69 results on '"Kun-yong Kim"'
Search Results
2. Regulation of the DNA Methylation Landscape in Human Somatic Cell Reprogramming by the miR-29 Family
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Eriona Hysolli, Yoshiaki Tanaka, Juan Su, Kun-Yong Kim, Tianyu Zhong, Ralf Janknecht, Xiao-Ling Zhou, Lin Geng, Caihong Qiu, Xinghua Pan, Yong-Wook Jung, Jijun Cheng, Jun Lu, Mei Zhong, Sherman M. Weissman, and In-Hyun Park
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Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Reprogramming to pluripotency after overexpression of OCT4, SOX2, KLF4, and MYC is accompanied by global genomic and epigenomic changes. Histone modification and DNA methylation states in induced pluripotent stem cells (iPSCs) have been shown to be highly similar to embryonic stem cells (ESCs). However, epigenetic differences still exist between iPSCs and ESCs. In particular, aberrant DNA methylation states found in iPSCs are a major concern when using iPSCs in a clinical setting. Thus, it is critical to find factors that regulate DNA methylation states in reprogramming. Here, we found that the miR-29 family is an important epigenetic regulator during human somatic cell reprogramming. Our global DNA methylation and hydroxymethylation analysis shows that DNA demethylation is a major event mediated by miR-29a depletion during early reprogramming, and that iPSCs derived from miR-29a depletion are epigenetically closer to ESCs. Our findings uncover an important miRNA-based approach to generate clinically robust iPSCs.
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- 2016
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3. Tgif1 Counterbalances the Activity of Core Pluripotency Factors in Mouse Embryonic Stem Cells
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Bum-Kyu Lee, Wenwen Shen, Jiwoon Lee, Catherine Rhee, Haewon Chung, Kun-Yong Kim, In-Hyun Park, and Jonghwan Kim
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Biology (General) ,QH301-705.5 - Abstract
Core pluripotency factors, such as Oct4, Sox2, and Nanog, play important roles in maintaining embryonic stem cell (ESC) identity by autoregulatory feedforward loops. Nevertheless, the mechanism that provides precise control of the levels of the ESC core factors without indefinite amplification has remained elusive. Here, we report the direct repression of core pluripotency factors by Tgif1, a previously known terminal repressor of TGFβ/activin/nodal signaling. Overexpression of Tgif1 reduces the levels of ESC core factors, whereas its depletion leads to the induction of the pluripotency factors. We confirm the existence of physical associations between Tgif1 and Oct4, Nanog, and HDAC1/2 and further show the level of Tgif1 is not significantly altered by treatment with an activator/inhibitor of the TGFβ/activin/nodal signaling. Collectively, our findings establish Tgif1 as an integral member of the core regulatory circuitry of mouse ESCs that counterbalances the levels of the core pluripotency factors in a TGFβ/activin/nodal-independent manner.
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- 2015
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4. Transcriptome Signature and Regulation in Human Somatic Cell Reprogramming
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Yoshiaki Tanaka, Eriona Hysolli, Juan Su, Yangfei Xiang, Kun-Yong Kim, Mei Zhong, Yumei Li, Kartoosh Heydari, Ghia Euskirchen, Michael P. Snyder, Xinghua Pan, Sherman Morton Weissman, and In-Hyun Park
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Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Reprogramming of somatic cells produces induced pluripotent stem cells (iPSCs) that are invaluable resources for biomedical research. Here, we extended the previous transcriptome studies by performing RNA-seq on cells defined by a combination of multiple cellular surface markers. We found that transcriptome changes during early reprogramming occur independently from the opening of closed chromatin by OCT4, SOX2, KLF4, and MYC (OSKM). Furthermore, our data identify multiple spliced forms of genes uniquely expressed at each progressive stage of reprogramming. In particular, we found a pluripotency-specific spliced form of CCNE1 that is specific to human and significantly enhances reprogramming. In addition, single nucleotide polymorphism (SNP) expression analysis reveals that monoallelic gene expression is induced in the intermediate stages of reprogramming, while biallelic expression is recovered upon completion of reprogramming. Our transcriptome data provide unique opportunities in understanding human iPSC reprogramming.
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- 2015
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5. X Chromosome of Female Cells Shows Dynamic Changes in Status during Human Somatic Cell Reprogramming
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Kun-Yong Kim, Eriona Hysolli, Yoshiaki Tanaka, Brandon Wang, Yong-Wook Jung, Xinghua Pan, Sherman Morton Weissman, and In-Hyun Park
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Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Induced pluripotent stem cells (iPSCs) acquire embryonic stem cell (ESC)-like epigenetic states, including the X chromosome. Previous studies reported that human iPSCs retain the inactive X chromosome of parental cells, or acquire two active X chromosomes through reprogramming. Most studies investigated the X chromosome states in established human iPSC clones after completion of reprogramming. Thus, it is still not fully understood when and how the X chromosome reactivation occurs during reprogramming. Here, we report a dynamic change in the X chromosome state throughout reprogramming, with an initial robust reactivation of the inactive X chromosome followed by an inactivation upon generation of nascent iPSC clones. iPSCs with two active X chromosomes or an eroded X chromosome arise in passaging iPSCs. These data provide important insights into the plasticity of the X chromosome of human female iPSCs and will be crucial for the future application of such cells in cell therapy and X-linked disease modeling.
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- 2014
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6. Ethanol upregulates NMDA receptor subunit gene expression in human embryonic stem cell-derived cortical neurons.
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Yangfei Xiang, Kun-Yong Kim, Joel Gelernter, In-Hyun Park, and Huiping Zhang
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Medicine ,Science - Abstract
Chronic alcohol consumption may result in sustained gene expression alterations in the brain, leading to alcohol abuse or dependence. Because of ethical concerns of using live human brain cells in research, this hypothesis cannot be tested directly in live human brains. In the present study, we used human embryonic stem cell (hESC)-derived cortical neurons as in vitro cellular models to investigate alcohol-induced expression changes of genes involved in alcohol metabolism (ALDH2), anti-apoptosis (BCL2 and CCND2), neurotransmission (NMDA receptor subunit genes: GRIN1, GRIN2A, GRIN2B, and GRIN2D), calcium channel activity (ITPR2), or transcriptional repression (JARID2). hESCs were differentiated into cortical neurons, which were characterized by immunostaining using antibodies against cortical neuron-specific biomarkers. Ethanol-induced gene expression changes were determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). After a 7-day ethanol (50 mM) exposure followed by a 24-hour ethanol withdrawal treatment, five of the above nine genes (including all four NMDA receptor subunit genes) were highly upregulated (GRIN1: 1.93-fold, P = 0.003; GRIN2A: 1.40-fold, P = 0.003; GRIN2B: 1.75-fold, P = 0.002; GRIN2D: 1.86-fold, P = 0.048; BCL2: 1.34-fold, P = 0.031), and the results of GRIN1, GRIN2A, and GRIN2B survived multiple comparison correction. Our findings suggest that alcohol responsive genes, particularly NMDA receptor genes, play an important role in regulating neuronal function and mediating chronic alcohol consumption-induced neuroadaptations.
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- 2015
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7. MeCP2 regulates the synaptic expression of a Dysbindin-BLOC-1 network component in mouse brain and human induced pluripotent stem cell-derived neurons.
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Jennifer Larimore, Pearl V Ryder, Kun-Yong Kim, L Alex Ambrose, Christopher Chapleau, Gaston Calfa, Christina Gross, Gary J Bassell, Lucas Pozzo-Miller, Yoland Smith, Konrad Talbot, In-Hyun Park, and Victor Faundez
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Medicine ,Science - Abstract
Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD.
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- 2013
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8. The Influence of Blood Glucose Meter Resistance Variation on the Performance of a Biosensor with a Gold-Coated Circuit Board.
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Kun-Yong Kim, Ho Chang, Win-Der Lee, Yi-Fan Cai, and You-Jia Chen
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- 2019
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9. Supplementary Table 1 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
- Abstract
Supplementary Table 1 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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10. Supplementary Figure 4 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
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Supplementary Figure 4 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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11. Supplementary Figure Legends 1-4 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
- Abstract
Supplementary Figure Legends 1-4 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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12. Supplementary Figure 3 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
- Abstract
Supplementary Figure 3 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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13. Data from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
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Low serum levels of adiponectin are a high risk factor for various types of cancer. Although adiponectin inhibits proliferation and metastasis of breast cancer cells, the underlying molecular mechanisms remain obscure. In this study, we show that adiponectin-activated AMPK reduces the invasiveness of MDA-MB-231 cells by stimulating dephosphorylation of AKT by increasing protein phosphatase 2A (PP2A) activity. Among the various regulatory B56 subunits, B56γ was directly phosphorylated by AMPK at Ser298 and Ser336, leading to an increase of PP2A activity through dephosphorylation of PP2Ac at Tyr307. We also show that both the blood levels of adiponectin and the tissue levels of PP2A activity were decreased in breast cancer patients and that the direct administration of adiponectin into tumor tissues stimulates PP2A activity. Taken together, these findings show that adiponectin, derived from adipocytes, negatively regulates the invasiveness of breast cancer cells by activating the tumor suppressor PP2A. [Cancer Res 2009;69(9):4018–26]
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- 2023
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14. Supplementary Figure 1 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
- Abstract
Supplementary Figure 1 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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15. Supplementary Figure 2 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Young Yang, Keun Il Kim, Jong-Seok Lim, Dea Ho Cho, Myeong-Sok Lee, Joon Jeong, Yeon A. Choi, Ji-Eun Hwang, Ahmi Baek, and Kun-yong Kim
- Abstract
Supplementary Figure 2 from Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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- 2023
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16. The RNA exosome nuclease complex regulates human embryonic stem cell differentiation
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Kun-Yong Kim, In-Hyun Park, Soyeong Sim, Cedric Belair, Sandra L. Wolin, and Yoshiaki Tanaka
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Regulation of gene expression ,0303 health sciences ,Exosome complex ,Cellular differentiation ,RNA ,Cell Biology ,Biology ,Exosome ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,Transcription (biology) ,Transcription factor ,030217 neurology & neurosurgery ,Exosome Multienzyme Ribonuclease Complex ,030304 developmental biology - Abstract
A defining feature of embryonic stem cells (ESCs) is the ability to differentiate into all three germ layers. Pluripotency is maintained in part by a unique transcription network that maintains expression of pluripotency-specific transcription factors and represses developmental genes. While the mechanisms that establish this transcription network are well studied, little is known of the posttranscriptional surveillance pathways that degrade differentiation-related RNAs. We report that the surveillance pathway mediated by the RNA exosome nuclease complex represses ESC differentiation. Depletion of the exosome expedites differentiation of human ESCs into all three germ layers. LINE-1 retrotransposons and specific miRNAs, lncRNAs, and mRNAs that encode developmental regulators or affect their expression are all bound by the exosome and increase in level upon exosome depletion. The exosome restrains differentiation in part by degrading transcripts encoding FOXH1, a transcription factor crucial for mesendoderm formation. Our studies establish the exosome as a regulator of human ESC differentiation and reveal the importance of RNA decay in maintaining pluripotency.
