• 한국축산식품학회지
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• 제26권3호
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• pp.402-409
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• 2006

Although microorganisms are, in fact, the most diverse and abundant type of organism on Earth, the ecological functions of microbial populations remains poorly understood. A variety of bacteria including marine Vibrios encounter numerous ecological challenges, such as UV light, predation, competition, and seasonal variations in seawater including pH, salinity, nutrient levels, temperature and so forth. In order to survive and proliferate under variable conditions, they have to develop elaborate means of communication to meet the challenges to which they are exposed. In bacteria, a range of biological functions have recently been found to be regulated by a population density-dependent cell-cell signaling mechanism known as quorum-sensing (QS). In other words, bacterial cells sense population density by monitoring the presence of self-produced extracellular autoinducers (AI). N-acylhomoserine lactone (AHL)-dependent quorum-sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeriis the paradigm of Gram-negative quorum-sensing systems. At high population density, the accumulated signalstrigger the expression of target genes and thereby initiate a new set of biological activities. Several QS systems have been identified so far. Among them, an AHL-dependent QS system has been found to control biofilm formation in several bacterial species, including Pseudomonas aeruginosa, Aeromonas hydrophila, Burkholderia cepacia, and Serratia liquefaciens. Bacterial biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix that adheres to an inert or living surface. Extracellular signal molecules have been implicated in biofilm formation. Agrobacterium tumefaciens strain NT1(traR, tra::lacZ749) and Chromobacterium violaceum strain CV026 are used as biosensors to detect AHL signals. Quorum sensing in lactic acid bacteria involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular regulator. In the nisin autoregulation process in Lactococcus lactis, the NisK protein acts as the sensor for nisin, and NisR protein as the response regulator activatingthe transcription of target genes. For control over growth and survival in bacterial communities, various strategies need to be developed by which receptors of the signal molecules are interfered with or the synthesis and release of the molecules is controlled. However, much is still unknown about the metabolic processes involved in such signal transduction and whether or not various foods and food ingredients may affect communication between spoilage or pathogenic bacteria. In five to ten years, we will be able to discover new signal molecules, some of which may have applications in food preservation to inhibit the growth of pathogens on foods.

• 대한본초학회지
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• 제35권4호
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• pp.9-16
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• 2020

Objective : To identify the effects of the water extract of Liriope platyphylla tuber (Liriopis tuber, LT) on the activation of astocytes, we investigated the regulatory effects of LT extract on H₂O₂-induced oxidative damage in C6 rat astrocytes. Methods : LT extract was extracted with boiling water. C6 cell line were treated with LT extract at 1, 2, and 3 mg/㎖ or without for 30 min and then stimulated with H₂O₂ at 5 ㎛ for 24 hr. The cell viability was measured by MTT assay. The expression of glial fibrillary acidic protein (GFAP), signal transducer and activator of transcription 3 (STAT3), phospho-STAT3 (pSTAT3), cyclooxygenase (COX-2), Nuclear factor-κB (NF-κB), superoxide dismutase 2 (SOD2), heme oxygenase-1 (HO-1), catalase, Akt, phospho-Akt (p-Akt) phosphoinositide 3-kinases (PI3K), and protein kinase C alpha (PKCα) proteins were determined by Western blot, respectively. GFAP expression was also observed with immunocytochemistry under a fluorescence microscope. Results : LT extract induced cell proliferation in H₂O₂-stimulated C6 cells. LT extract significantly inhibited the expression of GFAP, NF-κB and COX-2 and increased the expression of HO-1 and the phosphorylation of STAT3 in H₂O₂-stimulated C6 cells. LT extract also significantly increased the phosphorylation of Akt and decreased the expression of PKCα in a dose-dependent manner in H₂O₂-stimulated C6 cells. Conclusions : LT extract can regulate H₂O₂-induced activation of astrocytes through inhibiting the expression of NF-κB, COX-2 and regulating Akt / HO-1, STAT3 or PKCα signaling pathway.

