• Title/Summary/Keyword: degradation pathway

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Tumor-suppressor Protein p53 Sensitizes Human Colorectal Carcinoma HCT116 Cells to 17α-estradiol-induced Apoptosis via Augmentation of Bak/Bax Activation (17α-Estradiol에 의한 인체 대장암 세포주 HCT116의 에폽토시스에 수반되는 Bak/Bax의 활성화에 미치는 종양억제단백질 p53의 강화효과)

  • Han, Cho Rong;Lee, Ji Young;Kim, Dongki;Kim, Hyo Young;Kim, Se Jin;Jang, Seokjoon;Kim, Yoon Hee;Jun, Do Youn;Kim, Young Ho
    • Journal of Life Science
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    • v.23 no.10
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    • pp.1230-1238
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    • 2013
  • The regulatory effect of the tumor-suppressor protein p53 on the apoptogenic activity of $17{\alpha}$-estradiol ($17{\alpha}-E_2$) was compared between HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells. When the HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells were treated with $2.5{\sim}10{\mu}M$ $17{\alpha}-E_2$ for 48 h or with $10{\mu}M$for various time periods, cytotoxicity and an apoptotic sub-$G_1$ peak were induced in the HCT116 ($p53^{+/+}$) cells in a dose- and time-dependent manner. However, the HCT116 ($p53^{-/-}$) cells were much less sensitive to the apoptotic effect of $17{\alpha}-E_2$. Although $17{\alpha}-E_2$ induced aberrant mitotic spindle organization and incomplete chromosome congregation at the equatorial plate, $G_2/M$ arrest was induced to a similar extent in both cell types. In addition, $17{\alpha}-E_2$-induced activation of Bak and Bax, ${\Delta}{\Psi}m$ loss, and PARP degradation were more dominant in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells. In accordance with enhancement of p53 phosphorylation (Ser-15) and p53 levels, p21 and Bax levels were elevated in the HCT116 ($p53^{+/+}$) cells treated with $17{\alpha}-E_2$. The HCT116 ($p53^{-/-}$) cells exhibited barely or undetectable levels of p21 and Bax, regardless of $17{\alpha}-E_2$ treatment. On the other hand, although the level of Bcl-2 was slightly lower in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells, it remained relatively constant after the $17{\alpha}-E_2$ treatment. Together, these results show that among the components of the $17{\alpha}-E_2$-induced apoptotic-signaling pathway, which proceeds through mitotic spindle defects causing mitotic arrest, subsequent activation of Bak and Bax and the mitochondria-dependent caspase cascade, leading to PARP degradation, $17{\alpha}-E_2$-induced activation of Bak and Bax is the upstream target of proapoptotic action of p53.

Differential Effects of Acute and Chronic Exercise on Autophagy-related Gene Expression in Drosophila melanogaster (일회성 및 만성적 유산소운동이 초파리의 자가포식 관련 유전자 발현에 미치는 영향)

  • Kim, Hee Yeon;Kim, Hye Jin;Hwang, Ji Sun;Lee, Won Jun
    • Journal of Life Science
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    • v.24 no.11
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    • pp.1180-1186
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    • 2014
  • Autophagy, the lysosomal degradation pathway, is an intracellular recycling system that is necessary for the metabolic benefits of exercise and for producing lasting beneficial effects of exercise in various diseases. However, the most recent studies have only examined the effect of a single bout of exercise or resistance exercise on autophagic responses. To determine the differential effects of acute and chronic exercise on the expression of autophagy-related genes in D. melanogaster, white-eyed mutant D. melanogaster were assigned randomly to four groups: control, acute exercise, 2 hr chronic exercise, and 3 hr chronic exercise. The flies were exercised using a mechanized platform known as the Power Tower. Our results revealed that a single bout of exercise resulted in increased mRNA levels of the Atg8a gene (~20%, p<0.05). However, Atg1 and Atg6 mRNA expression were not induced by acute exercise. Transcript levels of Atg6 (~29%, p<0.05) related to the nucleation of autophagosomes were significantly induced by 2 hr of chronic exercise. However, this chronic exercise was not enough to increase Atg1 and Atg8a mRNA expression. On the other hand, 3 hr of exercise for 7 days significantly increased Atg1, Atg6, and Atg8a gene expression-about 57%, 37%, and 71%, respectively (p<0.05). These results suggest that a single bout of exercise is not enough to induce full activation of selected autophagy-related genes in D. melanogaster. Our results demonstrated that chronic regular exercise induced autophagy-related gene expression, suggesting that chronic regular exercise training might be required to activate autophagic responses important for producing beneficial effects of exercise in various diseases.