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- 2019
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17. Jetting Dispenser Height Effect on the Accuracy of Test Strip for Blood Glucose
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Ho Chang, Yi-Cheng Lee, Kun-Yong Kim, Hong-Wei Wu, and Rahn-Fang Lee
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0301 basic medicine ,Jet (fluid) ,Materials science ,medicine.diagnostic_test ,biology ,Biomedical Engineering ,02 engineering and technology ,General Medicine ,STRIPS ,021001 nanoscience & nanotechnology ,complex mixtures ,law.invention ,Test strips ,03 medical and health sciences ,030104 developmental biology ,law ,Electrode ,medicine ,biology.protein ,Glucose test ,Glucose oxidase ,Composite material ,0210 nano-technology - Abstract
This study explores the application of Jetting Dispensers to dispense droplets of glucose oxidase enzyme solution onto blood test strips of immersion gold-plated printed circuit boards. Each droplet must contain the same weight of glucose oxidase enzyme solution, and the jetting dispensing must be within the reaction area of test strip while wrapping around the golden electrodes. Experimental results show that the height at which the droplets of glucose oxidase enzyme solution are jet dispensed onto the test strip reaction area significantly affects the glucose test strip. A dispensing machine with a jet dispensing height of 1.3 mm produces droplets in the test strip area that are all the shape of arc beads. Therefore, test strips have lower standard deviation (STD) and coefficient of variation (CV) when dispensed at 1.3 mm than at heights of 1.1 and 1.5 mm. This study confirms that the optimum jet dispensing height parameter with respect to enzyme compound is 1.3 mm.
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- 2018
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18. Dysregulation of BRD4 Function Underlies the Functional Abnormalities of MeCP2 Mutant Neurons
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Sherman M. Weissman, Wanshan Wang, Bilal Cakir, Young-Jin Kang, Prabir Patra, Eriona Hysolli, Ethan M. Clement, Mei Zhong, Yangfei Xiang, Benjamin Patterson, In-Hyun Park, Yoshiaki Tanaka, Gareth J. Sullivan, Yee Sook Cho, Kun-Yong Kim, Sung Min Hwang, and Sang-Hun Lee
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Male ,congenital, hereditary, and neonatal diseases and abnormalities ,Methyl-CpG-Binding Protein 2 ,Mutant ,Human Embryonic Stem Cells ,Induced Pluripotent Stem Cells ,Rett syndrome ,Cell Cycle Proteins ,Biology ,Article ,MECP2 ,BET inhibitor ,Transcriptome ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Interneurons ,mental disorders ,medicine ,Rett Syndrome ,Animals ,Humans ,Molecular Biology ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Chromatin binding ,Brain ,Cell Biology ,Human brain ,Azepines ,Triazoles ,medicine.disease ,Phenotype ,Cell biology ,nervous system diseases ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Mutation ,Female ,030217 neurology & neurosurgery ,Transcription Factors - Abstract
Rett syndrome (RTT), mainly caused by mutations in the methyl-CpG binding protein 2 (MeCP2), is one of the most prevalent intellectual disorders without effective therapeutics. Here, we used two-dimensional and three-dimensional human brain cultures to investigate MeCP2 function. We found that MeCP2 mutations cause severe abnormalities in human interneurons (INs). Surprisingly, the treatment with a BET inhibitor, JQ1, rescued the molecular and functional phenotypes of MeCP2 mutant INs. We uncovered that abnormal increases in the chromatin binding of BRD4 and the enhancer-promoter interactions underlie the abnormal transcription in MeCP2 mutant INs, which were recovered to normal levels by JQ1. We revealed the cell type-specific transcriptome impairment in MeCP2 mutant region-specific human brain organoids, which were rescued by JQ1. Finally, JQ1 ameliorated RTT-like phenotypes in mice. These data demonstrate BRD4 dysregulation is a critical driver for RTT etiology, and suggest targeting BRD4 could be a potential therapeutic opportunity for RTT.
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- 2019
19. Generation and Fusion of Human Cortical and Medial Ganglionic Eminence Brain Organoids
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In-Hyun Park, Bilal Cakir, Kun-Yong Kim, Tanaka Yoshiaki, Benjamin Patterson, Yee Sook Cho, and Yangfei Xiang
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0301 basic medicine ,Pluripotent Stem Cells ,Brain development ,Ganglionic eminence ,Neurogenesis ,Biology ,Article ,Interneuron migration ,03 medical and health sciences ,Organ Culture Techniques ,Interneurons ,Cortex (anatomy) ,medicine ,Organoid ,Humans ,Median Eminence ,Brain ,Cell Biology ,General Medicine ,Human brain ,Embryonic stem cell ,Organoids ,Brain region ,030104 developmental biology ,medicine.anatomical_structure ,Neuroscience ,Developmental Biology - Abstract
Three-dimensional (3D) brain organoid culture has become an essential tool for investigating human brain development and modeling neurological disorders during the past few years. Given the specific regionalization during brain development, it is important to produce distinct brain organoids that reproduce different brain regions and their interaction. The authors' laboratory recently established the platform to generate brain organoids resembling the medial ganglionic eminence (MGE), a specific brain region responsible for interneurogenesis, and found when fusing with organoid resembling the cortex, the fused organoids enabled modeling of interneuron migration in the brain. This unit describes four basic protocols that have been successfully applied in the authors' laboratory, covering the generation of embryonic body (EB) with neuroectodermal fate, the production of MGE organoids (hMGEOs) and cortical organoids (hCOs), and the fusion of the two organoids.
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- 2019
20. Engineering of human brain organoids with a functional vascular-like system
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Mei Zhong, Pingnan Sun, Yangfei Xiang, Bilal Cakir, Sang-Hun Lee, Kun-Yong Kim, Fahmeed Hyder, Benjamin Patterson, Yifan Yuan, Young Sup Yoon, Jake Dengelegi, Young-Jin Kang, Laura E. Niklason, Sangho Lee, Mehmet H. Kural, Micha Sam Brickman Raredon, Prabir Patra, Yoshiaki Tanaka, Kayley Chapeton, Chang-Shun He, In-Hyun Park, and Maxime Parent
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Endothelium ,Human Embryonic Stem Cells ,Blood–brain barrier ,Biochemistry ,Article ,03 medical and health sciences ,Mice ,Single-cell analysis ,In vivo ,medicine ,Organoid ,Animals ,Humans ,Molecular Biology ,Cells, Cultured ,030304 developmental biology ,0303 health sciences ,Tight junction ,Tissue Engineering ,Chemistry ,Brain ,Cell Biology ,Human brain ,Embryonic stem cell ,Cell biology ,Organoids ,medicine.anatomical_structure ,Blood-Brain Barrier ,Single-Cell Analysis ,Biotechnology ,Transcription Factors - Abstract
Human cortical organoids (hCOs), derived from human embryonic stem cells (hESCs), provide an excellent platform to study human brain development and diseases in complex 3D tissue. However, current hCOs lack microvasculature, resulting in limited oxygen and nutrient delivery to the inner-most parts of hCOs. Here, we engineered hESCs to ectopically express human ETS variant 2 (hETV2) to create in vitro vasculature in hCOs, namely vhCOs (vascularized hCOs). hETV2-expressing cells in hCOs contributed to forming a complex vascular-like network in hCOs. Importantly, the presence of vascularization resulted in enhanced functional maturation of organoids. We found that vhCOs acquired several blood-brain barrier (BBB) characteristics, including an increase in the expression of tight junctions, nutrient transporters, and trans-endothelial electrical resistance. Finally, hETV2-induced endothelium supported the formation of perfused blood vessels in vivo. These vhCOs form vasculature that resemble the early prenatal brain, and present a robust model to study brain disease in vitro.
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- 2018
21. The Influence of Needle Assembly Sliding of the Jetting Dispenser on the Characteristics of Blood Glucose Test Strip
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Win-Der Lee, Ho Chang, Yi-Fan Cai, You-Jia Chen, and Kun-Yong Kim
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Blood glucose test strip ,Jet (fluid) ,Materials science ,medicine.diagnostic_test ,biology ,Nozzle ,engineering.material ,Coating ,Grease ,Electrode ,engineering ,medicine ,biology.protein ,Glucose test ,Glucose oxidase ,Composite material - Abstract
This study investigates the application of the jet dispensing technique for the dispensing of glucose oxidase (GOD) on blood glucose test strips. In this study, the experimental results indicated that the working principle of the jet dispensing valve is based on the collision of the sliding needle assembly with the seat, causing glucose oxidase (GOD) droplets to eject from the nozzle. During the process, the sliding of the needle assembly will have certain amount of friction, leading to a minute change in the weight of GOD droplets. Such small variation in the weight of GOD droplets will in turn affect the accuracy of blood glucose test strip readings. Special grease which varies in weight was coated on the surface of the needle assembly for dispensing investigation. The results showed that coating the needle assembly with 0.02g of grease will make the ejected GOD on the test strip reaction zone form an arch-shaped droplet, completely covering the electrode on the test strip reaction zone and allowing the test strip to have lower standard deviation (STD) as well as coefficient of variation (CV). It has been evidenced in this study that applying a small amount of grease on the surface of the needle assembly can improve the accuracy of blood glucose test strip.
