41 results on '"Ham YW"'
Search Results
2. Panax ginseng protects against global ischemia injury in rat hippocampus.
- Author
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Kim YO, Kim H, Kim GS, Park HG, Lim SJ, Seong NS, Ham YW, Lee SD, Jang K, Jung KH, Chung J, and Kang SA
- Published
- 2009
- Full Text
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3. G721-0282 Exerts Anxiolytic-Like Effects on Chronic Unpredictable Mild Stress in Mice Through Inhibition of Chitinase-3-Like 1-Mediated Neuroinflammation.
- Author
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Ham HJ, Lee YS, Lee HP, Ham YW, Yun J, Han SB, and Hong JT
- Abstract
Chronic stress is thought to be a major contributor to the onset of mental disorders such as anxiety disorders. Several studies have demonstrated a correlation between anxiety state and neuroinflammation, but the detailed mechanism is unclear. Chitinase-3-like 1 (CHI3L1) is expressed in several chronic inflammatorily damaged tissues and is well known to play a major role in mediating inflammatory responses. In the present study, we investigated the anxiolytic-like effect of N-Allyl-2-[(6-butyl-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin-5-yl)sulfanyl]acetamide (G721-0282), an inhibitor of CHI3L1, on mice treated with chronic unpredictable mild stress (CUMS), as well as the mechanism of its action. We examined the anxiolytic-like effect of G721-0282 by conducting several behavioral tests with oral administration of G721-0282 to CUMS-treated BALB/c male mice. We found that administration of G721-0282 relieves CUMS-induced anxiety. Anxiolytic-like effects of G721-0282 have been shown to be associated with decreased expressions of CUMS-induced inflammatory proteins and cytokines in the hippocampus. The CUMS-elevated levels of CHI3L1 and IGFBP3 were inhibited by treatment with G721-0282 in vivo and in vitro . However, CHI3L1 deficiency abolished the anti-inflammatory effects of G721-0282 in microglial BV-2 cells. These results suggest that G721-0282 could lower CUMS-induced anxiety like behaviors by regulating IGFBP3-mediated neuroinflammation via inhibition of CHI3L1., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ham, Lee, Lee, Ham, Yun, Han and Hong.)
- Published
- 2022
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4. A small molecule targeting CHI3L1 inhibits lung metastasis by blocking IL-13Rα2-mediated JNK-AP-1 signals.
- Author
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Lee YS, Yu JE, Kim KC, Lee DH, Son DJ, Lee HP, Jung JK, Kim ND, Ham YW, Yun J, Han SB, and Hong JT
- Subjects
- Animals, Cell Line, Tumor, Humans, Lung Neoplasms secondary, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Small Molecule Libraries, Chitinase-3-Like Protein 1 drug effects, Interleukin-13 Receptor alpha2 Subunit antagonists & inhibitors, Lung Neoplasms prevention & control, MAP Kinase Kinase 4 metabolism, Signal Transduction drug effects, Transcription Factor AP-1 metabolism
- Abstract
Our previous big data analyses showed a high level of association between chitinase 3 like1 (CHI3L1) expression and lung tumor development. In the present study, we investigated whether a CHI3L1-inhibiting chemical, 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284), could inhibit lung metastasis and studied its mechanism of action. We investigated the antitumor effect of K284 both in vitro and in vivo. K284 (0.5 mg·kg
-1 body weight) significantly inhibited lung metastasis in in vivo models after injection of murine melanoma cells (B16F10) or adenocarcinomic human alveolar basal epithelial cells (A549). K284 significantly and concentration-dependently also inhibited cancer cell proliferation and migration in the A549 and H460 lung cancer cell lines. We found that the binding of K284 to the chitin-binding domain (CBD) of CHI3L1 prevented the binding of CHI3L1 to its receptor, interleukin-13 receptor subunit alpha-2 (IL-13Rα2), thereby suppressing the CHI3L1 signal. This blocking of the CHI3L1-IL-13Rα2 signal caused the inhibition of c-Jun N-terminal kinase (JNK)-activator protein 1 (AP-1) signals, resulting in the prevention of lung metastasis and cancer cell growth. Our data demonstrate that K284 may serve as a potential candidate anticancer compound targeting CHI3L1., (© 2021 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)- Published
- 2022
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5. Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis.
- Author
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Park KR, Yun HM, Yoo K, Ham YW, Han SB, and Hong JT
- Subjects
- Allografts, Animals, Cell Line, Tumor, Cell Nucleus metabolism, Cell Proliferation, Chitinase-3-Like Protein 1 chemistry, Down-Regulation, Humans, Mice, Inbred C57BL, Mice, Knockout, Neoplasm Metastasis, Protein Binding, Protein Stability, Transcription, Genetic, Ubiquitination, Carcinogenesis pathology, Chitinase-3-Like Protein 1 metabolism, Lung Neoplasms metabolism, Lung Neoplasms pathology, Tumor Suppressor Protein p53 metabolism
- Abstract
Background: Chitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development., Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1
KO(-/-) ) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis., Results: We established lung metastasis induced by i.v. injections of B16F10 in Chi3L1KO(-/-) . The lung tumor nodules were significantly reduced in Chi3L1KO(-/-) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1KO(-/-) , while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1KO(-/-) . Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient., Conclusions: Our studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.- Published
- 2020
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6. Bee venom phospholipase A2 ameliorates amyloidogenesis and neuroinflammation through inhibition of signal transducer and activator of transcription-3 pathway in Tg2576 mice.
- Author
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Ham HJ, Han SB, Yun J, Yeo IJ, Ham YW, Kim SH, Park PH, Choi DY, and Hong JT
- Abstract
Background: Neuroinflammation and accumulation of β-amyloid (Aβ) play a significant role in the onset and progression of Alzheimer's disease (AD). Our previous study demonstrated that signal transducer and activator of transcription-3 (STAT3) plays a major role in neuroinflammation and amyloidogenesis., Methods: In the present study, we investigated the inhibitory effect of bee venom phospholipase A2 (bvPLA2) on memory deficiency in Tg2576 mice, which demonstrate genetic characteristics of AD and the mechanism of its action at the cellular and animal level. For in vivo study, we examined the effect of bvPLA2 on improving memory by conducting several behavioral tests with the administration of bvPLA2 (1 mg/kg) to Tg2576 mice. For in vitro study, we examined the effect of bvPLA2 on amyloidogenesis and neuroinflammation by treating bvPLA2 on LPS-activated BV2 cells., Results: We found that bvPLA2 alleviated memory impairment in Tg2576 mice, as demonstrated in the behavioral tests assessing memory. In the bvPLA2-treated group, Aβ, amyloid precursor protein (APP), and β-secretase 1 (BACE1) levels and β-secretase activity were significantly decreased. Expression of pro-inflammatory cytokines and inflammation-related proteins decreased in the brain of bvPLA2-treated group, whereas anti-inflammatory cytokines increased. In addition, bvPLA2 reduced STAT3 phosphorylation in the brains of the bvPLA2-treated group. At the cellular level, bvPLA2 inhibits production of nitric oxide, pro-inflammatory cytokines, and inflammation-related proteins including p-STAT3. Additionally, bvPLA2 inhibits the production of Aβ in cultured BV-2 cells. Results from the docking experiment, pull-down assay, and the luciferase assay show that bvPLA2 directly binds STAT3 and, thus, regulates gene expression levels. Moreover, when the STAT3 inhibitor and bvPLA2 were administered together, the anti-amyloidogenic and anti-inflammatory effects were further enhanced than when they were administered alone., Conclusion: These results suggest that bvPLA2 could restore memory by inhibiting the accumulation of Aβ and inflammatory responses via blockage of STAT3 activity., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s). 2019.)
- Published
- 2019
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7. Astaxanthin Ameliorates Lipopolysaccharide-Induced Neuroinflammation, Oxidative Stress and Memory Dysfunction through Inactivation of the Signal Transducer and Activator of Transcription 3 Pathway.
- Author
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Han JH, Lee YS, Im JH, Ham YW, Lee HP, Han SB, and Hong JT
- Subjects
- Amyloid beta-Protein Precursor antagonists & inhibitors, Amyloid beta-Protein Precursor biosynthesis, Animals, Antioxidants pharmacology, Avoidance Learning drug effects, Cell Line, Maze Learning drug effects, Memory Disorders chemically induced, Mental Recall drug effects, Mice, Mice, Inbred ICR, Microglia drug effects, Oxidative Stress drug effects, Signal Transduction drug effects, Xanthophylls therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Inflammation chemically induced, Inflammation prevention & control, Lipopolysaccharides, Memory Disorders prevention & control, STAT3 Transcription Factor drug effects
- Abstract
Astaxanthin (AXT), a xanthophyll carotenoid compound, has potent antioxidant, anti-inflammatory and neuroprotective properties. Neuroinflammation and oxidative stress are significant in the pathogenesis and development of Alzheimer's disease (AD). Here, we studied whether AXT could alleviate neuroinflammation, oxidative stress and memory loss in lipopolysaccharide (LPS) administered mice model. Additionally, we investigated the anti-oxidant activity and the anti-neuroinflammatory response of AXT in LPS-treated BV-2 microglial cells. The AXT administration ameliorated LPS-induced memory loss. This effect was associated with the reduction of LPS-induced expression of inflammatory proteins, as well as the production of reactive oxygen species (ROS), nitric oxide (NO), cytokines and chemokines both in vivo and in vitro. AXT also reduced LPS-induced β-secretase and Aβ
1⁻42 generation through the down-regulation of amyloidogenic proteins both in vivo and in vitro. Furthermore, AXT suppressed the DNA binding activities of the signal transducer and activator of transcription 3 (STAT3). We found that AXT directly bound to the DNA- binding domain (DBD) and linker domain (LD) domains of STAT3 using docking studies. The oxidative stress and inflammatory responses were not downregulated in BV-2 cells transfected with DBD-null STAT3 and LD-null STAT3. These results indicated AXT inhibits LPS-induced oxidant activity, neuroinflammatory response and amyloidogenesis via the blocking of STAT3 activity through direct binding.- Published
- 2019
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8. Piperlongumine Improves Lipopolysaccharide-Induced Amyloidogenesis by Suppressing NF-KappaB Pathway.
