75 results on '"Hyoung-Pyo Kim"'
Search Results
2. 4D nucleome: dynamic three-dimensional genome organization over time
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Hyoung-Pyo Kim
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Medicine ,Biochemistry ,QD415-436 - Published
- 2024
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3. CTCF controls three-dimensional enhancer network underlying the inflammatory response of bone marrow-derived dendritic cells
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Bobae Yang, Sueun Kim, Woong-Jae Jung, Kyungwoo Kim, Sugyung Kim, Yong-Jin Kim, Tae-Gyun Kim, Eun-Chong Lee, Jung-Sik Joo, Chae Gyu Park, Sumin Oh, Kyung Hyun Yoo, and Hyoung-Pyo Kim
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Science - Abstract
The role of 3D genome organization is not well understood in the transcriptional regulation of dendritic cells. Here the authors show that activation of dendritic cells in vitro induces dynamic reprogramming of the chromatin looping and enhancer activity linked to changes in gene expression and implicates a role for the chromatin architecture protein CTCF in the inflammatory response of dendritic cells.
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- 2023
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4. Human induced pluripotent stem cell line YCMi007-A generated from a dilated cardiomyopathy patient with a heterozygous dominant c.613C > T (p. Arg205Trp) variant of the TNNT2 gene
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Sae-Bom Jeon, Hyoeun Kim, Kyeong-Hyeon Chun, Jaewon Oh, Chulan Kwon, Hyo-Kyoung Choi, Sangwoo Kim, Hyoung-Pyo Kim, In-Cheol Kim, Jung-Yoon Yoo, Sahng Wook Park, Seok-Min Kang, and Seung-Hyun Lee
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Biology (General) ,QH301-705.5 - Abstract
Cardiac muscle troponin T protein binds to tropomyosin and regulates the calcium-dependent actin–myosin interaction on thin filaments in cardiomyocytes. Recent genetic studies have revealed that TNNT2 mutations are strongly linked to dilated cardiomyopathy (DCM). In this study, we generated YCMi007-A, a human induced pluripotent stem cell (hiPSC) line from a DCM patient with a p. Arg205Trp mutation in the TNNT2 gene. The YCMi007-A cells show high expression of pluripotent markers, normal karyotype, and differentiation into three germ layers. Thus, YCMi007-A—an established iPSC—could be useful for the investigation of DCM.
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- 2023
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5. An induced pluripotent stem cell line (YCMi006-A) generated from a patient with hypertrophic cardiomyopathy who carries the ACTA1 mutation p.Ile343Met
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Hyoeun Kim, Hyeong-Jin Kim, Jaewon Oh, Seung-Tae Lee, Dongju Won, Hyo-Kyoung Choi, Jong Rak Choi, Sangwoo Kim, Hyoung-Pyo Kim, Seok-Jun Kim, Sahng Wook Park, Seok-Min Kang, and Seung-Hyun Lee
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Biology (General) ,QH301-705.5 - Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiovascular disease and is characterized by hypertrophy of the left ventricle. We reprogrammed peripheral blood mononuclear cells (PBMCs) from a HCM patient into pluripotent stem cells (iPSC) (YCMi006-A) carrying a heterozygous c.1029C > G mutation in ACTA1. The YCMi006-A cells expressed high levels of pluripotent markers, had a normal 46XX karyotype and demonstrated the capacity to differentiate into derivatives of all three germ layers. This cell line can be a valuable tool for investigating the pathogenesis of HCM.
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- 2022
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6. Liver-Specific Deletion of Mouse CTCF Leads to Hepatic Steatosis via Augmented PPARγ SignalingSummary
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Yeeun Choi, Min-Ji Song, Woong-Jae Jung, Haengdueng Jeong, Seokjae Park, Bobae Yang, Eun-Chong Lee, Jung-Sik Joo, Dahee Choi, Seung-Hoi Koo, Eun-Kyoung Kim, Ki Taek Nam, and Hyoung-Pyo Kim
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Liver Steatosis ,CTCF ,PPARγ ,CD36 ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background & Aims: The liver is the major organ for metabolizing lipids, and malfunction of the liver leads to various diseases. Nonalcoholic fatty liver disease is rapidly becoming a major health concern worldwide and is characterized by abnormal retention of excess lipids in the liver. CCCTC-binding factor (CTCF) is a highly conserved zinc finger protein that regulates higher-order chromatin organization and is involved in various gene regulation processes. Here, we sought to determine the physiological role of CTCF in hepatic lipid metabolism. Methods: We generated liver-specific, CTCF-ablated and/or CD36 whole-body knockout mice. Overexpression or knockdown of peroxisome proliferator-activated receptor (PPAR)γ in the liver was achieved using adenovirus. Mice were examined for development of hepatic steatosis and inflammation. RNA sequencing was performed to identify genes affected by CTCF depletion. Genome-wide occupancy of H3K27 acetylation, PPARγ, and CTCF were analyzed by chromatin immunoprecipitation sequencing. Genome-wide chromatin interactions were analyzed by in situ Hi-C. Results: Liver-specific, CTCF-deficient mice developed hepatic steatosis and inflammation when fed a standard chow diet. Global analysis of the transcriptome and enhancer landscape revealed that CTCF-depleted liver showed enhanced accumulation of PPARγ in the nucleus, which leads to increased expression of its downstream target genes, including fat storage-related gene CD36, which is involved in the lipid metabolic process. Hepatic steatosis developed in liver-specific, CTCF-deficient mice was ameliorated by repression of PPARγ via pharmacologic blockade or adenovirus-mediated knockdown, but hardly rescued by additional knockout of CD36. Conclusions: Our data indicate that liver-specific deletion of CTCF leads to hepatosteatosis through augmented PPARγ DNA-binding activity, which up-regulates its downstream target genes associated with the lipid metabolic process.
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- 2021
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7. Vorinostat-induced acetylation of RUNX3 reshapes transcriptional profile through long-range enhancer-promoter interactions in natural killer cells
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Eun-Chong Lee, Kyungwoo Kim, Woong-Jae Jung, and Hyoung-Pyo Kim
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General Medicine ,Molecular Biology ,Biochemistry - Published
- 2023
8. CTCF-mediated chromatin looping provides a topological framework for the formation of phase-separated transcriptional condensates
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Ryanggeun Lee, Moo-Koo Kang, Yong-Jin Kim, Bobae Yang, Hwanyong Shim, Sugyung Kim, Kyungwoo Kim, Chul Min Yang, Byeong-gyu Min, Woong-Jae Jung, Eun-Chong Lee, Jung-Sik Joo, Gunhee Park, Won-Ki Cho, and Hyoung-Pyo Kim
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CCCTC-Binding Factor ,Mediator Complex Subunit 1 ,Genetics ,Humans ,Cell Cycle Proteins ,RNA Polymerase II ,Chromatin Assembly and Disassembly ,HCT116 Cells ,Chromatin ,Epigenesis, Genetic ,Transcription Factors - Abstract
CTCF is crucial to the organization of mammalian genomes into loop structures. According to recent studies, the transcription apparatus is compartmentalized and concentrated at super-enhancers to form phase-separated condensates and drive the expression of cell-identity genes. However, it remains unclear whether and how transcriptional condensates are coupled to higher-order chromatin organization. Here, we show that CTCF is essential for RNA polymerase II (Pol II)-mediated chromatin interactions, which occur as hyperconnected spatial clusters at super-enhancers. We also demonstrate that CTCF clustering, unlike Pol II clustering, is independent of liquid-liquid phase-separation and resistant to perturbation of transcription. Interestingly, clusters of Pol II, BRD4, and MED1 were found to dissolve upon CTCF depletion, but were reinstated upon restoration of CTCF, suggesting a potent instructive function for CTCF in the formation of transcriptional condensates. Overall, we provide evidence suggesting that CTCF-mediated chromatin looping acts as an architectural prerequisite for the assembly of phase-separated transcriptional condensates.
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- 2021
9. CTCF deficiency causes expansion of the sensory domain in the mouse cochlea
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Ji-Hyun Ma, Jeong Oh Shin, and Hyoung-Pyo Kim
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0301 basic medicine ,CCCTC-Binding Factor ,Biophysics ,Sensory system ,Bone Morphogenetic Protein 4 ,GATA3 Transcription Factor ,Biology ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,SOX2 ,Hair Cells, Auditory ,Conditional gene knockout ,otorhinolaryngologic diseases ,medicine ,Animals ,Inner ear ,Molecular Biology ,Cochlea ,Mice, Knockout ,Hair cell differentiation ,SOXB1 Transcription Factors ,PAX2 Transcription Factor ,Gene Expression Regulation, Developmental ,Cell Differentiation ,Cell Biology ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,CTCF ,030220 oncology & carcinogenesis ,embryonic structures ,Ectopic expression ,sense organs ,Fibroblast Growth Factor 10 ,Jagged-1 Protein - Abstract
The cochlea in the mammalian inner ear is a sensitive and sharply organized sound-detecting structure. The proper specification of neurosensory-competent domain in the otic epithelium is required for the formation of mature neuronal and sensory domains. Genetic studies have provided many insights into inner ear development, but there have been few epigenetic studies of inner ear development. CTCF is an epigenetic factor that plays a pivotal role in the organization of global chromatin conformation. To determine the role of CTCF in the otic sensory formation, we made a conditional knockout of Ctcf in the developing otic epithelium by crossing Ctcffl/fl mice with Pax2-Cre mice. Ctcf deficiency resulted in extra rows of auditory hair cells in the shortened cochlea on mouse embryonic day 14.5 (E14.5) and E17.5. The massive and ectopic expression of sensory specifiers such as Jag1 and Sox2 indicated that the sensory domain was expanded in the Ctcf-deficient cochlea. Other regulators of the sensory domain such as Bmp4, Gata3, and Fgf10 were not affected. These results suggest that CTCF plays a role in the regulation of the sensory domain in mammalian cochlear development.
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- 2019
10. Mechanism mediated by a noncoding RNA, nc886, in the cytotoxicity of a DNA-reactive compound
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Yong Sun Lee, Yeon-Su Lee, Jiyoung Joan Jang, Hyun-Sung Lee, Yoosik Kim, Hye-ram Jo, Betty H. Johnson, Jong-Lyul Park, Hyoung-Pyo Kim, Jae-Hoon Jeong, Nawapol Kunkeaw, Wonkyun Ronny Im, Yongsuk Ku, Min-Ji Song, Ju Seog Lee, Sangmin Kang, Bobae Yang, Seon-Young Kim, and In-Hoo Kim
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RNA polymerase III ,RNA, Untranslated ,DNA damage ,Apoptosis ,Biochemistry ,doxorubicin ,Cell Line ,eIF-2 Kinase ,chemistry.chemical_compound ,nc886 ,Transcription (biology) ,Humans ,Cytotoxic T cell ,Cytotoxicity ,Multidisciplinary ,Chemistry ,protein kinase R ,DNA ,Biological Sciences ,Protein kinase R ,Cell biology ,MicroRNAs ,Cancer cell ,cytotoxicity ,Signal Transduction - Abstract
Significance DNA-reactive compounds target actively proliferating cells. Therefore, they are presupposed to kill cancer cells selectively, and many of them are used as chemotherapeutic agents. In this study, we have discovered a cell death pathway involving nc886 and PKR as another mechanism for the cytotoxicity. Our study provides an insight how a proapoptotic protein responds to a DNA-reactive compound via a regulatory noncoding RNA (ncRNA) as a molecular signal. Since the nc886/PKR pathway operates in most normal cells including nonproliferating ones, our finding may answer to a conundrum why a DNA-damaging compound harms quiescent cells and is of future clinical utility by considering nc886/PKR when designing a chemotherapeutic regimen with minimal side effects on normal cells., DNA-reactive compounds are harnessed for cancer chemotherapy. Their genotoxic effects are considered to be the main mechanism for the cytotoxicity to date. Because this mechanism preferentially affects actively proliferating cells, it is postulated that the cytotoxicity is specific to cancer cells. Nonetheless, they do harm normal quiescent cells, suggesting that there are other cytotoxic mechanisms to be uncovered. By employing doxorubicin as a representative DNA-reactive compound, we have discovered a cytotoxic mechanism that involves a cellular noncoding RNA (ncRNA) nc886 and protein kinase R (PKR) that is a proapoptotic protein. nc886 is transcribed by RNA polymerase III (Pol III), binds to PKR, and prevents it from aberrant activation in most normal cells. We have shown here that doxorubicin evicts Pol III from DNA and, thereby, shuts down nc886 transcription. Consequently, the instantaneous depletion of nc886 provokes PKR and leads to apoptosis. In a short-pulse treatment of doxorubicin, these events are the main cause of cytotoxicity preceding the DNA damage response in a 3D culture system as well as the monolayer cultures. By identifying nc886 as a molecular signal for PKR to sense doxorubicin, we have provided an explanation for the conundrum why DNA-damaging drugs can be cytotoxic to quiescent cells that have the competent nc886/PKR pathway.
