• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.109-114
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• 2005

Ion fluxes across the plasma membrane activated by 1 mM $Ce^{4+}$, cell apoptosis and taxol biosynthesis in suspension cultures of Taxus cusp/data were studied. The extracellular pH sharply decreased upon the addition of 1 mM $Ce^{4+}$, then increased gradually and exceeded the initial pH value over a time period of 12 h. The extracellular $Ca^{2+}$ concentration decreased within the first 3 h after the addition of $Ce^{4+}$, then gradually decreased to one third of initial value in control at about 72 h and remained unchanged afterwards. Experiments with an ion channel blocker and a $Ca^{2+}$-channel blocker indicated that the dynamic changes in extracellular pH and the $Ca^{2+}$ concentration resulted from the $Ce^{4+}$-induced activation of W uptake and $Ca^{2+}$ influx across the plasma membrane via ion channels. A pretreatment of the ion channel blocker initiated $Ce^{4+}$-treated cells to undergo necrosis, and the prior addition of the $Ca^{2+}$-channel blocker inhibited $Ce^{4+}$-induced taxol biosynthesis and apoptosis. It is thus inferred that W uptake is necessary for cells to survive a $Ce^{4+}$-caused acidic environment and is one of the mechanisms of $Ce^{4+}$-induced apoptosis. Furthermore, the $Ca^{2+}$ influx across the plasma membrane mediated both the $Ce^{4+}$-induced apoptosis and taxol biosynthesis.

• 대한본초학회지
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• 제32권6호
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• pp.23-29
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• 2017

Objective : Hyperuricemia is a metabolic disease characterized by elevated blood uric acid levels, and its prevalence is rapidly increasing worldwide. Alpiniae Oxyphyllae Fructus (AO) belonging to Zingiberaceae is one of well-known traditional medicines in China and Korea, and has been used to treat intestinal disorders, urosis, diuresis, and chronic glomerulonephritis traditionally. However, the effect of AO has not been studied. In this study we investigated the anti-hyperuricemic effect of AO, and the mechanisms underlying the effect in potassium oxonate (PO)-induced hyperuricemic rats. Methods : To examine the anti-hyperuricemic effects of the AO extract, serum uric acid levels were analyzed in normal and PO-induced hyperuricemic rats. The mechanism underlying the effects of the AO extract on uric acid levels was studied through xanthine oxidase (XOD) activity test and uric acid uptake assay in vitro. The chemical finger printing of the AO extract was analyzed using HPLC-DAD. Results : The AO extract significantly reduced serum uric acid levels in normal as well as PO-induced hyperuricemic rats. It also significantly inhibited the uptake of uric acid in oocytyes and human embryonic kidney cells (HEK293) expressing urate transporter (URAT)1, but not XOD activity in vitro. The chemical finger printing analysis of the AO extract showed nootkatone as a main component. Conclusion : The AO extract exhibits anti-hyperuricemic effects, and these effect were accompanied by increasing excretion of uric acid in kidney. Therefore, the AO extract could be used for prevention or treatment of hyperuicemia and gout.

• BMB Reports
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• 제37권2호
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• pp.239-245
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• 2004

We have previously demonstrated that the redox reactant pyruvate prevents apoptosis in the oxidant model of bovine pulmonary artery endothelial cells (BPAEC), and that the anti-apoptotic mechanism of pyruvate is mediated in part via the mitochondrial matrix compartment. However, cytosolic mechanisms for the cytoprotective feature of pyruvate remain to be elucidated. This study investigated the pyruvate protection against endothelial cytotoxicity when the glycolysis inhibitor 2-deoxy-D-glucose (2DG) was applied to BPAEC. Millimolar 2DG blocked the cellular glucose uptake in a concentration- and time-dependent manner with >85% inhibition at $\geq$5 mM within 24 h. The addition of 2DG evoked BPAEC cytotoxicity with a substantial increase in lipid peroxidation and a marked decrease in intracellular total glutathione. Exogenous pyruvate partially prevented the 2DG-induced cell damage with increasing viability of BPAEC by 25-30%, and the total glutathione was also modestly increased. In contrast, 10 mM L-lactate, as a cytosolic reductant, had no effect on the cytotoxicity and lipid peroxidation that are evoked by 2DG. These results suggest that 2DG toxicity may be a consequence of the diminished potential of glutathione antioxidant, which was partially restored by exogenous pyruvate but not L-lactate. Therefore, pyruvate qualifies as a cytoprotective agent for strategies that attenuate the metabolic dysfunction of the endothelium, and cellular glucose oxidation is required for the functioning of the cytosolic glutathione/NADPH redox system.

