicine for the treatment of various diseases. In the present study, we found the functional role of a nanosphere loaded with curcumin (CN) in the promotion of the motility of human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) during the wound closure. We found that the efficacy of hUCB-MSCs migration induced by CN was 1000-fold higher than that of curcumin powder. CN significantly increased the motility of hUCB-MSCs by activating c-Src, which is responsible for the phosphorylation of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK). CN induced the expression levels of α-actinin-1, profilin-1 and filamentous-actin, as regulated by the phosphorylation of nuclear factor-kappa B during its promotion of cell migration. In a mouse skin excisional wound model, we found that transplantation of UCB-MSCs pre-treated with CN enhances wound closure, granulation, and re-epithelialization at mouse skin wound sites. These results indicate that CN is a functional agent that promotes the mobilization of UCB-MSCs for cutaneous wound repair.

• 한국식품영양과학회지
• /
• 제36권3호
• /
• pp.269-275
• /
• 2007

불가사리 추출물을 이용하여 생쥐 비장에 있는 면역세포 활성화 효과에 대해 실험한 결과, 다음과 같은 결과를 얻었다. 첫째, 별불가사리 추출물 중에서 B세포와 대식세포를 활성화시키는 성분은 아세톤처리로 추출할 수 있었다. 둘째, 이 성분은 농도 의존적으로 생쥐 비장세포의 증식반응을 유도하였으며, IL-6와 $IFN-{\gamma}$의 생산을 유도하였다. 셋째, 이 성분은 B세포의 증식을 유도하였으며, 이 때 면역글로불린 IgM과 IgG의 생산도 유도하였다. 넷째, 이 성분은 대식세포주의 일산화질소 생산을 유도하였으며, 또 $TNF-{\alpha}$, GM- CSF와 IL-6의 분비를 유도하였다. 이상의 실험 결과, 본 실험에서 사용한 별불가사리 추출물에는 B세포와 대식세포 같은 면역세포의 증식과 각종 사이토카인을 생산을 유도하여, 면역반응을 조절하는 성분이 포함되어 있는 것으로 생각된다.

• 생명과학회지
• /
• 제22권8호
• /
• pp.1107-1113
• /
• 2012

동양에서 한약 재료로 사용되는 칡(Pueraria thunbergiana)은 항산화, 항균효과 및 골다공증 치료 등의 다양한 효과가 있는 것으로 밝혀지고 있지만, 생태학적으로는 산림생태계를 파괴하는 종으로 알려져 있다. 본 연구는 칡의 면역학적 효과를 검증하여 유용한 자원으로 활용하는데 목적이 있다. 칡 추출물을 이용하여 생쥐 비장에 있는 면역세포 활성화 작용을 실험한 결과, 칡 추출물은 첫째, 농도 의존적으로 생쥐 비장세포의 증식 유도하였으며 IL-6, TNF-${\alpha}$, IL-2, IFN-${\gamma}$의 cytokine 생산을 증가시켰다. 둘째, 특히 비장세포 중 칡 추출물은 B세포를 자극하여 세포증식 및 IgM의 생산을 증가시켰다. 셋째, 대식세포주의 일산화질소 생산을 유도하였으며, 또 TNF-${\alpha}$, IL-6 및 IL-$1{\beta}$의 cytokine 분비를 유도하였다. 이상의 실험 결과, 본 실험에서 사용한 칡 추출물은 B세포와 대식세포 같은 면역세포의 증식과 각종 사이토카인을 생산을 유도하기 때문에, 면역반응을 조절하는 성분이 포함되어 있는 것으로 생각되며 특히, 아세톤 추출물이 물 추출물에 비하여 효과적이었다. 따라서 추가적인 실험을 통해, 면역반응을 조절하는 성분을 분리 정제하여 그 특성을 명확히 규명한다면, 각종 의약품이나 건강식품을 개발할 수 있는 원재료로서 칡을 이용할 수 있으며, 부수적으로 산림생태계에 복원에도 기여할 수 있을 것으로 사료된다.

• 한국엔터테인먼트산업학회논문지
• /
• 제15권3호
• /
• pp.153-170
• /
• 2021

이 연구는 선수, 구단, 연맹, 에이전시 등 프로스포츠 관계자를 대상으로 심층인터뷰를 실시하여 승부조작 유발요인을 탐색하고 이를 바탕으로 예방전락을 도출함으로써 프로스포츠 활성화를 위한 전략적 시사점을 도출하고자 시도되었다. 스노우볼 샘플링 기법을 활용하여 프로스포츠계에서 근무한 경력이 3년 이상인 사람을 8명 선정하였다. 이들을 대상으로 반구조화된 심층인터뷰 방법을 적용하여 자료를 수집·분석하였다. 분석결과 승부조작 유발요인으로 첫째, 대학 진학을 위한 카르텔로부터의 학습효과 둘째, 합숙환경에서 학습된 문화 셋째, 잠재학습 효과의 발현 넷째, 인적 네트워크의 부정적 효과 다섯째, 개인의 성향을 핵심범주로 도출하였다. 승부조작 예방 전략으로는 첫째, 개인능력 중심으로의 대학입시제도 개선 둘째, 학생선수 교육시스템의 개선 셋째, 예방시스템의 구축 넷째, 지속적인 교육 다섯째, 에이전트 제도의 활성화를 핵심범주로 도출하였다. 도출된 연구결과에 대한 시사점과 향후 연구방향에 대하여 논의하였다.