• Title/Summary/Keyword: Stat1

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4-(Tert-butyl)-2,6-bis(1-phenylethyl)phenol induces pro-apoptotic activity

  • Kim, Jun Ho;Lee, Yunmi;Kim, Mi-Yeon;Cho, Jae Youl
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.3
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    • pp.253-259
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    • 2016
  • Previously, we found that KTH-13 isolated from the butanol fraction of Cordyceps bassiana (Cb-BF) displayed anti-cancer activity. To improve its antiproliferative activity and production yield, we employed a total synthetic approach and derivatized KTH-13 to obtain chemical analogs. In this study, one KTH-13 derivative, 4-(tert-butyl)-2,6-bis(1-phenylethyl)phenol (KTH-13-t-Bu), was selected to test its anti-cancer activity. KTH-13-t-Bu diminished the proliferation of C6 glioma, MDA-MB-231, LoVo, and HCT-15 cells. KTH-13-t-Bu induced morphological changes in C6 glioma cells in a dose-dependent manner. KTH-13-t-Bu also increased the level of early apoptotic cells stained with annexin V-FITC. Furthermore, KTH-13-t-Bu increased the levels of cleaved caspase-3 and -9. In contrast, KTH-13-t-Bu upregulated the levels of pro- and cleaved forms of caspase-3, -8, and -9 and Bcl- 2. Phospho-STAT3, phospho-Src, and phospho-AKT levels were also diminished by KTH13-t-Bu treatment. Therefore, these results strongly suggest that KTH-13-t-Bu can be considered a novel anti-cancer drug displaying pro-apoptotic activity.

Curcumin suppresses the production of interleukin-6 in Prevotella intermedia lipopolysaccharide-activated RAW 264.7 cells

  • Kim, Sung-Jo
    • Journal of Periodontal and Implant Science
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    • v.41 no.3
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    • pp.157-163
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    • 2011
  • Purpose: Curcumin is known to exert numerous biological effects including anti-inflammatory activity. In this study, we investigated the effects of curcumin on the production of interleukin-6 (IL-6) by murine macrophage-like RAW 264.7 cells stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a major cause of inflammatory periodontal disease, and sought to determine the underlying mechanisms of action. Methods: LPS was prepared from lyophilized P. intermedia ATCC 25611 cells by the standard hot phenol-water method. Culture supernatants were collected and assayed for IL-6. We used real-time polymerase chain reaction to detect IL-6 mRNA expression. $I{\kappa}B-{\alpha}$ degradation, nuclear translocation of NF-${\kappa}B$ subunits, and STAT1 phosphorylation were characterized via immunoblotting. DNA-binding of NF-${\kappa}B$ was also analyzed. Results: Curcumin strongly suppressed the production of IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW 264.7 cells. Curcumin did not inhibit the degradation of $I{\kappa}B-{\alpha}$ induced by P. intermedia LPS. Curcumin blocked NF-${\kappa}B$ signaling through the inhibition of nuclear translocation of NF-${\kappa}B$ p50 subunit. Curcumin also attenuated DNA binding activity of p50 and p65 subunits and suppressed STAT1 phosphorylation. Conclusions: Although further study is required to explore the detailed mechanism of action, curcumin may contribute to blockade of the host-destructive processes mediated by IL-6 and appears to have potential therapeutic values in the treatment of inflammatory periodontal disease.

Comparative Analysis of Growth-Phase-Dependent Gene Expression in Virulent and Avirulent Streptococcus pneumoniae Using a High-Density DNA Microarray

  • Ko, Kwan Soo;Park, Sulhee;Oh, Won Sup;Suh, Ji-Yoeun;Oh, TaeJeong;Ahn, Sungwhan;Chun, Jongsik;Song, Jae-Hoon
    • Molecules and Cells
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    • v.21 no.1
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    • pp.82-88
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    • 2006
  • The global pattern of growth-dependent gene expression in Streptococcus pneumoniae strains was evaluated using a high-density DNA microarray. Total RNAs obtained from an avirulent S. pneumoniae strain R6 and a virulent strain AMC96-6 were used to compare the expression patterns at seven time points (2.5, 3.5, 4.5, 5.5, 6.0, 6.5, and 8.0 h). The expression profile of strain R6 changed between log and stationary growth (the Log-Stat switch). There were clear differences between the growth-dependent gene expression profiles of the virulent and avirulent pneumococcal strains in 367 of 1,112 genes. Transcripts of genes associated with bacterial competence and capsular polysaccharide formation, as well as clpP and cbpA, were higher in the virulent strain. Our data suggest that late log or early stationary phase may be the most virulent phase of S. pneumoniae.

