Jaeho Pyee

Pinosylvin Induces Cell Survival, Migration and Anti-Adhesiveness of Endothelial Cells via Nitric Oxide Production

Pinosylvin is a phenolic compound mainly found in the Pinus species. To determine the vascular functions of pinosylvin, we first examined both proliferation and apoptosis of bovine aortic endothelial cells (BAECs) in the presence of pinosylvin. When BAECs were treated with pinosylvin, etoposide‐ or starvation‐induced apoptosis was shown to be significantly reduced. The anti‐apoptotic effect of pinosylvin was mediated by inhibition of caspase‐3. Moreover, pinosylvin was shown to activate endothelial nitric oxide synthetase (eNOS). At 1 pM, pinosylvin appeared to have a cell‐proliferative effect in the endothelial cell. The pinosylvin‐induced cell proliferation was declined by treatment with L‐NAME, an eNOS inhibitor. Then, we found that pinosylvin had a stimulatory effect on cell migration and tube formation. These stimulatory effects suggest that pinosylvin is likely to act as a pro‐angiogenic factor. Yet another effect of pinosylvin was inhibition of lipopolysaccharide‐induced THP‐1 cell adhesion to endothelial cells. Altogether, we propose that pinosylvin may be utilized as a phytotherapic agent for the prevention of cardiovascular inflammatory diseases. Copyright

Extract from Acanthopanax senticosus prevents LPS-induced monocytic cell adhesion via suppression of LFA-1 and Mac-1

A crude extract from Acanthopanax senticosus (AS) has drawn increased attention because of its potentially beneficial activities, including anti-fatigue, anti-stress, anti-gastric-ulcer, and immunoenhancing effects. We previously reported that AS crude extract exerts anti-inflammatory activity through blockade of monocytic adhesion to endothelial cells. However, the underlying mechanisms remained unknown, and so this study was designed to investigate the pathways involved. It was confirmed that AS extract inhibited lipopolysaccharide (LPS)-induced adhesion of monocytes to endothelial cells, and we found that whole extract was superior to eleutheroside E, a principal functional component of AS. A series of PCR experiments revealed that AS extract inhibited LPS-induced expression of genes encoding lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1) in THP-1 cells. Consistently, protein levels and cell surface expression of LFA-1 and Mac-1 were noticeably reduced upon treatment with AS extract. This inhibitory effect was mediated by the suppression of LPS-induced degradation of IκB-α, a known inhibitor of nuclear factor-κB (NF-κB). In conclusion, AS extract exerts anti-inflammatory activity via the suppression of LFA-1 and Mac-1, lending itself as a potential therapeutic galenical for the prevention and treatment of various inflammatory diseases.

Quantitative evaluation of resveratrol enrichment induced by UV stimulus in harvested grapes

A mathematical model was proposed to quantitatively describe resveratrol induction in harvested grapes. In the model, k1 and k2 were defined, which were the reaction rate constants for induction during direct UV irradiation and for the time-delayed induction after removing UV irradiation, respectively. During storage after UV irradiation, k2 decreased with time, whereas k1 remained constant. The portion induced by the direct irradiation effect was much more than that induced by the time-delayed effect. When UV energy of 610.2 mJ/cm2 was applied to ‘Gerbong’ grapes with an initial resveratrol content of 1.15 μg/g, their contents were 8.99 and 9.20 μg/g at day 1 and 6 during storage at 0°C, respectively. In the same situation, resveratrol content of 8.99 μg/g improved to 10.56 μg/g during storage at 20°C. This approach which enriched a health-functional compound through the modulation of metabolism after harvest might be a valueadding method for fresh food industry.

Chunghyul-dan acts as an anti-inflammatory agent in endothelial cells by regulating gene expression

Abstract Chunghyul-dan (CHD) is a combinatorial drug known to exert anti-inflammatory effects in endothelial cells. In this study, we employed global transcriptional profiling using cDNA microarrays to identify molecular mechanisms responsible for the anti-inflammatory activity of CHD in endothelial cells. An analysis of the microarray data revealed that transcript levels of monocyte chemotactic protein-1 (MCP-1), vascular cell-adhesion molecule-1 (VCAM-1) and activated leukocyte cell-adhesion molecule were dramatically altered in CHD-treated endothelial cells. These changes in gene expression were confirmed by RT-PCR, Western blotting and ELISA. Chronic CHD treatment also appeared to decrease MCP-1 secretion, probably as a result of decreased MCP-1 expression. In addition, we determined that chronic CHD treatment inhibited lipopolysaccharide-stimulated adhesion of THP-1 leukocytes to endothelial cells. The inhibitory effect of CHD on LPS-stimulated adhesion resulted from down-regulation of VCAM-1 expression. Transmigration of THP-1 leukocytes through endothelial cells was also inhibited by chronic CHD treatment. In conclusion, CHD controls a variety of inflammatory activities by regulating MCP-1 and VCAM-1 gene expression.