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- 2018
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22. Effect of filling pressure in jetting dispenser on the performance of blood glucose test strips using immersion gold-plated printed circuit board
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Kun-Yong Kim, Jen-Fang Lee, Yi-Cheng Lee, Win-Der Lee, Ho Chang, and Fu-Chuan Lin
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Blood Glucose ,0209 industrial biotechnology ,Materials science ,Electrical Equipment and Supplies ,02 engineering and technology ,STRIPS ,law.invention ,Printed circuit board ,020901 industrial engineering & automation ,law ,Immersion ,medicine ,Immersion (virtual reality) ,Pressure ,Glucose test ,Glucose oxidase ,Composite material ,Reagent Strips ,medicine.diagnostic_test ,biology ,Mechanical Engineering ,General Medicine ,021001 nanoscience & nanotechnology ,Electrode ,biology.protein ,Printing ,Gold ,0210 nano-technology ,Blood Chemical Analysis - Abstract
To ensure accurate glucose readings when dispensing glucose oxidase enzyme solution from a jetting dispenser onto glucose test strips fabricated from an immersion gold-plated printed circuit board, every drop of the enzyme solution needs to have nearly the same weight and to be dispensed on the reaction zone of the test strips. Experimental results in this study show that the filling pressure in the fluid reservoir containing the glucose enzyme solution to dispense onto the test strips significantly affect the glucose test results. A filling pressure of 12 psi produces test strips with lower coefficient of variation and standard deviation than 10 and 14 psi. Proper filling pressure for dispensing glucose enzyme onto glucose test strips needs to be determined for any enzyme compound formulation.
- Published
- 2018
23. X Chromosome of Female Cells Shows Dynamic Changes in Status during Human Somatic Cell Reprogramming
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Yoshiaki Tanaka, In-Hyun Park, Brandon J. Wang, Sherman M. Weissman, Xinghua Pan, Kun-Yong Kim, Eriona Hysolli, and Yong Wook Jung
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Somatic cell ,Induced Pluripotent Stem Cells ,Future application ,Biology ,Biochemistry ,Polymorphism, Single Nucleotide ,Article ,Genetics ,Humans ,Epigenetics ,10. No inequality ,Induced pluripotent stem cell ,lcsh:QH301-705.5 ,X chromosome ,Cells, Cultured ,Chromosomes, Human, X ,lcsh:R5-920 ,Cell Biology ,Cellular Reprogramming ,Embryonic stem cell ,lcsh:Biology (General) ,XIST ,Female ,lcsh:Medicine (General) ,Reprogramming ,Developmental Biology - Abstract
Summary Induced pluripotent stem cells (iPSCs) acquire embryonic stem cell (ESC)-like epigenetic states, including the X chromosome. Previous studies reported that human iPSCs retain the inactive X chromosome of parental cells, or acquire two active X chromosomes through reprogramming. Most studies investigated the X chromosome states in established human iPSC clones after completion of reprogramming. Thus, it is still not fully understood when and how the X chromosome reactivation occurs during reprogramming. Here, we report a dynamic change in the X chromosome state throughout reprogramming, with an initial robust reactivation of the inactive X chromosome followed by an inactivation upon generation of nascent iPSC clones. iPSCs with two active X chromosomes or an eroded X chromosome arise in passaging iPSCs. These data provide important insights into the plasticity of the X chromosome of human female iPSCs and will be crucial for the future application of such cells in cell therapy and X-linked disease modeling., Graphical Abstract, Highlights • The X chromosome state changes dynamically during human somatic cell reprogramming • Ectopic reprogramming factors transiently activate the inactive X chromosome • Nascent iPSC colonies carry an inactive X chromosome • Class I and class III iPSCs arise from nascent iPSCs, Determining the X chromosome state in human iPSCs is crucial for modeling X-linked diseases. Park and colleagues trace the X chromosome state in reprogramming and show that reprogramming reactivates the inactive X chromosome in female cells. Activated X chromosomes are randomly inactivated in nascent iPSCs. In early passaging, iPSC clones arise that contain two active X chromosomes or an eroded X chromosome.
- Published
- 2014
24. hESC-Derived Thalamic Organoids Form Reciprocal Projections When Fused with Cortical Organoids
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Xinran Liu, Yangfei Xiang, Prabir Patra, Pingnan Sun, Mei Zhong, Bilal Cakir, Benjamin Patterson, Young-Jin Kang, Sang-Hun Lee, Yoshiaki Tanaka, Sherman M. Weissman, Kun-Yong Kim, and In-Hyun Park
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Human Embryonic Stem Cells ,Thalamus ,Biology ,Models, Biological ,Article ,03 medical and health sciences ,0302 clinical medicine ,Cortex (anatomy) ,Genetics ,medicine ,Organoid ,Humans ,030304 developmental biology ,Cerebral Cortex ,0303 health sciences ,Cerebrum ,Cell Biology ,Human brain ,Embryonic stem cell ,Organoids ,medicine.anatomical_structure ,Forebrain ,Molecular Medicine ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Human brain organoid techniques have rapidly advanced to facilitate investigating human brain development and diseases. These efforts have largely focused on generating telencephalon due to its direct relevance in a variety of forebrain disorders. Despite its importance as a relay hub between cortex and peripheral tissues, the investigation of three-dimensional (3D) organoid models for the human thalamus has not yet been explored. Here, we describe a method to differentiate human embryonic stem cells (hESCs) to thalamic organoids (hThOs) that specifically recapitulate the development of thalamus. Single-cell RNA sequencing revealed a formation of distinct thalamic lineages, which diverge from telencephalic fate. Importantly, we developed a 3D system to create the reciprocal projections between thalamus and cortex by fusing the two distinct region-specific organoids representing the developing thalamus or cortex. Our study provides a platform for understanding human thalamic development and modeling circuit organizations and related disorders in the brain.
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- 2019
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25. Dnmt1 regulates the myogenic lineage specification of muscle stem cells
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Renjing Liu, Kun-Yong Kim, In-Hyun Park, and Yong Wook Jung
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0301 basic medicine ,DNA (Cytosine-5-)-Methyltransferase 1 ,Inhibitor of Differentiation Protein 1 ,Biology ,Muscle Development ,environment and public health ,Article ,Myoblasts ,03 medical and health sciences ,Mice ,Conditional gene knockout ,Myocyte ,Animals ,Cell Lineage ,Epigenetics ,Muscle, Skeletal ,Regulation of gene expression ,Multidisciplinary ,Myogenesis ,urogenital system ,Stem Cells ,Transdifferentiation ,Gene Expression Regulation, Developmental ,Cell Differentiation ,DNA Methylation ,Molecular biology ,Cell biology ,Benzomorphans ,030104 developmental biology ,DNA methylation ,embryonic structures ,DNMT1 - Abstract
DNA methylation is an important epigenetic mark that regulates gene expression. Dnmt1 plays an important role in maintaining DNA methylation patterns on daughter DNA strands. Studies have shed light into the functional role of Dnmt1 regulation in the hematopoietic and epidermal systems. Here we show that Dnmt1 is required for myogenesis. Loss of Dnmt1 results in reduced expression of myogenic genes and defects in myogenic differentiation. We have utilized a conditional knockout mouse approach to examine the functional consequences of Dnmt1 depletion specifically in the developing muscle. These mice were born runted, with smaller body weights, and reduced ability to form myotubes in vitro. We show that expression of Id-1, a negative regulator of myogenesis, is enhanced in Dnmt1-deficient cultures, leading to enhanced transdifferentiation of myoblasts toward the osteogenic lineage. Thus, these studies demonstrate that Dnmt1 influences cellular identity and determines lineage fidelity.
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- 2016
26. Cellular reprogramming: a novel tool for investigating autism spectrum disorders
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In-Hyun Park, Yong Wook Jung, Kun-Yong Kim, Gareth J. Sullivan, and Leeyup Chung
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medicine.medical_specialty ,Induced Pluripotent Stem Cells ,Timothy syndrome ,Rett syndrome ,Biology ,medicine.disease ,Models, Biological ,behavioral disciplines and activities ,Article ,Fragile X syndrome ,Neurodevelopmental disorder ,Child Development Disorders, Pervasive ,Autism spectrum disorder ,Child, Preschool ,mental disorders ,medicine ,Animals ,Humans ,Molecular Medicine ,Autism ,Psychiatry ,Induced pluripotent stem cell ,Molecular Biology ,Reprogramming ,Neuroscience - Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in reciprocal social interaction and communication, as well as the manifestation of stereotyped behaviors. Despite much effort, ASDs are not yet fully understood. Advanced genetics and genomics technologies have recently identified novel ASD genes, and approaches using genetically engineered murine models or postmortem human brain have facilitated understanding ASD. Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) provides unprecedented opportunities in generating human disease models. Here, we present an overview of applying iPSCs in developing cellular models for understanding ASD. We also discuss future perspectives in the use of iPSCs as a source of cell therapy and as a screening platform for identifying small molecules with efficacy for alleviating ASD.