Cardiopulmonary Bypass Strategies to Maintain Brain Perfusion during Lung Transplantation in a Patient with Severe Hypercapnia

  • Sohn, Bongyeon;Park, Samina;Lee, Hyun Joo;Jeong, Jin Hee;Choi, Sun Mi;Lee, Sang-Min;Seo, Jeong-Hwa;Kim, Young Tae
    • Journal of Chest Surgery
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    • v.52 no.1
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    • pp.58-60
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    • 2019
  • Herein, we report a case of lung transplantation in a patient with profound preoperative hypercapnia, focusing on the cardiopulmonary bypass strategy used for brain perfusion during the operation. We applied the pH-stat method for acid-base regulation, and thereby achieved the desired outcome without any neurologic deficit.

Effect of all-trans retinoic acid on casein and fatty acid synthesis in MAC-T cells

  • Liao, Xian-Dong;Zhou, Chang-Hai;Zhang, Jing;Shen, Jing-Lin;Wang, Ya-Jing;Jin, Yong-Cheng;Li, Sheng-Li
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.6
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    • pp.1012-1022
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    • 2020
  • Objective: Caseins and fatty acids of milk are synthesized and secreted by the epithelial cells of the mammary gland. All-trans retinoic acid (ATRA), an active metabolite of vitamin A, has been shown to promote mammary development. This study was conducted to determine the effect of ATRA on casein synthesis and fatty acid composition in MAC-T cells. Methods: MAC-T cells were allowed to differentiate for 4 d, treated with ATRA (0, 1.0, 1.5, and 2.0 μM), and incubated for 3 d. We analyzed the fatty acid composition, the mRNA expression of casein and fatty acid synthesis-related genes, and the phosphorylation of casein synthesis-related proteins of MAC-T cells by gas chromatography, quantitative polymerase chain reaction, and western blotting, respectively. Results: In MAC-T cells, ATRA increased the mRNA levels of αS1-casein and β-casein, janus kinase 2 (JAK2) and E74-like factor 5 of the signal transducer and activator of transcription 5 β (STAT5-β) pathway, ribosomal protein S6 kinase beta-1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 of the mammalian target of rapamycin (mTOR) pathway, inhibited the mRNA expression of phosphoinositide 3-kinase and eukaryotic initiation factor 4E of the mTOR pathway, and promoted the phosphorylation of STAT5-β and S6K1 proteins. Additionally, ATRA increased the de novo synthesis of fatty acids, reduced the content of long-chain fatty acids, the ratio of monounsaturated fatty acids to saturated fatty acids (SFA), the ratio of polyunsaturated fatty acids (PUFA) to SFA, and the ratio of ω-6 to ω-3 PUFA. The mRNA levels of acetyl-CoA carboxylase 1, fatty acid synthase, lipoprotein lipase, stearoyl-CoA desaturase, peroxisome proliferator-activated receptor gamma, and sterol regulatory element-binding protein 1 (SREBP1) were enhanced by ATRA. Conclusion: ATRA promotes the synthesis of casein by regulating JAK2/STAT5 pathway and downstream mTOR signaling pathway, and it improves the fatty acid composition of MAC-T cells by regulating SREBP1-related genes.

ON THE WEAK LAW FOR RANDOMLY INDEXED PARTIAL SUMS FOR ARRAYS

  • Hong, Dug-Hun;Sung, Soo-Hak;Andrei I.Volodin
    • Communications of the Korean Mathematical Society
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    • v.16 no.2
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    • pp.291-296
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    • 2001
  • For randomly indexed sums of the form (Equation. See Full-text), where {X(sub)ni, i$\geq$1, n$\geq$1} are random variables, {N(sub)n, n$\geq$1} are suitable conditional expectations and {b(sub)n, n$\geq$1} are positive constants, we establish a general weak law of large numbers. Our result improves that of Hong [3].

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Effect of Fucoidan on Angiogenesis and Gene Expression in Human Umbilical Vein Endothelial Cells (후코이단이 혈관 내피세포의 신생혈관 생성 효과 및 관련 유전자의 발현에 미치는 영향)

