• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.87-92
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• 2013

Microalgae have been suggested as a promising feedstock for producing biofuel because of their potential of lipid production. In this study, a first principles ODE model for microalgae growth and neutral lipid synthesis proposed by Surisetty et al. (2010) is investigated for the purpose of maximizing the rate of microalgae growth and the amount of neutral lipid. The model has 6 states and 12 parameters and follows the assumption of Droop model which explains the growth as a two-step phenomenon; the uptake of nutrients is first occurred in the cell, and then use of intra-cellular nutrient to support cells growth. In this study, optimal input design using D-optimality criterion is performed to compute the system input profile and sensitivity analysis is also performed to determine which parameters have a negligible effect on the model predictions. Furthermore, model predictive control based on successive linearization is implemented to maximize the amount of neutral lipid contents.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.819-825
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• 2003

pharbitis nil and Taraxacum mongolicum are representative herbs that have been used for cancer treatment in Korean traditional medicine. To understand the molecular basis of the antitumor function, we analyzed the effect of these herbs on proliferation and apoptosis of tumor cells using a gastric cancer cell line AGS. Cell counting assay showed that pharbitis nil strongly inhibit cell proliferation Of AGS whereas Taraxacum mongolicum exhibit no detectable effect on cellular growth. [³H]thymidine uptake analysis also demonstrated that DNA replication of AGS is suppressed in a dose-dependent manner by treatment with pharbitis nil. Additionally, tryphan blue exclusion assay showed that Pharbitis nil induce apoptotic cell death of AGS in a dose-dependent. To explore whether anti antiproliferative and/or proapototic property of Pharbitis nil is associated with their effect on gene expression, we performed RT-PCR analysis of cell cycle- and apoptosis-related genes. Interestingly, mRNA expression levels of c-Jun, c-Fos, c-Myc, and Cyclin D1 were markedly reduced by Pharbitis nil. Taraxacum mongolicum also showed inhibitory action on expression of these growth-promoting protooncogene but there effects are less significant, as compared to Pharbitis nil. Furthermore, it was also found that Pharbitis nil activates expression of the p53 tumor suppressor and its downstream effector p21Waf1, which induce G1 cell cycle arrest and apoptosis. Collectively, our data demonstrate that Pharbitis nil induce growth inhibition and apoptosis of human gastric cancer cells and these effects are accompanied with down-and up-regulation of growth-regulating protooncogenes and tumor suppressor genes, respectively. This observation thus suggests that the anticancer effect of Pharbitis nil might be associated with its regulatory capability of tumor-related gene expression.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.295-300
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• 2014

The actin cytoskeleton plays an important role in macrophage-mediated inflammatory responses by modulating the activation of Src and subsequently inducing nuclear factor (NF)-${\kappa}B$ translocation. In spite of its critical functions, few papers have examined how the actin cytoskeleton can be regulated by the activation of toll-like receptor (TLR). Therefore, in this study, we further characterized the biological value of the actin cytoskeleton in the functional activation of macrophages using an actin cytoskeleton disruptor, cytochalasin B (Cyto B), and explored the actin cytoskeleton's involvement in morphological changes, cellular attachment, and signaling events. Cyto B strongly suppressed the TLR4-mediated mRNA expression of inflammatory genes such as cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-${\alpha}$, and inducible nitric oxide (iNOS), without altering cell viability. This compound also strongly suppressed the morphological changes induced by lipopolysaccharide (LPS), a TLR4 ligand. Cyto B also remarkably suppressed NO production under non-adherent conditions but not in an adherent environment. Cyto B did not block the co-localization between surface glycoprotein myeloid differentiation protein-2 (MD2), a LPS signaling glycoprotein, and the actin cytoskeleton under LPS conditions. Interestingly, Cyto B and PP2, a Src inhibitor, enhanced the phagocytic uptake of fluorescein isothiocyanate (FITC)-dextran. Finally, it was found that Cyto B blocked the phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at 1 min and the phosphorylation of heat shock protein 27 (HSP27) at 5 min. Therefore, our data suggest that the actin cytoskeleton may be one of the key components involved in the control of TLR4-mediated inflammatory responses in macrophages.

• Molecules and Cells
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• v.26 no.6
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• pp.583-589
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• 2008

In the present study, we investigated whether rosmarinic acid, which has been suggested to exhibit anti-inflammatory properties, can suppress the expressions of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-$1{\alpha}$ ($MIP-1{\alpha}$) via the MAPK pathway in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) in the presence of GM-CSF and IL-4 in media. The effects of rosmarinic acid were investigated in BMDCs with respect to the following; cytotoxicity, surface molecule expression, dextran-FITC uptake, cell migration, chemokine gene expression, and the MAPK signaling pathway. Rosmarinic acid was found to significantly inhibit the expressions of CD80, CD86, MHC class I, and MHC class II in LPS-stimulated mature BMDCs, and rosmarinic acid-treated BMDCs were found to be highly efficient with regards to antigen capture via mannose receptor-mediated endocytosis. In addition, rosmarinic acid reduced cell migration by inducing the expression of a specific chemokine receptor on LPS-induced mature BMDCs. Rosmarinic acid also significantly reduced the expressions of MCP-1 and $MIP-1{\alpha}$ induced by LPS in BMDCs and inhibited LPS-induced activation of MAPK and the nuclear translocation of $NF-{\kappa}B$. These findings broaden current perspectives concerning our understanding of the immunopharmacological functions of rosmarinic acid, and have ramifications that concern the development of therapeutic drugs for the treatment of DC-related acute and chronic diseases.

• Molecules and Cells
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• v.38 no.7
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• pp.657-662
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• 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells.