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- 2012
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27. Human induced pluripotent stem cells and neurodegenerative disease
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Eriona Hysolli, Kun-Yong Kim, Yong Wook Jung, In-Hyun Park, and Yoshiaki Tanaka
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Pluripotent Stem Cells ,Extramural ,business.industry ,Cellular differentiation ,Cell Differentiation ,Neurodegenerative Diseases ,Disease ,Article ,Cell therapy ,Kruppel-Like Factor 4 ,Neurology ,Humans ,Medicine ,Neurology (clinical) ,Human Induced Pluripotent Stem Cells ,business ,Induced pluripotent stem cell ,Neuroscience ,Cell Proliferation ,Stem Cell Transplantation - Abstract
The lack of effective treatments for various neurodegenerative disorders has placed huge burdens on society. We review the current status in applying induced pluripotent stem cell (iPSC) technology for the cellular therapy, drug screening, and in-vitro modeling of neurodegenerative diseases.iPSCs are generated from somatic cells by overexpressing four reprogramming factors (Oct4, Sox2, Klf4, and Myc). Like human embryonic stem cells, iPSCs have features of self-renewal and pluripotency, and allow in-vitro disease modeling, drug screening, and cell replacement therapy. Disease-specific iPSCs were derived from patients of several neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and spinal muscular atrophy. Neurons differentiated from these iPSCs recapitulated the in-vivo phenotypes, providing platforms for drug screening. In the case of Parkinson's disease, iPSC-derived dopaminergic neurons gave positive therapeutic effect on a rodent Parkinson's disease model as a proof of principle in using iPSCs as sources of cell replacement therapy. Beyond iPSC technology, much effort is being made to generate neurons directly from dermal fibroblasts with neuron-specific transcription factors, which does not require making iPSCs as an intermediate cell type.We summarize recent progress in using iPSCs for modeling the progress and treatment of neurodegenerative diseases and provide evidence for future perspectives in this field.
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- 2012
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28. Neuronal maturation defect in induced pluripotent stem cells from patients with Rett syndrome
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Eriona Hysolli, In-Hyun Park, and Kun-Yong Kim
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Adult ,congenital, hereditary, and neonatal diseases and abnormalities ,Methyl-CpG-Binding Protein 2 ,Induced Pluripotent Stem Cells ,Molecular Sequence Data ,Rett syndrome ,Biology ,X-inactivation ,MECP2 ,Kruppel-Like Factor 4 ,X Chromosome Inactivation ,Genetic model ,Rett Syndrome ,medicine ,Humans ,Amino Acid Sequence ,Child ,Induced pluripotent stem cell ,Embryonic Stem Cells ,X chromosome ,Neurons ,Chromosomes, Human, X ,Multidisciplinary ,Base Sequence ,Cell Differentiation ,Biological Sciences ,Fibroblasts ,medicine.disease ,Molecular biology ,Embryonic stem cell ,Cell biology ,Gene Expression Regulation ,Child, Preschool ,Female ,Reprogramming ,Biomarkers - Abstract
Rett syndrome (RTT) is one of the most prevalent female neurodevelopmental disorders that cause severe mental retardation. Mutations in methyl CpG binding protein 2 (MeCP2) are mainly responsible for RTT. Patients with classical RTT exhibit normal development until age 6–18 mo, at which point they become symptomatic and display loss of language and motor skills, purposeful hand movements, and normal head growth. Murine genetic models and postmortem human brains have been used to study the disease and enable the molecular dissection of RTT. In this work, we applied a recently developed reprogramming approach to generate a novel in vitro human RTT model. Induced pluripotent stem cells (iPSCs) were derived from RTT fibroblasts by overexpressing the reprogramming factors OCT4, SOX2, KLF4, and MYC. Intriguingly, whereas some iPSCs maintained X chromosome inactivation, in others the X chromosome was reactivated. Thus, iPSCs were isolated that retained a single active X chromosome expressing either mutant or WT MeCP2, as well as iPSCs with reactivated X chromosomes expressing both mutant and WT MeCP2. When these cells underwent neuronal differentiation, the mutant monoallelic or biallelelic RTT-iPSCs displayed a defect in neuronal maturation consistent with RTT phenotypes. Our in vitro model of RTT is an important tool allowing the further investigation of the pathophysiology of RTT and the development of the curative therapeutics.
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- 2011
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29. A Novel PPARγ Agonist, SP1818, Shows Different Coactivator Profile with Rosiglitazone
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Yun Sun Park, Jiwon Choi, Young Yang, Sukjoon Yoon, Jong-Seok Lim, and Kun-yong Kim
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Pharmacology ,chemistry.chemical_classification ,medicine.medical_specialty ,Peroxisome proliferator-activated receptor ,Biochemistry ,Transactivation ,Endocrinology ,Nuclear receptor ,chemistry ,Adipogenesis ,Internal medicine ,Drug Discovery ,Coactivator ,medicine ,Molecular Medicine ,Scavenger receptor ,Receptor ,Rosiglitazone ,medicine.drug - Abstract
- Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor that is used as a target for anti-diabetic drug development. In a search for novel PPARγ agonists, the β-carboxyethyl-rhodanine derivative SP1818 was identified. We report here the characteristics of SP1818 as a selective PPARγ agonist. In transactivation assays, SP1818 selectively activated PPARγ, but the degree of PPARγ stimulation was less than with 1 μM rosiglitazone. SP1818 also stimulated glucose uptake in a concentration-dependent manner. The adipocyte differentiation markers adiponectin, scavenger receptor CD36 and aP2 were weakly induced by treatment with SP1818, and TRAP220 subunit was specifically recruited into PPARγ activated by rosiglitazone but not PPARγ activated by SP1818.Keywords: Adipogenesis, Diabetes, Rosiglitazone INTRODUCTION The peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptor superfamily of ligand-acti-vated transcription factors (Lehmann
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- 2010
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30. Adiponectin-Activated AMPK Stimulates Dephosphorylation of AKT through Protein Phosphatase 2A Activation
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Yeon A. Choi, Keun Il Kim, Joon Jeong, Jong-Seok Lim, Ahmi Baek, Young Yang, Myeong Sok Lee, Ji Eun Hwang, Dea Ho Cho, and Kun-yong Kim
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Cancer Research ,medicine.medical_specialty ,Breast Neoplasms ,Metastasis ,Dephosphorylation ,Mice ,AMP-Activated Protein Kinase Kinases ,Cell Line, Tumor ,Internal medicine ,medicine ,Animals ,Humans ,Protein Phosphatase 2 ,Neoplasm Metastasis ,Phosphorylation ,Protein kinase B ,Mice, Inbred BALB C ,Adiponectin ,Chemistry ,Cell Membrane ,Cancer ,AMPK ,Protein phosphatase 2 ,medicine.disease ,Enzyme Activation ,Isoenzymes ,Endocrinology ,Oncology ,Female ,Protein Kinases ,Proto-Oncogene Proteins c-akt - Abstract
Low serum levels of adiponectin are a high risk factor for various types of cancer. Although adiponectin inhibits proliferation and metastasis of breast cancer cells, the underlying molecular mechanisms remain obscure. In this study, we show that adiponectin-activated AMPK reduces the invasiveness of MDA-MB-231 cells by stimulating dephosphorylation of AKT by increasing protein phosphatase 2A (PP2A) activity. Among the various regulatory B56 subunits, B56γ was directly phosphorylated by AMPK at Ser298 and Ser336, leading to an increase of PP2A activity through dephosphorylation of PP2Ac at Tyr307. We also show that both the blood levels of adiponectin and the tissue levels of PP2A activity were decreased in breast cancer patients and that the direct administration of adiponectin into tumor tissues stimulates PP2A activity. Taken together, these findings show that adiponectin, derived from adipocytes, negatively regulates the invasiveness of breast cancer cells by activating the tumor suppressor PP2A. [Cancer Res 2009;69(9):4018–26]
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- 2009
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31. Adipocyte culture medium stimulates production of macrophage inhibitory cytokine 1 in MDA-MB-231 cells
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Jong-Seok Lim, Su Hee Lee, Keun Il Kim, Jung Hyeong Lee, Eun-Yi Moon, Kwang Kyu Kim, Kun-yong Kim, Jae Hyeong Kim, Ji-Eun Hwang, Jae-Ha Ryu, Hee Gu Lee, Young Yang, and Jun Ho Jeon
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MAPK/ERK pathway ,Cancer Research ,medicine.medical_specialty ,Growth Differentiation Factor 15 ,Ductal cells ,medicine.medical_treatment ,Blotting, Western ,Palmitates ,Adipose tissue ,Breast Neoplasms ,Biology ,p38 Mitogen-Activated Protein Kinases ,Mice ,chemistry.chemical_compound ,Immune system ,Cell Movement ,Internal medicine ,Adipocyte ,Gene expression ,Adipocytes ,medicine ,Animals ,Humans ,Neoplasm Invasiveness ,RNA, Messenger ,Extracellular Signal-Regulated MAP Kinases ,Cells, Cultured ,Wound Healing ,Reverse Transcriptase Polymerase Chain Reaction ,JNK Mitogen-Activated Protein Kinases ,NF-kappa B ,Cancer ,Microarray Analysis ,medicine.disease ,Culture Media ,Cell biology ,Cytokine ,Endocrinology ,Oncology ,chemistry ,NIH 3T3 Cells ,Cytokines - Abstract
Obesity is one of the potential risk factors in causing breast cancer. As a result, adipose tissue surrounding breast ductal cells may play an important role in the breast cancer development or progression. To identify the genes that are regulated by factors secreted from adipocytes in breast cancer cells, MDA-MB-231 cells were treated with the culture medium of adipocytes. Most of induced genes were related to immune function and wound healing, which share a common gene expression signature with cancer progression. In present study macrophage inhibitory cytokine 1 (MIC-1) gene was studied among the induced genes. It was found that both MIC-1 mRNA and protein were dramatically increased by the culture medium of adipocytes. Furthermore, proteinase K-treated adipocyte culture supernatants also induced MIC-1 expression. These findings indicate that proteins are not major MIC-1 inducing factors in adipocyte culture medium. Consequently, we examined the effect of free fatty acids such as palmitate and oleate on MIC-1 induction and found that palmitate markedly induced MIC-1 gene expression, whereas oleate did not. Adipocyte culture medium- and palmitate-induced MIC-1 gene expression was mediated by the activation of p38 MAPK, but not by the activation of JNK, ERK, and NF-kappaB pathway. In addition, adipocyte-CM-induced MIC-1 also increased invasiveness of MDA-MB-231 cells.