• 생명과학회지
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• 제24권9호
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• pp.973-980
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• 2014

본 연구에서는 식물에 존재하는 신규 기능성 소재 개발의 일환으로 Decaisnea insignis 에탄올 추출물(DIEE)의 항산화 및 항염증 생리활성을 분석하였다. 먼저 DIEE의 항산화능을 DPPH 라디칼 소거능을 통해 분석한 결과 양성 대조군으로 사용한 아스코르빈산과 유사한 정도의 높은 소거활성을 보여 DIEE가 매우 강한 항산화능을 보유함을 확인하였다. 또한 RAW 264.7 세포주에서 $H_2O_2$ 및 LPS에 의해 유도된 ROS에 대한 DIEE의 소거능을 분석한 결과, 농도의존적인 강한 ROS 소거능을 보였다. 뿐만 아니라 대표적인 항산화효소 중 하나로 항산화능 보유 천연물에 의해 발현이 유도되는 hemeoxygenase 1 (HO-1) 및 그 전사 인자인 nuclear factor-E2-related factor 2(Nrf2)의 단백질 발현이 DIEE의 처리에 의해 유의적으로 증가됨을 보였으며 이러한 HO-1 및 Nrf2의 발현 유도는 상위신호전달계인 MAPKs에 의해 조절될 가능성을 보였다. 한편 DIEE가 LPS에 의해 유도된 NO 생성에 미치는 영향을 분석한 결과 농도의존적인 NO 생성 저해능을 보였으며 이는 NO 생성 단백질인 iNOS의 발현 저해에서 기인함을 확인하였다. 이와 같은 DIEE의 NO 생성 억제 효과는 염증 상위신호전달계인 $NF-{\kappa}B$ 및 AP-1의 조절을 통해 일어날 가능성을 보였다. 이러한 결과를 통해 DIEE의 높은 항산화능과 항염증 활성을 처음으로 확인하였으며 향후 기능성 소재로서 유용하게 활용될 수 있을 것으로 판단된다.

• Molecules and Cells
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• 제40권3호
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• pp.230-242
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• 2017

In the Arabidopsis genome, approximately 80 MAP3Ks (mitogen-activated protein kinase kinase kinases) have been identified. However, only a few of them have been characterized, and the functions of most MAP3Ks are largely unknown. In this paper, we report the function of MAP3K16 and several other MAP3Ks, MAP3K14/15/17/18, whose expression is salt-inducible. We prepared MAP3K16 overexpression (OX) lines and analyzed their phenotypes. The result showed that the transgenic plants were ABA-insensitive during seed germination and cotyledon greening stage but their root growth was ABA-hypersensitive. The OX lines were more susceptible to water-deficit condition at later growth stage in soil. A MAP3K16 knockout (KO) line, on the other hand, exhibited opposite phenotypes. In similar transgenic analyses, we found that MAP3K14/15/17/18 OX and KO lines displayed similar phenotypes to those of MA3K16, suggesting the functional redundancy among them. MAP3K16 possesses in vitro kinase activity, and we carried out two-hybrid analyses to identify MAP3K16 substrates. Our results indicate that MAP3K16 interacts with MKK3 and the negative regulator of ABA response, ABR1, in yeast. Furthermore, MAP3K16 recombinant protein could phosphorylate MKK3 and ABR1, suggesting that they might be MAP3K16 substrates. Collectively, our results demonstrate that MAP3K16 and MAP3K14/15/17/18 are involved in ABA response, playing negative or positive roles depending on developmental stage and that MAP3K16 may function via MKK3 and ABR1.

• Nutrition Research and Practice
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• 제11권1호
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• pp.3-10
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• 2017

BACKGROUND/OBJECTIVES: Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. MATERIALS/METHODS: CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-${\kappa}B$, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer. RESULTS: The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells ($IC_{50}$ value: $95.7{\mu}g/mL$). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-${\alpha}$ and IL-$1{\beta}$, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-${\kappa}B$ p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan. CONCLUSIONS: Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

• Nutrition Research and Practice
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• 제12권3호
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• pp.199-207
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• 2018

