• Journal of Life Science
• /
• v.25 no.10
• /
• pp.1103-1109
• /
• 2015

Cholinergic innervation of the hippocampus is known to be correlated with learning and memory. The cholinergic agonist carbachol (CCh) modulate synaptic plasticity and produced long-term synaptic depression (LTD) in the hippocampus. However, the exact mechanisms by which the cholinergic system modifies synaptic functions in the hippocampus have yet to be determined. This study introduces an acetylcholine receptor-mediated LTD that requires internalization of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors on the postsynaptic surface and their intracellular mechanism in the hippocampus. In the present study, we showed that the application of the cholinergic agonist CCh reduced the surface expression of GluA2 on synapses and that this reduction was prevented by the M1 muscarinic acetylcholine receptor antagonist pirenzepine in primary hippocampal neurons. The interaction between GluA2 and the glutamate receptor-interacting protein 1 (GRIP1) was disrupted in a hippocampal slice from a rat upon CCh simulation. Under the same conditions, the binding of GluA2 to adaptin-α, a protein involved in clathrin-mediated endocytosis, was enhanced. The current data suggest that the activation of LTD, mediated by the acetylcholine receptor, requires the internalization of the GluA2 subunits of AMPA receptors and that this may be controlled by the disruption of GRIP1 in the PDZ ligand domain of GluA2. Therefore, we can hypothesize that one mechanism underlying the LTD mediated by the M1 mAChR is the internalization of the GluA2 AMPAR subunits from the plasma membrane in the hippocampal cholinergic system.

• Development and Reproduction
• /
• v.2 no.2
• /
• pp.205-212
• /
• 1998

A sodium-independent facilitative glucose transporter 1 (Glut1) is a major route by which glucose can be transported across the plasma membrane of mouse embryo. Although it has been known that insulin-like growth factor-I (IGF-I) promotes glucose transport into the mouse embryo, whether IGF-I directly regulates transcription of Glut1 has been uncovered in mouse preimplantation embryo. This study was aimed to elucidate the role of glucose and IGF-I in development and Glut1 expression in preimplantation mouse embryo. Two-cell embryos developed in blastocyst regardless of the glucose in the presence of pyruvate. IGF-I significantly increased the number of blastomeres in the mid-blastula. Deprivation of glucose did not affect the amount of Glut1 transcripts in morula cultured from 2-cell embryo. IGF-I potentiated Glut1 expression in morula cultured from 2-cell embryo even in the absence of glucose. Taken together, it is concluded that depletion of glucose does not promote Glut1 expression the in morula cultured form 2-cell embryo, and that increment of Glut1 expression possibly mediates embryotropic effect of IGF-I on preimplantation mouse embryo.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.10 no.1
• /
• pp.103-106
• /
• 1981

A strain of Staphylococcus aureus resistant against cadmium was cultivated by using a liquid medium containing 10ppm cadmium ion, and then, it was fractionated into several fractions as described in the previous paper. Content of the metal in each fraction was determined through an atomic absorption spectrometery. The results are as follows; (1) A $690.9{\mu}g$ cadmium was contained in one gram dry cell. (2) A 39.9% of total cadmium was easily extracted by TCA, however a 52.2% was unextractable even by series of extraction with TCA, ethanol-ehter, perchloric acid and ammonium water. (3) Among the fractions prepared along the cellular structure, plasma membrane fraction showed a highest content of the metal by containing a 59.1%. (4) The fraction of cytoplasm and cell wall contained a 26.8 and 14.1%, respectively. (5) More than 90% of the metal contained in the cell wall was detected from the fraction of lipopolysaccharide. It is considered from these results tht at least a 70% of the cadmium up taken by the resistant cell associates with membranous structure in the cell surface.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.10 no.1
• /
• pp.85-91
• /
• 1981