- Author
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Gu SM, Lee HP, Ham YW, Son DJ, Kim HY, Oh KW, Han SB, Yun J, and Hong JT
- Subjects
- Alzheimer Disease metabolism, Amyloid beta-Peptides biosynthesis, Animals, Astrocytes drug effects, Astrocytes metabolism, Cell Death drug effects, Cells, Cultured, Cytokines antagonists & inhibitors, Dioxolanes administration & dosage, Dioxolanes therapeutic use, Disease Models, Animal, Inflammation chemically induced, Inflammation drug therapy, Inflammation metabolism, Lipopolysaccharides pharmacology, Male, Memory drug effects, Mice, Microglia drug effects, Microglia metabolism, NF-kappa B p50 Subunit metabolism, Piper chemistry, Alzheimer Disease drug therapy, Amyloid beta-Peptides antagonists & inhibitors, Dioxolanes pharmacology, NF-kappa B p50 Subunit antagonists & inhibitors
- Abstract
Amyloidogenesis is known to cause Alzheimer's disease. Our previous studies have found that lipopolysaccharide (LPS) causes neuroinflammation and amyloidogenesis through activation of nuclear factor kappaB (NF-κB). Piperlongumine (PL) is an alkaloid amide found naturally in long pepper (Piper longum) isolates; it was reported to have inhibitory effects on NF-κB activity. We therefore investigated whether PL exhibits anti-inflammatory and anti-amyloidogenic effects by inhibiting NF-κB. A murine model of LPS-induced memory impairment was made via the intraperitoneal (i.p.) injection of LPS (0.25 mg/kg/day, i.p.). We then injected PL (1.5 or 3.0 mg/kg/day, i.p.) for 7 days in three groups of mice to observe effects on memory. We also conducted an in vitro study with astrocytes and microglial BV-2 cells, which were treated with LPS (1 µg/mL) or PL (0.5 or 1.0 or 2.5 µM). Results from our behavioral tests showed that PL inhibited LPS-induced memory. PL also prevented LPS-induced beta-amyloid (Aβ) accumulation and inhibited the activities of β- and γ-secretases. The expression of inflammatory proteins also was decreased in PL-treated mice, cultured BV-2, and primary astrocyte cells. These effects were associated with the inhibition of NF-κB activity. A docking model analysis and pull-down assay showed that PL binds to p50. Taken together, our findings suggest that PL diminishes LPS-induced amyloidogenesis and neuroinflammation by inhibiting NF-κB signaling; PL therefore demonstrates potential for the treatment of Alzheimer's disease.
- Published
- 2018
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9. MMPP Attenuates Non-Small Cell Lung Cancer Growth by Inhibiting the STAT3 DNA-Binding Activity via Direct Binding to the STAT3 DNA-Binding Domain.
- Author
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Son DJ, Zheng J, Jung YY, Hwang CJ, Lee HP, Woo JR, Baek SY, Ham YW, Kang MW, Shong M, Kweon GR, Song MJ, Jung JK, Han SB, Kim BY, Yoon DY, Choi BY, and Hong JT
- Subjects
- A549 Cells, Animals, Apoptosis drug effects, Carcinoma, Non-Small-Cell Lung metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Humans, Lung Neoplasms metabolism, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Signal Transduction drug effects, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Carcinoma, Non-Small-Cell Lung drug therapy, DNA metabolism, DNA-Binding Proteins metabolism, Lung Neoplasms drug therapy, Phthalic Acids pharmacology, STAT3 Transcription Factor metabolism
- Abstract
Rationale: Signal transducer and activator of transcription-3 (STAT3) plays a pivotal role in cancer biology. Many small-molecule inhibitors that target STAT3 have been developed as potential anticancer drugs. While designing small-molecule inhibitors that target the SH2 domain of STAT3 remains the leading focus for drug discovery, there has been a growing interest in targeting the DNA-binding domain (DBD) of the protein. Methods: We demonstrated the potential antitumor activity of a novel, small-molecule (E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol (MMPP) that directly binds to the DBD of STAT3, in patient-derived non-small cell lung cancer (NSCLC) xenograft model as well as in NCI-H460 cell xenograft model in nude mice. Results: MMPP effectively inhibited the phosphorylation of STAT3 and its DNA binding activity in vitro and in vivo . It induced G1-phase cell cycle arrest and apoptosis through the regulation of cell cycle- and apoptosis-regulating genes by directly binding to the hydroxyl residue of threonine 456 in the DBD of STAT3. Furthermore, MMPP showed a similar or better antitumor activity than that of docetaxel or cisplatin. Conclusion: MMPP is suggested to be a potential candidate for further development as an anticancer drug that targets the DBD of STAT3., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.
- Published
- 2017
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10. (E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol suppresses ovarian cancer cell growth via inhibition of ERK and STAT3.
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Zheng J, Son DJ, Lee HL, Lee HP, Kim TH, Joo JH, Ham YW, Kim WJ, Jung JK, Han SB, and Hong JT
- Subjects
- Aldehydes pharmacology, Animals, Apoptosis Regulatory Proteins metabolism, Carcinoma, Ovarian Epithelial, Cell Line, Tumor, Cell Proliferation drug effects, DNA, Neoplasm metabolism, Female, Guaiacol chemistry, Guaiacol pharmacology, Humans, Male, Mice, Mice, Inbred BALB C, Phenols pharmacology, Protein Binding drug effects, Aldehydes chemistry, Antineoplastic Agents pharmacology, Extracellular Signal-Regulated MAP Kinases antagonists & inhibitors, Guaiacol analogs & derivatives, Neoplasms, Glandular and Epithelial drug therapy, Ovarian Neoplasms drug therapy, Phenols chemistry, STAT3 Transcription Factor antagonists & inhibitors
- Abstract
In the present study, we synthesized several non-aldehyde analogues of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal which showed anti-cancer effect. Interestingly, among the 16 compounds, we found that (E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol (MMPP) showed the most significant anti-proliferative effect on PA-1 and SK-OV-3 ovarian epithelial cancer cells. MMPP treatment (0-15 µg/mL) induced apoptotic cell death, enhanced the expression of cleaved caspase-3, and cleaved caspase-9 in a concentration dependent manner. Notably, DNA binding activity of STAT3, phosphorylation of extracellular signal-regulated kinase (ERK) and p38 was significantly decreased by MMPP treatment. However, ERK siRNA augmented MMPP-induced inhibitory effect on cell growth rather than p38 siRNA or JNK siRNA. Moreover, combination treatment of MMPP with ERK inhibitor U0126 (10 µM) augmented MMPP-induced inhibitory effect on cell growth and DNA binding activity of STAT3, and enhanced expression of cleaved caspase-3 and cleaved caspase-9. In addition, STAT3 siRNA transfection augmented MMPP-induced cell growth inhibition. In PA-1 bearing xenograft mice model, MMPP (5 mg/kg) suppressed tumor growth significantly. Immunohistochemistry staining showed that the expression levels of p-ERK, PCNA, p-STAT3 were decreased while the expression level of caspase-3 was increased by MMPP treatment. Thus, MMPP may be a promising anti-cancer agent in ovarian epithelial cancer treatment., (© 2017 Wiley Periodicals, Inc.)
- Published
- 2017
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11. A small molecule, (E)-2-methoxy-4-(3-(4-methoxyphenyl) prop-1-en-1-yl) phenol suppresses tumor growth via inhibition of IkappaB kinase β in colorectal cancer in vivo and in vitro .
- Author
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Zheng J, Park MH, Lee HP, Hyun BK, Chun HO, Jung SH, Seo HO, Ham YW, Han SB, and Hong JT
- Abstract
Here we report that a novel synthesized compound (E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol (MMPP) which exhibits better stability, drug-likeness and anti-cancer effect than (E)-2,4-bis(p-hydroxyphenyl)-2-butenal (BHPB) that we previously reported. Of all newly synthesized BHPB analogues, MMPP showed the most significant inhibitory effect on colon cancer cell growth. Thus, we evaluated the anti-cancer effects and possible mechanisms of MMPP in vitro and in vivo . MMPP treatment (0-15 μg/mL) induced apoptotic cell death and enhanced the expression of cleaved caspase-3 and cleaved caspase-8 in a concentration dependent manner. Notably, the expression of death receptor (DR)5 and DR6 was significantly increased by MMPP treatment. Moreover, DR5 siRNA or DR6 siRNA transfection partially abolished MMPP-induced cell growth inhibition. Pull down assay and docking experiment showed that MMPP bound directly to IkappaB kinase β (IKKβ). It was noteworthy that IKKβ mutant (C99S) partially abolished MMPP-induced cell growth inhibition and enhanced expression of DR5 and DR6. In addition, MMPP enhanced TRAIL-induced apoptosis, cell growth inhibition and expression of DRs. In xenograft mice model, MMPP (2.5-5 mg/kg) suppressed tumor growth in a dose dependent manner. Immunohistochemistry analysis showed that the expression levels of DR5 and DR6 and active caspase-3 were increased while the expression levels of PCNA and p-IKKβ were decreased in a dose dependent manner. Thus, MMPP may be a promising anti-cancer agent in colon cancer treatment., Competing Interests: CONFLICTS OF INTEREST The authors declare that they have no competing interests.