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- 2019
11. p53 expression confers sensitivity to 5-fluorouracil via distinct chromatin accessibility dynamics in human colorectal cancer
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Yong-Jin Kim, Hyoung-Pyo Kim, Chul Min Yang, Woong-Jae Jung, Moo-Koo Kang, Jung-Sik Joo, and Yeeun Choi
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p53 ,Cancer Research ,Programmed cell death ,apoptosis ,Articles ,Cell cycle ,Biology ,DNA-binding protein ,Chromatin ,Cell biology ,Oncology ,chromatin accessibility ,Gene expression ,5-fluorouracil ,Epigenetics ,drug sensitivity ,Gene ,Transcription factor - Abstract
One of the most commonly used drugs in chemotherapy, 5-fluorouracil (5-FU) has been shown to be effective in only 10-15% of patients with colon cancer. Thus, studies of the mechanisms affecting 5-FU sensitivity in these patients are necessary. The tumor suppressor protein p53 is a transcription factor that serves important roles in cell apoptosis by regulating the cell cycle. It has also been characterized as a key factor influencing drug sensitivity. Furthermore, accessible chromatin is a hallmark of active DNA regulatory elements and functions as a crucial epigenetic factor regulating cancer mechanisms. The present study assessed the genetic regulatory landscape in colon cancer by performing RNA sequencing and Assay for Transposase-Accessible Chromatin sequencing, and investigated the effects of 5-FU on chromatin accessibility and gene expression. Notably, while treatment with 5-FU mediated global increases in chromatin accessibility, chromatin organization in several genomic regions differed depending on the expression status of p53. Since the occupancy of p53 does not overlap with accessible chromatin regions, the 5-FU-mediated changes in chromatin accessibility were not regulated by direct binding of p53. In the p53-expressing condition, the 5-FU-mediated accessible chromatin region was primarily associated with genes encoding cell death pathways. Additionally, 5-FU was revealed to induce open chromatin conformation at regions containing binding motifs for AP-1 family transcription factors, which may drive expression of apoptosis pathway genes. In conclusion, expression of p53 may confer 5-FU sensitivity by regulating chromatin accessibility of distinct genes associated with cell apoptosis in a transcription-independent manner.
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- 2020
12. CTCF is required for maintenance of auditory hair cells and hearing function in the mouse cochlea
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Jeong Oh Shin, Hyoung-Pyo Kim, Ji-Hyun Ma, and Jinwoong Bok
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Male ,0301 basic medicine ,CCCTC-Binding Factor ,Hearing loss ,Neurogenesis ,Biophysics ,Biology ,Biochemistry ,Epigenesis, Genetic ,Stereocilia ,Mice ,03 medical and health sciences ,Hearing ,Cell Movement ,Hair Cells, Auditory ,Basic Helix-Loop-Helix Transcription Factors ,otorhinolaryngologic diseases ,medicine ,Animals ,Profound hearing impairment ,Molecular Biology ,Cochlea ,Spiral ganglion ,Mice, Knockout ,Integrases ,integumentary system ,SOXB1 Transcription Factors ,Gene Expression Regulation, Developmental ,Cell Differentiation ,Cell Biology ,Chromatin ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Organ of Corti ,CTCF ,Female ,sense organs ,Hair cell ,medicine.symptom ,Spiral Ganglion - Abstract
Auditory hair cells play an essential role in hearing. These cells convert sound waves, mechanical stimuli, into electrical signals that are conveyed to the brain via spiral ganglion neurons. The hair cells are located in the organ of Corti within the cochlea. They assemble in a special arrangement with three rows of outer hair cells and one row of inner hair cells. The proper differentiation and preservation of auditory hair cells are essential for acquiring and maintaining hearing function, respectively. Many genetic regulatory mechanisms underlying hair-cell differentiation and maintenance have been elucidated to date. However, the role of epigenetic regulation in hair-cell differentiation and maintenance has not been definitively demonstrated. CTCF is an essential epigenetic component that plays a primary role in the organization of global chromatin architecture. To determine the role of CTCF in mammalian hair cells, we specifically deleted Ctcf in developing hair cells by crossing Ctcffl/fl mice with Gfi1Cre/+ mice. Gfi1Cre; Ctcffl/fl mice did not exhibit obvious developmental defects in hair cells until postnatal day 8. However, at 3 weeks, the Ctcf deficiency caused intermittent degeneration of the stereociliary bundles of outer hair cells, resulting in profound hearing impairment. At 5 weeks, most hair cells were degenerated in Gfi1Cre; Ctcffl/fl mice, and defects in other structures of the organ of Corti, such as the tunnel of Corti and Nuel's space, became apparent. These results suggest that CTCF plays an essential role in maintaining hair cells and hearing function in mammalian cochlea.
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- 2018
13. FAM188B enhances cell survival via interaction with USP7
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Kyung Tae Kim, Hyonchol Jang, Eun-Seok Choi, Chang Hun Lee, Yong-Nyun Kim, Hyoung-Pyo Kim, Jee Young Sung, Sung-Ho Goh, and Hanna Lee
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0301 basic medicine ,Cancer Research ,Small interfering RNA ,Carcinogenesis ,Cell Survival ,Immunology ,Down-Regulation ,Mice, Nude ,Apoptosis ,Article ,Ubiquitin-Specific Peptidase 7 ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Downregulation and upregulation ,Cell Line, Tumor ,Animals ,Humans ,Gene silencing ,Gene Silencing ,lcsh:QH573-671 ,Cell Proliferation ,Regulation of gene expression ,Gene knockdown ,Oncogene ,Protein Stability ,Cell growth ,Chemistry ,lcsh:Cytology ,Ubiquitination ,Nuclear Proteins ,Cell Biology ,Cell biology ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,Ubiquitin-Specific Proteases ,Tumor Suppressor Protein p53 ,Signal transduction ,Colorectal Neoplasms ,Protein Binding ,Signal Transduction - Abstract
We have previously reported that FAM188B showed significant differential exon usage in cancers (NCBI GEO GSE30727), but the expression and function of FAM188B is not well characterized. In the present study, we explored the functions of FAM188B by a knockdown strategy, using siRNAs specific for FAM188B in colon cancer cell lines. FAM188B is a novel gene that encodes a protein that is evolutionarily conserved among mammals. Its mRNA has been found to be highly expressed in most solid tumors, including colorectal cancer. FAM188B knockdown induced cell growth inhibition due to an increase in apoptosis in colon cancer cell lines. Interestingly, siFAM188B treatment induced the upregulation and activation of p53, and consequently increased p53-regulated pro-apoptotic proteins, PUMA and BAX. Proteomic analysis of FAM188B immunocomplexes revealed p53 and USP7 as putative FAM188B-interacting proteins. Deletion of the putative USP7-binding motif in FAM188B reduced complex formation of FAM188B with USP7. It is noteworthy that FAM188B knockdown resulted in a decrease in overall ubiquitination in the p53 immunocomplexes, as well as p53 ubiquitination, because USP7 is involved in p53 deubiquitination. FAM188B knockdown inhibited both colony formation and anchorage-independent growth in vitro. In addition, FAM188B knockdown by siRNA reduced tumor growth in xenografted mice, with an increase in p53 proteins. Taken together, our data suggest that FAM188B is a putative oncogene that functions via interaction with USP7. Therefore, control of FAM188B could be a possible target to inhibit tumor growth.
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- 2018
14. Skin-Specific CD301b+ Dermal Dendritic Cells Drive IL-17−Mediated Psoriasis-Like Immune Response in Mice
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Moah Sohn, Tae-Gyun Kim, Sung Hee Kim, Soo Min Kim, Hyoung-Pyo Kim, Wanho Choi, Jae Won Lee, Hye Young Na, Chae Gyu Park, Min Geol Lee, Jeyun Park, Jae-Hoon Choi, Do Young Kim, and Minseok Lee
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0301 basic medicine ,education.field_of_study ,Langerhans cell ,integumentary system ,Population ,Cell Biology ,Dermatology ,Dendritic cell ,Biology ,Biochemistry ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,medicine.anatomical_structure ,FMS-like tyrosine kinase 3 ligand ,Immunology ,medicine ,Interleukin 17 ,Progenitor cell ,Signal transduction ,education ,Molecular Biology ,Conventional Dendritic Cell - Abstract
Conventional dendritic cells (cDCs) are composed of heterogeneous subsets commonly arising from dendritic cell (DC)−committed progenitors. A population of CD301b-expressing DCs has recently been identified in non-lymphoid barrier tissues such as skin. However, whether CD301b + DCs in the skin represent an ontogenetically unique subpopulation of migratory cDCs has not been fully addressed. Here, we demonstrated that CD301b + dermal DCs were distinct subpopulation of FMS-like tyrosine kinase 3 ligand (FLT3L)−dependent CD11b + cDC2 lineage, which required an additional GM-CSF cue for the adequate development. Although the majority of lymphoid-resident cDC2 lacked CD301b expression, dermal migratory cDC2 contained a substantial fraction of CD301b + subset. Similar to CD301b − population, CD301b + dermal DC development was closely regulated by FLT3 signaling, suggesting their common origin from FLT3L-responsive cDC progenitors. However, FLT3L-driven cDC progenitor culture was not sufficient, but additional GM-CSF treatment was required to produce CD301b + cDC2. In vivo development of CD301b + cDC2 was significantly augmented by exogenous GM-CSF, while the repopulation of CD301b + dermal cDC2 was abrogated by GM-CSF neutralization. Functionally, CD301b + cDC2 was capable of producing a high level of IL-23, and the depletion of CD301b + cDC2 effectively prevented IL-17−mediated psoriasiform dermatitis. Therefore, our findings highlight the differentiation program of a distinct CD301b + dermal cDC2 subset in the skin and its involvement in psoriatic inflammation.