The growing cells of S. aureus were fractionated along the Schmidt-Thannhauser-Schneider's technique into several fractions such as TCA(trichloroacetic acid)-soluble, lipid, nucleic acid, protein and residue fraction. They were also fractionated according to their cellular structure into Sonic-supernatant, SDS(sodium lauryl sulfate)-soluble, Formamide-soluble and Residue fraction. Fractionation was carried out by orderly treatment of the Sonic pellet with 1.0% SDS and hot$(150^{\circ}C)$ formamide, and the pellet was prepared by centrifugation of the cells sonic osillated for 20 minutes at 150 watt. Sonic-supernatant fraction contained a 91.3% of total DNA while other fractions contained less than 9.5%. SDS-soluble fraction showed a high activity of malate dehydrogenase(13.67 unit/mg protein) and which was higher 22.3 times than the activity found from unsoluble fraction. Formamide-soluble fraction prepared from SDS-undoluble pellet by using the hot formamide exhibited a clear action of reducing sugars against the Anthronesulfate, while it exhibited no clear action against the ninhydrin. However, contrastly, the residue remainnning after extraction with formamide exhibited a clear action against ninhydrin and glucosamine was detected form the hydrolysate of residue by paper chromatography. From these results it is considered that the Sonic-supernatant fraction is mainly consisted of plasmic component of the cells. Other fractions, SDS-soluble, Formamide-soluble and Residue, should be consisted of plasma membrane, lipoplysaccharide and peptidoglycan of the cell, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.6
• /
• pp.1253-1261
• /
• 1998

Effects of dietary cholesterol and taurine supplementation on hepatic total and phospholipid fatty acid compositions were evaluated in rats fed one of the following semisynthetic diets for 5 weeks : control diet(CD, cholesterol free and taurine free diet); high cholesterol diet(HCD, CD＋1.5% cho lesterol); high cholesterol, high taurine diet(HCHTD, HCD＋1.5% taurine). Diet induced changes in hepatic total fatty acid compositions were very similar to those in hepatic phospholipid fatty acid compositions. The HCD significantly decreased the percentage of total saturated fatty acids(SFA), and increased the percentage of total monounsaturated fatty acids(MUFA) of hepatic total lipids and phospholipids as compared to the values for the control rats(p<0.001). HCHTD significantly elevated the percentage of $\Sigma$SFA and lowered the percentage of $\Sigma$MUFA compared to the values for the HCD(p<0.001). Percentages of hepatic total and phospholipid 18:3$\omega$3, 20:5$\omega$3, 18:2$\omega$6 and 20:3$\omega$6 were significantly higher in rats fed the HCD than the values for the control rats, and the percentages of their elongation and desaturation products(22:5$\omega$3, 22:6$\omega$3, 20:4$\omega$6, 22l:4$\omega$6 and 22: 5$\omega$6) were significantly lower in rats fed the HCD compared to those for the control rats. HCD significantly lowered the Δ5 desaturation(20:3$\omega$6⇒20:4$\omega$6) and Δ4 desaturation(22:4$\omega$6⇒22:5$\omega$6) indices, and the elongation index of $\omega$3 fatty acid(20:5 $\omega$3⇒22:5$\omega$3) in rat liver. HCHTD reversed the cholesterol induced changes in the compositions of $\omega$3 and $\omega$6 fatty acids. These results suggest the possibility that dietary cholesterol and taurine supplementations affect plasma and liver lipid levels, at least in part, by changing the hepatic phospholipid fatty acid compositions and thereby modulating the physical characteristics of the membrane and the activities of microsomal enzymes involved in lipid metabolism.

• Molecules and Cells
• /
• v.19 no.2
• /
• pp.191-197
• /
• 2005

The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD) is responsible for highly efficient protein transduction across plasma membranes. In a previous study, we showed that Tat-Cu,Zn-superoxide dismutase (Tat-SOD) can be directly transduced into mammalian cells across the lipid membrane barrier. In this study, we fused the human SOD gene with a Tat PTD transduction vector at its N- and/or C-terminus. The fusion proteins (Tat-SOD, SOD-Tat, Tat-SOD-Tat) were purified from Escherichia coli and their ability to enter cells in vitro and in vivo compared by Western blotting and immunohistochemistry. The transduction efficiencies and biological activities of the SOD fusion protein with the Tat PTD at either terminus were equivalent and lower than the fusion protein with the Tat PTD at both termini. The availability of a more efficient SOD fusion protein provides a powerful vehicle for therapy in human diseases related to this anti-oxidant enzyme and to reactive oxygen species.