• Journal of Acupuncture Research
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• 제25권1호
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• pp.57-72
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• 2008

Objectives : The Herb-combined Remedy(HCR) for diabetes mellitus is known as an anti-hyperglycaemic agent. But its exact mechanisms are unclear. The present study was carried out to investigate its anti-hyperglycaemic and anti-oxidative effects in STZ-induced diabetic rats. Methods : Experimental diabetes was induced by injection of STZ(80mg/kg) to ratsvia the peritoneum. The experimental animals were divided into 4 groups : normal group, control group(STZ-induced diabetic rats with no treatment), HCR group(STZ-induced diabetic rats with HCR treatment), MF group(STZ-induced diabetic rats with Metformin treatment). The effects of HCR on STZ-induced diabetes was observed by measuring fasting blood glucose, changes of body weight, food uptake, and water uptake glucose levels in the normal state decline rates in blood glucose levels DPPH free-radical scavenging activity superoxide dismutase in RBC lysate catalase activity in RBC lysate and glutathione reductase activity in RBC lysate. Results : Treatment with HCR regulated blood glucose levels. Treatment with HCR also prevented weight loss in STZ-induced diabetic rats. In addition, oral glucose tolerance decreased following treatment with HCR. Direct anti-oxidative effects on DPPH free-radical scavenging were not observed, but treatment with HCR elevated SOD levels in blood cell lysates from STZ-induced diabetic rats. In addition, the HCR-treatment group showed an elevated tendency to glutathione reductase activity. Conclusions : These results demonstrate that HCR has anti-hyperglycaemic and anti-oxidative effects in STZ-induced diabetic rats.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.270-279
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• 2024

Macrophages are versatile immune cells that play crucial roles in tissue repair, immune defense, and the regulation of immune responses. In the context of skeletal muscle, they are vital for maintaining muscle homeostasis but macrophage-induced chronic inflammation can lead to muscle dysfunction, resulting in skeletal muscle atrophy characterized by reduced muscle mass and impaired insulin regulation and glucose uptake. Although the involvement of macrophage-secreted factors in inflammation-induced muscle atrophy is well-established, the precise intracellular signaling pathways and secretion factors affecting skeletal muscle homeostasis require further investigation. This study aimed to explore the regulation of macrophage-secreted factors and their impact on muscle atrophy and glucose metabolism. By employing RNA sequencing (RNA-seq) and proteome array, we uncovered that factors secreted by lipopolysaccharide (LPS)-stimulated macrophages upregulated markers of muscle atrophy and pro-inflammatory cytokines, while concurrently reducing glucose uptake in muscle cells. The RNA-seq analysis identified alterations in gene expression patterns associated with immune system pathways and nutrient metabolism. The utilization of gene ontology (GO) analysis and proteome array with macrophage-conditioned media revealed the involvement of macrophage-secreted cytokines and chemokines associated with muscle atrophy. These findings offer valuable insights into the regulatory mechanisms of macrophage-secreted factors and their contributions to muscle-related diseases.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.4-4
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• 2017

Atmospheric carbon dioxide enrichment ($eCO_2$) often increases soil nitrous oxide ($N_2O$) emissions, but the underlying mechanisms are not fully understood. Emerging evidence suggests that $eCO_2$ alters plant N preference in favor of ammonium ($NH_4{^+}-N$) over nitrate ($NO_3{^-}-N$). Yet, whether and how this attributes to the enhancement of $N_2O$ emissions has not been investigated. We examined the effects of $eCO_2$ on soil $N_2O$ emissions in the presence of two N forms ($NH_4{^+}-N$ or $NO_3{^-}-N$), using wheat (Triticum aestivum L.) as a model plant. Our results showed that N forms dominated $eCO_2$ effects on plant and microbial N utilization, and thus soil $N_2O$ emissions. Elevated $CO_2$ significantly increased the rate and the sum of $N_2O$ emissions by three to four folds when $NO_3{^-}-N$, but not $NH_4{^+}-N$, was supplied. Enhanced $N_2O$ emission was related to the reduced plant $NO_3{^-}-N$ uptake in wheat. We propose a new conceptual model in which $eCO_2$-inhibition of plant $NO_3{^-}-N$ uptake and/or $CO_2$-enhancement of soil labile C enhances the N and/or C availability for denitrifiers and increases the intensity and/or the duration of $N_2O$ emissions. Together, these findings suggest that to enhance plant N use efficiency and reduce $N_2O$ emission, crop breeding and management need to consider altered plant preference of N sources under future $CO_2$ scenarios.

