• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.323-327
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• 2005

Although many studies have been performed to elucidate the molecular consequence of ultraviolet irradiation on an aging, little is known about the effect of natural products. Matrix metalloproteinases (MMPs) we known to play an important role in (a) photoaging. Hete we investigated the effect of $1,2,4,6-tetra-O-galloyl-{\beta}-{_D}-gluco- pyranose (1)$ and 3,4,5-trihydroxybenzoic acid (2) on the expression of MMP-1 in UVA-irradiated human skin fibroblasts (products), (on the) activity of MMP-1, and (on the) scavenging activities of free radicals. Compounds 1 and 2 were isolated from Melothria heterophylla (Cucurbitaceae). These compounds were found to scavenge free radicals and reactive oxygen species (ROS) and were measured to have the $SC_{50}$ values of $3.9{\mu}M\;and\;13.3{\mu}M$ against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and $4.3{\mu}M\;and\; 4.0{\mu}M$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. Compounds 1 and 2 showed a dose-dependent inhibitory effect on the e):pression and activity of MMP-1 in the UVA-irradiated human skin fibroblasts. Therefore, we concluded that compounds 1 and 2 significantly inhibited MMP-1 expression at the protein level. Also, these compounds were determined to have a potent antioxidant activity. From these results, we suggest that these compounds nay be used as (a) new anti-aging agents for the photo-damaged skin.

• The Korean Journal of Pharmacology
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• v.20 no.2
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• pp.35-47
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• 1984

Contents of immunoreactive ${\beta}-endorphin$ and maximum of $^3H-morphine$ binding was measured in the rat midbrain homogenates from different subgroups at 24 hour interval over 24 hours. Animals were adapted to the light-dark cycle(L : D, 12: 12) or constant darkness (D : D, 12 : 12) for 3 weeks. After the adaptation, 0.5ml of physiologic saline or drug was administered twice a day for 2 weeks. A highly significant circadian rhythm with the peak$(94.8{\pm}7.7\;fmole/mg\;protein)$ at 06:00 and the nadir $(27.6{\pm}2.4\;fmole/mg\;protein)$ at 18:00 was observed in constant of group. Constant dark or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir, shape, phase amplitude and 24 hour mean of ${\beta}-endorphin$ contents. Opiate receptor binding by $^3H-morphine$ also showed highly significant diurnal change in control and constant dark adapted rats. Statistical analysis by one-way analysis of variance and two-way analysis of variance indicates that the·re are highly significant differences between the diurnal change of ${\beta}-endorphin$ in control and those constant dark adapted and drug treated groups. However diurnal change of Maximum $^3H-morphine$ binding is closely related to the change of ${\beta}-endorphin$ contents. The results are interpreted with regard to the circadian rhythm of beta-endorphin contents, its modification by psychoactive drugs and possible mechanism of diurnal change of opiate receptor in brain.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.359-366
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• 2004

Iron (Fe) is an essential metal in biological processes, which maintains a homeostasis in the human body. Divalent metal transporter 1 (DMT1) has been known as an iron transporting membrane protein, which is involved in the uptake Fe at the apical portion of intestinal epithelium, and may transport Fe across the membrane of acidified endosome in peripheral tissues. In this study, we studied the tissue distribution of DMT1 in the Fe supplemented (FeS) diet fed rats, and the regulation of DMT1 expression by depleting body Fe. Sprague-Dawley rats were divided into two groups, and fed FeS (120 mg Fe/kg) diet or Fe deficient (FeD, 2∼6 mg Fe/kg) diet for 4 weeks. The evaluation of body Fe status was monitored by measuring sFe, UIBC and tissue Fe concentration. Additionally, DMT1 mRNA levels were analyzed in the peripheral tissues by using the quantitative real time RT-PCR method. In the FeS diet fed rats, the tissue Fe was maintained at a relatively high level, and DMT1 was eventually expressed in all tissues studied. DMT1 was highly expressed in the testis, kidney and spleen, while a moderate levels of DMT1 expression was detected in the brain, liver and heart. In the digestive system, the highest level of DMT1 was found in the duodenum. Feeding the FeD diet caused a reduced body weight gain and depletion of body Fe with finding of decreased sFe, increased UIBC and decreased tissue Fe concentration. The depletion of body Fe upregulated DMT1 expression in the peripheral tissue. The expression of DMT1 was very sensitive to the body Fe depletion in the small intestine, especially in the duodenum, showing dramatically higher levels in the FeD rats than those of the FeS group. In the FeD diet fed animals, the expression of DMT1 was low significantly in other tissues compared with the duodenum. The expression of DMT1, however, was 60∼120% higher in the testis, kidney and spleen, and 30∼50% higher in the lung, liver and heart, compared to the FeS diet fed rats. In summary, DMT1 expression was ubiquitous in mammalian tissue, and the level of expression was the organ-dependent. The expression of DMT1 in peripheral tissues was upregulated by depletion of body Fe. Duodenum was the most sensitive tissue among organs studied during Fe depletion, and expressed the greatest level of DMT1, while other tissues were less higher than in duodenum. This study supports that DMT1 plays a role in maintaining the body Fe level through intestinal uptake as well as homeostasis of Fe in the peripheral tissue.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.495-501
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• 2019