- Published
- 2017
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12. Loss of Parkin reduces inflammatory arthritis by inhibiting p53 degradation.
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Jung YY, Son DJ, Lee HL, Kim DH, Song MJ, Ham YW, Kim Y, Han SB, Park MH, and Hong JT
- Subjects
- Animals, Arthritis, Rheumatoid chemically induced, Arthritis, Rheumatoid genetics, Cell Nucleus metabolism, Cyclooxygenase 2 metabolism, Disease Models, Animal, HEK293 Cells, Humans, Male, Mice, Mice, Transgenic, NF-kappa B metabolism, Nitric Oxide Synthase Type II metabolism, Protein Binding, Proteolysis, RAW 264.7 Cells, Tumor Suppressor Protein p53 chemistry, Ubiquitin-Protein Ligases chemistry, Up-Regulation, Arthritis, Rheumatoid metabolism, Lipopolysaccharides adverse effects, Tumor Suppressor Protein p53 metabolism, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism
- Abstract
Parkin is associated with various inflammatory diseases, including Parkinson's disease (PD) and rheumatoid arthritis (RA). However, the precise role of Parkin in RA is unclear. The present study addressed this issue by comparing the development of RA between non-transgenic (non-Tg) mice and PARK2 knockout (KO) mice. We found that cyclooxygenase-2 and inducible nitric oxide synthase expression and nuclear factor-κB activity were reduced but p53 activation was increased in PARK2 KO as compared to non-Tg mice. These effects were associated with reduced p53 degradation. Parkin was found to interact with p53; however, this was abolished in Parkin KO mice, which prevented p53 degradation. Treatment of PARK2 KO mice with p53 inhibitor increased Parkin expression as well as inflammation and RA development while decreasing nuclear p53 translocation, demonstrating that PARK2 deficiency inhibits inflammation in RA via suppression of p53 degradation. These results suggest that RA development may be reduced in PD patients., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2017
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13. Inhibitory effect of punicalagin on lipopolysaccharide-induced neuroinflammation, oxidative stress and memory impairment via inhibition of nuclear factor-kappaB.
- Author
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Kim YE, Hwang CJ, Lee HP, Kim CS, Son DJ, Ham YW, Hellström M, Han SB, Kim HS, Park EK, and Hong JT
- Subjects
- Amyloid Precursor Protein Secretases metabolism, Amyloid beta-Protein Precursor metabolism, Animals, Aspartic Acid Endopeptidases metabolism, Astrocytes drug effects, Behavior, Animal drug effects, Brain metabolism, Cells, Cultured, I-kappa B Proteins metabolism, Lipopolysaccharides, Male, Memory Disorders chemically induced, Mice, Microglia drug effects, Molecular Docking Simulation, Rats, Hydrolyzable Tannins pharmacology, Inflammation prevention & control, Inflammation Mediators metabolism, Memory Disorders prevention & control, NF-kappa B antagonists & inhibitors, Oxidative Stress drug effects
- Abstract
Neuroinflammation is significant in the pathogenesis and development of Alzheimer's disease (AD). Previously, we showed lipopolysaccharide (LPS)-induced neuroinflammation caused memory impairment. We investigated the possible preventive effects of punicalagin (PUN), a component of pomegranate, on memory deficiency caused by LPS, along with the fundamental mechanisms. LPS-treated cultured astrocytes and microglial BV-2 cells were investigated for anti-neuroinflammatory effects of PUN. PUN (1.5 mg/kg) ameliorates LPS (250 μg/kg daily 7 times)-induced memory impairment as well as prevents the LPS-induced expression of inflammatory proteins. In in vitro study, we also found that PUN (1 μg/ml) inhibited the LPS-(10, 20 and 50 μM) induced expression of iNOS and Cox-2 as well as the production of ROS, NO, TNF-α and IL-1β. PUN also suppress activation of NF-κB via inhibition of IκB degradation as well as p50 and p65 translocation into the nucleus in LPS treated mouse brain and cultured astrocytes and microglial BV-2 cells. Consistent with the inhibitory effect on neuro inflammation, PUN inhibited LPS-induced Aβ
1-42 generation through down-regulation of APP and BACE1 expression in in vivo and in vitro study. Moreover, PUN directly binds to NF-κB subunit p50 evidenced by a docking model and pull down assay. These results suggest that PUN inhibits LPS-induced memory impairment via anti-inflammatory and anti-amylogenic mechanisms through inhibition of NF-κB activation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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14. Novel synthetic (E)-2-methoxy-4-(3-(4-methoxyphenyl) prop-1-en-1-yl) phenol inhibits arthritis by targeting signal transducer and activator of transcription 3.
- Author
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Son DJ, Kim DH, Nah SS, Park MH, Lee HP, Han SB, Venkatareddy U, Gann B, Rodriguez K, Burt SR, Ham YW, Jung YY, and Hong JT
- Subjects
- Aged, Aged, 80 and over, Animals, Arthritis, Experimental metabolism, Arthritis, Rheumatoid metabolism, Female, Gene Expression Regulation drug effects, Humans, Male, Mice, Middle Aged, Phenols pharmacology, RAW 264.7 Cells, Signal Transduction drug effects, Synoviocytes metabolism, Arthritis, Experimental drug therapy, Arthritis, Rheumatoid drug therapy, Phenols administration & dosage, Phenols chemical synthesis, STAT3 Transcription Factor metabolism
- Abstract
Rheumatoid arthritis (RA) is a severely debilitating chronic autoimmune disease that leads to long-term joint damage. Signal transducer and activator of transcription 3 (STAT3)-targeted small molecules have shown promise as therapeutic drugs for treating RA. We previously identified (E)-2,4-bis(p-hydroxyphenyl)-2-butenal (BHPB), a tyrosine-fructose Maillard reaction product, as a small molecule with potent anti-inflammatory and anti-arthritic properties, mediated through the inhibition of STAT3 activation. The aim of this study was to develop a novel BHPH derivative with improved anti-arthritic properties and drug-likeness. We designed and synthesised (E)-2-methoxy-4-(3-(4-methoxyphenyl) prop-1-en-1-yl) phenol (MMPP), a novel synthetic BHPB analogue, and investigated its anti-inflammatory and anti-arthritic activities in experimentally-induced RA. We showed that MMPP strongly inhibited pro-inflammatory responses by inhibiting in vitro STAT3 activation and its downstream signalling in murine macrophages and human synoviocytes from patients with RA. Furthermore, we demonstrated that MMPP exhibited potent anti-arthritic activity in a collagen antibody-induced arthritis (CAIA) mouse model in vivo. Collectively, our results suggest that MMPP has great potential for use in the treatment of RA.
- Published
- 2016
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15. Piperlongumine inhibits lung tumor growth via inhibition of nuclear factor kappa B signaling pathway.
- Author
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Zheng J, Son DJ, Gu SM, Woo JR, Ham YW, Lee HP, Kim WJ, Jung JK, and Hong JT
- Subjects
- A549 Cells, Animals, Antineoplastic Agents, Phytogenic pharmacology, Carcinoma, Non-Small-Cell Lung metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Dioxolanes pharmacology, Dose-Response Relationship, Drug, Gene Expression Regulation, Neoplastic drug effects, Humans, Lung Neoplasms metabolism, Models, Molecular, Molecular Docking Simulation, NF-kappa B chemistry, Protein Binding drug effects, Signal Transduction drug effects, Xenograft Model Antitumor Assays, Antineoplastic Agents, Phytogenic administration & dosage, Carcinoma, Non-Small-Cell Lung drug therapy, Dioxolanes administration & dosage, Lung Neoplasms drug therapy, NF-kappa B metabolism
- Abstract
Piperlongumine has anti-cancer activity in numerous cancer cell lines via various signaling pathways. But there has been no study regarding the mechanisms of PL on the lung cancer yet. Thus, we evaluated the anti-cancer effects and possible mechanisms of PL on non-small cell lung cancer (NSCLC) cells in vivo and in vitro. Our findings showed that PL induced apoptotic cell death and suppressed the DNA binding activity of NF-κB in a concentration dependent manner (0-15 μM) in NSCLC cells. Docking model and pull down assay showed that PL directly binds to the DNA binding site of nuclear factor-κB (NF-κB) p50 subunit, and surface plasmon resonance (SPR) analysis showed that PL binds to p50 concentration-dependently. Moreover, co-treatment of PL with NF-κB inhibitor phenylarsine oxide (0.1 μM) or p50 siRNA (100 nM) augmented PL-induced inhibitory effect on cell growth and activation of Fas and DR4. Notably, co-treatment of PL with p50 mutant plasmid (C62S) partially abolished PL-induced cell growth inhibition and decreased the enhanced expression of Fas and DR4. In xenograft mice model, PL (2.5-5 mg/kg) suppressed tumor growth of NSCLC dose-dependently. Therefore, these results indicated that PL could inhibit lung cancer cell growth via inhibition of NF-κB signaling pathway in vitro and in vivo.