Apoptotic Effect of Pinosylvin at a High Concentration Regulated by c-Jun N-Terminal Kinase in Bovine Aortic Endothelial Cells

Pinosylvin is a stilbenoid found in the Pinus species. Pinosylvin at ~pM to ~nM concentrations induces cell proliferation, cell migration and anti-inflammatory activity in endothelial cells. However, it was recently reported that pinosylvin at high concentrations (50 to 100 μM) induces cell death in bovine aortic endothelial cells. In this study, we conducted a series of experiments to discover how pinosylvin at a high concentration (50 μM) induces endothelial cell death. Pinosylvin at the high concentration was shown to induce endothelial cell apoptosis through enhancing caspase-3 activity, flip-flop of phosphatidyl serine, and nuclear fragmentation. We found that pinosylvin at the high concentration additively increased caspase-3 activity enhanced by serum-starvation or treatment with 100 μM etoposide. We also determined that pinosylvin at the high concentration promoted activations of c-Jun N-terminal kinase (JNK) and endothelial nitric oxide synthetase (eNOS). We further ran a series of experiments to find out which signaling molecule plays a critical role in the pinosylvin-induced apoptosis. We finally found that SP-600125, a JNK inhibitor, had an inhibitory effect on the pinosylvin-induced endothelial cell death, but L-NAME, an eNOS inhibitor, had no effect. These data indicate that JNK is involved in the pinosylvin-induced apoptosis. Collectively, pinosylvin at high doses induces cell apoptosis via JNK activation.

Regeneration of grape (Vitis labruscana cv. Kyoho) by shoot-tip culture

We investigated the optimal levels of growth regulators, culture media, and pH on callus growth and organogenesis of in-vitro cultured ‘Kyoho’ grapes. Calli were induced by culturing leaf blades on an MS basal medium supplemented with 1 mg/IL BA and 0.01 mg/L 2,4-D. In addition, calli originating from the exocarp and mesocarp of grape fruits devel-oped on MS media supplemented with 0.1 mg/L IAA, NAA, or 2,4-D, or with 0.2 mg/L BA. In testing the potential for plant regeneration from shoot tips on various media, we found that the Nitsch medium, with I mg/L BA, was optimal for caulogenesis. The type of shoot development depended on the pH of the medium, with vigorous multiple-shoot devel-opment occurring at pH 6.0, and single shoots forming at pH 5.0. Finally, we were able to obtain rooted seedlings from the regenerated shoots that had been cultured on 1/4-strength Nitsch medium supplemented with 0.03 mg/L NAA.

Extract from Prunus mume Sieb. et Zucc. Fruit Prevents LPS-induced Homotypic Aggregation of Monocytic THP-1 Cells via Suppression of Nitric Oxide Production and NF-κB Activation

Homotypic cell adhesion (homotypic aggregation) in activated monocytes plays a central role in physiological and pathological processes including inflammatory responses, differentiation and migration. The extract of the Prunus mume Sieb. et Zucc. fruit (Maesil) has potential benefits to human health; such as anti-viral, anti-microbial, and anti-cancer activities. Indeed, Maesil extract may modulate inflammatory responses via interference with homotypic aggregation in monocytes. In the present study, the molecular mechanisms underpinning the therapeutic efficacy of Maesil extract in inflammatory diseases were investigated. It was found that Maesil extract inhibited homotypic aggregation in lipopolysaccharide (LPS)-activated monocytes. This was mediated by reduction of nitric oxide (NO) production, partly via inhibition of inducible nitric oxide synthase (iNOS) expression in LPS-activated THP-1 cells. It was confirmed that NO inhibition is a key mechanism in Maesil induced blockade of monocyte aggregation through identification of reversal of this inhibitory effect by the NO-producing agent S-nitroso-N-acetyl penicillamine (SNAP). In addition, Maesil extract significantly attenuated LPS-induced IκB-α phosphorylation and NF-κB translocation into the nucleus. In conclusion, Maesil extract exerts anti-inflammatory effects via inhibition of homotypic aggregation of LPS-activated monocytes through mechanisms involving the suppression of NO production and NF-κB activity, suggesting Maesil extract as a potential therapeutic candidate for the prevention and treatment of chronic inflammatory diseases.

Preparation and characterization of organic light emitting devices using hybrid encapsulation materials properties of OLED using hybrid encapuslaton materials

Many researchers have been focusing on the development of the new energy saving devices. The optoelectronic devices such as organic solar cells (OSCs) and organic light emitting diodes (OLEDs) have been regarded as the next generation energy saving devices. In addition, those devices can also be applied to the Internet of Things (IoT), which is the interconnection of identifiable objects through the wireless internet systems. In addition, IoT is expected to provide advanced connectivity of the devices, systems, and services. In this study, for future applications of smart farm and buildings, the flexible OLEDs were prepared by the spin coating and thermal evaporation methods. The stability of the devices by introducing of the hybrid encapsulation materials using organic and inorganic passivation materials were investigated. The lifetime of the devices are affected by the humidity and oxygen environment. Therefore, encapsulations using hybrid inorganic and organic materials of the devices would be important technologies in order to prevent the devices from the oxygen and moisture. As a result, the prepared OLED device with the hybrid encapsulation materials showed better stability and reliability compared with glass capped OLED devices.

Cloning of a polyubiquitin gene fromNicotiana tabacum and comparison to other polyubiquitin genes

Using a tobacco cDNA clone as a probe, a genomic clone named TUQG-4, coding for a tobacco polyubiquitin protein with the five head-to-tail repeats of ubiquitin monomer was isolated. The five ubiquitin units were completely conserved except for the extra phenylalanine at the carboxy terminus of the last ubiquitin monomer. The putative open reading frame identified from the nucleotide sequence showed two possible intron sequences in the coding region for the first ubiquitin monomer. When the amino acid sequence deduced from the nucleotide sequence of TUQG-4 was compared to the amino acid sequences coded by other polyubiquitin genes of tobacco, there were three or four amino acid differences in the sequence. When the nucleotide sequences coding for the ubiquitin monomers were compared for various species origins, the degree of identity was at the highest between the ubiquitin monomers in one polyubiquitin and did not reflect the distance of the phylogenetic relationship.