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- 2018
15. Keap1 knockdown in melanocytes induces cell proliferation and survival via HO-1-associated β-catenin signaling
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Tae-Gyun Kim, Sang Ho Oh, Ji-Young Kim, Mikyoung Kim, Hyoung-Pyo Kim, Eun Jung Lee, and Hemin Lee
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Keratinocytes ,0301 basic medicine ,Cell Survival ,NF-E2-Related Factor 2 ,Primary Cell Culture ,Cell ,Down-Regulation ,Dermatology ,Melanocyte ,Biology ,Biochemistry ,03 medical and health sciences ,Downregulation and upregulation ,medicine ,Humans ,Gene silencing ,RNA, Small Interfering ,Molecular Biology ,beta Catenin ,Cell Proliferation ,Melanins ,Gene knockdown ,Kelch-Like ECH-Associated Protein 1 ,Cell growth ,Hydrogen Peroxide ,Microphthalmia-associated transcription factor ,Molecular biology ,Up-Regulation ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Epidermal Cells ,Gene Knockdown Techniques ,Melanocytes ,RNA Interference ,Epidermis ,Signal transduction ,Heme Oxygenase-1 ,Signal Transduction - Abstract
Background Nrf2-Keap1 signaling pathway protects cells against photo-oxidative stress. Yet in recent works, its role in melanogenesis together with cell protection functions against oxidative stress has been gaining interest. However, its effect on melanogenesis still has contradictory results from different studies. Objective The aims of our study were to investigate the effect of Keap1 silencing in melanocyte on melanogenesis and its associated mechanism. Methods Primary human epidermal melanocytes and melan-a cell line were used for this experiment. RNA sequencing was done to identify genes involved in melanocyte biology using Keap1 knockdown through siRNA techniques. And melanogenesis and the expression of melanogenesis-associated molecules were evaluated in Keap1 silenced melanocyte to examine the effects of Keap1 on melanogenesis, melanocyte growth, and related pathways. Results RNA-sequencing data revealed that Keap1 knockdown in primary human epidermal melanocytes (PHEMs) induced cell survival-related gene expression. Additionally, siRNA-mediated inhibition of Keap1 led to upregulation of MITF and melanogenesis-associated molecules along with Nrf2 activation in PHEMs. HO-1, a major gene that is upregulated in RNA-sequencing using Keap1-silenced PHEMs, protected melanocytes against H2O2-induced cell death and upregulated MITF and β-catenin expression. Further, increased expression of melanogenesis-associated molecules after Keap1 silencing was validated to occur through HO-1-associated β-catenin activation in a Keap1 and HO-1 double knockdown experiment. Conclusion This work suggests that Keap1 silencing in melanocytes induced melanogenesis and the expression of melanogenesis-associated molecules through HO-1-associated β-catenin activation. Keap1 downregulation in melanocytes is important for cell proliferation and survival.
- Published
- 2017
16. Epigenetic regulation of long noncoding RNA UCA1 by SATB1 in breast cancer
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Mikyoung Kim, Hyoung-Pyo Kim, and Jong-Joo Lee
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0301 basic medicine ,Chromatin Immunoprecipitation ,Blotting, Western ,Breast Neoplasms ,Biology ,Real-Time Polymerase Chain Reaction ,Methylation ,Biochemistry ,Histone methylation ,Epigenesis, Genetic ,Epigenetic regulation ,Histones ,03 medical and health sciences ,Breast cancer ,SATB1 ,0302 clinical medicine ,Genes, Reporter ,RNA interference ,Cell Line, Tumor ,Gene expression ,Humans ,RNA, Messenger ,Epigenetics ,RNA, Small Interfering ,Molecular Biology ,Gene ,UCA1 ,Sequence Analysis, RNA ,Matrix Attachment Region Binding Proteins ,General Medicine ,Flow Cytometry ,Up-Regulation ,Chromatin ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer research ,H3K4me3 ,Female ,RNA Interference ,RNA, Long Noncoding ,Research Article - Abstract
Special AT-rich sequence binding protein 1 (SATB1) is a nuclear matrix-associated DNA-binding protein that functions as a chromatin organizer. SATB1 is highly expressed in aggressive breast cancer cells and promotes growth and metastasis by reprograming gene expression. Through genome-wide cross-examination of gene expression and histone methylation, we identified SATB1 target genes for which expression is associated with altered epigenetic marks. Among the identified genes, long noncoding RNA urothelial carcinoma-associated 1 (UCA1) was upregulated by SATB1 depletion. Upregulation of UCA1 coincided with increased H3K4 trimethylation (H3K4me3) levels and decreased H3K27 trimethylation (H3K27me3) levels. Our study showed that SATB1 binds to the upstream region of UCA1 in vivo, and that its promoter activity increases with SATB1 depletion. Furthermore, simultaneous depletion of SATB1 and UCA1 potentiated suppression of tumor growth and cell survival. Thus, SATB1 repressed the expression of oncogenic UCA1, suppressing growth and survival of breast cancer cells. [BMB Reports 2016; 49(10): 578-583]
- Published
- 2016
17. House dust mite allergen Der f 1 induces IL-8 in human basophilic cells via ROS-ERK and p38 signal pathways
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Chung Ryul Kim, Hyoung-Pyo Kim, Tai Soon Yong, Tae Yun Kim, Myung Hee Yi, and Kyoung Yong Jeong
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MAPK/ERK pathway ,p38 mitogen-activated protein kinases ,Immunology ,Biology ,Basophil ,p38 Mitogen-Activated Protein Kinases ,Biochemistry ,Arthropod Proteins ,Allergic inflammation ,Cell Line, Tumor ,medicine ,Humans ,Immunology and Allergy ,Antigens, Dermatophagoides ,RNA, Messenger ,Interleukin 8 ,Cloning, Molecular ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Molecular Biology ,Inflammation ,Interleukin-8 ,Interleukin ,Hematology ,Immunoglobulin E ,Cysteine protease ,Molecular biology ,Acetylcysteine ,Basophils ,Cysteine Endopeptidases ,medicine.anatomical_structure ,Reactive Oxygen Species ,Signal Transduction - Abstract
Der f 1, a major house dust mite allergen and member of the papain-like cysteine protease family, can provoke immune responses with its proteolytic activity. To understand the role of Der f 1 in inflammatory immune responses, we studied the mechanism of the regulation of interleukin (IL)-8 expressions in human basophilic cell KU812 by proteolytically active recombinant Der f 1. Not only production of IL-8 mRNA was induced but also the DNA binding activity of activator protein-1 (AP-1) and phosphorylation of NF-κB p65 were increased in Der f 1-treated KU812. Furthermore, Der f 1 induction of IL-8 expression was sensitive to pharmacological inhibition of ERK and p38 mitogen activated protein kinase (MAPK) pathways. Der f 1 also activated ERK and p38 MAPK phosphorylation and rapidly induced reactive oxygen species (ROS) production. The antioxidant N-acetyl-cysteine (NAC) inhibited phosphorylation of ERK, but not p38, suggesting that secretion of IL-8 in KU812 cells treated with Der f 1 is dependent on ROS, ERK MAPK and p38 MAPK. We describe the mechanism of Der f 1-induced IL-8 secretion from human basophilic cells, which are thought to be important for allergic inflammation independent of IgE antibodies. These findings improve our understanding of the inflammatory immune response in human basophils to protease allergens.
- Published
- 2015
18. Cross-reactivity between group-5 and -21 mite allergens from Dermatophagoides farinae, Tyrophagus putrescentiae and Blomia tropicalis
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Ho‑Joon Shin, Hyoung-Pyo Kim, Myung Hee Yi, Kyoung Yong Jeong, Tai Soon Yong, and Chung Ryul Kim
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Adult ,Male ,Cancer Research ,Allergy ,Adolescent ,Molecular Sequence Data ,Cross Reactions ,Immunoglobulin E ,medicine.disease_cause ,Biochemistry ,Cross-reactivity ,Tyrophagus putrescentiae ,Young Adult ,Allergen ,Antibody Specificity ,Hypersensitivity ,Genetics ,medicine ,Mite ,Animals ,Humans ,Amino Acid Sequence ,Antigens, Dermatophagoides ,Child ,Molecular Biology ,Dermatophagoides farinae ,biology ,Pyroglyphidae ,Allergens ,Middle Aged ,biology.organism_classification ,medicine.disease ,Asthma ,Recombinant Proteins ,Oncology ,Immunology ,biology.protein ,Molecular Medicine ,Female ,Antibody ,Sequence Alignment - Abstract
Group-5 and group-21 allergens, produced by house dust mites and storage mites are 36.6-55.8% identical in their sequences and are recognized by at least 50% of immunoglobulin (Ig)E from the sera of individuals allergic to dust mites. In the present study, recombinant group-5 and ‑21 allergens from three mite species, Dermatophagoides farinae (rDer f 5 and 21), Tyrophagus putrescentiae (rTyr p 5 and 21), and Blomia tropicalis (rBlo t 5 and 21), were purified from Escherichia coli, and the IgE reactivities and cross‑reactivities of these allergen variants were assessed. The IgE binding frequencies of rDer f 5, rDer f 21, rTyr p 5, rTyr p 21, rBlo t and rBlo t 21 proteins were 64.95, 65.98, 30.41, 41.24, 30.93 and 21.65%, respectively. The IgE reactivity of rDer f 5 correlated highly with that of rDer f 21 (r=0.733). rTyr p 5 exhibited the highest level of correlation with rTyr p 21 (r=0.950), while the correlation of rBlo t 5 with rBlo t 21 was the lowest observed (r=0.104). The binding of IgE to rDer f 5 and rDer f 21 was not inhibited by any allergens but themselves. While rDer f 5 inhibited only 60.3% of IgE binding to rBlo t 5, rDer f 21 exhibited a high inhibitory effect against rTyr p 5 (93.01%), rTyr p 21 (92.12%), rBlo t 5 (86.97%) and rBlo t 21 (70.30%), implying cross‑reactivity among mite species. The results of the present study demonstrated that the majority of the IgE reactivity to group-5 and -21 storage mite allergens is due to cross‑reaction. It is therefore imperative to develop an accurate, component‑resolved diagnosis for dust mite allergies.