BACKGROUND/OBJECTIVES: Fermented Laminaria japonica (FL), a type sea tangle used as a functional food ingredient, has been reported to possess cognitive improving properties that may aid in the treatment of common neurodegenerative disorders, such as dementia. MATERIALS/METHODS: We examined the effects of FL on scopolamine (Sco)- and ethanol (EtOH)-induced hippocampus-dependent memory impairment, using the Passive avoidance (PA) and Morris water maze (MWM) tests. To examine the underlying mechanisms associated with neuroprotective effects, we analyzed acetylcholine (ACh) and acetylcholinesterase (AChE) activity, brain tissue expression of muscarinic acetylcholine receptor (mAChR), cAMP response element binding protein (CREB) and extracellular signal-regulated kinases 1/2 (ERK1/2), and immunohistochemical analysis, in the hippocampus of mice, compared to current drug therapy intervention. Biochemical blood analysis was carried out to determine the effects of FL on alanine transaminase (ALT), aspartate transaminase (AST), and triglyceride (TG) and total cholesterol (TC) levels. 7 groups (n = 10) consisted of a control (CON), 3 Sco-induced dementia and 3 EtOH-induced dementia groups, with both dementia group types containing an untreated group (Sco and EtOH); a positive control, orally administered donepezil (Dpz) (4mg/kg) (Sco + Dpz and EtOH + Dpz); and an FL (50 mg/kg) treatment group (Sco + FL50 and EtOH + FL50), orally administered over the 4-week experimental period. RESULTS: FL50 significantly reduced EtOH-induced increase in AST and ALT levels. FL50 treatment reduced EtOH-impaired step-through latency time in the PA test, and Sco- and EtOH-induced dementia escape latency times in the MWM test. Moreover, anticholinergic effects of Sco and EtOH on the brain were reversed by FL50, through the attenuation of AChE activity and elevation of ACh concentration. FL50 elevated ERK1/2 protein expression and increased p-CREB (ser133) in hippocampus brain tissue, according to Western blot and immunohistochemistry analysis, respectively. CONCLUSION: Overall, these results suggest that FL may be considered an efficacious intervention for Sco- and EtOH-induced dementia, in terms of reversing cognitive impairment and neuroplastic dysfunction.

• Journal of Korean Neurosurgical Society
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• 제29권4호
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• pp.471-476
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• 2000

Objective : p16/INK4a, a kind of tumor suppressor genes, encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. This prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumor suppressor protein(pRb), thus preventing exit from the G1 phase. According to previous reports, over 50% of glioma tissue and 80% of glioma cell lines have been demonstrated inactivation of p16/INK4a gene. The purpose of this study was to determine whether recombinant adenovirus-p16 virus is a suitable candidate for gene replacement therapy in cases of glioma. Methods : Three human glioma cell lines(U251MG, U87MG and U373MG) that express mutant p16 protein were used. Replication-deficient adenovirus was utilized as an expression vector to transfer exogenous p16 cDNA into the cells ; control cells were infected with the Ad-${\beta}$-gal expressing ${\beta}$-galactosidase. To monitor gene transfer and the expression of exogenous genes, we used Western Blotting analysis. Flow cytometry studies of cellular DNA content were performed to determine the cell cycle phenotype of the glioma cells before and after treatment. Results : We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16 induced growth suppression in vitro. Flow cytometric study revealed that Ad-CMV-p16 infected U87MG cells were arrested during the G0-G1 phase of the cell cycle. Expression of p16 transferred by Ad-CMV-p16 in glioma cells was highly efficient and maintained for more than seven days. Conclusions : Our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.

• 생명과학회지
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• 제31권8호
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• pp.745-754
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• 2021