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- 2008
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32. A novel adipokine CTRP1 stimulates aldosterone production
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Jun Ho Jeon, Seung Hyun Han, Jong-Wan Kim, Hyungin Cho, Keun Il Kim, Jong-Seok Lim, Ahmi Baek, Eunjoon Kim, Young Ho Lee, Do-Hee Kim, Young Yang, Kun-yong Kim, Soo Hyun Kim, Do Young Yoon, Jae Hyeong Kim, and Goo Taeg Oh
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Male ,Aldosterone synthase ,Receptors, Steroid ,medicine.medical_specialty ,Receptors, Cytoplasmic and Nuclear ,Stimulation ,Biology ,Biochemistry ,Losartan ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Adipokines ,Internal medicine ,Nuclear Receptor Subfamily 4, Group A, Member 2 ,Renin–angiotensin system ,Nuclear Receptor Subfamily 4, Group A, Member 1 ,Tumor Cells, Cultured ,Genetics ,medicine ,Animals ,Cytochrome P-450 CYP11B2 ,Humans ,RNA, Messenger ,Aldosterone ,Molecular Biology ,Adrenal cortex ,Angiotensin II ,Proteins ,Rats ,DNA-Binding Proteins ,Adrenal Cortical Cell ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Zona glomerulosa ,Hypertension ,biology.protein ,Calcium ,Transcription Factors ,Biotechnology - Abstract
Complement-C1q TNF-related protein 1 (CTRP1), a member of the CTRP superfamily, is expressed at high levels in adipose tissues of obese Zucker diabetic fatty (fa/fa) rats, and CTRP1 expression is induced by proinflammatory cytokines, including TNF-alpha and IL-1beta. In the present study, we investigated stimulation of aldosterone production by CTRP1, since it was observed that CTRP1 was specifically expressed in the zona glomerulosa of the adrenal cortex, where aldosterone is produced. Increased aldosterone production by CTRP1 in cells of the human adrenal cortical cell line H295R was dose-dependent. Expression levels of aldosterone synthase CYP11B2 were examined to investigate the molecular mechanisms by which CTRP1 enhances the production of aldosterone. The expression of CYP11B2 was greatly increased by treatment with CTRP1, as was the expression of the transcription factors NGFIB and NURR1, which play critical roles in stimulation of CYP11B2 gene expression. It was also revealed that angiotensin II-induced aldosterone production is, at least in part, mediated by the stimulation of CTRP1 secretion, not by the increase of CTRP1 mRNA transcription. In addition, the levels of CTRP1 were significantly up-regulated in hypertensive patients' serum. As CTRP1 was highly expressed in obese subjects as well as up-regulated in hypertensive patients, CTRP1 may be a newly identified molecular link between obesity and hypertension.
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- 2008
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33. Regulation of the DNA Methylation Landscape in Human Somatic Cell Reprogramming by the miR-29 Family
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Mei Zhong, Juan Su, Kun-Yong Kim, Tianyu Zhong, Xiao Ling Zhou, In-Hyun Park, Sherman M. Weissman, Ralf Janknecht, Jijun Cheng, Yoshiaki Tanaka, Jun Lu, Yong Wook Jung, Caihong Qiu, Xinghua Pan, Eriona Hysolli, and Lin Geng
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0301 basic medicine ,Human Embryonic Stem Cells ,Induced Pluripotent Stem Cells ,Biology ,Biochemistry ,Article ,Epigenesis, Genetic ,03 medical and health sciences ,Kruppel-Like Factor 4 ,Genetics ,Humans ,Epigenetics ,Induced pluripotent stem cell ,lcsh:QH301-705.5 ,Epigenomics ,lcsh:R5-920 ,Cell Biology ,DNA Methylation ,Cellular Reprogramming ,Cell biology ,MicroRNAs ,030104 developmental biology ,DNA demethylation ,Histone ,lcsh:Biology (General) ,KLF4 ,DNA methylation ,embryonic structures ,biology.protein ,lcsh:Medicine (General) ,Reprogramming ,Developmental Biology - Abstract
Summary Reprogramming to pluripotency after overexpression of OCT4, SOX2, KLF4, and MYC is accompanied by global genomic and epigenomic changes. Histone modification and DNA methylation states in induced pluripotent stem cells (iPSCs) have been shown to be highly similar to embryonic stem cells (ESCs). However, epigenetic differences still exist between iPSCs and ESCs. In particular, aberrant DNA methylation states found in iPSCs are a major concern when using iPSCs in a clinical setting. Thus, it is critical to find factors that regulate DNA methylation states in reprogramming. Here, we found that the miR-29 family is an important epigenetic regulator during human somatic cell reprogramming. Our global DNA methylation and hydroxymethylation analysis shows that DNA demethylation is a major event mediated by miR-29a depletion during early reprogramming, and that iPSCs derived from miR-29a depletion are epigenetically closer to ESCs. Our findings uncover an important miRNA-based approach to generate clinically robust iPSCs., Graphical Abstract, Highlights • Depletion of the miR-29a family improves reprogramming efficiency • DNA demethylation is a major change induced by miR-29a depletion • Methylation at the CpG island shore is highly regulated by the miR-29a family • iPSC derived by depletion of the miR-29a family is epigenetically close to ESCs, In this article, Park and colleagues provide robust DNA methylome change induced by change in expression of the miR-29a family. In somatic cells, miR-29a depletion highly induced DNA demethylation and improved reprogramming efficiency. iPSC derived in the presence of miR-29a depletion acquire an epigenetic state close to ESCs. The data provide an important approach to improve the quality of iPSCs.
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- 2015
34. Ethanol upregulates NMDA receptor subunit gene expression in human embryonic stem cell-derived cortical neurons
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Joel Gelernter, In-Hyun Park, Yangfei Xiang, Huiping Zhang, and Kun-Yong Kim
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Transcriptional Activation ,Alcohol Drinking ,Cellular differentiation ,Human Embryonic Stem Cells ,lcsh:Medicine ,Synaptic Transmission ,03 medical and health sciences ,0302 clinical medicine ,Gene expression ,Humans ,lcsh:Science ,030304 developmental biology ,Regulation of gene expression ,Cerebral Cortex ,Neurons ,0303 health sciences ,Multidisciplinary ,biology ,Ethanol ,lcsh:R ,GRIN1 ,Cell Differentiation ,Molecular biology ,3. Good health ,Gene Expression Regulation ,biology.protein ,NMDA receptor ,GRIN2A ,lcsh:Q ,GRIN2B ,Signal transduction ,030217 neurology & neurosurgery ,Signal Transduction ,Research Article - Abstract
Chronic alcohol consumption may result in sustained gene expression alterations in the brain, leading to alcohol abuse or dependence. Because of ethical concerns of using live human brain cells in research, this hypothesis cannot be tested directly in live human brains. In the present study, we used human embryonic stem cell (hESC)-derived cortical neurons as in vitro cellular models to investigate alcohol-induced expression changes of genes involved in alcohol metabolism (ALDH2), anti-apoptosis (BCL2 and CCND2), neurotransmission (NMDA receptor subunit genes: GRIN1, GRIN2A, GRIN2B, and GRIN2D), calcium channel activity (ITPR2), or transcriptional repression (JARID2). hESCs were differentiated into cortical neurons, which were characterized by immunostaining using antibodies against cortical neuron-specific biomarkers. Ethanol-induced gene expression changes were determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). After a 7-day ethanol (50 mM) exposure followed by a 24-hour ethanol withdrawal treatment, five of the above nine genes (including all four NMDA receptor subunit genes) were highly upregulated (GRIN1: 1.93-fold, P = 0.003; GRIN2A: 1.40-fold, P = 0.003; GRIN2B: 1.75-fold, P = 0.002; GRIN2D: 1.86-fold, P = 0.048; BCL2: 1.34-fold, P = 0.031), and the results of GRIN1, GRIN2A, and GRIN2B survived multiple comparison correction. Our findings suggest that alcohol responsive genes, particularly NMDA receptor genes, play an important role in regulating neuronal function and mediating chronic alcohol consumption-induced neuroadaptations.
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- 2015
35. Tumor necrosis factor-α and interleukin-1β increases CTRP1 expression in adipose tissue
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Young Yang, Sukjoon Yoon, Chul-Ho Lee, Young Ho Lee, Do Young Yoon, Do-Hyung Kim, Kun-yong Kim, Hwa Young Kim, Jae Hyeong Kim, Keun Il Kim, Myeong Sok Lee, Jong-Seok Lim, Dae Ho Cho, and Seung Hyun Han
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Lipopolysaccharides ,Male ,medicine.medical_specialty ,DNA, Complementary ,Molecular Sequence Data ,Biophysics ,Adipokine ,Adipose tissue ,CTRP ,White adipose tissue ,Biology ,Biochemistry ,Proinflammatory cytokine ,Rats, Sprague-Dawley ,Mice ,Adipokines ,Structural Biology ,Internal medicine ,Gene expression ,Genetics ,medicine ,Animals ,Humans ,Amino Acid Sequence ,Obesity ,RNA, Messenger ,Cloning, Molecular ,Molecular Biology ,Proinflammatory cytokines ,Regulation of gene expression ,Tumor Necrosis Factor-alpha ,Gene Expression Profiling ,Proteins ,Interleukin ,Cell Differentiation ,Cell Biology ,Rats ,Rats, Zucker ,Endocrinology ,Adipose Tissue ,Gene Expression Regulation ,Tumor necrosis factor alpha ,Sequence Alignment ,Interleukin-1 - Abstract
CTRP1, a member of the CTRP superfamily, consists of an N-terminal signal peptide sequence followed by a variable region, a collagen repeat domain, and a C-terminal globular domain. CTRP1 is expressed at high levels in adipose tissues of LPS-stimulated Sprague-Dawley rats. The LPS-induced increase in CTRP1 gene expression was found to be mediated by TNF-α and IL-1β. Also, a high level of expression of CTRP1 mRNA was observed in adipose tissues of Zucker diabetic fatty (fa/fa) rats, compared to Sprague-Dawley rats in the absence of LPS stimulation. These findings indicate that CTRP1 expression may be associated with a low-grade chronic inflammation status in adipose tissues.