- Published
- 2015
19. Modulation of dendritic cell function by Trichomonas vaginalis-derived secretory products
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Min Ji Song, Hyoung-Pyo Kim, Myeong Heon Shin, Mik Young Kim, Ye Eun Choi, Youn Wook Chung, Jong Joo Lee, Young Hee Nam, and Tae-Gyun Kim
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Lipopolysaccharides ,Chromatin Immunoprecipitation ,Cellular differentiation ,Antigen presentation ,Down-Regulation ,Antigens, Protozoan ,Bone Marrow Cells ,Biochemistry ,Immune tolerance ,Mice ,Trichomonas vaginalis ,Animals ,Antigen-presenting cell ,Molecular Biology ,Cytokine ,CD40 ,Follicular dendritic cells ,biology ,Chromatin ,Dendritic cells ,Tolerance ,Granulocyte-Macrophage Colony-Stimulating Factor ,Cell Differentiation ,General Medicine ,Dendritic cell ,Dendritic Cells ,Interleukin-12 ,Cell biology ,Interleukin-10 ,Up-Regulation ,Mice, Inbred C57BL ,biology.protein ,Interleukin 12 ,Research-Article ,Female ,Endopeptidase K - Abstract
Trichomoniasis caused by the parasitic protozoan Trichomonas vaginalis is the most common sexually transmitted disease in the world. Dendritic cells are antigen presenting cells that initiate immune responses by directing the activation and differentiation of naïve T cells. In this study, we analyzed the effect of Trichomonas vaginalis-derived Secretory Products on the differentiation and function of dendritic cells. Differentiation of bone marrow-derived dendritic cells in the presence of T. vaginalis-derived Secretory Products resulted in inhibition of lipopolysaccharide-induced maturation of dendritic cells, down-regulation of IL-12, and up-regulation of IL-10. The protein components of T. vaginalis-derived Secretory Products were shown to be responsible for altered function of bone marrow-derived dendritic cells. Chromatin immunoprecipitation assay demonstrated that IL-12 expression was regulated at the chromatin level in T. vaginalis-derived Secretory Productstreated dendritic cells. Our results demonstrated that T. vaginalis-derived Secretory Products modulate the maturation and cytokine production of dendritic cells leading to immune tolerance. [BMB Reports 2015; 48(2): 103-108]
- Published
- 2015
20. Skin-Specific CD301b
- Author
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Tae-Gyun, Kim, Sung Hee, Kim, Jeyun, Park, Wanho, Choi, Moah, Sohn, Hye Young, Na, Minseok, Lee, Jae Won, Lee, Soo Min, Kim, Do-Young, Kim, Hyoung-Pyo, Kim, Jae-Hoon, Choi, Chae Gyu, Park, and Min-Geol, Lee
- Subjects
Mice, Inbred C57BL ,Disease Models, Animal ,Immunity, Cellular ,Mice ,Interleukin-17 ,Animals ,Psoriasis ,Lectins, C-Type ,Dendritic Cells ,Dermis ,Cells, Cultured ,Signal Transduction - Abstract
Conventional dendritic cells (cDCs) are composed of heterogeneous subsets commonly arising from dendritic cell (DC)-committed progenitors. A population of CD301b-expressing DCs has recently been identified in non-lymphoid barrier tissues such as skin. However, whether CD301b
- Published
- 2017
21. Epigenome mapping highlights chromatin-mediated gene regulation in the protozoan parasite Trichomonas vaginalis
- Author
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Hyoung-Pyo Kim, Juri Kim, Soon-Jung Park, Mikyoung Kim, Tai Soon Yong, Min Ji Song, Yeeun Choi, and Myung Hee Yi
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Epigenomics ,0301 basic medicine ,Transcription, Genetic ,Protozoan Proteins ,Biology ,Article ,Histone Deacetylases ,Epigenesis, Genetic ,Histones ,03 medical and health sciences ,Histone H3 ,0302 clinical medicine ,Trichomonas vaginalis ,Transcriptional regulation ,Animals ,Parasites ,Epigenetics ,Regulation of gene expression ,Genome ,Multidisciplinary ,Epigenome ,DNA Methylation ,Chromatin ,Cell biology ,030104 developmental biology ,Gene Expression Regulation ,H3K4me3 ,Histone deacetylase ,030217 neurology & neurosurgery - Abstract
Trichomonas vaginalis is an extracellular flagellated protozoan parasite that causes trichomoniasis, one of the most common non-viral sexually transmitted diseases. To survive and to maintain infection, T. vaginalis adapts to a hostile host environment by regulating gene expression. However, the mechanisms of transcriptional regulation are poorly understood for this parasite. Histone modification has a marked effect on chromatin structure and directs the recruitment of transcriptional machinery, thereby regulating essential cellular processes. In this study, we aimed to outline modes of chromatin-mediated gene regulation in T. vaginalis. Inhibition of histone deacetylase (HDAC) alters global transcriptional responses and induces hyperacetylation of histones and hypermethylation of H3K4. Analysis of the genome of T. vaginalis revealed that a number of enzymes regulate histone modification, suggesting that epigenetic mechanisms are important to controlling gene expression in this organism. Additionally, we describe the genome-wide localization of two histone H3 modifications (H3K4me3 and H3K27Ac), which we found to be positively associated with active gene expression in both steady and dynamic transcriptional states. These results provide the first direct evidence that histone modifications play an essential role in transcriptional regulation of T. vaginalis, and may help guide future epigenetic research into therapeutic intervention strategies against this parasite.
- Published
- 2017
22. The pathophysiological role of dendritic cell subsets in psoriasis
- Author
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Tae-Gyun Kim, Dae Suk Kim, Min Geol Lee, and Hyoung-Pyo Kim
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Tumor Necrosis Factor-alpha ,Thrombomodulin ,Nitric Oxide Synthase Type II ,Human skin ,Dendritic Cells ,Review Article ,General Medicine ,Disease ,Dendritic cell ,Biology ,medicine.disease ,Biochemistry ,Proinflammatory cytokine ,Pathogenesis ,Antigen ,Psoriasis ,Antigens, Surface ,Immunology ,medicine ,Animals ,Humans ,Tumor necrosis factor alpha ,Molecular Biology ,Skin - Abstract
Psoriasis is a chronic inflammatory disorder characterized by an erythematous scaly plaque of the skin and is occasionally accompanied by systemic complications. In the psoriatic lesions, an increased number of cytokine-producing dendritic cells and activated T cells are observed, which indicate that psoriasis is a prototype of an immune-mediated dermatosis. During the last decade, emerging studies demonstrate novel roles for the dendritic cell subsets in the process of disease initiation and maintenance of psoriasis. In addition, recently discovered anti-psoriatic therapies, which specifically target inflammatory cytokines produced by lesional dendritic cells, bring much better clinical improvement compared to conventional treatments. These new therapies implicate the crucial importance of dendritic cells in psoriasis pathogenesis. This review will summarize and discuss the dendritic cell subsets of the human skin and their pathophysiological involvement in psoriasis based on mouse- and patient-oriented studies. [BMB Reports 2014; 47(2): 60-68]
- Published
- 2014
23. CCCTC-binding factor regulates the development and function of dendritic cells
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Bobae Yang, Tae-Gyun Kim, Sueun Kim, and Hyoung-Pyo Kim
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Immunology ,Immunology and Allergy - Abstract
Dendritic cells (DCs) are professional antigen presenting cells, which present antigen to cognate T cells. DC activation through diverse toll-like receptors is prerequisite for triggering efficient immune responses to foreign antigens. CCCTC-binding factor (CTCF) is a DNA binding protein that regulates 3D genome structure which is believed to be important to control of gene expression. Here we described that CTCF is required for development and function in DCs. CTCF is critically required for the FLT3L-dependent CD11c+ DCs (FL-DCs) development, unlike for those in the GM-CSF-dependent CD11c+ DC (GM-DCs) development. However, the resultant CTCF-deficient DC number was decreased by 50% in both FLT3L- and GM-CSF-supplemented culture conditions. Although CTCF was required for bone marrow (BM) progenitor proliferation in both FLT3L-and GM-CSF-supplemented cultures, CTCF-deficient GM-DCs showed normal cellular apoptosis rate and higher CD11c+ DC differentiation. Upon TLR4 ligation, CTCF-deficient DCs showed higher expression levels of surface MHCII and co-stimulatory molecules compared to those WT DCs. Thus, our data indicate that CTCF plays a critical role in the overall differentiation, survival, and maturation of DCs.
- Published
- 2019
24. Transcriptional and epigenetic networks in the development and maturation of dendritic cells
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Jong Hoon Park, Young Joon Kim, Hyoung-Pyo Kim, and Yeon-Su Lee
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Genetics ,Cancer Research ,Cell Differentiation ,Dendritic Cells ,Epigenome ,Adaptive Immunity ,Biology ,Chromatin ,Immunity, Innate ,Epigenesis, Genetic ,Cell biology ,Transcriptome ,Haematopoiesis ,Immune system ,DNA methylation ,Cytokines ,Humans ,Cell Lineage ,Gene Regulatory Networks ,Epigenetics ,Transcription factor ,Signal Transduction - Abstract
Dendritic cells (DCs) are professional antigen-presenting cells that provide a critical link between the innate and adaptive immune responses. The genetic program required for differentiation of DCs from their hematopoietic precursors is controlled by both cytokines and transcription factors. The signals transduced from cytokines recruit specific transcription factors, enabling the expression of a distinct transcriptome that is required for specification of different DC lineages. The establishment of a distinct transcriptome also depends on chromatin modifications associated with critical cis elements of lineage-specific genes. In this review, recent advances in the understanding of the transcriptional network governing DC lineage specification are summarized, along with current views of the dynamic DC epigenome.
- Published
- 2013
25. Tumor Necrosis Factor-producing T-regulatory Cells Are Associated With Severe Liver Injury in Patients With Acute Hepatitis A
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Won Kim, Hyoung-Pyo Kim, Yoon Seok Choi, Jeewon Lee, Su-Hyung Park, Jun Yong Park, Sang Hoon Ahn, Hyun Woong Lee, Sung Hoon Choi, Seong Jin Choi, Jun R. Huh, Hyung Joon Kim, Jong Joo Lee, Dong Hyeon Lee, Eui-Cheol Shin, and Min Kyung Jung
- Subjects
0301 basic medicine ,Time Factors ,medicine.medical_treatment ,chemical and pharmacologic phenomena ,Inflammation ,Severity of Illness Index ,T-Lymphocytes, Regulatory ,Epigenesis, Genetic ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,RAR-related orphan receptor gamma ,Antigens, CD ,medicine ,Humans ,IL-2 receptor ,Cells, Cultured ,Hepatology ,business.industry ,Tumor Necrosis Factor-alpha ,Apyrase ,Gastroenterology ,Interleukin-2 Receptor alpha Subunit ,FOXP3 ,hemic and immune systems ,Carboxyfluorescein succinimidyl ester ,Forkhead Transcription Factors ,DNA Methylation ,Hepatitis A ,Nuclear Receptor Subfamily 1, Group F, Member 3 ,030104 developmental biology ,Cytokine ,Phenotype ,chemistry ,Liver ,030220 oncology & carcinogenesis ,Case-Control Studies ,Immunology ,Acute Disease ,Host-Pathogen Interactions ,Th17 Cells ,Tumor necrosis factor alpha ,Hepatitis A virus ,medicine.symptom ,business ,Signal Transduction - Abstract
Background and Aims CD4 + CD25 + Foxp3 + T-regulatory (Treg) cells control immune responses and maintain immune homeostasis. However, under inflammatory conditions, Treg cells produce cytokines that promote inflammation. We investigated production of tumor necrosis factor (TNF) by Treg cells in patients with acute hepatitis A (AHA), and examined the characteristics of these cells and association with clinical factors. Methods We analyzed blood samples collected from 63 patients with AHA at the time of hospitalization (and some at later time points) and 19 healthy donors in South Korea. Liver tissues were collected from patients with fulminant AHA during liver transplantation. Peripheral blood mononuclear cells were isolated from whole blood and lymphocytes were isolated from liver tissues and analyzed by flow cytometry. Cytokine production from Treg cells (CD4 + CD25 + Foxp3 + ) was measured by immunofluorescence levels following stimulation with anti-CD3 and anti-CD28. Epigenetic stability of Treg cells was determined based on DNA methylation patterns. Phenotypes of Treg cells were analyzed by flow cytometry and an RORγt inhibitor, ML-209, was used to inhibit TNF production. Treg cell suppression assay was performed by co-culture of Treg-depleted peripheral blood mononuclear cells s and isolated Treg cells. Results A higher proportion of CD4 + CD25 + Foxp3 + Treg cells from patients with AHA compared with controls produced TNF upon stimulation with anti-CD3 and anti-CD28 (11.2% vs 2.8%). DNA methylation analysis confirmed the identity of the Treg cells. TNF-producing Treg cells had features of T-helper 17 cells, including up-regulation of RORγt, which was required for TNF production. The Treg cells had reduced suppressive functions compared with Treg cells from controls. The frequency of TNF-producing Treg cells in AHA patients' blood correlated with their serum level of alanine aminotransferase. Conclusions Treg cells from patients with AHA have altered functions compared with Treg cells from healthy individuals. Treg cells from patients with AHA produce higher levels of TNF, gain features of T-helper 17 cells, and have reduced suppressive activity. The presence of these cells is associated with severe liver injury in patients with AHA.