Anti-Inflammmatiry Effects of Nerium indicum Ethanol Extracts through Suppression of NF-kappaB Activation (NF-κB 활성 저해를 통한 협죽도 에탄올 추출물의 항염증 효능)

  • Kim, Tae-Hwan;Ko, Seog-Soon;Park, Cheol;Park, Sang-Eun;Hong, Sang-Hoon;Kim, Byung-Woo;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.20 no.8
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    • pp.1221-1229
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    • 2010
  • Nerium indicum, an India-Pakistan-originated shrub belonging to the oleander family, is reported to possess many pharmacological activities including cardiac muscle stimulation, and anti-diabetes, anti-angiogenesis, anti-cancer and neuro-protective activities. However, the anti-inflammatory properties of N. indicum were unclear. In this study, we investigated the effects of ethanol extract of the N. indicum leaf and stem (ENIL and ENIS) on the expression of anti-inflammatory mediators in U937 human pre-monocytic cell models. In U937 cells stimulated with phorbol 12-myristate-13-acetate (PMA), pre-treatment with ENIS significantly inhibited the expression of both cyclooxygenase-2 (COX-2) mRNA and protein, which are associated with inhibition of the release of prostaglandin $E_2\;(PGE_2)$, whereas the inhibitory effects appeared weakly in ENIL. Moreover, ENIS significantly attenuated PMA-induced IkappaB ($I{\kappa}B$) degradation and suppressed elevated nuclear factor kappa B (NF-${\kappa}B$) nuclear translocation. Taken together, these findings provide important new insights that N. indicum exhibits anti-inflammatory properties by suppressing the transcription of pro-inflammatory cytokine genes through the NF-kB signaling pathway.

Inhibitory Effect of Camp Antagonist and Pka Inhibitors, and Stimulatory Effect of Adenylate Cyclase Agonist on Cathepsin K Processing in Cultured Mouse Osteoclasts (cAMP 길항제와 PKA 억제제 및 Adenylate Cyclase 촉진제의 백서 파골세포에서 Cathepsin K 생성에 대한 효과)

  • Shim, Youn-Soo
    • Journal of dental hygiene science
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    • v.6 no.1
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    • pp.1-9
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    • 2006
  • Cathepsin K (cat K) is the major cysteine protease expressed in osteoclasts and was thought to play a key role in matrix degradation during bone resorption. It was shown that the intracellular maturation of cat K was prevented by the cAMP antagonist, Rp-cAMP, and the protein kinase A (PKA) inhibitors of KT5720 and H89. In contrast, forskolin, a adenylate cyclase agonist, rather induced Cat K processing and maturation in osteoclasts. Furthermore, to determine whether cat K processing and maturation signaling involves protein kinase C (PKC), mouse total bone cells were treated with calphostin C, a specific inhibitor of PKC, however, no effect was observed, indicating that calphostin C did not affect to osteoclast-mediated cat K processing and maturation. Thus, it is indicated that the cAMP-PKA signaling pathway regulates cat K maturation in osteoclasts. Since secreted proenzymes have the potential to reenter the cell via M6P receptor, to prevent this possibility, it was tested cAMP antagonist Rp-cAMP and the PKA inhibitors KT5720 and H89 in the absence or presence of M6P. Inhibition of cat K processing by Rp-cAMP, KT5720, or H89 was observed in a dose-dependent manner. Furthermore, the addition of M6P resulted in enhanced potency of Rp-cAMP, KT5720 and H89. These dose-dependently inhibited in vitro bone resorption with a potency similar to that observed for inhibition of cat K processing.

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Effect of Steroid Administration Ex Vivo on the IκB/NF-κB Pathway in Human Peripheral Blood Monocytes (스테로이드의 투여가 말초혈액 단핵구에서 IkB/NF-κB경로에 미치는 영향)