- Published
- 2016
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16. Anti-cancer effect of bee venom on colon cancer cell growth by activation of death receptors and inhibition of nuclear factor kappa B.
- Author
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Zheng J, Lee HL, Ham YW, Song HS, Song MJ, and Hong JT
- Subjects
- Animals, Apoptosis Regulatory Proteins metabolism, Cell Proliferation drug effects, Cell Survival drug effects, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Dose-Response Relationship, Drug, HCT116 Cells, Humans, Mice, Inbred BALB C, Mice, Nude, NF-kappa B p50 Subunit genetics, NF-kappa B p50 Subunit metabolism, RNA Interference, Receptors, TNF-Related Apoptosis-Inducing Ligand metabolism, Signal Transduction drug effects, Time Factors, Transfection, Tumor Burden drug effects, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Apoptosis drug effects, Bee Venoms pharmacology, Colonic Neoplasms drug therapy, NF-kappa B p50 Subunit antagonists & inhibitors, Receptors, TNF-Related Apoptosis-Inducing Ligand agonists
- Abstract
Bee venom (BV) has been used as a traditional medicine to treat arthritis, rheumatism, back pain, cancerous tumors, and skin diseases. However, the effects of BV on the colon cancer and their action mechanisms have not been reported yet. We used cell viability assay and soft agar colony formation assay for testing cell viability, electro mobility shift assay for detecting DNA binding activity of nuclear factor kappa B (NF-κB) and Western blotting assay for detection of apoptosis regulatory proteins. We found that BV inhibited growth of colon cancer cells through induction of apoptosis. We also found that the expression of death receptor (DR) 4, DR5, p53, p21, Bax, cleaved caspase-3, cleaved caspase-8, and cleaved caspase-9 was increased by BV treatment in a dose dependent manner (0-5 μg/ml). Consistent with cancer cell growth inhibition, the DNA binding activity of nuclear factor kappa B (NF-κB) was also inhibited by BV treatment. Besides, we found that BV blocked NF-κB activation by directly binding to NF-κB p50 subunit. Moreover, combination treatment with BV and p50 siRNA or NF-κB inhibitor augmented BV-induced cell growth inhibition. However, p50 mutant plasmid (C62S) transfection partially abolished BV-induced cell growth inhibiton. In addition, BV significantly suppressed tumor growth in vivo. Therefore, these results suggested that BV could inhibit colon cancer cell growth, and these anti-proliferative effects may be related to the induction of apoptosis by activation of DR4 and DR5 and inhibition of NF-κB.
- Published
- 2015
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17. (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol inhibits growth of colon tumors in mice.
- Author
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Zheng J, Park MH, Son DJ, Choi MG, Choi JS, Nam KT, Kim HD, Rodriguez K, Gann B, Ham YW, Han SB, and Hong JT
- Subjects
- Allyl Compounds metabolism, Animals, Antineoplastic Agents metabolism, Antineoplastic Combined Chemotherapy Protocols pharmacology, Apoptosis drug effects, Arsenicals pharmacology, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Cyclic S-Oxides pharmacology, Dose-Response Relationship, Drug, HCT116 Cells, Humans, Male, Mice, Inbred BALB C, Mice, Nude, Molecular Docking Simulation, NF-kappa B p50 Subunit antagonists & inhibitors, NF-kappa B p50 Subunit genetics, NF-kappa B p50 Subunit metabolism, Phenols metabolism, Protein Binding, RNA Interference, Receptors, Tumor Necrosis Factor, Member 25 metabolism, STAT3 Transcription Factor antagonists & inhibitors, STAT3 Transcription Factor genetics, STAT3 Transcription Factor metabolism, Signal Transduction drug effects, Time Factors, Transfection, Tumor Burden drug effects, Xenograft Model Antitumor Assays, fas Receptor metabolism, Allyl Compounds pharmacology, Antineoplastic Agents pharmacology, Cell Proliferation drug effects, Colonic Neoplasms drug therapy, Phenols pharmacology
- Abstract
In our previous study, we found that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal showed anti-cancer effect, but it showed lack of stability and drug likeness. We have prepared several (E)-2,4-bis(p-hydroxyphenyl)-2-butenal analogues by Heck reaction. We selected two compounds which showed significant inhibitory effect of colon cancer cell growth. Thus, we evaluated the anti-cancer effects and possible mechanisms of one compound (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol in vitro and in vivo. In this study, we found that (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol induced apoptotic cell death in a dose dependent manner (0-15 μg/ml) through activation of Fas and death receptor (DR) 3 in HCT116 and SW480 colon cancer cell lines. Moreover, the combination treatment with (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol and nuclear factor κB (NF-κB) inhibitor, phenylarsine oxide (0.1 μM) or signal transducer and activator of transcription 3 (STAT3) inhibitor, Stattic (50 μM) increased the expression of Fas and DR3 more significantly. In addition, (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol suppressed the DNA binding activity of both STAT3 and NF-κB. Knock down of STAT3 or NF-κB p50 subunit by STAT3 small interfering RNA (siRNA) or p50 siRNA magnified (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol-induced inhibitory effect on colon cancer cell growth. Besides, the expression of Fas and DR3 was increased in STAT3 siRNA or p50 siRNA transfected cells. Moreover, docking model and pull-down assay showed that (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol directly bound to STAT3 and NF-κB p50 subunit. Furthermore, (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol inhibited colon tumor growth in a dose dependent manner (2.5 mg/kg-5 mg/kg) in mice. Therefore, these findings indicated that (E)-4-(3-(3,5-dimethoxyphenyl)allyl)-2-methoxyphenol may be a promising anti-cancer agent for colon cancer with more advanced research.
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- 2015
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18. Anti-cancer effect of snake venom toxin through down regulation of AP-1 mediated PRDX6 expression.
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Lee HL, Park MH, Son DJ, Song HS, Kim JH, Ko SC, Song MJ, Lee WH, Yoon JH, Ham YW, Han SB, and Hong JT
- Subjects
- Animals, Apoptosis drug effects, Cell Line, Tumor, Down-Regulation drug effects, Humans, Lung Neoplasms genetics, Lung Neoplasms metabolism, Lung Neoplasms pathology, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Molecular Docking Simulation, Peroxiredoxin VI genetics, Peroxiredoxin VI metabolism, Snake Venoms chemistry, Transcription Factor AP-1 genetics, Transfection, Xenograft Model Antitumor Assays, Lung Neoplasms drug therapy, Peroxiredoxin VI antagonists & inhibitors, Peroxiredoxin VI biosynthesis, Snake Venoms pharmacology, Transcription Factor AP-1 metabolism
- Abstract
Snake venom toxin (SVT) from Vipera lebetina turanica contains a mixture of different enzymes and proteins. Peroxiredoxin 6 (PRDX6) is known to be a stimulator of lung cancer cell growth. PRDX6 is a member of peroxidases, and has calcium-independent phospholipase A2 (iPLA2) activities. PRDX6 has an AP-1 binding site in its promoter region of the gene. Since AP-1 is implicated in tumor growth and PRDX6 expression, in the present study, we investigated whether SVT inhibits PRDX6, thereby preventing human lung cancer cell growth (A549 and NCI-H460) through inactivation of AP-1. A docking model study and pull down assay showed that SVT completely fits on the basic leucine zipper (bZIP) region of c-Fos of AP-1. SVT (0-10 μg/ml) inhibited lung cancer cell growth in a concentration dependent manner through induction of apoptotic cell death accompanied by induction of cleaved caspase-3, -8, -9, Bax, p21 and p53, but decreased cIAP and Bcl2 expression via inactivation of AP-1. In an xenograft in vivo model, SVT (0.5 mg/kg and 1 mg/kg) also inhibited tumor growth accompanied with the reduction of PRDX6 expression, but increased expression of proapoptotic proteins. These data indicate that SVT inhibits tumor growth via inhibition of PRDX6 activity through interaction with its transcription factor AP-1.
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- 2015
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19. Enhanced cell growth inhibition by thiacremonone in paclitaxel-treated lung cancer cells.
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Ban JO, Hwang CJ, Park MH, Hwang IK, Jeong HS, Lee HP, Hyun BK, Kim JY, Youn HS, Ham YW, Yoon DY, Han SB, Song MJ, and Hong JT
- Subjects
- Apoptosis drug effects, Caspase 8 biosynthesis, Cell Cycle drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Drug Synergism, G2 Phase Cell Cycle Checkpoints drug effects, Humans, NF-kappa B antagonists & inhibitors, NF-kappa B p50 Subunit metabolism, Neoplastic Stem Cells drug effects, Poly(ADP-ribose) Polymerases biosynthesis, Antineoplastic Agents pharmacology, Growth Inhibitors pharmacology, Lung Neoplasms drug therapy, Lung Neoplasms pathology, Paclitaxel pharmacology, Thiophenes pharmacology
- Abstract
Activation of nuclear factor kappa-B (NF-κB) is implicated in drug resistant of lung cancer cells. Our previous data showed that thiacremonone inhibited activation of NF-κB. In the present study, we investigated whether thiacremonone enhanced susceptibility of lung cancer cells to a common anti-cancer drug paclitaxel by further inhibition of NF-κB. Thus, we used the threefold lower doses of IC50 values (50 μg/ml thiacremonone and 2.5 nM paclitaxel). We found that combination treatment with thiacremonone and paclitaxel was more susceptible (combination index; 0.40 in NCI-H460 cells and 0.46 in A549 cells) in cell growth inhibition of two types of lung cancer cell lines compared to a single agent treatment. Consistent with the combination effect on cancer cell growth inhibition, the combination treatment further induced apoptotic cell death and arrested the cancer cells in G2/M phase accompanied with a much lower expression of cdc2 and cyclin B1, and inhibited colony formation. Much more inactivation of NF-κB and greater expression of NF-κB target apoptosis regulated genes such as caspase-8 and PARPs were found by the combination treatment. Molecular model and pull down assay as well as MALDI-TOF analysis demonstrated that thiacremonone directly binds to p50. These data indicated that thiacremonone leads to increased apoptotic cell death in lung cancer cell lines through greater inhibition of NF-κB by the combination treatment with paclitaxel.