면역 기능의 저하는 각종 감염에 대한 저항력의 부족을 초래하여 다양한 질병 유발에 기여하며, 면역 억제제의 부작용을 감소시키거나 면역력을 높이기 위해 면역 조절 생체 물질이 사용되고 있다. 침향은 침향나무의 방향족수지 부분이며 전통적으로 다양한 질병을 치료하기 위한 목적으로 사용되어왔다. 비록 선행 연구들에 의하여 침향이 신체의 면역력을 향상시킬 수 있다는 사실이 밝혀졌지만 이에 대한 근거는 여전히 부족한 실정이다. 본 연구에서는 인도네시아에서 구입한 A. malaccensisd 침향 메탄올 추출물의 면역 자극 효과를 RAW 264.7 대식세포 모델에서 평가하였다. 본 연구의 결과에 의하면 침향 추출물은 세포 독성이 없는 조건에서 식작용을 현저하게 향상시켰으며다. 또한 침향 추출물 처리된 RAW 264.7 세포는 활성화된 대식세포의 전형적인 형태를 보였으며, iNOS 발현 증가에 따른 NO 생성의 생성을 크게 증가시켰다. 아울러 TNF-α, IL-1β 및 IL-6과 같은 cytokine의 발현과 분비를 증가시켰으며, MAPKs 신호 전달 경로를 활성화시켰다. 따라서 본 연구의 결과는 고대 서적을 기반으로 침향의 효과를 확인하는 데 중요한 의미가 있으며, 침향이 잠재적인 면역 강화 효과가 있다는 근거를 제시하는 것이다.

• 대한본초학회지
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• 제38권1호
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• pp.11-19
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• 2023

Objectives : Neuroinflammation is a common pathological mechanism of neurodegenerative diseases, and the development of therapeutic agents is urgently needed. Red ginseng has been known to be good for the immune stimulation in Eastern Asia. Although the immuno-stimulatory activity of red ginseng are already known, the neuro-protective effects of cultivated red ginseng with fermented complex mushroom-cereal mycelium (RGFM) have not been conducted. Thus, in this study, we tried to investigate the anti-neuroinflammatory effect of RGFM water extract on lipopolysaccharide (LPS) stimulated BV2 cells. Methods : BV2 cells were pretreated with RGFM 1 h prior to LPS exposure. To determine the neuro-protective effects of RGFM water extract, we measured the expression of inflammatory mediators including inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and nitric oxide (NO) and pro-inflammatory cytokines such as interleukin (IL)-1𝛽, IL-6 and tumor necrosis factor (TNF)-𝛼 in LPS-stimulated BV2 cells. In addition, to find out the regulatory mechanism of RGFM water extract, we assessed the protein levels of mitogen-activated protein kinases (MAPKs) and inhibitory 𝜅B𝛼 (I𝜅B𝛼) by western blotting. Results : In our study, treatment of RGFM reduced the mRNA expression of iNOS and COX-2 and suppressed NO production in LPS-stimulated BV2 cells. Additionally, the secretion of IL-1𝛽 and TNF-𝛼 but not IL-6 was significantly inhibited by RGFM. Furthermore, RGFM water extract inhibited the phosphorylation of c-Jun N-terminal kinase (JNK). Conclusions : Taken together, these findings suggest that RGFM water extract has a protective effect on neuroinflammation through inhibition of JNK.

• 대한본초학회지
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• 제28권3호
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• pp.53-60
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• 2013

Objectives : DojukSan is known to be effective for treating a urinary diseases and stomatitis. However, there has been a lack of studies regarding the effects of Dojuksan on the inflammatory activities and effector inflammatory disease mechanism about macrophage before is not known. To elucidate the molecular mechanisms of Dojuksan water extract (DJS) on pharmacological and biochemical actions in inflammation, we examined the effect of DJS on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophages. Methods : In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and western blot analysis to measure the activation of MAPKs. Cells were treated with 200 ng/mL of LPS 1 h prior to the addition of DJS. Cell viability was measured by MTS assay. The investigation focused on whether DJS inhibited nitric oxide (NO) and prostaglandin E2 ($PGE_2$) productions, as well as the expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW 264.7 cells. Results : We found that DJS inhibited LPS-induced NO, $PGE_2$ and IL-6 productions as well as the expressions of iNOS and COX-2. Furthermore, DJS suppressed the LPS-induced phosphorylation of p38 MAPK and c-Jun NH2-protein kinase (JNK). Conclusions : These results suggest that DJS has inhibitory effects on LPS-induced $PGE_2$, NO, and IL-6 production, as well as the expressions of iNOS and COX-2 in the murine macrophage. These inhibitory effects occur through blockades on the MAPKs phosphorylation.