  • Park, Ho;Kim, Beom-Su
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.4
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    • pp.323-328
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    • 2017
  • Angiogenesis is a process including members of the angiogenic factors. In particular, fibroblast growth factor 2 (FGF2) is considered the most potent angiogenic factor because it promotes cell proliferation and tube formation. A recent study reported that fucoidan derived from marine plant potentiated FGF-2 induced tube formation in human endothelial cells. On the other hand, the molecular mechanisms involved in the angiogenic activity of fucoidan and FGF2 are unknown. In this study, a fucoidan treatment promoted angiogenesis induced by FGF2. The effects of fucoidan on FGF2-induced angiogenesis were confirmed by a proliferation assay using a CellTiter96 Aqueous One solution after a treatment with fucoidan and FGF2. The tube formation and wound healing assay for the angiogenic activity were also confirmed. Reverse transcription PCR showed a change in the mRNA of vascular endothelial growth factor-A (VEGF-A), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase9 (MMP9), and the signal transducer and activator of transcription3 (STAT3). In summary, the Fucoidan/FGF2 treatment induced an increase in cell proliferation, improved the tube formation and wound healing activity, and altered the STAT3, VEGF-A, ICAM-1, and MMP9 mRNA expression levels. Further research will be needed to provide a scientific explanation in terms of cell-signaling and confirm the present findings.

Involvement of adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 in diallyl trisulfide-induced cytotoxicity in hepatocellular carcinoma cells

  • Guan, Feng;Ding, Youming;He, Yikang;Li, Lu;Yang, Xinyu;Wang, Changhua;Hu, Mingbai
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.6
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    • pp.457-468
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    • 2022
  • It has been demonstrated that APPL1 (adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1) is involved in the regulation of several growth-related signaling pathways and thus closely associated with the development and progression of some cancers. Diallyl trisulfide (DAT), a garlic-derived bioactive compound, exerts selective cytotoxicity to various human cancer cells through interfering with pro-survival signaling pathways. However, whether and how DAT affects survival of human hepatocellular carcinoma (HCC) cells remain unclear. Herein, we tested the hypothesis of the involvement of APPL1 in DAT-induced cytotoxicity in HCC HepG2 cells. We found that Lys 63 (K63)-linked polyubiquitination of APPL1 was significantly decreased whereas phosphorylation of APPL1 at serine residues remained unchanged in DAT-treated HepG2 cells. Compared with wild-type APPL1, overexpression of APPL1 K63R mutant dramatically increased cell apoptosis and mitigated cell survival, along with a reduction of phosphorylation of STAT3, Akt, and Erk1/2. In addition, DAT administration markedly reduced protein levels of intracellular TNF receptor-associated factor 6 (TRAF6). Genetic inhibition of TRAF6 decreased K63-linked polyubiquitination of APPL1. Moreover, the cytotoxicity impacts of DAT on HepG2 cells were greatly attenuated by overexpression of wild-type APPL1. Taken together, these results suggest that APPL1 polyubiquitination probably mediates the inhibitory effects of DAT on survival of HepG2 cells by modulating STAT3, Akt, and Erk1/2 pathways.

Effect of Environmental pH on End Products, Fermentation Balances and Bioenergetic As-pects of Lactobacillus bulg-aricus in a Glucose-limited “pH Stat” Continuous Culture.

  • Rhee, Sang-Ki;Pack, Moo-Young
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1979.10a
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    • pp.246.1-246
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    • 1979
  • A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80% higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

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Based on morphology and molecular data, Palisada rigida comb. nov. and Laurencia decussata comb. et stat. nov. (Rhodophyta, Rhodomelaceae) are proposed

  • Metti, Yola
    • ALGAE
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    • v.37 no.1
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    • pp.15-32
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    • 2022
  • Inspecting herbaria collections of Laurencia rigida highlighted frequent misidentifications between L. rigida and L. heteroclada f. decussata, two poorly studied taxa from Australia. Recent collections of DNA material, including from topotype material, allowed for re-examination of these two taxa using molecular techniques. Detailed morphological and molecular analyses based on two markers (rbcL and COI-5P) strongly supported these two taxa as being distinct from each other and requiring nomenclatural changes. Comprehensive morphological analyses highlighted features useful for accurate identifications. Interestingly, L. rigida was found to belong to the genus Palisada with evidence from both the morphology and molecular data. Therefore, this study proposed recognizing L. rigida as Palisada rigida comb. nov. Molecular data for L. heteroclada f. decussata on the other hand supported its separation from L. heteroclada, with too great a molecular distance to be considered a variety. Morphological characters that best separated P. rigida from L. decussata included seven characters; number of pericentral cells per vegetative axial segment, the presence of secondary pit connections, the presence of lenticular thickenings, tetrasporangia alignment, the presence of corps en cerise, holdfast morphology, and overall plant shape. Morphologically, L. heteroclada f. decussata was also separated from L. heteroclada, particularly by the following characteristics; ultimate branchlets morphologies, lower order branch lengths, primary axis and holdfast morphologies. Therefore, it was proposed that L. heteroclada f. decussata is recognized at a species level as L. decussata comb. et stat. nov.