- Published
- 2015
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20. Anticancer effect of tectochrysin in colon cancer cell via suppression of NF-kappaB activity and enhancement of death receptor expression.
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Park MH, Hong JE, Park ES, Yoon HS, Seo DW, Hyun BK, Han SB, Ham YW, Hwang BY, and Hong JT
- Subjects
- Animals, Antineoplastic Agents chemistry, Apoptosis drug effects, Apoptosis Regulatory Proteins metabolism, Caspase 3 metabolism, Cell Proliferation drug effects, Drug Resistance, Neoplasm drug effects, Flavonoids chemistry, HCT116 Cells, Humans, Male, Mice, Inbred BALB C, Mice, Nude, RNA, Small Interfering metabolism, TNF-Related Apoptosis-Inducing Ligand pharmacology, Xenograft Model Antitumor Assays, fas Receptor metabolism, Antineoplastic Agents pharmacology, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Flavonoids pharmacology, NF-kappa B metabolism, Receptors, Death Domain metabolism
- Abstract
Background: Flavonoids are a diverse family of natural phenolic compounds commonly found in fruits and vegetables. Epidemiologic studies showed that flavonoids also reduce the risk of colon cancer. Tectochrysin is one of the major flavonoids of Alpinia oxyphylla Miquel. However, the anti-cancer effects and the molecular mechanisms of tectochrysin in colon cancer cells have not yet been reported. We investigated whether tectochrysin could inhibit colon cancer cell growth at 1, 5, 10 μg/ml. In in vivo study, we injected a tectochrysin treatment dose of 5 mg/kg to each mouse., Results: Tectochrysin suppressed the growth of SW480 and HCT116 human colon cancer cells. The expression of DR3, DR4 and Fas were significantly increased, and pro-apoptotic proteins were also increased. Tectochrysin treatment also inhibited activity of NF-κB. A docking model indicated that tectochrysin binds directly to the p50 unit. In in vivo, tumor weights and volumes in mice were reduced when treated with tectochrysin. Tectochrysin leads to apoptotic cell death in colon cancer cells through activation of death receptors expression via the inhibition of NF-κB., Conclusions: Tectochrysin can be a useful agent for the treatment of colon cancer cell growth as well as an adjuvant agent for chemo-resistant cancer cells growth.
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- 2015
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21. Bee venom ameliorates lipopolysaccharide-induced memory loss by preventing NF-kappaB pathway.
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Gu SM, Park MH, Hwang CJ, Song HS, Lee US, Han SB, Oh KW, Ham YW, Song MJ, Son DJ, and Hong JT
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- Amyloid beta-Peptides metabolism, Animals, Astrocytes drug effects, Astrocytes metabolism, Behavior, Animal drug effects, Behavior, Animal physiology, Cyclooxygenase 2 metabolism, Glial Fibrillary Acidic Protein, In Vitro Techniques, Inflammation chemically induced, Inflammation physiopathology, Inflammation prevention & control, Lipopolysaccharides pharmacology, Male, Maze Learning drug effects, Maze Learning physiology, Memory Disorders physiopathology, Mice, Mice, Inbred ICR, Microglia drug effects, Microglia metabolism, Models, Animal, NF-kappa B drug effects, Nerve Tissue Proteins metabolism, Nitric Oxide Synthase Type II metabolism, Signal Transduction physiology, Bee Venoms pharmacology, Bee Venoms therapeutic use, Lipopolysaccharides adverse effects, Memory Disorders chemically induced, Memory Disorders prevention & control, NF-kappa B antagonists & inhibitors, Signal Transduction drug effects
- Abstract
Background: Accumulation of beta-amyloid and neuroinflammation trigger Alzheimer's disease. We previously found that lipopolysaccharide (LPS) caused neuroinflammation with concomitant accumulation of beta-amyloid peptides leading to memory loss. A variety of anti-inflammatory compounds inhibiting nuclear factor kappaB (NF-κB) activation have showed efficacy to hinder neuroinflammation and amyloidogenesis. We also found that bee venom (BV) inhibits NF-κB., Methods: A mouse model of LPS-induced memory loss used administration of BV (0.8 and 1.6 μg/kg/day, i.p.) to ICR mice for 7 days before injection of LPS (2.5 mg/kg/day, i.p.). Memory loss was assessed using a Morris water maze test and passive avoidance test. For in vitro study, we treated BV (0.5, 1, and 2 μg/mL) to astrocytes and microglial BV-2 cells with LPS (1 μg/mL)., Results: We found that BV inhibited LPS-induced memory loss determined by behavioral tests as well as cell death. BV also inhibited LPS-induced increases in the level of beta-amyloid (Aβ), β-and γ-secretases activities, NF-κB and its DNA-binding activity and expression of APP, and BACE1 and neuroinflammation proteins (COX-2, iNOS, GFAP and IBA-1) in the brain and cultured cells. In addition, pull-down assay and molecular modeling showed that BV binds to NF-κB., Conclusions: BV attenuates LPS-induced amyloidogenesis, neuroinflammation, and therefore memory loss via inhibiting NF-κB signaling pathway. Thus, BV could be useful for treatment of Alzheimer's disease.
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- 2015
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22. Anti-cancer effect of tectochrysin in NSCLC cells through overexpression of death receptor and inactivation of STAT3.
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Oh SB, Hwang CJ, Song SY, Jung YY, Yun HM, Sok CH, Sung HC, Yi JM, Park DH, Ham YW, Han SB, Hwang BY, and Hong JT
- Subjects
- Antineoplastic Agents, Phytogenic metabolism, Apoptosis drug effects, Binding Sites, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung pathology, Cell Line, Tumor, Cell Proliferation drug effects, DNA metabolism, Dose-Response Relationship, Drug, Flavonoids metabolism, Humans, Lung Neoplasms genetics, Lung Neoplasms pathology, Molecular Docking Simulation, Phosphorylation, RNA Interference, Receptors, Tumor Necrosis Factor, Member 25 genetics, Receptors, Tumor Necrosis Factor, Member 25 metabolism, Signal Transduction drug effects, Time Factors, Transfection, Up-Regulation, fas Receptor genetics, fas Receptor metabolism, Antineoplastic Agents, Phytogenic pharmacology, Carcinoma, Non-Small-Cell Lung metabolism, Flavonoids pharmacology, Lung Neoplasms metabolism, Receptors, Tumor Necrosis Factor, Member 25 drug effects, STAT3 Transcription Factor metabolism
- Abstract
Phenolic compounds (flavonoids and phenolic acid derivatives) are the most important pharmacologically active ingredients, and these compounds could inhibit proliferation of human cancer cells by inducing of apoptotic cell death. Here we focused on the anticancer effects of tectochrysin on human non-small-cell lung cancer (NSCLC) cells and its mechanism of action. We analysed the activity of tectochrysin on NSCLC cells (A549 and NCI-H460) by use of Western blot analysis for major apoptotic proteins and death receptor expression. We also used EMSA for effects on STAT3 DNA binding activity. Tectochrysin (0-80 μM) suppressed the growth of A549 and NCI-H460 lung cancer cells by inducing of apoptotic cell death in a concentration dependent manner. Expression of DR3 and Fas as well as DR downstream pro-apoptotic proteins including cleaved caspase-3, cleaved caspase-8, cleaved caspase-9 and Bax were concomitantly increased, but the expression of anti-apoptotic proteins; Bcl-2 was decreased in both cancer cells. In addition, tectochrysin treatment also inhibited phosphorylation of STAT3 in A549 and NCI-H460 cells. However, deletion of DR3 and Fas by small interfering RNA significantly reversed tectochrysin-induced cell growth inhibitory effect as well as down regulation of STAT3 in A549 and NCI-H460 lung cancer cells. Pull down assay and docking model showed interaction of tectochrysin with STAT3. We propose that tectochrysin leads to apoptotic cell death in NSCLC cells through activation of DR3 and Fas expression via inhibition of STAT3 phosphorylation., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
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23. Inhibitory effect of ent-Sauchinone on amyloidogenesis via inhibition of STAT3-mediated NF-κB activation in cultured astrocytes and microglial BV-2 cells.