- Published
- 2016
26. High dose bisphenol A impairs hippocampal neurogenesis in female mice across generations
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Seon Young Choi, Joo-Hong Park, Hyung Sik Kim, Wook-Jin Yang, Hee Ra Park, Young Jung Jang, Jaewon Lee, Jong-Joo Lee, Tae Hyung Kim, Eunjin Lee, Shin Bi Oh, and Hyoung-Pyo Kim
- Subjects
MAPK/ERK pathway ,endocrine system ,medicine.medical_specialty ,Offspring ,Neurogenesis ,Endocrine Disruptors ,Hippocampal formation ,Toxicology ,CREB ,Hippocampus ,Mice ,Cognition ,Phenols ,Pregnancy ,Neurotrophic factors ,Internal medicine ,medicine ,Animals ,Learning ,Estrogens, Non-Steroidal ,Epigenetics ,Benzhydryl Compounds ,Cyclic AMP Response Element-Binding Protein ,Maternal-Fetal Exchange ,biology ,urogenital system ,Brain-Derived Neurotrophic Factor ,Mice, Inbred C57BL ,Endocrinology ,DNA methylation ,biology.protein ,Female ,hormones, hormone substitutes, and hormone antagonists - Abstract
Bisphenol A (BPA) is used as a monomer during the manufacture of polycarbonate plastics and epoxy resins. However, BPA adversely affects reproductive organ growth and development, and it has been proposed that the detrimental effects of BPA could extend to future generations. The present study was conducted to evaluate the transgenerational effects of BPA on hippocampal neurogenesis and neurocognitive function. Pregnant female C57BL/6 mice (F0) were exposed to BPA (0.1–10 mg/kg) from gestation day 6 to 17, and female offspring (F2) from F1 generation mice were prepared. It was found that exposure of F0 mice to BPA at 10 mg/kg decreased the number of newly generated cells in the hippocampi of F2 female mice. Passive avoidance testing revealed that high-doses BPA (1 mg/kg and 10 mg/kg) decreased cross-over latency time in F2 mice, suggesting a BPA-mediated neurocognitive deficit in terms of memory retention. Furthermore, it was found that levels of phospho-ERK, brain-derived neurotrophic factor (BDNF), and phospho-CREB in hippocampi were significantly lower in F2 mice. Interestingly, the effects of BPA on hippocampal neurogenesis were found to be correlated with altered DNA methylation. In particular, high-dose BPA exposure increased DNA methylation of the CREB regulated transcription coactivator 1 (Crtc1) generated in F2 mice. These findings suggest that BPA exposure of pregnant mothers could adversely affect hippocampal neurogenesis and cognitive function in future generations by modulating the ERK and BDNF–CREB signaling cascades.
- Published
- 2012
27. Leukotriene B4 receptor BLT-mediated phosphorylation of NF-κB and CREB is involved in IL-8 production in human mast cells induced by Trichomonas vaginalis-derived secretory products
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Young Ah Lee, Kyeong Ah Kim, Hyoung-Pyo Kim, Kyoung-Ju Song, Deulle Min, Young Hee Nam, Seonghoon Kim, and Myeong Heon Shin
- Subjects
Thiosemicarbazones ,medicine.medical_specialty ,Chemokine ,Hot Temperature ,Immunology ,Trichomonas Infections ,Receptors, Cell Surface ,Cyclopentanes ,Biology ,CREB ,Leukotriene B4 ,Microbiology ,chemistry.chemical_compound ,Internal medicine ,Trichomonas vaginalis ,medicine ,Humans ,Mast Cells ,Interleukin 8 ,Phosphorylation ,Cyclic AMP Response Element-Binding Protein ,Cells, Cultured ,Interleukin-8 ,Leukotriene B4 receptor ,NF-kappa B ,Transcription Factor RelA ,NF-κB ,Lipase ,Lipid signaling ,Molecular biology ,Infectious Diseases ,Secretory protein ,Endocrinology ,Gene Expression Regulation ,chemistry ,Culture Media, Conditioned ,biology.protein ,Female ,Endopeptidase K ,Signal Transduction - Abstract
Trichomonas vaginalis is a protozoan parasite that causes acute tissue inflammation in vaginal trichomoniasis. In this study, we investigated the signaling mechanisms through which T. vaginalis-derived secretory products (TvSP) induce chemokine IL-8 production in human mast cells. Stimulation with TvSP induced up-regulation of IL-8 protein secretion in HMC-1 cells. In addition, TvSP induced phosphorylation of transcription factors NF-κB and CREB in HMC-1 cells. Pretreatment of TvSP with lipase, but not heat or proteinase K strongly abolished the stimulatory effect on IL-8 production. Moreover, TvSP-induced IL-8 production and phosphorylation of NF-κB or CREB were inhibited when HMC-1 cells were stimulated with modified TvSP collected from 5-lipooxygenase inhibitor-treated trichomonads. Indeed, T. vaginalis-secreted lipid mediator LTB(4) (700pg/ml) from 1×10(7) trichomonads. Furthermore, pretreatment of HMC-1 cells with antagonists for LTB(4) receptors BLT1 or BLT2 abolished the stimulatory effects of TvSP. Finally, TvSP-induced IL-8 production was inhibited by pretreatment with IκB or CREB inhibitors. These results suggest that T. vaginalis-derived secretory lipid mediator LTB(4) induces IL-8 production in mast cells via BLT-dependent activation of NF-κB and CREB.
- Published
- 2011
28. Transcriptional activation of the IL31 gene by NFAT and STAT6
- Author
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Keunhee Park, Jong-Joo Lee, Wook-Jin Yang, Min-Ji Song, Hyoung-Pyo Kim, and Joo-Hong Park
- Subjects
CD4-Positive T-Lymphocytes ,Male ,NFATC2 ,Transcription, Genetic ,Recombinant Fusion Proteins ,medicine.medical_treatment ,Molecular Sequence Data ,Immunology ,chemistry.chemical_element ,Regulatory Sequences, Nucleic Acid ,Calcium ,Biology ,Jurkat cells ,Jurkat Cells ,Mice ,Sequence Homology, Nucleic Acid ,medicine ,Animals ,Humans ,Immunology and Allergy ,Mast Cells ,Promoter Regions, Genetic ,Serum Albumin ,Interleukin 4 ,STAT6 ,Base Sequence ,NFATC Transcription Factors ,integumentary system ,Interleukins ,Ionomycin ,NFAT ,Cell Biology ,Molecular biology ,Rats ,Mice, Inbred C57BL ,HEK293 Cells ,Cytokine ,chemistry ,Tetradecanoylphorbol Acetate ,Interleukin-4 ,Signal transduction ,STAT6 Transcription Factor ,Sequence Alignment ,Dinitrophenols - Abstract
IL-31, a newly identified member of the IL-6 cytokine family, is involved in many pathological conditions, including atopic dermatitis and pruritis. In this study, we investigated how expression of IL-31 is regulated in T cells and mast cells. We observed that expression of IL-31 required a calcium signal and was dependent on the calcineurin-NFAT signaling pathway. Moreover, we found that IL-31 promoter contains a positive regulatory region that mediates calcium- and IL-4-dependent induction of the IL-31 gene and demonstrated that a change into an open chromatin conformation occurs in this region after stimulation with calcium and IL-4. Whereas IL-4 responsiveness required STAT6 binding sites, calcium responsiveness of IL-31 promoter required NFAT binding sites that bind NFATc1 and NFATc2 in vitro and in vivo. The induction of IL-31 promoter activity was impaired when these sites were mutated but was enhanced by CA-NFATc1 or STAT6 proteins and further increased synergistically by combinations of both proteins. Furthermore, the importance of STAT6 proteins was indicated by impaired, IL-4-mediated induction of IL-31 in STAT6-diminished Jurkat cells. Thus, our data demonstrate that calcium and IL-4 signals are required to mediate induction of IL-31 in Th2 cells and mast cells and that this induction appears to result from specific binding of NFAT and STAT6 proteins.
- Published
- 2011
29. Accessible chromatin structure permits factors Sp1 and Sp3 to regulate human TGFBI gene expression
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Hyoung-Pyo Kim, Joo-Hong Park, Keunhee Park, Tai Soon Yong, Eung Kweon Kim, Min Ji Song, Myeong Heon Shin, Wook Jin Yang, and Jong Joo Lee
- Subjects
Small interfering RNA ,Sp1 Transcription Factor ,Biophysics ,Biology ,Biochemistry ,Cell Line ,Histones ,Transforming Growth Factor beta ,Transcription (biology) ,Cell Line, Tumor ,Humans ,RNA, Messenger ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,Extracellular Matrix Proteins ,Gene knockdown ,Promoter ,Cell Biology ,Molecular biology ,Chromatin ,eye diseases ,Sp3 Transcription Factor ,Histone ,Gene Expression Regulation ,Gene Knockdown Techniques ,biology.protein ,RNA Interference ,TGFBI - Abstract
Transforming growth factor beta 1-induced (TGFBI) protein is an extracellular matrix (ECM) protein that is associated with other ECM proteins and functions as a ligand for various types of integrins. In this study, we investigated how human TGFBI expression is regulated in lung and breast cancer cells. We observed that the TGFBI promoter in A549 and MBA-MD-231 cells, which constitutively express TGFBI, existed in an open chromatin conformation associated with transcriptionally permissive histone modifications. Moreover, we found that TGFBI expression required Sp1 transcription elements that can bind transcription factors Sp1 and Sp3 in vitro. Occupancy of the TGFBI promoter by Sp1 and Sp3 in vivo was only observed in TGFBI-expressing cells, indicating that open chromatin conformation might facilitate the binding of Sp1 and Sp3 to the TGFBI promoter region. TGFBI promoter activity was impaired when Sp1 elements were mutated, but was increased when Sp1 or Sp3 factors was overexpressed. Furthermore, Sp1 inhibition in vivo by mithramycin A, as well as knockdown of Sp1 and/or Sp3 expression by short interfering RNA, significantly reduced TGFBI mRNA and protein levels. Thus, our data demonstrated that the expression of TGFBI is well correlated with chromatin conformation at the TGFBI promoter, and that factors Sp1 and Sp3 are the primary determinants for the control of constitutive expression of TGFBI gene.
- Published
- 2011
30. Programmed cell death ligand 1 alleviates psoriatic inflammation by suppressing IL-17A production from programmed cell death 1-high T cells
- Author
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Eui-Cheol Shin, Song Ee Kim, Tae-Gyun Kim, Jong Hoon Kim, Young Joon Choi, Soo Chan Kim, Byung Ha Lee, Young Chul Sung, Su-Hyung Park, Jihye Kim, Hyoung-Pyo Kim, Junsik Park, Chae Yeon Ban, and Mi Young Song
- Subjects
0301 basic medicine ,T cell ,Immunology ,Population ,Programmed Cell Death 1 Receptor ,Inflammation ,B7-H1 Antigen ,03 medical and health sciences ,0302 clinical medicine ,Adjuvants, Immunologic ,T-Lymphocyte Subsets ,Psoriasis ,PD-L1 ,medicine ,Immunology and Allergy ,Animals ,Humans ,education ,Skin ,Toll-like receptor ,education.field_of_study ,Imiquimod ,biology ,Interleukin-17 ,medicine.disease ,Recombinant Proteins ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,biology.protein ,Aminoquinolines ,Interleukin 17 ,medicine.symptom - Abstract
Background Psoriasis is one of the most common chronic inflammatory diseases of the skin. Recently, IL-17–producing T cells have been shown to play a critical role in psoriatic inflammation. Programmed cell death 1 (PD-1) is a coinhibitory receptor expressed on T cells in various chronic inflammatory diseases; however, the expression and function of PD-1 during psoriatic inflammation have not previously been characterized. Objective We examined PD-1 expression on IL-17A–producing T cells from imiquimod-treated mice and patients with psoriasis. Additionally, we investigated the therapeutic effect of recombinant programmed cell death ligand 1 (PD-L1) protein on imiquimod-induced psoriatic inflammation. Methods PD-1 expression on IL-17A–producing γδ T cells from imiquimod-treated mice was examined by means of multicolor flow cytometric analysis. In the psoriatic skin of patients, PD-1 and IL-17A expression was analyzed by using immunofluorescence. The therapeutic effect of PD-L1–Fc fusion protein (PD-L1-Fc) was assessed in imiquimod-treated mice ex vivo and in vivo . Results During imiquimod-induced psoriatic inflammation, PD-1 is overexpressed on CD27 − Vγ1 − γδ T cells. Furthermore, PD-1 expression on IL-17A + T cells was confirmed in psoriatic skin tissues from patients and imiquimod-treated mice. In the CD27 − Vγ1 − γδ T-cell population, Vγ4 − γδ T cells with Vγ6 mRNA expression showed a high level of PD-1 expression. Furthermore, these PD-1 hi Vγ4 − (Vγ6 + ) γδ T cells were specialized for anti-CD3–induced IL-17A production, which was inhibited by PD-L1-Fc treatment. In imiquimod-treated mice PD-L1-Fc reduced psoriatic inflammation when given alone and enhanced the therapeutic effect of anti-p40 when given in combination. Conclusion PD-1 is overexpressed in IL-17A–producing T cells in both imiquimod-treated mice and patients with psoriasis. Moreover, recombinant PD-L1-Fc alleviates psoriatic inflammation in imiquimod-treated mice.
