• BMB Reports
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• v.39 no.2
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• pp.132-139
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• 2006

Vascular endothelial cadherin (VE-cadherin), which belongs to the classical cadherin family, is localized at adherens junctions exclusively in vascular endothelial cells. Biochemical and biomechanical cues regulate the VE-cadherin adhesive potential by triggering the intracellular signals. VE-cadherin-mediated cell adhesion is required for cell survival and endothelial cell deadhesion is required for vascular development. It is therefore crucial to understand how VE-cadherin-based cell adhesion is controlled. This review summarizes the inter-endothelial cell adhesions and introduces our recent advance in Rap1-regulated VE-cadherin adhesion. A further analysis of the VE-cadherin recycling system will aid the understanding of cell adhesion/deadhesion mechanisms mediated by VE-cadherin in response to extracellular stimuli during development and angiogenesis.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.68-73
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• 2002

Modified polymer electrolyte membranes were fabricated by the applying dc magnetron sputter-deposited Pd thin layers on the surface of the $Nafion^{TM}$ membranes in argon atmosphere. The Pd thin films were characterized by investigating its morphology, methanol permeability, and protonic conductivity. The performance of a direct methanol fuel cell(DMFC) with the modifed polymer electrolyte membrane was also tested by the measurement of its currents and voltages under flowing methanol. The Pd thin film could be a barrier layer to methanol crossover, but the protonic conductivity of the modified polymer membrane was reduced. By using the modified polymer eletrolyte membranes, both the methanol permeability and the protonic conductivity were decreased with increasing the thickness of Pd thin film. However, the performances of DMFC were almost independent on the thickness of Pd thim films. The efffcts of methanol concentration in a feeding fuels on the protonic conductivity and the cell performance were also investigated.

• Journal of Pharmaceutical Investigation
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• v.29 no.4
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• pp.287-293
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• 1999

Transport study of horseradish peroxidase and transferrin-horseradish peroxidase conjugate was performed using an in vitro Caco-2 cell cultured monolayer grown on a polycarbonate membrane of $Transwell^{\circledR}$, Horseradish peroxidase was not transported across Caco-2 cell monolayer. Transferrin-horseradish peroxidase conjugate was transported through Caco-2 cell monolayer. The apparent membrane permeability coefficient $(P_{app})$ of transferrin horseradish peroxidase conjugate was $6.54{\times}10^{-7}\;cm/sec$. The $P_{app}$ value of transferrin-horseradish peroxidase conjugate across Caco-2 cell monolayer was increased to $11.9{\times}10^{-7}\;cm/sec$ in the presence of $50\;{mu}g/ml$ brefeldin-A. These results suggest the transferrin receptor mediated transcytosis of transferrin-horseradish peroxidase conjugate across Caco-2 cell monolayer.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.270-278
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• 2007

PEMFC electrodes with various gas diffusion layers (GDL) were characterized to find out the effect of GDL on fuel cell performance. The physical properties of GDL such as electric conductivity, porosity, air permeability, water flux, PTFE content, etc had close relationship each other and affected on the variation of the cell performance. It was observed that the micro-porous layer (MPL) on carbon paper or cloth changed the physical properties of GDL and changed the cell performance. The variation of cell performance as a function of the physical properties of GDL showed different behaviors according to the amount of current density.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.69-79
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• 2002

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.609-610
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• 2006

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.498-498
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• 2003

Sphingolipids are important structural components of the stratum corneum lipids and serve the epidermal permeability barrier function. Recent investigations on biological activities of sphingolipids have revealed that they have a number of important biological functions in the cell such as cell proliferation and differentiation, anti-inflammation, mediation of signal transduction and many more.(omitted)

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.23-28
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• 1994

This study was rimed out to examine the difference in the cell vitality between mesophyII protoplast (MP) and paraveinal mesophyII protoplast (PVMP) of Nicotiana tabaccum 'Xanti', Petunia hybrida 'Blue Star' and Chrysanthemum morifolium 'Baeckwang' by using urea permeability technique. The effects of various enzyme solutions and incubation time, NAA and thidiazron on plant regeneration from isolated protoplasts were also investigated. The vibratome technique was used for protoplast isolation and urea permeability test because the fresh living, thin tissue stripes (50 ${\mu}{\textrm}{m}$ of thickness) could be obtained with minimal damage with the vibratome. For the three plants examined, the urea permeability on the tested tissue stripes was relatively higher in PVMP than in MP by about Ks = 2.0 $\times$ 10$^{-5}$ cm/sec. The treatment of an enzyme mixture of 1.5% cellulase R-10, 1% Driselase, 0.5% Macerozyme R-10, and 0.5% Pectinase for 4 to 8 h was effective on the isolation of PVMP. The highest frequency of callus formation and plant regeneration from the isolated protoplasts was obtained with NAA 2 mg/L and thidiazuron 0.01 mg/L. Furthermore, the results demonstrated that cell devision and plantlet regeneration was more frequent in the PVMP than in the MP of the same leaf or plant We, therefore, conclude that UM is an excellent experimental material for the callus formation and regeneration from isolated protoplasts.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.319-321
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• 2014

• Journal of Life Science
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• v.19 no.9
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• pp.1200-1208
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• 2009

Tight junctions (TJs) that act as paracellular permeability barriers play an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. In this study, we investigated the correlation between the tightening of TJs, permeability and the invasive activity of genistein - a bioactive isoflavone of soybeans - in human breast carcinoma MCF-7 and MDA-MB-231 cells. The inhibitory effects of genistein on cell proliferation, motility and invasiveness were found to be associated with the increased tightness of the TJs, which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. Additionally, the immunoblotting results indicated that genistein repressed the levels of the proteins that comprise the major components of TJ, claudin-3 and claudin-4, which play a key role in the control and selectivity of paracellular transport. Furthermore, genistein decreased the metastasis-related gene expressions of insulin like growth factor-1 receptor and snail, while concurrently increasing that of thrombospondin-1 and E-cadherin. In addition, we demonstrated that claudins play an important role in the anti-motility and invasiveness of genistein using claudin-3 small interfering RNA. Taken together, our results indicate a possible role for genistein as an inhibitor of cancer cell invasion through the tightening of TJs, which may counteract the up-regulation of claudins. In addition, our results indicate that this may be beneficial for the inhibition of tumor metastasis.