- Author
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Song SY, Jung YY, Hwang CJ, Lee HP, Sok CH, Kim JH, Lee SM, Seo HO, Hyun BK, Choi DY, Han SB, Ham YW, Hwang BY, and Hong JT
- Subjects
- Animals, Animals, Newborn, Cell Survival drug effects, Cells, Cultured, Cyclooxygenase 2 metabolism, Electrophoretic Mobility Shift Assay, Glial Fibrillary Acidic Protein metabolism, Lipopolysaccharides pharmacology, Microglia drug effects, Nitric Oxide metabolism, Nitric Oxide Synthase Type II metabolism, Rats, Rats, Sprague-Dawley, Reactive Oxygen Species metabolism, STAT3 Transcription Factor genetics, Signal Transduction drug effects, Amyloid beta-Peptides metabolism, Astrocytes drug effects, Benzopyrans pharmacology, Dioxoles pharmacology, NF-kappa B metabolism, Peptide Fragments metabolism, STAT3 Transcription Factor metabolism
- Abstract
Background: ent-Sauchinone is a polyphenolic compound found in plants belonging to the lignan family. ent-Sauchinone has been shown to modulate the expression of inflammatory factors through the nuclear factor-kappa B (NF-κB) signaling pathway. It is well known that neuroinflammation is associated with amyloidogenesis. Thus, in the present study, we investigated whether ent-Sauchinone could have anti-amyloidogenic effects through the inhibition of NF-κB pathways via its anti-inflammatory property., Methods: To investigate the potential effect of ent-Sauchinone on anti-neuroinflammation and anti-amyloidogenesis in in vitro studies, we used microglial BV-2 cells and cultured astrocytes treated with ent-Sauchinone (1, 5, and 10 μM) for 24 hours. For the detection of anti-neuro-inflammatory responses, reative oxygen species (ROS) and Nitric oxide (NO) generation and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were measured with assay kits and western blotting. β-secretase and β-secretase activities and β-amyloid levels were determined for measuring the anti-amyloidogenic effects of ent-Sauchinone by enzyme assay kits. NF-κB and STAT3 signals were detected with electromobility shift assay (EMSA) to study the related signaling pathways. The binding of ent-Sauchinone to STAT3 was evaluated by a pull-down assay and by a docking model using Autodock VINA software (Hoover's Inc., Texas, United states)., Results: ent-Sauchinone (1, 5, and 10 μM) effectively decreased lipopolysaccharide (LPS)-(1 μg/ml) induced inflammatory responses through the reduction of ROS and NO generations and iNOS and COX-2 expressions in cultured astrocytes and microglial BV-2 cells. ent-Sauchinone also inhibited LPS-induced amyloidogenesis through the inhibition of β-secretase and β-secretase activity. NF- κB amyloid and STAT3, critical transcriptional factors regulating not only inflammation but also amyloidogenesis, were also inhibited in a concentration dependent manner by ent-Sauchinone by blocking the phosphorylation of I κB and STAT3 in cultured astrocytes and microglial BV-2 cells. The docking model approach showed that ent-Sauchinone binds to STAT3, and the employment of a STAT3 inhibitor and siRNA reversed ent-Sauchinone-induced inhibition NF-κB activation and Aβ generation., Conclusions: These results indicated that ent-Sauchinone inhibited neuroinflammation and amyloidogenesis through the inhibition of STAT3-mediated NF-κB activity, and thus could be applied in the treatment of neuro-inflammatory diseases, including Alzheimer's disease.
- Published
- 2014
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24. Anti-arthritis effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal are mediated by inhibition of the STAT3 pathway.
- Author
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Ban JO, Kim DH, Lee HP, Hwang CJ, Shim JH, Kim DJ, Kim TM, Jeong HS, Nah SS, Chen H, Dong Z, Ham YW, Kim Y, Han SB, and Hong JT
- Subjects
- Adult, Aged, Aldehydes therapeutic use, Animals, Anti-Inflammatory Agents therapeutic use, Arthritis, Experimental drug therapy, Arthritis, Experimental pathology, Cell Line, Cell Survival drug effects, Cells, Cultured, Cyclooxygenase 2 metabolism, Cytokines genetics, Dinoprostone metabolism, Female, Foot Joints pathology, Humans, I-kappa B Kinase metabolism, Lipopolysaccharides, Male, Mice, Mice, Inbred DBA, Middle Aged, NF-kappa B metabolism, Nitric Oxide metabolism, Nitric Oxide Synthase Type II metabolism, Phenols therapeutic use, RNA, Messenger metabolism, Reactive Oxygen Species metabolism, STAT3 Transcription Factor metabolism, Signal Transduction drug effects, Synovial Membrane cytology, Aldehydes pharmacology, Anti-Inflammatory Agents pharmacology, Arthritis, Experimental metabolism, Phenols pharmacology, STAT3 Transcription Factor antagonists & inhibitors
- Abstract
Background and Purpose: Products of Maillard reactions between aminoacids and reducing sugars are known to have anti-inflammatory properties. Here we have assessed the anti-arthritis effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal and its possible mechanisms of action., Experimental Approach: We used cultures of LPS-activated macrophages (RAW264.7 cells) and human synoviocytes from patients with rheumatoid arthritis for in vitro assays and the collagen-induced arthritis model in mice. NO generation, iNOS and COX2 expression, and NF-κB/IKK and STAT3 activities were measured in vitro and in joint tissues of arthritic mice, along with clinical scores and histopathological assessments. Binding of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal to STAT3 was evaluated by a pull-down assay and its binding site was predicted using molecular docking studies with Autodock VINA., Key Results: (E)-2,4-bis(p-hydroxyphenyl)-2-butenal (2.5-10 μg·mL(-1) ) inhibited LPS-inducedNO generation, iNOS and COX2 expression, and NF-κB/IKK and STAT3 activities in macrophage and human synoviocytes. This compound also suppressedcollagen-induced arthritic responses in mice by inhibiting expression of iNOS and COX2, and NF-κB/IKK and STAT3 activities; it also reduced bone destruction and fibrosis in joint tissues. A pull-down assay showed that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal interfered with binding of ATP to STAT3. Docking studies suggested that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal bound to the DNA-binding interface of STAT3 possibly inhibiting ATP binding to STAT3 in an allosteric manner., Conclusions and Implications: (E)-2,4-bis(p-hydroxyphenyl)-2-butenal exerted anti-inflammatory and anti-arthritic effects through inhibition of the NF-κB/STAT3 pathway by direct binding to STAT3. This compound could be a useful agent for the treatment of arthritic disease., (© 2014 The British Pharmacological Society.)
- Published
- 2014
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25. Inhibitory effect of a 2,4-bis(4-hydroxyphenyl)-2-butenal diacetate on neuro-inflammatory reactions via inhibition of STAT1 and STAT3 activation in cultured astrocytes and microglial BV-2 cells.
- Author
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Kim JA, Yun HM, Jin P, Lee HP, Han JY, Udumula V, Moon DC, Han SB, Oh KW, Ham YW, Jung HS, Song HS, and Hong JT
- Subjects
- Amyloid beta-Peptides metabolism, Animals, Astrocytes physiology, Cell Survival drug effects, Cell Survival physiology, Cells, Cultured, Cerebral Cortex drug effects, Cerebral Cortex immunology, Cyclooxygenase 2 metabolism, I-kappa B Kinase metabolism, Lipopolysaccharides toxicity, Microglia physiology, NF-kappa B metabolism, Nitric Oxide metabolism, Nitric Oxide Synthase Type II metabolism, Peptide Fragments metabolism, Rats, Reactive Oxygen Species metabolism, STAT1 Transcription Factor antagonists & inhibitors, STAT3 Transcription Factor antagonists & inhibitors, Acetates pharmacology, Aldehydes pharmacology, Anti-Inflammatory Agents pharmacology, Astrocytes drug effects, Microglia drug effects, STAT1 Transcription Factor metabolism, STAT3 Transcription Factor metabolism
- Abstract
2,4-Bis(p-hydroxyphenyl)-2-butenal (Butenal), a tyrosine-fructose Maillard reaction product has been demonstrated as an effective compound for prevention of neuroinflammatory diseases. However, this compound was vulnerable to environmental factors. Our research has been continuously made to improve druggability of Butenal and identified 2,4-bis(4-hydroxyphenyl)but-2-enal diacetate (HPBD) as an alternative. Herein, to investigate potential anti-neuroinflammatory and anti-amyloidogenic effects of HPBD, we treated HPBD (0.5, 1, and 2 μg/ml) on the lipopolysaccharides (LPS) (1 μg/ml) stimulated astrocytes and microglial BV-2 cell. HPBD inhibited LPS-induced NO and ROS production, and LPS-elevated expression of iNOS, COX2, β-site APP-cleaving enzyme 1 (BACE1), C99, and Aβ1-42 levels as well as attenuation of β-secretase activities. The activation of nuclear factor-kappaB (NF-κB), signal transducer and activator of transcription1 (STAT1), and STAT3 was concomitantly inhibited by HPBD. Moreover, siRNA targeting STAT3 abolished HPBD-induced inhibitory effects on neuro-inflammation and amyloidogenesis. In addition, pull down assay and docking model showed interaction of HPBD with STAT3. These findings suggest that HPBD may be useful and potentially therapeutic choices for the treatment of neuroinflammatory diseases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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26. (E)-2,4-Bis(p-hydroxyphenyl)-2-butenal inhibits tumor growth via suppression of NF-κB and induction of death receptor 6.
