• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.21-26
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• 2011

Ceramide is an important lipid mediator of extracellular signals that control various cellular functions, including apoptosis. In this study, we showed that ceramide induced apoptosis in U373MG human glioblastoma cells associated with G1 cell cycle arrest. Treatment of cells with ceramide increased proapoptotic Bax expression and inhibited the expression of antiapoptotic Bcl-2 and Bcl-xL Ceramide also downregulated cyclin E, cyclin D1, cdk 2, and cdk4 which are involved in regulating cell cycle. In addition, ceramide suppressed phosphorylation of Akt, Bad, p70 S6 kinase, and 4E-BP1, suggesting the involvement of Akt/mTOR signaling pathway. Additionally, okadaic acid, an inhibitor of protein phosphatase 2A, partially blocked the ceramide mediated inhibition of phosphorylation of Akt and 4E-BP1. These results suggest that ceramide induces apoptosis in U373MG glioblastoma cells by regulating multiple signaling pathways that involve cell cycle arrest associated with Akt signaling pathway.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1270-1281
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• 2018

Periodontal disease is triggered by the host immune response to pathogens in the microbial biofilm. Worsening of periodontal disease destroys the tooth-supporting tissues and alveolar bone. As oral inflammation can induce systemic diseases in humans, it is important to prevent periodontal disease. In this study, we demonstrated that Curcuma xanthorrhiza supercritical extract (CXS) and its active compound, xanthorrhizol (XAN), exhibit anti-inflammatory effects on lipopolysaccharide (LPS)-treated human gingival fibroblast-1 cells and anti-osteoclastic effects on receptor activator of nuclear factor kappa B ligand (RANKL)-treated RAW264.7 cells. LPS-upregulated inflammatory factors, such as nuclear factor kappa B p65 and $interleukin-1{\beta}$, were prominently reduced by CXS and XAN. In addition, RANKL-induced osteoclastic factors, such as nuclear factor of activated T-cells c1, tartrate-resistant acid phosphatase, and cathepsin K, were decreased in the presence of CXS and XAN. CXS and XAN inhibited the mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) signaling pathway. Collectively, these results provide evidence that CXS and XAN suppress LPS-induced inflammation and RANKL-induced osteoclastogenesis by suppressing the MAPK/AP-1 pathway.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.4-9
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• 1957

Effects of antibioties on micro-organism have been reported by many scientists, such as Krampitz and Werkman, Fisher, Gale and Rodwell, Klimick Cavalito and Bailey, Umbreit, etc. On the mechanism by which penicillin act, Fisher(1947), Platt(1947), and Cavallito, considered that penicillin might act on bacteria by inhibiting with the normal function of SH-group of glutathione in the metabolism of the cell. Resenbrance of penicillin to gultathione in structure and the inactivation of penicillin by cysteine make us approve of the above inhibiting theory of SH-group. Galland (1947) and Schmidt (1947) reported that penicillin inhibited the activity of ribonuclease, Phosphatase, and mononucleotidase. Gale (1948) discovered that the gram positive bacteria had lost the power to uptake glutamic acid by ribonucleic acid in the medium contained penicillin: growth of gram positive organism was inhibited by the results that penicillin inhibited the uptake of amino acid byribonucleic acid, acting on ribonucleic acid of gram positive bacteria. Hotchkiss (1950) cultured S. aureus in the medium contained glucose and amino acids, and studied the effect of penicillin on protein synthesis. Peptide formation in living cells was inhibited by penicillin, while amono acid was utilized as before the addition of penicillin. On the otherhand, Binkley (1951) found penicillin interfered hydrolase of glutath one, and Hans (1950) reported penicillin inhibited the transpeptidation. On the machanism by which streptomycin acts. Cohen (1947) reported steptomycin made a irreversible complex with desoxyribonucleic acid, by the fact that desoxyribonucleic acid formed the precipitates with diguanide group of steptomycin. Zeller (1951) reported, on the other hand, streptomycin inhibited diamine oxidease. Geiger (1947) and Umbreit (1949) reported that steptomycin inhibited condensation of oxaloacetate and pyruvate in E. Coli and Oginsky et al (1949) reported steptomycin inhibited oxaloacetate-pyruvate reaction in Kreb's cycle. On the mechanism by which terramycin acts, Hahn & Wisseman (1951) reported that the formation of adaptive enzyme was inhibited by terramycin in E. Coli cultivated in the medium contained loctose, and that the protein synthesis was inhibited by terramycin. However, effects of antibiotics on amino acid metabolism have not been discussed much in spite of its important role in living cells. Especislly, effects of anitibiotics on higher plants have scarcely been reported. Here, to prove the effect of antibiotics on higher plants, and the mechanism by which, through amino acid metabolism, they promote or inhibit growth of plants, amino acids in bean plants treated with penicillin, streptomycin, and terramycin were analyzed by paper chromatography. And to clarify the antagonis of cysteine (as SH-group) against penicillin, through amino acid metabolism, amino acids in bean plants treated with cystene and penicillin, at the same time, were also analyzed.