Aloin [1,8-Dihydroxy-10-(${\beta}$-D-glucopyranosyl)-3-(hydroxymethyl)-9(10H)-anthracenone], is a natural anthraquinone from aloe. It has been shown to have antioxidant and anticancer effects in various types of human cancer cells, but the anticancer effects of aloin in human colorectal cancer cells HT-29 have not been elucidated. In this study, possible mechanisms by which aloin exerts its apoptotic action in cultured human colorectal cancer HT-29 cells were investigated. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay shows that treatment with aloin (0, 100, 200, 300 and $400{\mu}M$) reduced cell viability in a concentration-dependent manner in HT-29 and showed no effects on cell proliferation in A375SM and AGS cells. In addition, it was confirmed that apoptotic body was significantly increased as shown by 4',6-diamidino-2-phenylindole (DAPI) staining, and increased apoptosis rate by flow cytometry in HT-29 cells treated with aloin (0, 200 and $400{\mu}M$). We confirmed by western blotting that aloin activated Bax (pro-apoptotic), cleaved-poly (ADP-ribose) polymerase (PARP) and caspase-3, -8 and Bcl-2 (anti-apoptotic) were not changed compared with the control. Aloin induced up-regulation of phospho-p38 and down-regulation of phospho-extracellular signal-regulated kinase (ERK)1/2. Therefore, aloin suppressed the growth inhibitory effects by the induction of apoptosis in human colorectal cancer cells and has potential as a cancer preventive medicine.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.2
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• pp.179-191
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• 2001

Objectives：This study evaluated the association between behavioral characteristics and polymorphisms in DAT1, DRD2, DRD3, and DRD4 genes. Methods：The subjects were 114 neonates, who were born by normal spontaneous vaginal delivery and had no physical problems. The behavioral characteristics were evaluated using Neonatal Behavioral Assessment Scale(NBAS) at $17.8{\pm}7.0$ hours after their birth to minimize environmental influences, and cord blood was used to analyze the gene polymorphisms. Results：In comparison to DAT1 gene 10/10 genotype group(N=93), other genotype group(N=19) showed significantly high NBAS scores on social-interaction, state organization, and state regulation. DRD2 gene Ser311/Cys311, TaqI A, and TaqI B polymorphisms showed no significant differences on NBAS scores when they were grouped by genotypes. DRD3 gene polymorphism and DRD4 gene promotor polymorphism showed no significant difference on NBAS scores when they were grouped by genotypes. In comparison to the short repeats(N=102), long repeats(N=10) in DRD4 gene showed significantly high habituation score of NBAS. Conclusion：These results suggest that the genetic effects of the neonatal behavioral characteristics may be mediated via DAT1 and DRD4 genes.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.219-227
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• 2008

The free-living photoheterotrophic Gram-negative bacterium Rhodobacter sphaeroides possesses a quorum-sensing (QS) regulatory system mediated by CerR-CerI, a member of the LuxR-LuxI family. To identify the genes affected by the regulatory system, random lacZ fusions were generated in the genome of R. sphaeroides strain 2.4.1 using a promoter-trapping vector, pSG2. About 20,000 clones were screened and 23 showed a significantly different level of ${\beta}$-gal activities upon the addition of synthetic 7,8-cis-N-tetradecenoyl-homoserine lactone (RAI). Among these 23 clones, the clone showing the highest level of induction was selected for further study, where about a ten-fold increase of ${\beta}$-gal activity was exhibited in the presence of RAI and induction was shown to be required for cerR. In this clone, the lacZ reporter was inserted in a putative gene that exhibited a low homology with catD. A genetic analysis showed that the expression of the catD homolog was initiated from a promoter of another gene present upstream of the catD. This upstream gene showed a strong homology with luxR and hence was named qsrR (quorum-sensing regulation regulator). A comparison of the total protein expression profiles for the wild-type cells and qsrR-null mutant cells using two-dimensional gel electrophoresis and a MALDI-TOF analysis allowed the identification of sets of genes modulated by the luxR homolog.