• The Korean Journal of Food And Nutrition
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• v.22 no.3
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• pp.456-462
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• 2009

Adlay, barley and rice bran were extracted using various concentrations of methanol(10% and 80%) and chloroform : methanol(2 : 1) to examine the biological activities of these raw grains. Extraction with 80% methanol resulted in high Vitamin C Equivalent Antioxidant Capacity(VCEAC), in the order of barley > rice bran > adlay, as determined by DPPH and ABTS assays. In addition, the extracts of adlay and rice bran showed high cellular antioxidant activity in HepG2 cells possibly due to the presence of polyphenol glycosides in these grains. We examined the expression of glucose/fatty acid metabolizing genes in differentiated 3T3-L1 adipocyte cells. Glut1 was downregulated after treatment with rice bran and no changes in the expression of Glut4 was observed. In contrast, genes involved in fatty acid metabolism, CD36 and aP2, were upregulated. Since these physiological changes were matched with peroxisome proliferator activating receptor $\gamma$(PPAR $\gamma$) agonism, we suggest that the extracts from adlay, barley and rice bran may play preventive roles against aging and diabetes via antioxidant activity and increased uptake of fatty acids by adipocytes.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.275-288
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• 1995

The inhibitory effect of cell wall extracts of streptococci, have been investigated to know host-parasite relationship or pathogenesis of abscess formation. Streptococci isolated from the infected root canals were sonicated to get cell wall extracts which have been known as one of the factors of pyogenesis. Lymphocytes separated by density gradient were stimulated with phytohemagglutinin and exposed to cell wall extracts of Streptococcus sanguis, S. mitis, S. uberis, S. mutans (ATCC 10449), and S. faecalis (ATCC 19433). [$^3H$]-thymidine uptake of lymphocytes was analyzed with scintillation counter and lactate dehyrogenase (LD) activity was measured with autochemistry analyzer. S. faeealis had the strongest inhibitory effect. beginning at $100\;{\mu}g/ml$ concentration of sonic extracts. S. sanguis and S. mitis had inhibitory effect at $300\;{\mu}g/ml$, while S. uberis and S. mutans showed no inhibitory, effect on DNA syntheis even at $300\;{\mu}g/ml$. Each streptococci showed different inhibitory effect on the DNA synthesis of lymphocytes, which finding indicated wide spectrum of susceptibility of lymphocytes according to streptococcus spp. There were no significant difference of LD activities between control and each streptococcal extracts. Streptococcal sonic extracts did not affect the morphological findings or number of colonies activated lymphocytes. These finding suggested the inhibitory effect of sonic extract of streptococci to lymphocytes could be detected by DNA synthesis inhibition, not by cellular membrane damage.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.532-541
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• 2010

Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in the distal pocket of peroxidases have successfully been introduced into that of the VHb. A 15-fold increase in catalytic constant ($k_{cat}$) was obtained in P54R variant,which was presumably attributable to the lower rigidity and higher hydrophilicity of the distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either $H_2O_2$ or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring the T29H mutation apparently demonstrated a spectral shift in both ferric and ferrous forms (406-408 to 411 nm, and 432 to 424-425 nm, respectively). All VHb proteins in the ferrous state had a $\lambda_{soret}$ peak at ~419 nm following the carbon monoxide (CO) binding. Expression of the P54R mutant mediated the downregulation of iron superoxide dismutase (FeSOD) as identified by two-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived $H_2O_2$, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of the $Fe^{2+}$-ferric uptake regulator protein ($Fe^{2+}$-Fur), an inducer of FeSOD expression.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1916-1924
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• 2017

In this study, we synthesized a glycosylated derivative of caffeic acid phenethyl ester (CAPE) using the amylosucrase from Deinococcus geothermalis with sucrose as a substrate and examined its solubility, chemical stability, and anti-inflammatory activity. Nuclear magnetic resonance spectroscopy showed that the resulting glycosylated CAPE (G-CAPE) was the new compound caffeic acid phenethyl ester-4-O-${\alpha}-{\small{D}}$-glucopyranoside. G-CAPE was 770 times more soluble than CAPE and highly stable in Dulbecco's modified Eagle's medium and buffered solutions, as estimated by its half-life. The glycosylation of CAPE did not significantly affect its anti-inflammatory activity, which was assessed by examining lipopolysaccharide-induced nitric oxide production and using a nuclear factor erythroid 2-related factor 2 reporter assay. Furthermore, a cellular uptake experiment using high-performance liquid chromatography analysis of the cell-free extracts of RAW 264.7 cells demonstrated that G-CAPE was gradually converted to CAPE within the cells. These results demonstrate that the glycosylation of CAPE increases its bioavailability by helping to protect this vital molecule from chemical or enzymatic oxidation, indicating that G-CAPE is a promising candidate for prodrug therapy.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.119-129
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• 2012

Lactic acid bacteria (LAB) have been used as starter cultures in the manufacturing processes of fermented dairy products such as cheese and yogurt. LAB have a proteolytic system to use the nitrogen source from milk for their growth. The proteolytic system involved in casein utilization provides cells with essential amino acids during growth in milk and is also of industrial importance, because of its contribution to the development of the organoleptic properties such as flavor of fermented milk products. In the most extensively studied LAB, Lactococcus lactis, the main features of the proteolytic system comprise 3 groups. The first is proteinase, which initially cleaves the milk protein to peptides. The second group consists of transport systems for the internalization of oligopeptides, which are involved in the cellular uptake of small peptides and amino acids. The third group, peptidases in the cell, cleaves peptides into smaller peptides and amino acids. This review is to provide the information about the proteolytic system of LAB.