• International Journal of Oral Biology
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• v.32 no.1
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• pp.1-5
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• 2007

Receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) induces osteoclast formation from hematopoietic cells via up-regulation of positive regulators, including $NF-{\kappa}B$, c-Fos, microphthalmia transcription factor (Mitf), PU.1, and nuclear factor of activated T cells (NFAT) c1. In addition to the positive regulation by these transcription factors, RANKL appears to regulate negative regulators such as MafB and inhibitors of differentiation (Ids). Ids and MafB are abundantly expressed in osteoclast precursors, bone marrowderived monocyte/macrophage lineage cells (BMMs). Expression levels of these genes are significantly reduced by RANKL during osteoclastogenesis. Overexpression of these genes in BMMs inhibits the formation of tartarate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts by down-regulation of NFATc1 and osteoclast-associated receptor (OSCAR), which are important for osteoclast differentiation. Furthermore, reduced expression of these genes enhances osteoclastogenesis and increases expression of NFATc1 and OSCAR. Taken together, RANKL induces osteoclastogenesis via up-regulation of positive regulators as well as down-regulation of negative regulators.

• Molecules and Cells
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• v.40 no.5
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• pp.371-377
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• 2017

Despite the importance of the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-RANK signaling mechanisms on osteoclast differentiation, little has been studied on how RANK expression is regulated or what regulates its expression during osteoclastogenesis. We show here that insulin signaling increases RANK expression, thus enhancing osteoclast differentiation by RANKL. Insulin stimulation induced RANK gene expression in time- and dose-dependent manners and insulin receptor shRNA completely abolished RANK expression induced by insulin in bone marrow-derived monocyte/macrophage cells (BMMs). Moreover, the addition of insulin in the presence of RANKL promoted RANK expression. The ability of insulin to regulate RANK expression depends on extracellular signal-regulated kinase 1/2 (ERK1/2) since only PD98059, an ERK1/2 inhibitor, specifically inhibited its expression by insulin. However, the RANK expression by RANKL was blocked by all three mitogen-activated protein (MAP) kinases inhibitors. The activation of RANK increased differentiation of BMMs into tartrate-resistant acid phosphatase-positive ($TRAP^+$) osteoclasts as well as the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and d2 isoform of vacuolar ($H^+$) ATPase (v-ATPase) Vo domain (Atp6v0d2), genes critical for osteoclastic cell-cell fusion. Collectively, these results suggest that insulin induces RANK expression via ERK1/2, which contributes to the enhancement of osteoclast differentiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.278-286
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• 2003

Alcohol is well known agent which can damage the human tissues such as liver via stimulating lipid peroxidation. On the other hand, carotenoids in addition to vitamins A, C and I play important roles in protecting these oxidative damages as well as preventing the production of free radicals. This study was carried out to investigate the effect of dietary vitamin A on lipid peroxidation and antioxidants status in ethanol-treated rats. In the experiment, male Sprague-Dawley rats weighing 160~180 g were given a liquid diet containing 36% of total calories as ethanol for 7 weeks. The pair-fed control rats received an isocaloric amount of diet containing sucrose instead of ethanol on the following day Additionally, the liquid diet contained adequate amount of $\beta$-carotene, retinyl acetate or 13-sis-reinoic acid except vitamin A-deficient diet. The results obtained are as follows. The levels of plasma and hepatic lipid peroxide were increased after chronic ethanol feeding in rats. Retinyl acetate supplementation significantly reduced lipid peroxidation induced by ethanol feeding Glucose 6-phosphatase activity was significantly reduced in rats fed vitamin A-deficient diet with ethanol and alkaline phosphatase activity was significantly induced in rats fed 13-cis-reinoic acid diet with ethanol. Catalase and alcohol dehydrogenase activities did not show a consistent tendency in experiment groups. The hepatic antioxidant enzyme activities did not significantly changed by chronic ethanol feeding groups. The striking decrease in conversion of $\beta$-carotene to retinol was observed in rats fed a $\beta$-carotene diet with ethanol feeding The level of retinol and retinoic acid in plasma and liver was decreased after chronic ethanol administration Based on this result, these data suggest that ethanol feeding enhances oxidative stress especially in those fed a vitamin A-deficient diet, and vitamin A supplementation, especially, retinyl acetate intake can prevent enhanced lipid peroxidation and related damage to some extent.