  • Yoon, Ho Il;Lee, Hee-Seok;Lee, Chang-Hoon;Lee, Choon-Taek;Kim, Young Whan;Han, Sung Koo;Shim, Young-Soo;Yoo, Chul-Gyu
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.5
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    • pp.542-550
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    • 2003
  • Background : Synthetic glucocorticoids are widely used in many chronic inflammatory diseases because of their excellent anti-inflammatory activity. Enhancing the transcription of $I{\kappa}B$ and preventing activated NF-${\kappa}B$ from binding to ${\kappa}B$ sites are thought to be the underlying mechanisms. But these data are largely derived from in vitro studies using cell lines. In this study, after administrating a steroid to volunteers, we evaluated the effect on the NF-${\kappa}B$ system. Methods : Prednisolone(0.5mg/kg/d) was orally administered to 5 healthy volunteers for 7 days. Before and after the administration, we sampled their peripheral blood monocytes, and performed western blot analysis both with stimulation, using IL-$1{\beta}$, LPS, TNF, and without stimulation(baseline). We also performed EMSA after stimulation with LPS. Results : After ingestion of the steroid, baseline expressions of $I{\kappa}B{\alpha}$ were increased in two of the subjects, while suppressed degradations of $I{\kappa}B{\alpha}$ to stimulations were observed in all five. In addition, the binding capacity of NF-${\kappa}B$ after the administration was decreased. Conclusion : Steroid plays such roles as enhancing the transcription of $I{\kappa}B{\alpha}$, suppressing the DNA binding capacity of NF-${\kappa}B$, and suppressing the degradation of $I{\kappa}B{\alpha}$.

Expressions of Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-2 with Changes of Interleukin-6 and Interleukin-18 in Atherosclerotic Lesions of Hypercholesterolemic Rabbits (고콜레스테롤혈증 가토의 죽상경화성 병변에서 Interleukin-6와 Interleukin-18의 변화 및 Matrix Metalloproteinase-9과 Tissue Inhibitor of Metalloproteinase-2의 발현)

  • 권영무;김성숙;장봉현
    • Journal of Chest Surgery
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    • v.35 no.6
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    • pp.407-419
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    • 2002
  • Atherosclerosis is a chronic inflammatory disease of the arterial wall characterized by progressive accumulation of lipids, cells, and extracellular matrix. Matrix metalloproteinases(MMPs) and tissue inhibitor of metalloproteinases(TIMPS) contribute to vascular matrix remodeling in atherosclerosis, and some cytokines may play role in the synthesis or activation of MMPs or TIMPs. Material and Method: We produced experimental atherosclerotic plaques in 9 rabbits by atherogenic hypercholesterol diet for 12 weeks, and 10 other rabbits were used as control group with standard laboratory chow, At that time, 19 rabbits were sacrificed and aorta, coronary arteries and blood specimens were prepared. The expressions of MMP-9, TIMP-2 and interleukin(IL)-18, and the bioactivity of IL-6 were investigated with H&E stain, immunohistochemical stain, immunoblotting(Western blot analysis), and bioassay. Result: Serum cholesterol in the experimental group increased up to 1258$\pm$262 mg/dL(control group: 41$\pm$7 mg/dL). All experimental group showed well-developed atherosclerotic plaques in aorta and coronary artery. The expression of MMP-9 in aorta and coronary artery of the experimental group showed significant increase than that of the control group by immunohistochemistry. Among the experimental group, complicated lesions with intimal rupture or complete luminal occlusion, demonstrated stronger expression of MMP-9. Interestingly, there was no difference in expression of TIMP-2 between the experimental and the control group. These findings were confirmed by Western blot analysis. The bioassay revealed significant up-regulation of serum bioactivity of IL-6 in the experimental group(4819.60$\pm$2021.25 IU/$m\ell$) compared to that of IL-6 in the control group(27.20 $\pm$ 12.19 IU/$m\ell$). IL-18 was expressed in all atherosclerotic plaques, whereas little or no expression was detected in the control group. Conclusion: The increased MMP-9 expression along with the unchanged TIMP-2 expression seem to be contributory factors in extracellular matrix degradation in atherosclerosis. Focal overexpression of MMP-9 may promote plaque destabilization and cause complications of atherosclerotic plaques such as thrombosis with/without acute coronary syndrome. Elevation of IL-6 and IL-18 may be more than just markers of atherosclerosis but actual participants in lesion development. Identification of critical regulatory pathway is important to improve the understanding of the cellular and molecular basis of atherosclerosis and may open the way for novel therapeutic strategies.

Anti-inflammatory effects of Cudrania tricuspidata twig sawdust fermented with Ganoderma lucidum mycelium (영지버섯균 발효 꾸지뽕나무 가지 톱밥 추출물의 항염증 활성)

  • Park, Se-Eun;Kim, Myung Kon;Kim, Seung
    • Journal of Mushroom
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    • v.19 no.3
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    • pp.225-233
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    • 2021
  • In this study, we evaluated the anti-inflammatory effect of extract from Cudrania tricuspidata twig sawdust fermented with Ganoderma lucidum mycelium. Fermented Cudrania tricuspidata twig sawdust extracted with 70% ethanol and elucidated the potential signaling pathway in lipopolysaccharide (LPS)-induced RAW264.7 cells. Fermented Cudrania tricuspidata twig sawdust inhibits LPS-stimulated nitric oxide (NO) production without affecting cell viability in a dose-dependent manner and production of LPS-induced pro-inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and prostaglandin2 (PGE2). Fermented Cudrania tricuspidata twig sawdust also suppressed the expression of the pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 cells. Moreover, Fermented Cudrania tricuspidata twig sawdust significantly attenuated LPS-induced IkappaB (IκB) degradation and suppressed nuclear factor kappa B (NF-κB) nuclear translocation. These results suggest that fermented Cudrania tricuspidata twig sawdust may have great potential for the development of anti-inflammatory agent.