• Korean Journal of Clinical Pharmacy
• /
• v.13 no.2
• /
• pp.82-90
• /
• 2003

Dopamine is an effective pressor for the treatment of shock and hypotension when patients do not respond to plasma volume expansion. Two dopamine intravenous delivery systems are currently available in Korea. The objective of this study was to compare dopamine premixed with prefilled system in terms of supply costs (preparation costs + personnel time), contamination rates and convenience. Time-and-motion studies were conducted to determine the time and costs associated with preparation and administration of the two systems. They were analyzed and compared by Mann-Whitney test. To evaluate the contaminaton rates of the two systems, both systems were prepared in an open environment similar to that of practical situations. Premixed and compounded solutions were then filtered by $0.22{\mu}m$ membrane filters, which were cultured at $37^{\circ}C$ for 10 days and their contents were visually checked for bacterial contamination. The convenience of the two systems was compared by itemized user assessments on preparation, dose calculation, admixture, administration and disposal of waste matters. They were analyzed by Wilcoxon's signed rank test and 100 part percentage. It was found that the preparation costs $(mean{\pm}SD)$ for premixed and prefilled systems were $271.70\pm293.55\;Won$ (Korean currency) and $1521.04\pm510.63\;Won$, respectively. The preparation time $(mean{\pm}SD)$ for premixed system was $68.10\pm35.69\;sec.$ while at for prefilled system was $154.03\pm50.06\;sec.$ (n=59 each, p<0.001). No bacterium was observed in the samples of both systems (n=20, each). User assessments indicated that the premixed system was more convenient than the prefilled system except for the item of dose calculation (n=24, p<0.001). Subjective evaluations have proven that the use of the dopamine premixed system resulted in increased efficiency of intravenous preparation by allowing personnel to devote more time to other labor-intensive duties and lower total medical costs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.3
• /
• pp.200-208
• /
• 2006

Amino acids are required for protein synthesis and energy sources in all living cells. The amino acid transport system L is a major nutrient transport system that is responsible for $Na^+$-independent transport of neutral amino acids including several essential amino acids. In malignant tumors, the L-type amino acid transporter 1 (LAT1), the first isoform of system L, is highly expressed to support tumor cell growth. In the present study, the expression and functional characterization of amino acid transport system L were, therefore, investigated in Saos2 human osteogenic sarcoma cells. RT-PCR and western blot analyses have revealed that the Saos2 cells expressed the LAT1 and the L-type amino acid transporter 2 (LAT2), the second isoform of system L, together with their associating protein heavy chain of 4F2 antigen (4F2hc) in the plasma membrane, but the expression of LAT2 was very weak. The uptakes of [${14}^C$]L-leucine by Saos2 cells were $Na^+$-independent and were completely inhibited by the system L selective inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). The affinity of [${14}^C$]L-leucine uptake and the inhibition profiles of [${14}^C$]L-leucine uptake by various amino acids in the Saos2 cells were comparable with those for the LAT1 expressed in Xenopus oocytes. The majority of [${14}^C$]L-leucine uptake is, therefore, mediated by LAT1 in the Saos2 cells. These results suggest that the transports of neutral amino acids including several essential amino acids into Saos2 human osteogenic sarcoma cells are for the most part mediated by LAT1. Therefore, the Saos2 human osteogenic sarcoma cells are excellent tools for examine the properties of LAT1. Moreover, the specific inhibition of LAT1 in tumor cells might be a new rationale for anti-tumor therapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.5
• /
• pp.525-531
• /
• 2008