• Korean Journal of Animal Reproduction
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• v.11 no.3
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• pp.196-205
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• 1987

This study was conducted in order to obtain the informatin of the histochemical changes in each of 6 segments of the epididymal ducts in 32 Korean native male goats. The male goats were examined, dividing into 7 groups, at 4 잔 intervlas from 8 to 32 wks of age. The reuslts obtained were as follows: 1. PAS reaction showed positive on the basal and upper part beyond the nucleus of the peithelium of effernt ductules throughout all the classes of age. It was also positive on the free border and basal and upper part beyond the nucleus of the caput, on the free border andbasal parts of the corpus, and on the basal part of the cauda of the epididymal epithelium. 2. Acid phosphatase reaction was negative on the every part of epididymal epithelium at the age of 8 weeks, however, with the aging it became strangly positive on the areas between the free border and the nucleus, and moderately positive on the basal part of epithelium of the caput and corpus. In the free border adn basal part of the cauda, it was slightly positive. alkaline phosphatase reactin was negative on the every part of epididymal epithelium until 12 weeks of age. From 16 weeks, free border of epididymal epithelium becaqme slightly positive, and from 20 weeks, the reaction became stronger on the basal part but weekend on the free border with the aging. 3. In the sudan black B staining, many blue black granules between the free border and the nucleus, some granules on the basal part, and a few granules on the cytoplasm around the nucleus of the epididymal epithelium were observed from 8 weeks of age as early, and the granules were increased in number with the aging. 4. In Azan staining, reddish violet granules below the nucleus and blue granules on the upper part beyond the nucleus in some cells of epithelia of efferent ductules were noted at 12th and 16th week, and after 24th week, the granules were decreased with the aging. Golgi apparatus were clearly observable on the upper part beyond the nucleus of all parts of epididymal epithelium from 8th week, and also number of intracytoplasmic vacuoles(smaller ones on the upper part and larger ones on the basal part beyond the nucleus) and fine granules were increased with the aging. 5. In the toluidin blue staining, reddish purple granules on the basal part of the epithelium in all the parts of epididymal ducts, particularly brilliant in the cauda, were observed from 8th week as early. 6. In the Cowdry staining, numerous mitochondria, according to aging, were observed between the free border of epithelium and the upper part beyond the nucleus particularly in the catus and corpus of the epididymal ducts.

• Journal of Aquaculture
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• v.16 no.4
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• pp.233-239
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• 2003

Growth and activities of digestive enzymes in slime flounder (Microstomus achne) larvae were measured from hatching to near the end of larval development (day 58). Larvae reared under starved and fed conditions and the changes of acid phosphatase (ACPase) specific activity, alkaline phosphatase (ALPase) specific activity, trypsin-like enzyme activity and pepsin-like enzyme activity were described with growth and developmental stage of larvae. Total length of the starved larvae was gradually increased for 7 days post hatching and then almost unchanged. Total length of the fed larvae ranged from 5.13$\pm$0.178 mm at the day of hatching to 13.43$\pm$1.395 mm at 58 days after hatching. In starved group, dry body weight decreased from 0.l0$\pm$0.020 mg at the day of hatching to 0.05$\pm$0.012 mg at 12 days after hatching. Dry body weight of fed larvae decreased during the prelarva stage like starved group and then gradually increased. ACPase and ALPase specific activity in the starved larvae increased until all larvae died, however those activities in the fed larvae increased until 20 days and then decreased until 58 days after hatching, with no significant difference between groups. Trypsin-like enzyme activity in the starved larvae was unchanged until 3 days and then was the highest on 5 days after hatching, but not detected after completion of yolksac absorption. Those of fed larvae decreased until 3 days and sharply increased until completion of yolksac absorption. The highest trypsin-like enzyme activity in the fed group was observed at 20 days after hatching. Trypsin-like enzyme activity in the fed larvae was significantly higher than that in the starved larvae from 8 days after hatching. Pepsin-like enzyme activity was increased in 5 days after hatching in both groups. There was significant difference at 8 and 10 days after hatching between both groups. Based on above results, digestive enzyme activities were correspondingly changed to a growth and morphological transformation. Trypsin-like enzyme and pepsin-like enzyme activities are able to be a useful indices for health and growth status in larval slime flounder, because there was significant difference in digestive enzyme activities with developmental stages, growth or feed supply.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.199-208
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• 1977