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- 2006
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36. Adiponectin Is a Negative Regulator of NK Cell Cytotoxicity
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Eunjoon Kim, Jeong Hyung Lee, Do Young Yoon, Jae Kwang Kim, Jin Woong Chung, Jong-Seok Lim, Keun Il Kim, Dae Ho Cho, Inpyo Choi, Young Yang, Kun-yong Kim, Suk Ran Yoon, Myeong Sok Lee, and Seung Hyun Han
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Cytotoxicity, Immunologic ,medicine.medical_specialty ,Immunology ,Down-Regulation ,Biology ,Lymphocyte Activation ,Fas ligand ,Interferon-gamma ,Mice ,Interleukin 21 ,Internal medicine ,medicine ,Animals ,Humans ,Immunology and Allergy ,Cytotoxic T cell ,Phosphorylation ,Cytotoxicity ,Protein kinase A ,Cells, Cultured ,Innate immune system ,Adiponectin ,NF-kappa B ,NFKB1 ,Recombinant Proteins ,Killer Cells, Natural ,Mice, Inbred C57BL ,Endocrinology ,Cancer research ,Interleukin-2 ,Female ,I-kappa B Proteins ,Inflammation Mediators - Abstract
NK cells are a key component of innate immune systems, and their activity is regulated by cytokines and hormones. Adiponectin, which is secreted from white adipose tissues, plays important roles in various diseases, including hypertension, cardiovascular diseases, inflammatory disorders, and cancer. In this study the effect of adiponectin on NK cell activity was investigated. Adiponectin was found to suppress the IL-2-enhanced cytotoxic activity of NK cells without affecting basal NK cell cytotoxicity and to inhibit IL-2-induced NF-κB activation via activation of the AMP-activated protein kinase, indicating that it suppresses IL-2-enhanced NK cell cytotoxicity through the AMP-activated protein kinase-mediated inhibition of NF-κB activation. IFN-γ enhances NK cell cytotoxicity by causing an increase in the levels of expression of TRAIL and Fas ligand. The production of IFN-γ, one of the NF-κB target genes in NK cells, was also found to be suppressed by adiponectin, accompanied by the subsequent down-regulation of IFN-γ-inducible TRAIL and Fas ligand expression. These results clearly demonstrate that adiponectin is a potent negative regulator of IL-2-induced NK cell activation and thus may act as an in vivo regulator of anti-inflammatory functions.
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- 2006
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37. Heat shock factor regulates VDUP1 gene expression
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Jae Kwang Kim, Kun-yong Kim, Sun Mi Shin, Inpyo Choi, Young Yang, and Sang Gi Paik
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Time Factors ,Transcription, Genetic ,Ultraviolet Rays ,Blotting, Western ,Molecular Sequence Data ,Biophysics ,Biology ,Transfection ,Biochemistry ,Culture Media, Serum-Free ,Cell Line ,HSPA1B ,HSPA4 ,Thioredoxins ,Heat Shock Transcription Factors ,Heat shock protein ,Humans ,RNA, Messenger ,Luciferases ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,HSPA14 ,HSPA12A ,Base Sequence ,Dose-Response Relationship, Drug ,Reverse Transcriptase Polymerase Chain Reaction ,Cell Cycle ,Promoter ,Cell Biology ,Blotting, Northern ,Molecular biology ,Up-Regulation ,DNA-Binding Proteins ,Heat shock factor ,Gene Expression Regulation ,Carrier Proteins ,Reactive Oxygen Species ,Gene Deletion ,Plasmids ,Protein Binding ,Transcription Factors - Abstract
The vitamin D3 up-regulated protein 1 (VDUP1) is identified as interacting protein with thioredoxin (TRX) and functions as a natural antagonist of TRX. Its expression is regulated by various stresses including ROS, UV, and heat shock. In the present study, we observed an inducible expression of VDUP1 in Bosc cells by high density and serum deprivation cultures. To determine transcription factors associated with the induction of VDUP1 by stresses, the promoter region of VDUP1 was cloned. Through reporter assays with plasmids having various deletion of its promoter region and analysis of putative cis-elements, heat shock factor element (HSE) was identified. The deletion of HSE abolished transcriptional activity of VDUP1 promoter by stresses and the binding of heat shock factor (HSF) to HSE was confirmed by gel-shift and supershift assays using nuclear extracts prepared from stressed Bosc cells. Also, the enforced expression of HSF or heat shock increased the transcription of endogenous VDUP1. These imply that HSF is an important transcription factor involved in up-regulation of VDUP1 expression by stresses such as high density and serum deprivation cultures.
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- 2004
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38. Dexamethasone reverses TGF-β-mediated inhibition of primary rat preadipocyte differentiation
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In Pyo Choi, Jae Kwang Kim, Suk Ran Yoon, Sun Mi Shin, Young Yang, and Kun-yong Kim
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Male ,medicine.medical_specialty ,Cellular differentiation ,Biophysics ,Context (language use) ,Peroxisome proliferator-activated receptor γ ,Biochemistry ,Dexamethasone ,Cell Line ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Transforming Growth Factor beta ,Structural Biology ,Internal medicine ,Adipocyte ,Enhancer binding ,Adipocytes ,CCAAT-Enhancer-Binding Protein-alpha ,Genetics ,medicine ,Animals ,Rat preadipocyte ,Receptor ,Molecular Biology ,Cells, Cultured ,Stem Cells ,Transforming growth factor-β ,Cell Differentiation ,Cell Biology ,Rats ,Endocrinology ,CCAAT/enhancer binding protein-α ,chemistry ,Peroxisome proliferator-activated receptor alpha ,Cell Division ,medicine.drug ,Transforming growth factor - Abstract
Dexamethasone and transforming growth factor-beta (TGF-beta) show contrary effects on differentiation of adipocytes. Dexamethasone stimulates adipocyte differentiation whereas TGF-beta inhibits it. In the present study, we investigated whether dexamethasone could reverse the TGF-beta-mediated inhibition of preadipocyte differentiation. Primary rat preadipocytes, obtained from Sprague-Dawley rats, were pretreated with dexamethasone in the presence or absence of TGF-beta, prior to the induction of differentiation. Co-treatment of dexamethasone and TGF-beta before inducing differentiation reversed the TGF-beta-mediated inhibition of preadipocyte differentiation. In order to elucidate the mechanism by which dexamethasone reversed the effect of TGF-beta on the inhibition of preadipocyte differentiation, the expression of CCAAT/enhancer binding protein-alpha (C/EBPalpha) and peroxisome proliferator-activated receptor gamma (PPARgamma) was examined. Dexamethasone increased C/EBPalpha and PPARgamma expression in the absence of TGF-beta and also recovered the TGF-beta-mediated suppression of C/EBPalpha expression in preadipocytes. Its effect was sustained in differentiated adipocytes as well. However, those effects were not observed in 3T3-L1 preadipocytes or differentiated adipocytes. These results indicate that dexamethasone reverses the TGF-beta-mediated suppression of adipocyte differentiation by regulating the expression of C/EBPalpha and PPARgamma, which is dependent on the cellular context.
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- 2003
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39. Interleukin-12 p40 Gene Expression Is Induced in Lipopolysaccharide-Activated Pituitary Glands in vivo
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Kun-yong Kim, Inpyo Choi, Hyun Kim, Sun Mi Shin, Kwang Ho Pyun, Seung Hyun Han, Changmee Kim, and Young Yang
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Lipopolysaccharides ,Male ,endocrine system ,medicine.medical_specialty ,Lipopolysaccharide ,Endocrinology, Diabetes and Metabolism ,Lipopolysaccharide Receptors ,Gene Expression ,macromolecular substances ,Proinflammatory cytokine ,Rats, Sprague-Dawley ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Organ Culture Techniques ,Endocrinology ,Immune system ,Pituitary Gland, Anterior ,In vivo ,Internal medicine ,Receptors, Adrenergic, beta ,Gene expression ,medicine ,Animals ,RNA, Messenger ,In Situ Hybridization ,Regulation of gene expression ,Interleukin-12 Subunit p40 ,Reverse Transcriptase Polymerase Chain Reaction ,Endocrine and Autonomic Systems ,Chemistry ,NF-kappa B ,Interleukin ,DNA ,Blotting, Northern ,Interleukin-12 ,Rats ,Transcription Factor AP-1 ,Protein Subunits ,nervous system ,Pituitary Gland ,Interleukin 12 ,hormones, hormone substitutes, and hormone antagonists - Abstract
Proinflammatory cytokines have several functions including activation of the hypothalamo-pituitary-adrenal (HPA) axis and regulation of the immune system. The present study focuses on the regulation of interleukin 12 (IL-12) and its receptor gene expression in the HPA axis under artificially induced immune stress, brought on by administration of lipopolysaccharide (LPS) to Sprague-Dawley (SD) rats. RT-PCR analyses showed that expression of the IL-12 p40 gene was significantly increased and peaked at 2 h in the pituitary gland, but not in the hypothalamus. LPS-induced IL-12 p40 gene induction in the pituitary gland was suppressed after β-adrenoceptor agonist pretreatment in vivo. Both IL-12 p40 gene induction and IL-12 production were also observed when freshly isolated pituitary glands from non-treated SD rats were incubated with LPS in vitro. Furthermore, CD14, which is known as a LPS receptor, was found to be expressed in the pituitary gland. Gel mobility shift assays using nuclear extracts prepared from the pituitary glands of rats administered LPS showed induction of NF-ĸB and AP-1 DNA-binding activity. These results suggest that LPS stimulates the pituitary gland directly in vivo to increase IL-12 p40 gene expression and IL-12 protein production.