- Author
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Ban JO, Jung YS, Kim DH, Park KR, Yun HM, Lee NJ, Lee HP, Shim JH, Jeong HS, Lee YH, Ham YW, Han SB, and Hong JT
- Subjects
- Aldehydes chemistry, Animals, Apoptosis drug effects, Cell Line, Tumor, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colonic Neoplasms physiopathology, Down-Regulation drug effects, Humans, I-kappa B Kinase chemistry, I-kappa B Kinase genetics, I-kappa B Kinase metabolism, Male, Mice, Inbred BALB C, Molecular Docking Simulation, NF-kappa B genetics, Phenols chemistry, Protein Structure, Tertiary, Receptors, Tumor Necrosis Factor genetics, Aldehydes administration & dosage, Cell Proliferation drug effects, Colonic Neoplasms drug therapy, NF-kappa B metabolism, Phenols administration & dosage, Receptors, Tumor Necrosis Factor metabolism
- Abstract
The Maillard reaction products are known to be effective in chemoprevention. Here, we focused on the anti-cancer effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal on in vitro and in vivo colon cancer. We analysed the anti-cancer activity of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal on colon cancer cells by using cell cycle and apoptosis analysis. To elucidate it's mechanism, NF-κB DNA binding activity, docking model as well as pull-down assay. Further, a xenograft model of colon cancer was studied to test the in vivo effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal. (E)-2,4-Bis(p-hydroxyphenyl)-2-butenal inhibited colon cancer cells (SW620 and HCT116) growth followed by induction of apoptosis in a concentration-dependent manner via down-regulation of NF-κB activity. In docking model as well as pull-down assay, (E)-2,4-bis(p-hydroxyphenyl)-2-butenal directly binds to three amino acid residues of IKKβ, thereby inhibited IKKβ activity in addition to induction of death receptor 6 (DR6) as well as their target apoptotic genes. Finally, (E)-2,4-bis(p-hydroxyphenyl)-2-butenal suppressed anchorage-independent cancer cell growth, and tumor growth in xenograft model accompanied with apoptosis through inhibition of IKKβ/NF-κB activity, and overexpression of DR6. These results suggest that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal inhibits colon cancer cell growth through inhibition of IKKβ/NF-κB activity and induction of DR6 expression.
- Published
- 2014
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27. Investigation of antibacterial mode of action for traditional and amphiphilic aminoglycosides.
- Author
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Udumula V, Ham YW, Fosso MY, Chan KY, Rai R, Zhang J, Li J, and Chang CW
- Subjects
- Aminoglycosides metabolism, Aminoglycosides pharmacology, Anti-Bacterial Agents metabolism, Anti-Bacterial Agents pharmacology, Escherichia coli drug effects, Fluorescent Dyes chemistry, Microbial Sensitivity Tests, Neomycin chemistry, Neomycin metabolism, Neomycin pharmacology, Protein Binding, RNA, Ribosomal chemistry, RNA, Ribosomal metabolism, Staphylococcus aureus drug effects, Aminoglycosides chemistry, Anti-Bacterial Agents chemistry, Neomycin analogs & derivatives
- Abstract
Aminoglycoside represents a class of versatile and broad spectrum antibacterial agents. In an effort to revive the antibacterial activity against aminoglycoside resistant bacteria, our laboratory has developed two new classes of aminoglycoside, pyranmycin and amphiphilic neomycin (NEOF004). The former resembles the traditional aminoglycoside, neomycin. The latter, albeit derived from neomycin, appears to exert antibacterial action via a different mode of action. In order to discern that these aminoglycoside derivatives have distinct antibacterial mode of action, RNA-binding affinity and fluorogenic dye were employed. These studies, together with our previous investigation, confirm that pyranmycin exhibit the traditional antibacterial mode of action of aminoglycosides by binding toward the bacterial rRNA. On the other hand, the amphiphilic neomycin, NEOF004 disrupts the bacterial cell wall. In a broader perspective, it verifies that structurally modified neomycin can exert different antibacterial mode of action leading to the revival of activity against aminoglycoside resistant bacteria., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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28. Growth Inhibitory Effect of (E)-2,4-bis(p-hydroxyphenyl)-2-Butenal Diacetate through Induction of Apoptotic Cell Death by Increasing DR3 Expression in Human Lung Cancer Cells.
- Author
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Lee US, Ban JO, Yeon ET, Lee HP, Udumula V, Ham YW, and Hong JT
- Abstract
The Maillard Reaction Products (MRPs) are chemical compounds which have been known to be effective in chemoprevention. Death receptors (DR) play a central role in directing apoptosis in several cancer cells. In our previous study, we demonstrated that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal, a MRP product, inhibited human colon cancer cell growth by inducing apoptosis via nuclear factor-κB (NF-κB) inactivation and G2/M phase cell cycle arrest. In this study, (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate, a new (E)-2,4-bis(p-hydroxyphenyl)-2-butenal derivative, was synthesized to improve their solubility and stability in water and then evaluated against NCI-H460 and A549 human lung cancer cells. (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate reduced the viability in both cell lines in a time and dose-dependent manner. We also found that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate increased apoptotic cell death through the upregulation of the expression of death receptor (DR)-3 and DR6 in both lung cancer cell lines. In addition to this, the transfection of DR3 siRNA diminished the growth inhibitory and apoptosis inducing effect of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate on lung cancer cells, however these effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate was not changed by DR6 siRNA. These results indicated that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal diacetate inhibits human lung cancer cell growth via increasing apoptotic cell death by upregulation of the expression of DR3.
- Published
- 2012
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29. Effect of visual input on normalized standing stability in subjects with recurrent low back pain.
- Author
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Lee DC, Ham YW, and Sung PS
- Subjects
- Adult, Biomechanical Phenomena, Cross-Sectional Studies, Disability Evaluation, Female, Humans, Lower Extremity physiology, Male, Middle Aged, Reference Values, Time Factors, Visual Perception physiology, Young Adult, Low Back Pain physiopathology, Postural Balance physiology, Posture physiology, Proprioception physiology
- Abstract
Although a number of studies have evaluated kinematic stability changes in subjects with low back pain (LBP), the combined sensitivity of normalized standing stability from the ground force and kinematic rotational angle of the body segment were not carefully examined for postural responses. The purpose of this study was to evaluate normalized standing stability in subjects with and without recurrent LBP while they stood quietly with the tested foot parallel to the other lower extremity at hip width. The subjects were then instructed to stand freely on one leg for 25 s with the contra lateral hip flexed 90° based on dominance side (dominant leg vs. non-dominant lower extremity) and visual condition (eyes open vs. eyes closed). A total of 42 subjects (27 subjects without LBP and 15 subjects with LBP) participated in the study. The dominant leg standing stability was significantly different during the eyes closed condition (0.68±0.30 for control vs. 0.37±0.32 for LBP, T=-3.23, p=0.002) compared to the eyes open condition. The standing kinematic stability, especially of the dominant thigh, was greater in the control subjects than in the subjects with LBP (T=-2.43, p=0.02). This sensitive detection of kinematic imbalance with postural stability is important for effective rehabilitation strategies and to understanding compensatory mechanisms in subjects with recurrent LBP., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
30. Rational design of SAM analogues targeting SAM-II riboswitch aptamer.
- Author
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Ham YW, Humphreys DJ, Choi S, and Dayton DL
- Subjects
- Crystallography, X-Ray, Molecular Structure, S-Adenosylmethionine chemistry, Drug Design, S-Adenosylmethionine analogs & derivatives
- Abstract
Riboswitches are noncoding RNA elements embedded in 5'-untranslated region of many bacterial mRNAs regulating gene expression in response to essential metabolites. They are unique from other RNA targets because they have evolved to form specific structural receptors for the purpose of binding small molecular metabolites suggesting that structure-based rational drug design approach may be used in designing metabolite mimics targeting riboswitches. We have developed a fluorescence binding assay for SAM-II riboswitch aptamer and identified an S-adenosylmethionine (SAM) analogue that selectively binds to SAM-II riboswitch aptamer with comparable binding affinity to its native metabolite using structure-based design approach., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
31. Conjugate of neamine and 2-deoxystreptamine mimic connected by an amide bond.
- Author
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Udumula V, Chittapragada M, Marble JB, Dayton DL, and Ham YW
- Subjects
- Carboxylic Acids chemistry, Hexosamines chemistry, Molecular Conformation, Molecular Mimicry, RNA chemistry, Stereoisomerism, Amides chemistry, Framycetin chemistry
- Abstract
An amino-functionalized 2-deoxystreptamine (2-DOS) mimic was conjugated by an amide bond to a neamine moiety containing a carboxylic acid in ring II. A library of A-site RNA and its mutants was prepared to examine RNA binding characteristics of the additional 2-DOS moiety attached to neamine. The 2-DOS mimic conjugated to the neamine increased binding affinity up to 200-folds compared to that of neamine. The conjugate binds to native A-site RNA and its mutants with up to 6-fold difference in sequence selectivity., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
32. Kinematic analyses of trunk stability in one leg standing for individuals with recurrent low back pain.
- Author
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Ham YW, Kim DM, Baek JY, Lee DC, and Sung PS
- Subjects
- Biomechanical Phenomena, Feedback, Sensory physiology, Female, Humans, Male, Prospective Studies, Young Adult, Low Back Pain physiopathology, Postural Balance physiology, Posture physiology
- Abstract
This prospective study examined normalized stability differences based on dominance side and visual feedback. Subjects with low back pain (LBP) (n=26; 9 men, 17 women) and without LBP (n=28; 11 men, 17 women) participated in this study. All subjects were asked to maintain single leg standing balance with the contralateral hip flexed 90° for 25s. The outcome measures included normalized holding duration and stability. The combined rotation (R(xyz)) was also calculated to compare the upper and lower thorax and lumbar axes relative to the core spine axis. The holding duration was significantly different between groups (T=-2.21, p=0.03). The subjects without recurrent LBP (control group) demonstrated longer hold duration times (24.60±4.2s) than the subjects with recurrent LBP (21.2±7.1s). For the normalized hold duration, there was a significant difference between groups based on visual input (F=7.13, p=0.009). There was also a significant difference in standing stability based on visual input (F=93.93, p=0.0001) and trunk area (F=101.51, p=0.0001). In addition, the normalized stability was significantly different based on dominance and visual input (F=11.28, p=0.002). Therefore, trunk stability could prompt an uncoordinated bracing effect with poor proprioception from injury to passive structures or due to interference of pain during central processing of information in subjects with recurrent LBP., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
33. Comparing postural strategy changes following adapted versus non-adapted responses in subjects with and without spinal stenosis.