Activities of various hydrolytic enzymes produced by three plant pathogenic fungi, Sclerotium rolfsii Sacc., Sclerotinia sclerotiorum (Lieb.) deBary and Helminthosporium sigmoideum var. irregulare Crallery et Tullius, were measured. Activties and amounts of the enzymes in mycelia, cultural filtrates, and sclerotia(except of sclerotia of H. sigmoideum var. irregulare) were estimated at various pH levels in order to find out optimal pH for their enzymatic activities. Enzymes such as cellulase (ex), invertase, xylanase, $\beta-amylase$, polymethylgalacturonase, polygalacturonase, phosphatase and protease were estimated. Culture solution for production of enzymes was prepared by adding of 10g, D-glucose, 1.3g $NH_4NO_3,\; 0.5g\; MgSO_4,\;7H_2O,\; and\; 1.0g\; KH_2PO_4$ into 1 liter of potato decoction plus 2ml of micro element solution consisting of 0.2mg. Fe, 0.2mg Zn, and 0.1mg Mn as the sulphates into 1 liter of distilled water. All tested mycelia and cultural filtrates were obtained from the cultures incubarted in previous solution for ten days at $25^{\circ}C$, and sclerotia were harvested from PDA plates of 3. days old, The crude enzyme solutions were prepared according to the method of Miyazaki etal. Ten days after incubation, activities of Cx produced by Scl. sclerotiorum were higher than those of the other fung and each of Cx from three fungi showed different pH optima, such as S. rolfsii and Scl. schlerotiorum in acid side (around pH 3.0), H. sigmoideum var. irregulare in neutral side (around pH 6.3). Invertase activities of S. rolfsii were 20 times higher than those of the other fungi in all samples. All tested fungi, however, showed no significant difference between the enzymatic activities of their cultural filtrate and mycelia and the activities in sclerotia of S. rolfsii and Scl. sclerotiorum were hardly recognized. There were multiple peaks on the xylanase activity curves of three fungi in terms of pH values. High activities of the xylanase were revealed in sclerotia of S. rolfsii and Scl. sclerotiorum, and in mycelia of H. sigmoideum var. irregulare. The highest activities of $\beta-amylase$ were shown both in mycelia and cultural filtrate of H. sigmoideum var. irregulae among the tested fungi, and their optimal pH was 6.2 in both mycelia and cultural filtrate. In the S. rofsii and Sel. sclerotiorum, however, the activities of cultural filtrates were higher than those of the other fungi, and optimal pH was 3.0 and 6.2 for cultural filtrate and both mycelia and sclerotia, respectively. Activities of PMG were high in cultural filtrates of all tested fungi, especially in Scl. sclerotiorum and H. sigmoideum var. irregulare. Mycelia of themalso showed the considerable activities. Optimal pH for enzymatic activities were variable with thekind of fungi or with the samples measured. The highest activities of PG were presented by mycelia of S. rolfsii and Scl. sclerotiorum. $9.l\mu /min.\; and\; 9.5\mu g/min.$, respectively. Optimal pH for activity of PG in mycelia was around 4.5 in S. rolfsii and around 3.0 in Scl. sclerotiorum. Phosphatase of S. rolfsii and Scl. sclerotiorum was more active in acid side (optimal PH3. 5) and that of H. sigmoideum var. irregulare showed one peak each in acid, neutral and alkaline side. But the highest peak was at pH 9.5. Protease of all tested fungi was more active at pH 10.0, especially that of the cultural filtrate of H. sigmoideum var. irregualre.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.11-20
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• 2019

Ecklonia cava, an edible marine brown alga (Laminariaceae), is a rich source of bioactive compounds such as fucoidan and phlorotannins. Ecklonia cava extract (ECE) was prepared using 70% ethanol extraction and ECE contained 67% and 10.6% of total phlorotannins and dieckol, respectively. ECE treatment significantly inhibited receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL)-induced osteoclast differentiation of RAW 264.7 cells and pit formation in bone resorption assay (p <0.05). Moreover, it suppressed RANKL-induced $NF-{\kappa}B$ and mitogen-activated protein kinase signaling in a dose dependent manner. Downregulated osteoclast-specific gene (tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9) expression and osteoclast proliferative transcriptional factors (nuclear factor of activated T cells-1 and c-fos) confirmed ECE-mediated suppression of osteoclastogenesis. ECE treatment ($100{\mu}g/ml$) increased heme oxygenase-1 expression by 2.5-fold and decreased intercellular reactive oxygen species production during osteoclastogenesis. The effective inhibition of RANKL-stimulated osteoclast differentiation and oxidative stress by ECE suggest that ECE has therapeutic potential in alleviating osteoclast-associated disorders.