CDH-13(T-cadherin), which is one of a kind among the 20 cadherins, can be found mainly in wall of aorta, neuron, spleen, blood vessel etc. It is also called H-cadherin. This structural difference can explain that CDH-13 is thought to play a key role in maintaining mutual relation between extra and intra-cellular environment rather than in cell adhesion. The main function of CDH-13 is to participate in blood vessel function. Additionally, it is known to regulate cell growth and cell contact inhibition. When cells are proliferating, cell surface perceives other cells so that substance such as CDH-13 can inhibit their growth or proliferation resulting in homeostasis without endless proliferation or invasion of connective tissue boundaries. However, tumor cell itself appears to be different from normal cells' growth, invasion or transmission. Therefore, it can be diagnosed that these characteristics are closely related to expression of CDH-13 in tumor cells. This study is to investigate expression of CDH-13 in SCC and its correlation with promoter methylation. 20 of tissue species for the study are excised and gathered from 20 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find development of CDH-13 in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1.Immunohistochemical staining: In normal oral squamous epithelial tissue, strong expression of CDH-13 was found in cell plasma membrane of basal cell layer. On the other hand, in case of low-differentiated oral SCC, development of CDH-13 was hardly seen. 2.The development of CDH-13 gene: In 9 of samples, expression of CDH-13 gene could be seen and 2 of them showed low expression compared to the others. And rest of the 11 samples showed no expression of CDH-13 gene. 3.Methylation of CDH-13 gene: Among 9 samples which expressed CDH-13 gene, 7 of them showed unmethylation. In addition, among 11 samples without CDH-13 gene expression, 10 showed methylation. According to the results stated above, promoter methylation were found in 13 samples(65%) among 20 of oral SCC samples. In low-differentiated SCC, suppression of gene expression could be seen accompanying promoter methylation. These phenomenon of gene expression was proved by immunohistochemical investigation. Finally, for development of oral SCC, conclusions can be made that suppression of CDH-13 played a main role and suppression of gene expression was originated from promoter methylation. Considering this, it is expected that suppression of CDH-13 from promoter methylation to be utilized as a good diagnostic marker of oral SCC.

• Herbal Formula Science
• /
• v.25 no.4
• /
• pp.509-526
• /
• 2017

Background and objectives : Soeumin Bojungykgi-tang (seBYTE) has been used to supplement qi in Korean medicine. It has been demonstrated to possess various biological functions such as anti-cancer, anti-aging and anti-inflammatory effects. The present study evaluated the protective roles of seBYTE in hepatotoxic in vitro and in vivo model. Methods : To investigate cytoprotective effect of seBYTE, HepG2 cells were pretreated with seBYTE and then subsequently exposed to $10{\mu}m$ AA for 12 h, followed by $5{\mu}m$ iron. Cell viability was examined by MTT assay, and expression of apoptosis-related proteins was evaluated by immunoblot analysis. For responsible molecular mechanisms, ROS production, GSH contents, and mitochondrial membrane potential were measured. In addition, hepatoprotective effect of seBYTE in vivo was assessed in $CCl_4$-induced animal model. Results : seBYTE prevented AA + iron-induced cytotoxicity in concentration dependent manner. In addition, ROS production, GSH depletion, and mitochondrial dysfunction induced by AA + iron were significantly reduced by seBYTE pretreatment. Furthermore, seBYTE recovered expression of the pro-apoptotic proteins such as PARP and pro-caspase-3. In animal experiment, plasma ALT and AST levels were significantly elevated in $CCl_4$ treatment, but seBYTE significantly decreased the ALT and AST levels. Moreover, seBYTE alleviated the numbers of histological activity index, percentages of degenerative regions, degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine- and 4-hydroxynonenal-positive cells in liver. Conclusions : These results showed that hepatoprotective effect of seBYTE against on $CCl_4$-induced hepatic damages is partly due to antioxidative and anti-apoptotic process.