• Nutrition Research and Practice
• /
• 제9권2호
• /
• pp.123-128
• /
• 2015

BACKGROUND/OBJECTIVES: Natural products or active components with a protective effect against oxidative stress have attracted significant attention for prevention and treatment of degenerative disease. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from Litchi chinensis Sonn. We investigated the protective effect and its related mechanism of oligonol against oxidative stress. MATERIALS/METHODS: Oxidative stress in C6 glial cells was induced by hydrogen peroxide ($H_2O_2$) and the protective effects of oligonol on cell viability, nitric oxide (NO) and reactive oxygen species (ROS) synthesis, and mRNA expression related to oxidative stress were determined. RESULTS: Treatment with oligonol inhibited NO and ROS formation under cellular oxidative stress in C6 glial cells. In addition, it recovered cell viability in a dose dependent-manner. Treatment with oligonol also resulted in down-regulated mRNA expression related to oxidative stress, nuclear factor kappa-B (NF-${\kappa}B$) p65, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), compared with the control group treated with $H_2O_2$. In particular, expression of NF-${\kappa}B$ p65, COX-2, and iNOS was effectively reduced to the normal level by treatment with $10{\mu}g/mL$ and $25{\mu}g/mL$ of oligonol. CONCLUSIONS: These results indicate that oligonol has protective activity against oxidative stress-induced inflammation. Oligonol might be a promising agent for treatment of degenerative diseases through inhibition of ROS formation and NF-${\kappa}B$ pathway gene expression.

• Journal of Microbiology and Biotechnology
• /
• 제21권8호
• /
• pp.830-837
• /
• 2011

A genomic DNA fragment encoding a putative maltooligosyltrehalose trehalohydrolase (NfMTH) for trehalose biosynthesis was cloned by the degenerate primer- PCR from cyanobacterium Nostoc flagelliforme. The ORF of NfMTH is 1,848 bp in length and encodes 615 amino acid residues, constituting a 70 kDa protein. The deduced amino acid sequence of NfMTH contains 4 regions highly conserved for MTHs. By expression of NfMTH in E. coli, the function of this protein was demonstrated, where the recombinant protein catalyzed the hydrolysis of maltooligosyl trehalose to trehalose. The expressions of MTH and maltooligosyltrehalose synthase in the filaments of N. flagelliforme were upregulated significantly under dehydration stress, NaCl stress, and high temperature-drought stress. The accumulations of both trehalose and sucrose in the filaments of N. flagelliforme were also improved significantly under the above stresses. Furthermore, trehalose accumulated in smaller quantities than sucrose did when under NaCl stress, but accumulated in higher quantities than sucrose did when under temperature-drought stress, indicating that both trehalose and sucrose were involved in N. flagelliforme adapted to stresses and different strategies conducted in response to various stress conditions.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2021년도 춘계학술대회
• /
• pp.60-60
• /
• 2021

Non-alcoholic fatty liver disease (NAFLD), especially including non-alcoholic steatohepatitis (NASH) is one of the common diseases with 25% of prevalence globally, but there is no thera-peutic access available. Amomum villosum var. xanthioides (Wall. ex Baker) T.L.Wu & S.J.Chen (AX), which is a medicinal herb and traditionally used for treating digestive tract disorders in Asia countries. We aimed to examine pharmacological effects of ethyl acetate fraction of AX (AXEF) against ER stress-induced NASH mice model using C57/BL6J male mice by tunicamycin (TM, 2 mg/kg) injection focusing on the oxidative stress. Mice were orally administrated AXEF (12.5, 25, or 50 mg/kg), silymarin (50 mg/kg) or distilled water daily for 5 days, and outcomes for fatty liver, inflammation, and oxidative stress were measured in serum or liver tissue levels. AXEF drastically attenuated hepatic ER stress-induced NASH which were evidenced by decreases of li-pid droplet accumulations, serum liver enzymes, hepatic inflammations, and cell death signals in the hepatic tissue or serum levels. Interestingly, AXEF showed potent antioxidant effects by quenching of reactive oxidative stress and its final product of lipid peroxide in the hepatic tissue, specifically increase of metallothionein (MT). To confirm underlying actions of AXEF, we ob-served that AXEF increase MT1gene promoter activities in the physiological levels. Collectively, AXEF showed antioxidant properties on TM-induced ER stress of NASH by enhancement of MTs.