• Genomics & Informatics
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• v.19 no.3
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• pp.29.1-29.10
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• 2021

In our previous studies, we have demonstrated the association of certain variants of the thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (TG) genes with congenital hypothyroidism. Herein, we explored the mechanistic basis for this association using different in silico tools. The mRNA 3'-untranslated region (3'-UTR) plays key roles in gene expression at the post-transcriptional level. In TSHR variants (rs2268477, rs7144481, and rs17630128), the binding affinity of microRNAs (miRs) (hsa-miR-154-5p, hsa-miR-376a-2-5p, hsa-miR-3935, hsa-miR-4280, and hsa-miR-6858-3p) to the 3'-UTR is disrupted, affecting post-transcriptional gene regulation. TPO and TG are the two key proteins necessary for the biosynthesis of thyroid hormones in the presence of iodide and H₂O₂. Reduced stability of these proteins leads to aberrant biosynthesis of thyroid hormones. Compared to the wild-type TPO protein, the p.S398T variant was found to exhibit less stability and significant rearrangements of intra-atomic bonds affecting the stoichiometry and substrate binding (binding energies, ΔG of wild-type vs. mutant: -15 vs. -13.8 kcal/mol; and dissociation constant, K_d of wild-type vs. mutant: 7.2E^-12 vs. 7.0E^-11 M). The missense mutations p.G653D and p.R1999W on the TG protein showed altered ΔG(0.24 kcal/mol and 0.79 kcal/mol, respectively). In conclusion, an in silico analysis of TSHR genetic variants in the 3'-UTR showed that they alter the binding affinities of different miRs. The TPO protein structure and mutant protein complex (p.S398T) are less stable, with potentially deleterious effects. A structural and energy analysis showed that TG mutations (p.G653D and p.R1999W) reduce the stability of the TG protein and affect its structure-functional relationship.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.82-87
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• 2013

In this work, the 1L grade integrated metal DOC/DPF filter that can install in engine manifold position was developed to investigate the effect of platinum-coating amount of filter on the improvement of filter activation temperature and reduction of particulate matter (PM). This filter was installed in 2.9L CI engine which meets the EURO-4 emission regulation. Tests for PM reduction efficiency of filter were conducted under ND-13 mode with full-load test condition. It was revealed that the time to reach the activation temperature of metal filter ($280^{\circ}C$) was shorter as the amount of platinum-coating increased. This short activation time can be helpful for the reduction of CO and HC emissions during cold start condition. At the same time, PM reduced as the coating amount increased. The reduction percentage of $DOC_{40}$, $DOC_{20}$, and $DOC_0$ were 96.7% (2.34 mg/kW'h), 95.1% (3.47 mg/kW'h), and 94.5% (3.69 mg/kW'h) compared to previous result (71.4 mg/kW'h), respectively.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2106-2115
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• 2016

To identify the global effects of (p)ppGpp in the gram-positive bacterium Deinococcus radiodurans, which exhibits remarkable resistance to radiation and other stresses, RelA/SpoT homolog (RSHs) mutants were constructed by direct deletion mutagenesis. The results showed that RelA has both synthesis and hydrolysis domains of (p)ppGpp, whereas RelQ only synthesizes (p)ppGpp in D. radiodurans. The growth assay for mutants and complementation analysis revealed that deletion of relA and relQ sensitized the cells to $H_2O_2$, heat shock, and amino acid limitation. Comparative proteomic analysis revealed that the bifunctional RelA is involved in DNA repair, molecular chaperone functions, transcription, the tricarboxylic acid cycle, and metabolism, suggesting that relA maintains the cellular (p)ppGpp levels and plays a crucial role in oxidative resistance in D. radiodurans. The D. radiodurans relA and relQ genes are responsible for (p)ppGpp synthesis/hydrolysis and (p)ppGpp hydrolysis, respectively. (p)ppGpp integrates a general stress response with a targeted re-programming of gene regulation to allow bacteria to respond appropriately towards heat shock, oxidative stress, and starvation. This is the first identification of RelA and RelQ involvement in response to oxidative, heat shock, and starvation stresses in D. radiodurans, which further elucidates the remarkable resistance of this bacterium to stresses.

• Journal of Power System Engineering
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• v.19 no.6
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• pp.47-53
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• 2015

Korea is the geographic location during the summer, the temperature rising to $35^{\circ}C$ and winter temperature is $-15^{\circ}C$ to reduce the air temperature changes, such as relatively large compared to other countries. This increase or decrease of the harmful exhaust gas discharged from automobile substantially inconvenience a significant impact on the active side of the car engine temperature and exhaust gas reducing device receives a large impact on the atmospheric temperature is regulation to be different. However, domestic vehicle emissions test temperature of $20{\sim}30^{\circ}C$ is it does not reflect this situation the actual test temperature to accurately measure the exhaust gas volume of the vehicle is difficult. In this study, domestic automobile exhaust gas test conditions of a test temperature $20{\sim}30^{\circ}C$ various temperatures, including (35, 25, 0, -7, -15, $-25^{\circ}C$) under the two vehicles (2.0L MPI, 2.4 L GDI) as was discussed with respect to the exhaust gas characteristics of the vehicle according to the ambient temperature gas. As a result, domestic emissions test temperature of $25^{\circ}C$ than average conditions were temperature decreases greenhouse gas emissions and increase overall increased by up to 15 times higher. Air temperature and the engine exhaust gas inconvenience a direct effect on the activation temperature required in the reduction unit is determined to be an increase of emissions and greenhouse gases, and also an increase in the variety of lubricants based lubricating and viscosity reduction, such as the engine oil due to the low temperature of these result It is considered that shows the.