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- 2002
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40. Fusion of Regionally Specified hPSC-Derived Organoids Models Human Brain Development and Interneuron Migration
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In-Hyun Park, Yangfei Xiang, Kun-Yong Kim, Adam P. Lombroso, Benjamin Patterson, Yoshiaki Tanaka, Sherman M. Weissman, Sung Min Hwang, Edouard G. Stanley, Janice R. Naegele, Sang-Hun Lee, Andrew G. Elefanty, Mei Zhong, Naomi Roselaar, Gubbi Govindaiah, Bilal Cakir, and Young-Jin Kang
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Pluripotent Stem Cells ,0301 basic medicine ,Interneuron ,Ganglionic eminence ,Population ,ATAC-seq ,Biology ,Bioinformatics ,Models, Biological ,Interneuron migration ,03 medical and health sciences ,Cell Movement ,Interneurons ,Genetics ,medicine ,Organoid ,Humans ,Cell Lineage ,Induced pluripotent stem cell ,education ,Cerebral Cortex ,education.field_of_study ,Sequence Analysis, RNA ,Median Eminence ,Brain ,Cell Differentiation ,Cell Biology ,Chromatin ,Organoids ,Corticogenesis ,030104 developmental biology ,medicine.anatomical_structure ,Molecular Medicine ,Transcriptome ,Neuroscience - Abstract
Organoid techniques provide unique platforms to model brain development and neurological disorders. Whereas several methods for recapitulating corticogenesis have been described, a system modeling human medial ganglionic eminence (MGE) development, a critical ventral brain domain producing cortical interneurons and related lineages, has been lacking until recently. Here, we describe the generation of MGE and cortex-specific organoids from human pluripotent stem cells that recapitulate the development of MGE and cortex domains, respectively. Population and single-cell RNA sequencing (RNA-seq) profiling combined with bulk assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) analyses revealed transcriptional and chromatin accessibility dynamics and lineage relationships during MGE and cortical organoid development. Furthermore, MGE and cortical organoids generated physiologically functional neurons and neuronal networks. Finally, fusing region-specific organoids followed by live imaging enabled analysis of human interneuron migration and integration. Together, our study provides a platform for generating domain-specific brain organoids and modeling human interneuron migration and offers deeper insight into molecular dynamics during human brain development.
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- 2017
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41. Transcriptional regulation in pluripotent stem cells by methyl CpG-binding protein 2 (MeCP2)
- Author
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Mei Zhong, Kun-Yong Kim, Yoshiaki Tanaka, Sherman M. Weissman, In-Hyun Park, and Xinghua Pan
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities ,Transcription, Genetic ,Methyl-CpG-Binding Protein 2 ,Mutant ,Induced Pluripotent Stem Cells ,Biology ,medicine.disease_cause ,MECP2 ,mental disorders ,Genetics ,medicine ,Rett Syndrome ,Humans ,Induced pluripotent stem cell ,Molecular Biology ,Genetics (clinical) ,X chromosome ,Cells, Cultured ,Embryonic Stem Cells ,Regulation of gene expression ,Mutation ,General Medicine ,Articles ,Embryonic stem cell ,nervous system diseases ,Gene Ontology ,Gene Expression Regulation ,XIST ,Female ,Transcriptome - Abstract
Rett syndrome (RTT) is one of the most prevalent female mental disorders. De novo mutations in methyl CpG-binding protein 2 (MeCP2) are a major cause of RTT. MeCP2 regulates gene expression as a transcription regulator as well as through long-range chromatin interaction. Because MeCP2 is present on the X chromosome, RTT is manifested in an X-linked dominant manner. Investigation using murine MeCP2 null models and post-mortem human brain tissues has contributed to understanding the molecular and physiological function of MeCP2. In addition, RTT models using human induced pluripotent stem cells derived from RTT patients (RTT-iPSCs) provide novel resources to elucidate the regulatory mechanism of MeCP2. Previously, we obtained clones of female RTT-iPSCs that express either wild-type or mutant MECP2 due to the inactivation of one X chromosome. Reactivation of the X chromosome also allowed us to have RTT-iPSCs that express both wild-type and mutant MECP2. Using these unique pluripotent stem cells, we investigated the regulation of gene expression by MeCP2 in pluripotent stem cells by transcriptome analysis. We found that MeCP2 regulates genes encoding mitochondrial membrane proteins. In addition, loss of function in MeCP2 results in de-repression of genes on the inactive X chromosome. Furthermore, we showed that each mutation in MECP2 affects a partly different set of genes. These studies suggest that fundamental cellular physiology is affected by mutations in MECP2 from early development, and that a therapeutic approach targeting to unique forms of mutant MeCP2 is needed.
- Published
- 2013
42. MeCP2 regulates the synaptic expression of a Dysbindin-BLOC-1 network component in mouse brain and human induced pluripotent stem cell-derived neurons
- Author
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In-Hyun Park, Pearl V. Ryder, Lucas Pozzo-Miller, Christina Gross, Christopher A. Chapleau, Gaston Calfa, Kun-Yong Kim, Jennifer L. Larimore, Alex Ambrose, Konrad Talbot, Victor Faundez, Yoland Smith, and Gary J. Bassell
- Subjects
Methyl-CpG-Binding Protein 2 ,Hippocampus ,Gene Expression ,Hippocampal formation ,Mice ,0302 clinical medicine ,Lectins ,Molecular Cell Biology ,Neurobiology of Disease and Regeneration ,Protein Interaction Maps ,Induced pluripotent stem cell ,Regulation of gene expression ,Genetics ,Neurons ,0303 health sciences ,Multidisciplinary ,Dysbindin ,purl.org/becyt/ford/3.1 [https] ,3. Good health ,Cell biology ,Medicina Básica ,Medicine ,purl.org/becyt/ford/3 [https] ,Membranes and Sorting ,Research Article ,CIENCIAS MÉDICAS Y DE LA SALUD ,Histology ,Science ,Induced Pluripotent Stem Cells ,Inmunología ,Rett syndrome ,Biology ,MECP2 ,03 medical and health sciences ,Genetic Mutation ,mental disorders ,medicine ,Rett Syndrome ,Animals ,Humans ,RNA, Messenger ,Mecp2 ,030304 developmental biology ,Dentate gyrus ,synapsis ,Computational Biology ,medicine.disease ,BDNF ,Gene Expression Regulation ,Cellular Neuroscience ,Genetics of Disease ,Dystrophin-Associated Proteins ,Synapses ,Molecular Neuroscience ,Carrier Proteins ,030217 neurology & neurosurgery ,Neuroscience - Abstract
Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD. Fil: Larimore, Jennifer. Agnes Scott College; Estados Unidos Fil: Ryder, Pearl V.. University of Emory; Estados Unidos Fil: Kim, Kun Yong. University of Yale. School of Medicine; Estados Unidos Fil: Ambrose, L. Alex. Agnes Scott College; Estados Unidos Fil: Chapleau, Christopher. University Of Alabama; Estados Unidos Fil: Calfa, Gaston Diego. University Of Alabama; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gross, Christina. University of Emory; Estados Unidos Fil: Bassell, Gary J.. University of Emory; Estados Unidos Fil: Pozzo Miller, Lucas. University Of Alabama; Estados Unidos Fil: Smith, Yoland. University of Emory; Estados Unidos Fil: Talbot, Konrad. The Pennsylvania State University; Estados Unidos Fil: Park, In Hyun. University of Yale. School of Medicine; Estados Unidos Fil: Faundez, Victor. University of Emory; Estados Unidos
- Published
- 2013
43. Modeling supravalvular aortic stenosis syndrome with human induced pluripotent stem cells
- Author
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Yongming Ren, Hongyu Zhao, Darrell N. Kotton, Wei Li, Peter J. Amos, Kathleen A. Martin, Amulya Iyer, Kun-Yong Kim, Xin Ge, Min Young Lee, Lixia Yue, Wei Zheng, In-Hyun Park, Zhichao Yue, George Tellides, Oscar Bartulos, Esra Cagavi Bozkulak, and Yibing Qyang
- Subjects
Adult ,Male ,Williams Syndrome ,Pathology ,medicine.medical_specialty ,RHOA ,Vascular smooth muscle ,Induced Pluripotent Stem Cells ,Exon ,Mice ,Physiology (medical) ,Medicine ,Animals ,Humans ,Induced pluripotent stem cell ,Child ,Actin ,Cells, Cultured ,biology ,business.industry ,medicine.disease ,Aortic Stenosis, Supravalvular ,Stenosis ,cardiovascular system ,biology.protein ,Cardiology and Cardiovascular Medicine ,business ,Elastin ,Supravalvular aortic stenosis - Abstract
Background— Supravalvular aortic stenosis (SVAS) is caused by mutations in the elastin ( ELN ) gene and is characterized by abnormal proliferation of vascular smooth muscle cells (SMCs) that can lead to narrowing or blockage of the ascending aorta and other arterial vessels. Having patient-specific SMCs available may facilitate the study of disease mechanisms and development of novel therapeutic interventions. Methods and Results— Here, we report the development of a human induced pluripotent stem cell (iPSC) line from a patient with SVAS caused by the premature termination in exon 10 of the ELN gene resulting from an exon 9 four-nucleotide insertion. We showed that SVAS iPSC-derived SMCs (iPSC-SMCs) had significantly fewer organized networks of smooth muscle α-actin filament bundles, a hallmark of mature contractile SMCs, compared with control iPSC-SMCs. The addition of elastin recombinant protein or enhancement of small GTPase RhoA signaling was able to rescue the formation of smooth muscle α-actin filament bundles in SVAS iPSC-SMCs. Cell counts and BrdU analysis revealed a significantly higher proliferation rate in SVAS iPSC-SMCs than control iPSC-SMCs. Furthermore, SVAS iPSC-SMCs migrated at a markedly higher rate to the chemotactic agent platelet-derived growth factor compared with the control iPSC-SMCs. We also provided evidence that elevated activity of extracellular signal-regulated kinase 1/2 is required for hyperproliferation of SVAS iPSC-SMCs. The phenotype was confirmed in iPSC-SMCs generated from a patient with deletion of elastin owing to Williams-Beuren syndrome. Conclusions— SVAS iPSC-SMCs recapitulate key pathological features of patients with SVAS and may provide a promising strategy to study disease mechanisms and to develop novel therapies.