• 생명과학회지
• /
• 제23권9호
• /
• pp.1104-1108
• /
• 2013

에틸렌 글리콜(ethylene glycol)은 자동차 부동액 주성분으로 우리 실생활에 널리 쓰이고 있다. 접근이 용이하고 달콤한 맛 때문에 자살목적이나 보관 및 사용 시 의도적으로 또는 실수로 인한 오용사고가 자주 발생한다. 에틸렌 글리콜은 그 자체로는 인체의 독성이 낮지만 생체에서 대사과정을 거치면서 독성이 높아진 유기산을 만들어 다양한 조직에서 광범위한 세포손상을 유발한다. 다양한 세포 스트레스가 소포체(ER) 샤페론과 소포체 스트레스 센서의 유전자 발현을 유도하는 것은 이미 알려져 있다. 본 연구에서는 rat 조직에서 소포체 샤페론과 소포체 스트레스 센서 유전자의 발현 조절이 에틸렌 글리콜에 의해 유도되고, 조직학적 변화도 H&E 염색 및 면역 형광염색에 의해 확인하였다.

• 대한한방내과학회지
• /
• 제32권4호
• /
• pp.487-496
• /
• 2011

Objectives : The aim of this study was to investigate the hepatoprotective effect of Soshiho-tang (SSH) in mouse primary liver cells against hydrogen peroxide ($H_2O_2$)-induced oxidative stress. We also elucidated the molecular mechanism of hepatoprotective effect by SSH. Methods : Cell viability, level of ALT, AST and LDH, intracellular ROS level, mRNA expression and activity of antioxidant enzymes were used to evaluate hepatoprotection of SSH against $H_2O_2$. Target gene expressions were analyzed by real-time PCR. Results : Pre-treatment with SSH for 1 hour prevented cytotoxicity against $H_2O_2$. $H_2O_2$-induced ROS level decreased under SSH pre-treatment. mRNA expression of GPx and SOD increased in SSH-treated cells. In addition, HSP72 and HSP40 gene expression were elevated under SSH-treatment. Conclusions : These results indicate that SSH protects mouse primary liver cells from $H_2O_2$-induced oxidative injury. This hepatoprotective activity of SSH is mediated by decreasing intracellular ROS and increasing antioxidant enzyme expression (GPx and SOD) and stress response protein (HSP72 and HSP40).

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.101.1-101
• /
• 2003

Lipopolysaccharide, siderophore, and cyclic dipeptide have been shown to be necessary for ISR induction by pseudomnads. However, there is no report on cloning of genes or generating specific mutants involving in ISR activity. A biological control bacteium P. chlororaphis O6 induces resistance to Erwinia carotovora subsp. carotovara SCCI in tobacco and induces drought resistance in Arabidopsis. To isolate genes involved in ISR activity and induction of drough resistance of O6, we constructed Tn5 mutants and were used to screen for ISR activity and drought resistance activity using microtiter assay with tobacco and Arabidopsis. Thirty-three ISR-deficient mutants were selected, and the nine ISR-deficient mutants were also lost activity of drought resistance. The flanking sequence analysis of the ISR and drought resistance-deficient mutants showed that a gacS gene encoding a two-component sensor kinase, and a mce gene encoding a protein involved in mycobacterial cell entry were mutated. The flanking sequence of each Tn5 mutant altered ISR activity is currently under investigation. These results indicate that gacS and mce are important genes in induction of ISR activity and drought resistance of P. chlororaphis O6. Our works will open opportunities for identification of bacterial genes or traits that are involved in ISR activity and induced drought resistance of P. chlororaphis O6.

• Journal of Plant Biotechnology
• /
• 제31권4호
• /
• pp.273-278
• /
• 2004

Differential display 방법으로 NaCl에 의하여 발현이 증가되는 cDNA들을 분리하였으며 그중 하나가 식물유래의 outer envelope membrane protein과 높은 유사성을 보였으므로 이를 ShOEP로 명명하였다. ShOEP는 1293 bp 길이에 359개의 아미노산으로 구성된 open reading frame을 포함하고 있으며, 이로부터 추정되는 분자량은 8.9 kDa이었다. ShOEP 단백질은 애기장대의 OEP와는 40.6%, 시금치와는 38%의 유사성을 나타내었다. Northern 분석결과, ShOEP 유전자는 NaCl의 농도가 증가함에 따라 발현량이 급격히 증가하는 것으로 나타났다. 염생식물인 퉁퉁마디의 OEP는 PEG에 의하여 발현이 증가하는 반면 비염생식물인 애기장대의 OEP는 큰 차이를 보이지 않았다. 효모 complementation 실험결과 ShOEP는 NaCl에 특이적이었으며 식물의 염분스트레스 내성 기작에 직접적으로 관여하고 있음을 알 수 있었다.