Geophysical Exploration of Songsalli Ancient Tombs and Analysis of King Muryeong's Tomb Structure, Gongju (공주 송산리 고분군(公州 宋山里 古墳群)에서의 물리탐사와 무령왕릉(武寧王陵)의 구조분석)

  • Oh, Hyun-dok
    • Korean Journal of Heritage: History & Science
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    • v.46 no.4
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    • pp.4-23
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    • 2013
  • Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.

Effects of Vitamin C on Airway Hyperresponsiveness in Heavy Smokers (흡연자의 기도 과민반응에 대한 비타민 C의 효과)

  • Lee, Sang-Gab;Kim, Ki-Ryang;Eim, Jeong-Ook;Kim, Heung-Up;Lee, Sang-Soo;Chung, Lee-Young;Kim, Hwi-Jong;Lee, Jong-Deog;Hwang, Young-Sil
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.4
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    • pp.723-735
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    • 1998
  • Background : Vitamin C has been reported to have a role in the decrease of airway hyperresponsiveness in animal models. This data is based on some metabolic actions of vitamin C, such as promotion of histamine degradation, producing more $PGE_2$ than $PGF_{2\alpha}$ in cyclooxygenase pathway, decrease of smooth muscle contraction, and acting as reducing agent of oxidant. It has been also known that heavy smokers have lower blood levels of vitamin C than nonsmokers and this deficiency in heavy smokers have been explained by several mechanisms, such as increased oxidation by oxidants and free radicals, increased biosynthesis of catecholamine and serotonin released by nicotine, and inadequate dietary intake. In this study, We attempted to assess effect of vitamin C on bronchial hyperresponsiveness in heavy smokers who have bronchial hyperresponsiveness and role of vitamin C on bronchial hyperresponsiveness. Method: To assess acute effect of vitamin C on airway hyperresponsiveness, blood sample for vitamin C level and spirometry, methacholine challenge test were done in 17 smokers and 8 nonsmokers, and one hour after oral administration of vitamin C 3 g, blood sample for vitamin C level and spirometry, methacholine challenge test were repeated. To assess chronic effect of vitamin C on airway hyperresponsiveness, after daily administration of vitamin C 1 g for one week in 17 smokers, blood sample for vitamin C level and spirometry, methacholine challenge test were done. To assess role of vitamin C, after oral administration of vitamin C 3 g plus indomethacin 100 mg in 12 of 15 smokers who were reactive to methacholine challenge test, spirometry and methacholine challenge test were done and after oral intake of indomethacin 100 mg in 12 smokers who were reactive to methacholine challenge test, spirometry and methacholine challenge test were repeated. Result: There were no significant differences in whole blood vitamin C levels between smokers($1.17{\pm}0.22$ mg/dL) and nonsmcikers($1.14{\pm}0.19$ mg/dL) (p>0.05). Fifteen of the 17 smokers(88.2%) were reactive to methacholine challenge test and 10 of the 15 smokers who were reactive to methacholine challenge test were less than 8 mg/dL in $PC_{20}FEV-2$, and 7 of the 8 nonsmokers(87.5%) were nonreactive to methacholine challenge test There were significant decrease in bronchial responsiveness after oral administration of vitamin C 3 g in 13 of the 15 smokers who were reactive to methacholine challenge test This significant decrease persisted with maintenance daily administration of 1 g for one week. $PC_{20}FEV-2$ were not correlated to vitamin C levels in smokers. After oral administration of indomethacin 100 mg, significant reduction of bronchial responsiveness that occured after oral administration of vitamin C 3 g in smokers were attenuated. Conclusion: Although there were no significant differences in whole blood vitamin C levels between smokers and nonsmokers. heavy smokers have significant increase in bronchial responsiveness than nonsmokers. This bronchial hyperresponsiveness of heavy smokers can be attenuated by vitamin C supplement. Disappearance of vitamin C effect by indomethacin supplement may suggest that vitamin C exert its effect via alteration of arachidonic acid metabolism.

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