- Published
- 2012
44. The lesser known story of X chromosome reactivation: a closer look into the reprogramming of the inactive X chromosome
- Author
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Yoshiaki Tanaka, In-Hyun Park, Eriona Hysolli, Yong Wook Jung, and Kun-Yong Kim
- Subjects
Pluripotent Stem Cells ,X Chromosome ,Ubiquitin-Protein Ligases ,Biology ,X-inactivation ,Histones ,X Chromosome Inactivation ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Induced pluripotent stem cell ,Molecular Biology ,X chromosome ,Regulation of gene expression ,Extra View ,Gene Expression Regulation, Developmental ,Cell Biology ,DNA Methylation ,Molecular biology ,medicine.anatomical_structure ,DNA methylation ,XIST ,RNA Interference ,Reprogramming ,Germ cell ,Developmental Biology - Abstract
X-chromosome inactivation (XCI) is an important mechanism employed by mammalian XX female cells to level X-linked gene expression with that of male XY cells. XCI occurs early in development as the pluripotent cells of the inner cell mass (ICM) in blastocysts successively differentiate into cells of all three germ layers. X-chromosome reactivation (XCR), the reversal of XCI, is critical for germ cell formation as a mechanism to diversify the X-chromosome gene pool. Here we review the characterization of XCR, and further explore its natural occurrence during development and the in vitro models of cellular reprogramming. We also review the key regulators involved in XCI for their role in suppressing the active histone marks and the genes in the active chromosome for their inhibition of X inactivation signals.
- Published
- 2012
45. Recent Advances and Future Perspectives on Somatic Cell Reprogramming
- Author
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Kun-Yong Kim and In-Hyun Park
- Subjects
Somatic cell ,Biology ,Reprogramming ,Cell biology - Published
- 2011
- Full Text
- View/download PDF
46. Increase in CIP2A expression is associated with doxorubicin resistance
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Eun-Yi Moon, Jeong Su Park, Junhye Kwon, Ki Sook Oh, Keun Il Kim, Kun-yong Kim, Young Yang, Mi Young Park, Yeon A. Choi, Do Young Yoon, Myung Sok Lee, and Jong-Seok Lim
- Subjects
p53 ,Mutant ,Biophysics ,Down-Regulation ,Breast Neoplasms ,Biochemistry ,Autoantigens ,Metastasis ,Cancerous inhibitor of PP2A ,Structural Biology ,Genetics ,medicine ,Humans ,Doxorubicin ,Molecular Biology ,Protein kinase B ,Cell Proliferation ,Cell growth ,Chemistry ,Akt ,Intracellular Signaling Peptides and Proteins ,Membrane Proteins ,Cell Biology ,Protein phosphatase 2 ,medicine.disease ,HCT116 Cells ,Molecular biology ,Gene Expression Regulation, Neoplastic ,Drug Resistance, Neoplasm ,Cancer cell ,Cancer research ,Female ,Mutant Proteins ,DOXORUBICIN RESISTANCE ,Tumor Suppressor Protein p53 ,Proto-Oncogene Proteins c-akt ,medicine.drug ,Signal Transduction - Abstract
The cancerous inhibitor of protein phosphatase 2A (CIP2A) increases the migration and metastasis of various cancer cells. Overexpression of CIP2A has been shown to increase the proliferation of MDA-MB-231 cells. We thus assessed whether CIP2A expression is associated with sensitivity to doxorubicin. MDA-MB-231 cells showed an increase in CIP2A expression after treatment with doxorubicin, while MCF-7 cells showed a decrease in CIP2A expression. The overexpression of CIP2A in MCF-7 cells overcame the inhibition of cell proliferation in response to doxorubicin treatment. CIP2A expression was not affected by wild-type or mutant p53. However, mutant p53 blocked doxorubicin-mediated CIP2A down-regulation in HCT116 cells. As a regulation mechanism of doxorubicin-mediated CIP2A expression, we showed that phosphorylated Akt was involved in the suppression of CIP2A expression.
- Published
- 2010
47. IFITM6 expression is increased in macrophages of tumor-bearing mice
- Author
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Ki Sook Oh, Sunyi Lee, Young Yang, Yun Sun Park, Kun-yong Kim, Jeong Su Park, Jong-Seok Lim, and Jeong Hye Han
- Subjects
Cancer Research ,Cellular differentiation ,medicine.medical_treatment ,Spleen ,Mammary Neoplasms, Animal ,Biology ,Mice ,Cell Line, Tumor ,Neoplasms ,Gene expression ,medicine ,Macrophage ,Animals ,Regulation of gene expression ,Toll-like receptor ,Mice, Inbred BALB C ,Membrane Glycoproteins ,Oncogene ,Macrophages ,Carcinoma ,Membrane Proteins ,General Medicine ,Molecular biology ,Up-Regulation ,Gene Expression Regulation, Neoplastic ,Transplantation, Isogeneic ,medicine.anatomical_structure ,Cytokine ,Oncology ,Multigene Family ,Cancer research ,Female ,Neoplasm Transplantation - Abstract
The family of interferon-induced transmembrane protein (IFITM) genes consists of IFITM1, 2, 3, 5, and 6. They encode cell surface proteins that modulate cell-cell adhesion and cell differentiation. In a previous study, we showed that IFITM1 is involved in the immune escape and metastasis of gastric cancer cells. In this study, we determined the difference in expression of IFITM family genes in tumor-bearing mice. IFITM1 and 6 were found to be significantly increased. IFITM6 gene expression was increased only in the spleen of tumor-bearing mice but not in the bone marrow, lymph node, or thymus. IFITM6 expression was induced in various macrophages, including splenic, thioglycollate-elicited, and bone marrow-derived macrophages, but not in T cells. Lipopolysaccharides (LPS) also increased IFITM6 expression 24 h after administration, and Toll-like receptor 1, 2, 3, 4, and 9 agonists stimulated IFITM6 expression. These findings imply that the increase in IFITM6 expression may be involved in macrophage functions of tumor-bearing mice.
- Published
- 2010
48. Bisulfite-independent analysis of CpG island methylation enables genome-scale stratification of single cells.
- Author
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Lin Han, Hua-Jun Wu, Haiying Zhu, Kun-Yong Kim, Marjani, Sadie L., Riester, Markus, Euskirchen, Ghia, Xiaoyuan Zi, Yang, Jennifer, Han, Jasper, Snyder, Michael, Park, In-Hyun, Irizarry, Rafael, Weissman, Sherman M., Michor, Franziska, Fan, Rong, and Xinghua Pan
- Published
- 2017
- Full Text
- View/download PDF
49. c-Jun N-terminal kinase is involved in the suppression of adiponectin expression by TNF-alpha in 3T3-L1 adipocytes
- Author
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In Pyo Choi, Jae Kwang Kim, Young Yang, Jun Ho Jeon, Suk Ran Yoon, and Kun-yong Kim
- Subjects
medicine.medical_specialty ,Biophysics ,Adipose tissue ,Adipokine ,Biochemistry ,Rosiglitazone ,Mice ,Internal medicine ,3T3-L1 Cells ,medicine ,Adipocytes ,Animals ,Promoter Regions, Genetic ,Molecular Biology ,Adiponectin ,Kinase ,Chemistry ,Tumor Necrosis Factor-alpha ,c-jun ,Intracellular Signaling Peptides and Proteins ,JNK Mitogen-Activated Protein Kinases ,3T3-L1 ,Cell Biology ,DNA ,Enzyme Activation ,PPAR gamma ,Endocrinology ,Gene Expression Regulation ,Intercellular Signaling Peptides and Proteins ,Tumor necrosis factor alpha ,Thiazolidinediones ,Reactive Oxygen Species ,medicine.drug ,Protein Binding - Abstract
Adiponectin, one of adipokines that is secreted from adipocytes, plays an important role in the regulation of glucose and lipid metabolism. Paradoxically, serum concentrations of adiponectin are decreased in obese and type 2 diabetic patients, although it is produced in adipose tissue. On the other hand, plasma TNF-alpha levels are increased in such subjects. In the present study, the mechanism by which adiponectin is regulated by TNF-alpha was investigated. The decreased adiponectin mRNA levels by TNF-alpha were partially recovered by treatment with a c-Jun N-terminal kinase (JNK) inhibitor or the PPAR-gamma agonist rosiglitazone in 3T3-L1 adipocytes. Interestingly, however, cotreatment with the JNK inhibitor and rosiglitazone led to a recovery of TNF-alpha-mediated adiponectin suppression to the control level. The JNK inhibitor regulated the expression of adiponectin by the increase of PPAR-gamma DNA binding activity and the recovery of its mRNA expression while rosiglitazone acted via a PPAR-gamma independent pathway which remains to be elucidated. These findings suggest that the JNK signaling pathway, activated by TNF-alpha, is involved in the regulation of adiponectin expression.
- Published
- 2004
50. The interferon-inducible 9-27 gene modulates the susceptibility to natural killer cells and the invasiveness of gastric cancer cells
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Young Ho Lee, Jeong Hyung Lee, Kun-yong Kim, Daeho Cho, Suk Ran Yoon, Hyun Keun Song, Kyu Sang Song, Jae Kwang Kim, Inpyo Choi, and Young Yang
- Subjects
Cancer Research ,Antineoplastic Agents ,Biology ,Adenocarcinoma ,Natural killer cell ,Transforming Growth Factor beta1 ,Interferon-gamma ,Immune system ,Interferon ,Cancer stem cell ,Cell Movement ,Stomach Neoplasms ,Transforming Growth Factor beta ,medicine ,Tumor Cells, Cultured ,Humans ,Neoplasm Invasiveness ,Lymphokine-activated killer cell ,Tumor Necrosis Factor-alpha ,Gene Expression Profiling ,Membrane Proteins ,Natural killer T cell ,Antigens, Differentiation ,Killer Cells, Natural ,medicine.anatomical_structure ,Oncology ,Immunology ,Cancer cell ,Cancer research ,Interleukin 12 ,medicine.drug - Abstract
As an effort to identify immune suppressive molecules in gastric cancer cells, a signal sequence trap was employed. Among the genes identified, 9-27 gene was highly expressed in gastric tumor tissues and in cancer cell lines. It was induced by IFN-γ treatment, but not by TNF-α or TGF-β1 treatment. The overexpression of 9-27 in the gastric cancer cells rendered tumor cells more resistant to natural killer cells. In addition, the 9-27-overexpressed cells showed an increased migration and an invasive capacity when compared with the control cells. Taken together, these data indicate that 9-27 plays a role in malignant progression by suppressing natural killer cells and by increasing the invasive potential of gastric cancer cells.
- Published
- 2004
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