- Author
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Sung PS and Ham YW
- Subjects
- Adaptation, Physiological, Adult, Female, Humans, Low Back Pain etiology, Low Back Pain rehabilitation, Male, Middle Aged, Musculoskeletal Manipulations, Sex Factors, Spinal Stenosis complications, Spinal Stenosis rehabilitation, Low Back Pain physiopathology, Posture, Spinal Stenosis physiopathology
- Abstract
Musculoskeletal evaluation skills are needed to examine postural compensation techniques, but little is known about ground reaction forces (GRF) in standing posture. Even though a number of studies have evaluated GRF in patients with low back pain (LBP) during vertical perturbations, it would be important to consider compensation characteristics which might be associated with abnormal patterns of postural responses. The vertical excursions of the body center of mass (BCOM) were measured with delay time and normalized amplitude of GRF. Overall, there was no difference based on the vertical excursion of the BCOM (F=0.12, p=0.90), amplitude of the normalized GRF (F=0.16, p=0.74), or response time (F=1.98, p=0.17) between subjects with and without spinal stenosis. There was a gender difference based on the vertical excursion of the normalized BCOM (F=5.92, p=0.02) as well as the normalized amplitude of GRF (F=4.17, p=0.04). It was shown that male subjects implemented better adjustment strategies during adapted and non-adapted responses in order to improve body stability. In this way, manual therapists should be aware that gender differences exist in patients with spinal stenosis since the condition may change the individual's postural adjustment ability.
- Published
- 2010
- Full Text
- View/download PDF
34. Aminoglycosides: molecular insights on the recognition of RNA and aminoglycoside mimics.
- Author
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Chittapragada M, Roberts S, and Ham YW
- Abstract
RNA is increasingly recognized for its significant functions in biological systems and has recently become an important molecular target for therapeutics development. Aminoglycosides, a large class of clinically significant antibiotics, exert their biological functions by binding to prokaryotic ribosomal RNA (rRNA) and interfering with protein translation, resulting in bacterial cell death. They are also known to bind to viral mRNAs such as HIV-1 RRE and TAR. Consequently, aminoglycosides are accepted as the single most important model in understanding the principles that govern small molecule-RNA recognition, which is essential for the development of novel antibacterial, antiviral or even anti-oncogenic agents. This review outlines the chemical structures and mechanisms of molecular recognition and antibacterial activity of aminoglycosides and various aminoglycoside mimics that have recently been devised to improve biological efficacy, binding affinity and selectivity, or to circumvent bacterial resistance.
- Published
- 2009
- Full Text
- View/download PDF
35. Small-molecule dimerization inhibitors of wild-type and mutant HIV protease: a focused library approach.
- Author
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Shultz MD, Ham YW, Lee SG, Davis DA, Brown C, and Chmielewski J
- Subjects
- Binding Sites, Dimerization, Drug Resistance, Viral genetics, HIV Protease genetics, HIV Protease Inhibitors chemical synthesis, Humans, Kinetics, Models, Molecular, Mutation, Structure-Activity Relationship, HIV Protease metabolism, HIV Protease Inhibitors chemistry, HIV Protease Inhibitors pharmacology
- Abstract
We demonstrate that a focused library based on truncated, cross-linked interfacial peptides of HIV-1 protease produces effective dimerization inhibitors of the enzyme. By combining individual changes of the library into a single compound, we obtained a significantly more potent agent and found that an additive increase in inhibitor efficacy was obtained. The good activity of library members against an active-site drug-resistant protease mutant bodes well for dimerization inhibition as a complementary method to targeting the active site.
- Published
- 2004
- Full Text
- View/download PDF
36. A powerful selection assay for mixture libraries of DNA alkylating agents.
- Author
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Ham YW and Boger DL
- Subjects
- Alkylating Agents chemistry, Alkylating Agents metabolism, Alkylation drug effects, Binding, Competitive, Chromatography, High Pressure Liquid, Combinatorial Chemistry Techniques methods, DNA drug effects, Duocarmycins, Indoles chemistry, Pyrroles chemistry, Pyrroles pharmacology, Pyrrolidinones chemistry, Pyrrolidinones pharmacology, Alkylating Agents pharmacology, DNA metabolism, Indoles pharmacology
- Abstract
A simple and powerful selection assay that permits the separation (rpHPLC), quantitation (ELSD), and identification (ESI-MS) of thermally released adenine adducts derived from duocarmycin analogues is detailed that can establish the most effective DNA alkylating agents in synthetic combinatorial mixtures.
- Published
- 2004
- Full Text
- View/download PDF
37. High-resolution assessment of protein DNA binding affinity and selectivity utilizing a fluorescent intercalator displacement (FID) assay.
- Author
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Ham YW, Tse WC, and Boger DL
- Subjects
- Animals, Chemical Phenomena, Chemistry, Physical, DNA-Binding Proteins pharmacology, Ethidium, Lymphoid Enhancer-Binding Factor 1, Mice, Nucleic Acid Conformation, Protein Binding, Protein Conformation, Transcription Factors pharmacology, DNA chemistry, Fluorescent Dyes chemistry, Intercalating Agents chemistry, Proteins chemistry
- Abstract
Protein titration displacement of ethidium bromide bound to hairpin deoxyoligonucleotides containing any sequence of interest provides a well-defined titration curve (measuring the loss of fluorescence derived from the DNA bound ethidium bromide) that provides both absolute binding constants (K(a)) and stoichiometry of binding. This use of a fluorescent intercalator displacement (FID) assay for establishing protein DNA binding affinity and selectivity is demonstrated with the examination of the LEF-1 HMG domain binding to hairpin deoxyoligonucleotides containing its commonly accepted consensus sequence 5'-CTTTGWW (W=A or T) and those modified (5'-CTNTGWW) to examine sequences implicated in early studies (5'-CTNTG). The effectiveness of the FID assay coupled with its technically non-demanding experimental use makes it an attractive alternative or complement to selection screening, footprinting or affinity cleavage, and electrophoretic mobility shift assays for detecting, characterizing, and quantitating protein DNA binding affinity and selectivity.
- Published
- 2003
- Full Text
- View/download PDF
38. The design of self-replicating helical peptides.
- Author
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Issac R, Ham YW, and Chmielewski J
- Subjects
- Amino Acid Sequence genetics, Catalysis, Evolution, Molecular, Models, Molecular, Molecular Conformation, Peptide Initiation Factors, Protein Engineering, DNA-Binding Proteins, Fungal Proteins chemistry, Peptides chemical synthesis, Peptides chemistry, Protein Kinases chemistry, Saccharomyces cerevisiae Proteins
- Abstract
The self-assembly of helical peptides and information transfer through autocatalysis and cross-catalysis are the foundation of peptide-based molecular evolution models. Many fundamental properties of living systems, such as environmental sensitivity, chiroselectivity, cross-catalysis, dynamic error correction and conditional selection, are exhibited by various self-replicating peptide systems. Recently, advances have been made in the design of peptide systems with autocatalytic and cross-catalytic properties.
- Published
- 2001
- Full Text
- View/download PDF
39. Small-Molecule Inhibitors of HIV-1 Protease Dimerization Derived from Cross-Linked Interfacial Peptides This work was supported by NIH (GM52739) and NSF (9457372-CHE).
- Author
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Shultz MD, Bowman MJ, Ham YW, Zhao X, Tora G, and Chmielewski J
- Published
- 2000
- Full Text
- View/download PDF
40. Synthesis and antibacterial activities of new 1 beta-methylcarbapenems having a 1,3-diazabicyclo[3.3.0]octan-2,4-dione moiety.
- Author
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Nam KH, Oh CH, Ham YW, Lee KS, and Cho JH
- Subjects
- Microbial Sensitivity Tests, Anti-Infective Agents chemical synthesis, Anti-Infective Agents pharmacology, Carbapenems chemical synthesis, Carbapenems pharmacology
- Abstract
The synthesis of a new series of 1 beta-methylcarbapenems having a 1,3-diazabicyclo[3.3.0]octane-2,4-dione moiety is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bateria are determined and the effect of substituent on the bicyclic ring as well as stereoisomerism was investigated.
- Published
- 1997
- Full Text
- View/download PDF
41. Synthesis and antibacterial activity of new 1 beta-methyl carbapenem having a thiazolo[3,2-a]benzimidazole moiety.
- Author
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Oh CH, Ham YW, Hong SY, and Cho JH
- Subjects
- Anti-Bacterial Agents pharmacology, Benzimidazoles pharmacology, Microbial Sensitivity Tests, Anti-Bacterial Agents chemical synthesis, Bacteria drug effects, Benzimidazoles chemical synthesis
- Published
- 1995
- Full Text
- View/download PDF
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