- Published
- 2015
31. Dynamic Long-Range Chromatin Interaction Controls Expression of IL-21 in CD4+ T Cells
- Author
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Min-Ji Song, Jong-Joo Lee, Yeeun Choi, Keunhee Park, Hyoung-Pyo Kim, and Joo-Hong Park
- Subjects
0301 basic medicine ,CD4-Positive T-Lymphocytes ,STAT3 Transcription Factor ,CCCTC-Binding Factor ,Chromosomal Proteins, Non-Histone ,Immunology ,Repressor ,Cell Cycle Proteins ,Biology ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Transcriptional regulation ,Immunology and Allergy ,Animals ,Humans ,Enhancer ,Promoter Regions, Genetic ,Gene ,ChIA-PET ,Conserved Sequence ,Regulation of gene expression ,Base Sequence ,NFATC Transcription Factors ,Interleukin-6 ,Interleukins ,Molecular biology ,Chromatin ,DNA-Binding Proteins ,Mice, Inbred C57BL ,Repressor Proteins ,030104 developmental biology ,Enhancer Elements, Genetic ,Gene Expression Regulation ,CTCF ,030215 immunology ,Signal Transduction - Abstract
IL-21, a pleiotropic cytokine strongly linked with autoimmunity and inflammation, regulates diverse immune responses. IL-21 can be potently induced in CD4+ T cells by IL-6; however, very little is known about the mechanisms underlying the transcriptional regulation of the Il21 gene at the chromatin level. In this study, we demonstrated that a conserved noncoding sequence located 49 kb upstream of the Il21 gene contains an enhancer element that can upregulate Il21 gene expression in a STAT3- and NFAT-dependent manner. Additionally, we identified enhancer-blocking insulator elements in the Il21 locus, which constitutively bind CTCF and cohesin. In naive CD4+ T cells, these upstream and downstream CTCF binding sites interact with each other to make a DNA loop; however, the Il21 promoter does not interact with any cis-elements in the Il21 locus. In contrast, stimulation of CD4+ T cells with IL-6 leads to recruitment of STAT3 to the promoter and novel distal enhancer region. This induces dynamic changes in chromatin configuration, bringing the promoter and the regulatory elements in close spatial proximity. The long-range interaction between the promoter and distal enhancer region was dependent on IL-6/STAT3 signaling pathway but was disrupted in regulatory T cells, where IL-21 expression was repressed. Thus, our work uncovers a novel topological chromatin framework underlying proper transcriptional regulation of the Il21 gene.
- Published
- 2015
32. Both integrated and differential regulation of components of the IL-2/IL-2 receptor system
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Warren J. Leonard, Hyoung-Pyo Kim, and Jean Imbert
- Subjects
Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Immunology ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Cyclic AMP Response Element Modulator ,Mice ,STAT5 Transcription Factor ,medicine ,Animals ,Humans ,Immunology and Allergy ,IL-2 receptor ,RNA Processing, Post-Transcriptional ,Cyclic AMP Response Element-Binding Protein ,Receptor ,Common gamma chain ,Genetics ,Regulation of gene expression ,NFATC Transcription Factors ,Growth factor ,Interleukin-2 Receptor alpha Subunit ,NF-kappa B ,Receptors, Interleukin-2 ,Phenotype ,Cell biology ,Interleukin-2 Receptor beta Subunit ,Transcription Factor AP-1 ,Cytokine ,Gene Expression Regulation ,Interleukin-21 receptor ,Interleukin-2 - Abstract
Interleukin-2 was discovered in 1976 as a T-cell growth factor. It was the first type I cytokine cloned and the first for which a receptor component was cloned. Its importance includes its multiple actions, therapeutic potential, and lessons for receptor biology, with three components differentially combining to form high, intermediate, and low-affinity receptors. IL-2Ralpha and IL-2Rbeta, respectively, are markers for double-negative thymocytes and regulatory T-cells versus memory cells. gamma(c), which is shared by six cytokines, is mutated in patients with X-linked severe-combined immunodeficiency. We now cover an under-reviewed area-the regulation of genes encoding IL-2 and IL-2R components, with an effort to integrate/explain this knowledge.
- Published
- 2006
33. Mechanism mediated by a noncoding RNA, nc886, in the cytotoxicity of a DNA-reactive compound.
- Author
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Kunkeaw, Nawapol, Yeon-Su Lee, Im, Wonkyun Ronny, Jiyoung Joan Jang, Min-Ji Song, Bobae Yang, Jong-Lyul Park, Seon-Young Kim, Yongsuk Ku, Yoosik Kim, Sangmin Kang, Hye-ram Jo, Jae-Hoon Jeong, Hyun-Sung Lee, Ju-Seog Lee, Hyoung-Pyo Kim, Johnson, Betty H., In-Hoo Kim, and Yong Sun Lee
- Subjects
NON-coding RNA ,CELL-mediated cytotoxicity ,CELL proliferation ,DNA damage ,CANCER cells - Abstract
DNA-reactive compounds are harnessed for cancer chemotherapy. Their genotoxic effects are considered to be the main mechanism for the cytotoxicity to date. Because this mechanism preferentially affects actively proliferating cells, it is postulated that the cytotoxicity is specific to cancer cells. Nonetheless, they do harm normal quiescent cells, suggesting that there are other cytotoxic mechanisms to be uncovered. By employing doxorubicin as a representative DNA-reactive compound, we have discovered a cytotoxic mechanism that involves a cellular noncoding RNA (ncRNA) nc886 and protein kinase R (PKR) that is a proapoptotic protein. nc886 is transcribed by RNA polymerase III (Pol III), binds to PKR, and prevents it from aberrant activation in most normal cells. We have shown here that doxorubicin evicts Pol III from DNA and, thereby, shuts down nc886 transcription. Consequently, the instantaneous depletion of nc886 provokes PKR and leads to apoptosis. In a short-pulse treatment of doxorubicin, these events are the main cause of cytotoxicity preceding the DNA damage response in a 3D culture system as well as the monolayer cultures. By identifying nc886 as a molecular signal for PKR to sense doxorubicin, we have provided an explanation for the conundrum why DNA-damaging drugs can be cytotoxic to quiescent cells that have the competent nc886/PKR pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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34. Interleukin-21 Receptor Gene Induction in Human T Cells Is Mediated by T-Cell Receptor-Induced Sp1 Activity
- Author
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Keji Zhao, Hong Liu, Zheng Wu, Hyoung-Pyo Kim, Hai-Hui Xue, and Warren J. Leonard
- Subjects
Transcriptional Activation ,Chromatin Immunoprecipitation ,Transcription, Genetic ,Sp1 Transcription Factor ,T-Lymphocytes ,Amino Acid Motifs ,Blotting, Western ,Molecular Sequence Data ,Receptors, Antigen, T-Cell ,Gene Expression ,Biology ,Transfection ,Chromatography, Affinity ,Mass Spectrometry ,Genes, Reporter ,Deoxyribonuclease I ,Humans ,Cytotoxic T cell ,Lymphocytes ,RNA, Messenger ,IL-2 receptor ,Phosphorylation ,RNA, Small Interfering ,Luciferases ,Promoter Regions, Genetic ,Receptor ,Molecular Biology ,Regulation of gene expression ,Sp1 transcription factor ,Base Sequence ,Models, Genetic ,Reverse Transcriptase Polymerase Chain Reaction ,ZAP70 ,T-cell receptor ,Interleukin-21 Receptor alpha Subunit ,DNA Restriction Enzymes ,Exons ,Receptors, Interleukin ,Cell Biology ,Molecular biology ,Sp3 Transcription Factor ,Gene Expression Regulation ,Interleukin-21 receptor ,Mutation ,Receptors, Interleukin-21 ,Protein Binding - Abstract
Interleukin-21 (IL-21) plays important roles in regulating the immune response. IL-21 receptor (IL-21R) mRNA is expressed at a low level in human resting T cells but is rapidly induced by mitogenic stimulation. We now investigate the basis for IL21R gene regulation in T cells. We found that the −80 to −20 region critically regulates IL-21R promoter activity and corresponds to a major DNase I-hypersensitive site. Electrophoretic mobility shift assays, DNA affinity chromatography followed by mass spectrometry, and chromatin immunoprecipitation assays revealed that Sp1 binds to this region in vitro and in vivo. Moreover, mutation of the Sp1 motif markedly reduced IL-21R promoter activity, and Sp1 small interfering RNAs effectively diminished IL-21R expression in activated T cells. Interestingly, upon T-cell receptor (TCR) stimulation, T cells increased IL-21R expression and Sp1 protein levels while decreasing Sp1 phosphorylation. Moreover, phosphatase inhibitors that increased phosphorylation of Sp1 diminished IL-21R transcription. These data indicate that TCR-induced IL-21R expression is driven by TCR-mediated augmentation of Sp1 protein levels and may partly depend on the dephosphorylation of Sp1.
- Published
- 2005
35. Smad-dependent Cooperative Regulation of Interleukin 2 Receptor α Chain Gene Expression by T Cell Receptor and Transforming Growth Factor-β
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Warren J. Leonard, Byung-Gyu Kim, John J. Letterio, and Hyoung-Pyo Kim
- Subjects
CD4-Positive T-Lymphocytes ,T-Lymphocytes ,T cell ,Smad Proteins ,Biology ,Biochemistry ,Mice ,Interleukin 21 ,Transforming Growth Factor beta ,Interleukin 26 ,Interleukin-4 receptor ,medicine ,Animals ,Cytotoxic T cell ,IL-2 receptor ,Molecular Biology ,Interleukin 3 ,Binding Sites ,Reverse Transcriptase Polymerase Chain Reaction ,Interleukin-2 Receptor alpha Subunit ,Receptors, Interleukin ,Cell Biology ,Molecular biology ,Mice, Inbred C57BL ,Interleukin 10 ,medicine.anatomical_structure ,Gene Expression Regulation ,Signal Transduction - Abstract
The interleukin 2 receptor alpha chain (IL-2Ralpha) is a component of high affinity IL-2 receptors and thus critically regulates T cell growth and other lymphoid functions. Five positive regulatory regions together control lineage-restricted and activation-dependent IL-2Ralpha induction in response to antigen and IL-2. We now show that TGF-beta cooperates with T cell receptor (TCR) signaling to increase IL-2Ralpha gene expression. Moreover, we identify a sixth positive regulatory region that regulates IL-2Ralpha expression in cells treated with anti-CD3 + anti-CD28 as well as TGF-beta and show that this region contains binding sites for Smad3, AP-1, and cAMP-responsive element-binding protein/ATF proteins. The importance of Smad complexes is indicated by impaired IL-2Ralpha induction by TGF-beta in CD4+ T cells from both Smad3-/- and Smad4-/- mice. Thus, we have identified a novel positive regulatory region in the IL-2Ralpha gene that mediates TGF-beta-dependent induction of the gene. These findings have implications related to IL-2Ralpha expression on activated T cells and regulatory T cells.