• 한국어병학회지
• /
• 제33권1호
• /
• pp.23-34
• /
• 2020

In recent years, global warming is causing dramatic environmental changes and deterioration, such as hypoxia, leading to reduced survival rate and growth performance of farmed aquatic animals. Hence, understanding systemic immuno-physiological changes in fish under environmental stress might be important to maximize aquaculture production. In this study, we investigated physiological changes in rainbow trout exposed to hypoxic stress by monitoring changes in blood chemistry, leukocyte population, and expression levels of related cytokine genes. Hematological and serological factors were evaluated in blood obtained from rainbow trout sampled at a dissolved level of 4.6 mg O₂ L^-1 and 2.1 mg O₂ L^-1. Blood and head kidney tissue obtained at each sampling time point were used to determine erythrocyte size, leukocyte population, and cytokine gene expression. The level of LDH and GPT in fish under progressive hypoxia were significantly increased in plasma. Likewise, the (Granulocyte + Macrophage)/lymphocyte ratio (%) of fish exposed to hypoxia was significantly lower than that in fish in the control group. Such changes might be due to the rapid movement of lymphocytes in fish exposed to acute hypoxia. In this study, significant up-regulation in expression levels of IL-1β and IL-6 gene appeared to be involved in the redistribution of leukocytes in rainbow trout. This is the first study to demonstrate the involvement of cytokines in leukocyte trafficking in fish exposed to hypoxia. It will help us understand systemic physiological changes and mechanisms involved in teleost under hypoxic stress.

• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.1119-1128
• /
• 2015

1-Aminocyclopropane-1-carboxylate (ACC) deaminase, which is encoded by some bacteria, can reduce the amount of ethylene, a root elongation inhibitor, and stimulate the growth of plants under various environmental stresses. The presence of ACC deaminase activity and the regulation of ACC in several rhizospheric bacteria have been reported. The nitrogen-fixing Pseudomonas stutzeri A1501 is capable of endophytic association with rice plants and promotes the growth of rice. However, the functional identification of ACC deaminase has not been performed. In this study, the proposed effect of ACC deaminase in P. stutzeri A1501 was investigated. Genome mining showed that P. stutzeri A1501 carries a single gene encoding ACC deaminase, designated acdS. The acdS mutant was devoid of ACC deaminase activity and was less resistant to NaCl and NiCl₂ compared with the wild-type. Furthermore, inactivation of acdS greatly impaired its nitrogenase activity under salt stress conditions. It was also observed that mutation of the acdS gene led to loss of the ability to promote the growth of rice under salt or heavy metal stress. Taken together, this study illustrates the essential role of ACC deaminase, not only in enhancing the salt or heavy metal tolerance of bacteria but also in improving the growth of plants, and provides a theoretical basis for studying the interaction between plant growth-promoting rhizobacteria and plants.

• BMB Reports
• /
• 제47권1호
• /
• pp.27-32
• /
• 2014

Plant abiotic stress tolerance has been modulated by engineering the trehalose synthesis pathway. However, many stress-tolerant plants that have been genetically engineered for the trehalose synthesis pathway also show abnormal development. The metabolic intermediate trehalose 6-phosphate has the potential to cause aberrations in growth. To avoid growth inhibition by trehalose 6-phosphate, we used a gene that encodes a bifunctional in-frame fusion (BvMTSH) of maltooligosyltrehalose synthase (BvMTS) and maltooligosyltrehalose trehalohydrolase (BvMTH) from the nonpathogenic bacterium Brevibacterium helvolum. BvMTS converts maltooligosaccharides into maltooligosyltrehalose and BvMTH releases trehalose. Transgenic rice plants that over-express BvMTSH under the control of the constitutive rice cytochrome c promoter (101MTSH) or the ABA-inducible Ai promoter (105MTSH) show enhanced drought tolerance without growth inhibition. Moreover, 101MTSH and 105MTSH showed an ABA-hyposensitive phenotype in the roots. Our results suggest that over-expression of BvMTSH enhances drought-stress tolerance without any abnormal growth and showes ABA hyposensitive phenotype in the roots.