• 한국토양비료학회지
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• 제40권4호
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• pp.280-291
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• 2007

토양중 중금속을 흡수해서 체내에 고농도로 축적할 수 있는 식물, 이른바 고축적식물(hyperaccumulator)의 발견으로 오염토양에 대한 식물복원(phytoremediation) 기술에 대한 많은 연구들이 수행되고 있다. 이들 연구의 방향은 크게 고축적식물의 중금속 축적 기작을 밝히기 위한 것과 축적효율을 높임으로써 복원 효율을 향상시키는 실용적인 기술개발로 나누어진다. 지금까지 고축적식물에 의한 중금속 축적 기작은 다섯 가지의 특이 기작으로 알려져 있는데, 1) 뿌리세포의 중금속 흡수 증진, 2) 식물체 조직내의 중금속 이동성 향상, 3) 중금속의 무독화(detoxification) 및 격리(sequestration), 4) 토양-뿌리 경계면에서의 중금속 유효도 증진, 그리고 5) 중금속 오염토양으로의 능동적인 뿌리의 성장 등이 이에 속한다. 일반적으로 토양 중 낮은 중금속 유효도는 식물복원 기술의 현장 적용에 있어 제한요소로 간주된다. 이를 극복하기 위해서는 위에 기술된 다섯 가지 기작 중 고축적식물의 뿌리가 근권 토양중 중금속의 화학변화에 미치는 영향을 이해하는 것이 매우 중요하다. 식물 뿌리에 의한 근권 토양의 pH 변화와 뿌리에서 나오는 분자량이 적은 유기산(low-molecular-weight organic acids, LMWOAs)과 같은 유기성 분비물은 근권부 토양의 화학적 특성을 변화시키고 결과적으로 중금속의 유효도를 변화시킨다. 예를 들어 뿌리에서 나오는 $H^+$ 이온은 토양 pH를 감소시키고 이에 따라 중금속의 유효도는 증가한다. 또한 고농도의 중금속에 노출된 뿌리는 많은 양의 유기물질을 분비하게 되고 근권 토양에 축적되는 이 유기물질은 토양중 중금속과 결합하여 유기복합물질(organo-metallic complexes)을 형성하면서 유효도를 증가시킨다.

• Journal of Microbiology and Biotechnology
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• 제32권11호
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• pp.1427-1434
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• 2022

Two novel, halotolerant strains of Martelella soudanensis, NC18^T and NC20, were isolated from deep subsurface sediment, deeply sequenced, and comparatively analyzed with related strains. Based on a phylogenetic analysis using 16S rRNA gene sequences, the two strains grouped with members of the genus Martelella. Here, we sequenced the complete genomes of NC18^T and NC20 to understand the mechanisms of their halotolerance. The genome sizes and G+C content of the strains were 6.1 Mb and 61.8 mol%, respectively. Moreover, NC18^T and NC20 were predicted to contain 5,849 and 5,830 genes, and 5,502 and 5,585 protein-coding genes, respectively. Both strains contain the identically predicted 6 rRNAs and 48 tRNAs. The harboring of halotolerant-associated genes revealed that strains NC18^T and NC20 might tolerate high salinity through the accumulation of potassium ions in a "salt-in" strategy induced by K⁺ uptake protein (kup) and the K⁺ transport system (trkAH and kdpFABC). These two strains also use the ectoine transport system (dctPQM), the glycine betaine transport system (proVWX), and glycine betaine uptake protein (opu) to accumulate "compatible solutes," such as ectoine and glycine betaine, to protect cells from salt stress. This study reveals the halotolerance mechanism of strains NC18^T and NC20 in high salt environments and suggests potential applications for these halotolerant and halophilic strains in environmental biotechnology.

• 유기물자원화
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• 제22권2호
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• pp.17-26
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• 2014

본 연구에서는 벤토나이트를 이용하여 수용액상에서 혼합 중금속의 흡착 특성을 평가하였다. 벤토나이트는 SEM과 FT-IR에 의해 물리 화학적 성상을 분석하였고, 중금속 흡착 특성은 Freundlich 및 Langmuir 방정식을 이용하여 해석하였다. 평형흡착 실험결과는 Langmuir 모델에 잘 부합되었으며, $Pb^{2+}$ > $Cu^{2+}$ > $Cd^{2+}$ > $$Zn^{2+}{\sim_=}Ni^{2+}$$순으로 평형 흡착량이 높았다. 용액의 pH가 6에서 10으로 증가함에 따라 흡착량은 증가하는 경향을 나타내었다. SEM과 FT-IR에 의한 벤토나이트의 표면 관찰결과에서 주 관능기는 Si-O 및 Si-O-Al 로 나타났다. 이러한 결과로부터 중금속 흡착 메카니즘은 표면흡착과 이온교환뿐만 아니라 표면 침전이다. 본 연구 결과를 통해 벤토나이트는 수용액 내 중금속을 효율적으로 제거할 수 있는 흡착제로 판단된다.