- Published
- 2005
36. Activation of RBL-2H3 Mast Cells Is Dependent on Tyrosine Phosphorylation of Phospholipase D2 by Fyn and Fgr
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Jun Ho Lee, Erk Her, Jeung Whan Han, Wahn Soo Choi, Takaaki Hiragun, Michael A. Beaven, Ahmed Chahdi, Hyoung-Pyo Kim, and Young Mi Kim
- Subjects
Biology ,Proto-Oncogene Proteins c-fyn ,environment and public health ,Receptor tyrosine kinase ,Cell Line ,chemistry.chemical_compound ,Proto-Oncogene Proteins ,Phospholipase D ,medicine ,Animals ,Humans ,Point Mutation ,Mast Cells ,Enzyme Inhibitors ,Phosphorylation ,RNA, Small Interfering ,Cell Growth and Development ,Molecular Biology ,Tyrosine-protein kinase CSK ,Receptors, IgE ,Degranulation ,Tyrosine phosphorylation ,Cell Biology ,Mast cell ,Rats ,Enzyme Activation ,enzymes and coenzymes (carbohydrates) ,Pyrimidines ,src-Family Kinases ,medicine.anatomical_structure ,chemistry ,Biochemistry ,biology.protein ,Tyrosine ,lipids (amino acids, peptides, and proteins) ,Vanadates ,Tyrosine kinase ,Proto-oncogene tyrosine-protein kinase Src - Abstract
Phospholipase D (PLD) is activated via receptors in a wide variety of cells where it is thought to regulate intracellular signaling processes and functions such as membrane trafficking, cytoskeletal organization, and degranulation of mast cells (reviewed in references 15, 25, and 31). PLD catalyzes the hydrolysis of phosphatidylcholine to form phosphatidic acid, which is rapidly converted to other biologically active molecules, namely, lysophosphatidic acid and diacylglycerol. In the presence of relatively low concentrations of primary alcohols, the production of phosphatidic acid is diverted to more metabolically inert phosphatidylalcohols by transphosphatidylation, a reaction that is unique to PLD and one that is utilized in the assay of PLD in vivo (39) and to unmask the physiologic roles of phosphatidic acid (62). Two isoforms of PLD have been cloned, PLD1 and PLD2, with PLD1 existing as two variants, PLD1a and PLD1b (11, 21). PLD1 is activated in vitro by small GTPases such as ARF and Rho and protein kinase C (PKC) α in the presence of phosphatidylinositol 1,4-bisphosphate (PIP2) (4, 21, 37, 43, 55). There is also evidence that PLD1 can be regulated in vivo by Rho kinase (48), Ca2+/calmodulin-dependent kinase II (35), and PKC in a catalytically dependent or independent manner (21, 26, 63). PLD2, in contrast, is activated in vitro by PIP2 alone, and this activity is minimally affected by the small GTPases or PKCα (11, 32, 54). However, the mechanisms regulating PLD2 activity in vivo are unclear. There are reports of tyrosine phosphorylation of PLD1 (33, 36) and PLD2 (1, 44, 51) and indications from pharmacological studies that tyrosine phosphorylation may regulate PLD activity (6, 27, 36, 44). In addition, PLD2 was shown to associate with, and be phosphorylated by, the tyrosine kinase receptor for epidermal growth factor (EGF) (51) and by Src kinase (1, 42). Nevertheless, the role of such phosphorylation is uncertain. Although tyrosine-11 was identified as the specific residue phosphorylated in PLD2, mutation of this site enhanced basal PLD2 activity but had no effect on the magnitude of the PLD2 response to EGF (51). Mast cells and blood basophils are responsible for a variety of allergic disorders (5, 59). These cells respond to immunoglobulin E (IgE)-directed antigens via the high-affinity receptor for IgE, namely, FcɛRI, by release of granules that contain preformed inflammatory mediators and the generation of inflammatory lipids and cytokines. PLD is thought to play an essential role in mast cell degranulation (7, 10, 58). PLD is activated in isolated mast cells (12) and cultured mast cell lines (10, 28, 30) by a variety of stimulants, including antigen. Cross-linking of the IgE/FcɛRI complex with antigen results in the recruitment and activation of Src kinases and subsequently other tyrosine kinases. The function of the individual PLD isoforms in mast cells has been studied in the RBL-2H3 cell line, which is now known to be an analog of rat mucosal mast cells (49). Studies with transiently expressed forms of both PLDs in RBL-2H3 cells indicate that PLD1b and PLD2 associate with granule membranes and the plasma membrane, respectively (7, 9), and that both isoforms are activated upon antigen stimulation (8, 40). The mechanisms of activation of these PLDs by antigen are unknown. However, the location of PLD2 at the plasma membrane makes this isoform particularly accessible to FcɛRI-associated tyrosine kinases. As reported here, activation of PLD and degranulation in antigen-stimulated RBL-2H3 cells is inhibited by low concentrations of the Src kinase inhibitor PP2. We investigated whether Src kinases regulate PLD directly by tyrosine phosphorylation and, if so, whether this phosphorylation is essential for degranulation. We show by coexpression studies, site-directed mutagenesis, and the use of small interfering RNAs (siRNAs) directed against Src kinases that Fyn and Fgr phosphorylate PLD2 but not PLD1b in vitro and in vivo and that this phosphorylation is required for the activation of PLD2 in vivo. Furthermore, suppression of this phosphorylation or the activation of PLD2 itself by various strategies also results in suppression of degranulation in stimulated RBL-2H3 cells.
- Published
- 2004
37. The basis for TCR-mediated regulation of the IL-2 receptor alpha chain gene: role of widely separated regulatory elements
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Warren J. Leonard and Hyoung-Pyo Kim
- Subjects
Transcriptional Activation ,Proto-Oncogene Proteins c-jun ,Response element ,Receptors, Antigen, T-Cell ,Mice, Transgenic ,Lymphocyte proliferation ,Biology ,Lymphocyte Activation ,Article ,General Biochemistry, Genetics and Molecular Biology ,Cell Line ,Mice ,Genes, Reporter ,Genes, Regulator ,Animals ,Enzyme Inhibitors ,Molecular Biology ,Transcription factor ,Regulation of gene expression ,Models, Genetic ,NFATC Transcription Factors ,General Immunology and Microbiology ,General Neuroscience ,T-cell receptor ,Nuclear Proteins ,Receptors, Interleukin-2 ,NFAT ,Molecular biology ,DNA-Binding Proteins ,Transcription Factor AP-1 ,Gene Expression Regulation ,Regulatory sequence ,Cyclosporine ,Signal Transduction ,Transcription Factors - Abstract
The interleukin-2 receptor alpha (IL-2Ralpha) chain is a component of high-affinity IL-2 receptors and thus is a key regulator of lymphocyte proliferation. Lineage-restricted and activation-dependent IL-2Ralpha transcription is controlled by four upstream positive regulatory regions (PRRs) and one downstream PRR. We now demonstrate that T-cell receptor (TCR) responsiveness requires both upstream sequences and an intronic region, PRRIV, previously identified as an IL-2 response element. Whereas IL-2 responsiveness requires Stat5 and HMG-I(Y) binding, TCR responsiveness of PRRIV requires two AP-1- and two NFAT-binding sites that bind Jun, Fos and NFAT family members in vitro and in vivo. Moreover, IL-2Ralpha induction is impaired in T lymphocytes from transgenic mice expressing a dominant-negative c-jun construct, or following treatment with cyclosporin A. Thus, our data indicate an important role for both AP-1 and NFAT proteins for TCR-induced IL-2Ralpha expression and establish that both upstream and intronic sequences mediate TCR responsiveness of the IL-2Ralpha gene. Moreover, our data reveal a previously unappreciated link between the TCR-mediated up-regulation of the IL-2 and IL-2Ralpha genes.
- Published
- 2002
38. CCCTC-binding factor is essential to the maintenance and quiescence of hematopoietic stem cells in mice
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Tae-Gyun Kim, Bobae Yang, Soyeon Jung, Mikyoung Kim, Sueun Kim, Hyoung-Pyo Kim, and Min Geol Lee
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Adult ,0301 basic medicine ,CCCTC-Binding Factor ,Cellular differentiation ,Clinical Biochemistry ,Biology ,Biochemistry ,Mice ,03 medical and health sciences ,Conditional gene knockout ,Animals ,Humans ,Progenitor cell ,Molecular Biology ,Bone Marrow Transplantation ,Cell Proliferation ,Progenitor ,Mice, Knockout ,Gene Expression Profiling ,Cell Cycle ,Cell Differentiation ,Cell cycle ,Hematopoietic Stem Cells ,Hematopoiesis ,Tamoxifen ,Haematopoiesis ,030104 developmental biology ,CTCF ,Cancer research ,RNA ,Molecular Medicine ,Original Article ,Stem cell ,Reactive Oxygen Species ,Biomarkers - Abstract
Hematopoiesis involves a series of lineage differentiation programs initiated in hematopoietic stem cells (HSCs) found in bone marrow (BM). To ensure lifelong hematopoiesis, various molecular mechanisms are needed to maintain the HSC pool. CCCTC-binding factor (CTCF) is a DNA-binding, zinc-finger protein that regulates the expression of its target gene by organizing higher order chromatin structures. Currently, the role of CTCF in controlling HSC homeostasis is unknown. Using a tamoxifen-inducible CTCF conditional knockout mouse system, we aimed to determine whether CTCF regulates the homeostatic maintenance of HSCs. In adult mice, acute systemic CTCF ablation led to severe BM failure and the rapid shrinkage of multiple c-Kithi progenitor populations, including Sca-1+ HSCs. Similarly, hematopoietic system-confined CTCF depletion caused an acute loss of HSCs and highly increased mortality. Mixed BM chimeras reconstituted with supporting BM demonstrated that CTCF deficiency-mediated HSC depletion has both cell-extrinsic and cell-intrinsic effects. Although c-Kithi myeloid progenitor cell populations were severely reduced after ablating Ctcf, c-Kitint common lymphoid progenitors and their progenies were less affected by the lack of CTCF. Whole-transcriptome microarray and cell cycle analyses indicated that CTCF deficiency results in the enhanced expression of the cell cycle-promoting program, and that CTCF-depleted HSCs express higher levels of reactive oxygen species (ROS). Importantly, in vivo treatment with an antioxidant partially rescued c-Kithi cell populations and their quiescence. Altogether, our results suggest that CTCF is indispensable for maintaining adult HSC pools, likely by regulating ROS-dependent HSC quiescence.
- Published
- 2017
39. CCCTC-binding factor controls the homeostatic maintenance and migration of Langerhans cells
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Jong Joo Lee, Tae-Gyun Kim, Mikyoung Kim, Jin Won Cho, Yeon-Su Lee, Yeeun Choi, Yangsin Lee, Min Geol Lee, Youn Wook Chung, Jeong Hwan Je, Chae Gyu Park, Sung Hee Kim, Min Ji Song, and Hyoung-Pyo Kim
- Subjects
CCCTC-Binding Factor ,Receptors, CCR7 ,Langerhans cell ,Immunology ,chemical and pharmacologic phenomena ,Biology ,Dermatitis, Contact ,Mice ,RNA interference ,Cell Movement ,Conditional gene knockout ,medicine ,Cell Adhesion ,Immunology and Allergy ,Skin immunity ,Animals ,Homeostasis ,Humans ,RNA, Small Interfering ,Regulation of gene expression ,Mice, Knockout ,integumentary system ,Gene Expression Profiling ,Dendritic cell ,Chromatin ,Cell biology ,Repressor Proteins ,medicine.anatomical_structure ,Gene Expression Regulation ,CTCF ,Langerhans Cells ,Epidermis ,Haptens ,Signal Transduction - Abstract
Background Langerhans cells (LCs) are skin-resident dendritic cells (DCs) that orchestrate skin immunity. CCCTC-binding factor (CTCF) is a highly conserved DNA-binding protein that regulates higher-order chromatin organization and is involved in various gene regulation processes. Objective We sought to clarify a possible role for CTCF in LC homeostasis and function in vivo . Methods We used a conditional gene deletion mouse system to generate DC- and LC-specific CTCF-ablated mice. Short hairpin RNA–mediated RNA interference was used to silence CTCF expression in human monocyte-derived Langerhans cells. DC populations were assessed by using flow cytometry and immunofluorescence. Gene expression arrays were performed to identify genes regulated by CTCF in LCs. Contact hypersensitivity and epicutaneous sensitization responses were measured to examine the functional significance of CTCF ablation. Results DC-specific CTCF deletion led to a reduced pool of systemic DCs, with LCs most severely affected. Decreases in epidermal LC numbers were specifically associated with self-turnover defects. Interestingly, CTCF-deficient LCs demonstrated impaired migration out of the epidermis. Whole-transcriptome analyses revealed that genes that promoted cell adhesion were highly expressed, but CCR7 was downregulated in CTCF-depleted LCs. Hapten-induced contact hypersensitivity responses were more sustained in LC-specific CTCF-deficient mice, whereas epicutaneous sensitization to protein antigen was attenuated, indicating that CTCF-dependent LC homeostasis is required for optimal immune function of LCs in a context-dependent manner. Conclusion Our results show that CTCF positively regulates the homeostatic pool and the efficient emigration of LCs, which are required for modulating the functional immune network of the skin.
- Published
- 2014
40. The Basis for IL-2-Induced IL-2 Receptor α Chain Gene Regulation
- Author
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Warren J. Leonard, John F. Kelly, and Hyoung-Pyo Kim
- Subjects
Regulation of gene expression ,biology ,Response element ,Immunology ,Molecular biology ,Upstream activating sequence ,Infectious Diseases ,Regulatory sequence ,Transcription (biology) ,biology.protein ,Immunology and Allergy ,Binding site ,Receptor ,STAT5 - Abstract
The interleukin-2 receptor α (IL-2Rα) chain is an essential component of high-affinity IL-2 receptors. Accordingly, IL-2Rα expression helps to regulate T cell growth and other lymphoid functions. Lineage-restricted and activation-dependent IL-2Rα transcription is controlled by three upstream positive regulatory regions (PRRs). We now describe an additional IL-2 response element, PRRIV, within intron 1, in humans and mice. PRRIV activity requires GAS motifs that bind Stat5 proteins and additional upstream HMG-I(Y) binding sites. Moreover, IL-2 induces the binding of HMG-I(Y), Stat5a, and Stat5b in vivo to PRRIV and PRRIII, which also functions as an IL-2 response element. Thus, the IL-2 inducibility of the IL-2Rα gene is unexpectedly mediated by two widely separated regulatory Stat5-dependent elements, located both upstream and downstream of the transcription initiation sites.
- Published
- 2001
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41. Transcriptional Activation of the Human Manganese Superoxide Dismutase Gene Mediated by Tetradecanoylphorbol Acetate
- Author
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Hyoung-Pyo Kim, Jung-Hye Roe, Moon B. Yim, and P. Boon Chock
- Subjects
Transcriptional Activation ,Molecular Sequence Data ,Biology ,Response Elements ,medicine.disease_cause ,Biochemistry ,Gene Expression Regulation, Enzymologic ,Tumor Cells, Cultured ,Transcriptional regulation ,medicine ,Humans ,Phosphorylation ,Cyclic AMP Response Element-Binding Protein ,Promoter Regions, Genetic ,Molecular Biology ,Gene ,Protein kinase C ,Activating Transcription Factor 1 ,Messenger RNA ,Mutation ,Base Sequence ,Superoxide Dismutase ,NADPH Oxidases ,Promoter ,Cell Biology ,Molecular biology ,DNA-Binding Proteins ,Tetradecanoylphorbol Acetate ,Transcription Factors - Abstract
Transcriptional activation of human manganese superoxide dismutase (MnSOD) mRNA induced by a phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was examined to identify the responsive transcriptional regulator. The effect of various deletions and mutations within the 5′-flanking region of the human MnSOD gene promoter was evaluated using the luciferase reporter system in A549 human lung carcinoma cells. Deletion of a region between −1292 and −1202 nucleotides upstream of the transcription start site abolished TPA-responsive induction, whereas deletion of the putative binding sequence for NF-κB or AP-1 did not. The region between −1292 and −1202 contains a cAMP-responsive element-like sequence, TGACGTCT, which we identified as the manganese superoxide dismutase TPA-responsive element, MSTRE. Site-specific mutation of the MSTRE abolished the TPA-responsive induction, validating the critical role of this sequence. We detected specific MSTRE activity from nuclear extracts and demonstrated by antibody supershift assay that this activity is closely related to CREB-1/ATF-1. TPA treatment rapidly induced phosphorylation of the CREB-1/ATF-1-like factor via the protein kinase C pathway. These results led us to conclude that the human MnSOD gene having the promoter construct used in this study is induced by TPA via activation of a CREB-1/ATF-1-like factor and not via either NF-κB or AP-1. In addition, we found that this induction was blocked by inhibitors of flavoproteins and NADPH oxidases, indicating involvement of enhanced generation of superoxide radical anion as an upstream signal.
- Published
- 1999
42. Transcription factors Sp1 and Sp3 regulate expression of human ABCG2 gene and chemoresistance phenotype
- Author
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Jong-Joo Lee, Hyoung-Pyo Kim, Keunhee Park, Wook-Jin Yang, Jong Hoon Park, Eun Young Park, Min-Ji Song, and Joo-Hong Park
- Subjects
animal structures ,Lung Neoplasms ,Sp1 Transcription Factor ,Response element ,E-box ,Electrophoretic Mobility Shift Assay ,Biology ,Cell Line ,Side population ,Sp3 transcription factor ,ATP Binding Cassette Transporter, Subfamily G, Member 2 ,Humans ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,Side-Population Cells ,Gene knockdown ,Binding Sites ,General transcription factor ,GATA2 ,Cell Biology ,General Medicine ,Plicamycin ,Articles ,Molecular biology ,Neoplasm Proteins ,Gene Expression Regulation, Neoplastic ,Sp3 Transcription Factor ,Drug Resistance, Neoplasm ,Gene Knockdown Techniques ,embryonic structures ,ATP-Binding Cassette Transporters ,sense organs ,Cisplatin - Abstract
ABCG2 is a member of the ATP binding cassette (ABC) transmembrane proteins that plays an important role in stem cell biology and drug resistance of cancer cells. In this study, we investigated how expression of human ABCG2 gene is regulated in lung cancer A549 cells. Binding of Sp1 and Sp3 transcription factors to the ABCG2 promoter in vitro and in vivo was elucidated by electro-phoretic mobility shift assay and chromatin immunoprecipitation assay. The ABCG2 promoter activity was impaired when Sp1 sites were mutated but was enhanced by over-expression of Sp1 or Sp3 proteins. Knockdown of Sp1 or Sp3 expression by short interfering RNA significantly decreased the expression of ABCG2 mRNA and protein, resulting in attenuated formation of the side population in A549 cells. In addition, Sp1 inhibition in vivo by mithramycin A suppressed the percentage of the side population fraction and sphere forming activities of A549 cells. Moreover, inhibiting Sp1- or Sp3-dependent ABCG2 expression caused chemosensitization to the anticancer drug cisplatin. Collectively, our results demonstrate that Sp1 and Sp3 transcription factors are the primary determinants for activating basal transcription of the ABCG2 gene and play an important role in maintaining the side population phenotype of lung cancer cells.
- Published
- 2013
43. CTCF Regulates Otic Neurogenesis via Histone Modification in the Neurog1 Locus.
- Author
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Jeong-Oh Shin, Jong-Joo Lee, Mikyoung Kim, Youn Wook Chung, Hyehyun Min, Jae-Yoon Kim, Hyoung-Pyo Kim, and Jinwoong Bok
- Abstract
The inner ear is a complex sensory organ responsible for hearing and balance. Formation of the inner ear is dependent on tight regulation of spatial and temporal expression of genes that direct a series of developmental processes. Recently, epigenetic regulation has emerged as a crucial regulator of the development of various organs. However, what roles higher-order chromatin organization and its regulator molecules play in inner ear development are unclear. CCCTCbinding factor (CTCF) is a highly conserved 11-zinc finger protein that regulates the three-dimensional architecture of chromatin, and is involved in various gene regulation processes. To delineate the role of CTCF in inner ear development, the present study investigated inner ear-specific Ctcf knockout mouse embryos (Pax2-Cre; Ctcff
l/fl ). The loss of Ctcf resulted in multiple defects of inner ear development and severely compromised otic neurogenesis, which was partly due to a loss of Neurog1 expression. Furthermore, reduced Neurog1 gene expression by CTCF knockdown was found to be associated with changes in histone modification at the gene's promoter, as well as its upstream enhancer. The results of the present study demonstrate that CTCF plays an essential role in otic neurogenesis by modulating histone modification in the Neurog1 locus. [ABSTRACT FROM AUTHOR]- Published
- 2018
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44. Differential Expression of Superoxide Dismutases Containing Ni and Fe/Zn in Streptomyces Coelicolor
- Author
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Jung-Hye Roe, Eun-Ja Kim, Yung Chil Hah, and Hyoung-pyo Kim
- Subjects
Paraquat ,Molecular Sequence Data ,SOD1 ,SOD2 ,Biochemistry ,Superoxide dismutase ,chemistry.chemical_compound ,Tetramer ,Nickel ,Gene Expression Regulation, Fungal ,Metals, Heavy ,Amino Acid Sequence ,Edetic Acid ,Chelating Agents ,chemistry.chemical_classification ,Sequence Homology, Amino Acid ,biology ,Superoxide Dismutase ,Streptomyces coelicolor ,Fungal genetics ,biology.organism_classification ,Streptomyces ,Amino acid ,Oxidative Stress ,chemistry ,Spectrophotometry ,biology.protein ,Electrophoresis, Polyacrylamide Gel - Abstract
Streptomyces coelicolor contains two distinct superoxide dismutase (SOD) activities detected on native PAGE. The level of each changed differently depending on growth media and scarcely responded to paraquat, a superoxide-generating agent. The total SOD activity doubled in late exponential phase compared with that in mid-exponential phase and less than double upon treatment with plumbagin, another superoxide-generating agent. The two SODs from S. coelicolor ATCC 10147 (Müller) strain were purified to near homogeneity. SOD1, a tetramer of 13.4-kDa subunits, was found to be a novel type of SOD containing 0.74 mol nickel/mol subunit as determined by atomic absorption spectroscopy. SOD2, a tetramer of 22.2-kDa subunits, was found to contain 0.36 mol iron and 0.26 mol zinc/mol subunit. The N-terminal amino acid sequences of both SODs were determined. SOD2 is similar to manganese-containing superoxide dismutases (MnSODs) and iron-containing superoxide dismutases (FeSODs) from other organisms, whereas SOD1 is less similar to known SODs but still contains a few conserved amino acids. The effects of metals and chelating agents on the expression of these two SODs were examined. The presence of nickel at micromolar concentrations in growth media induced the expression of SOD1 (nickel-containing superoxide dismutase; NiSOD), whereas the expression of SOD2 (iron/zinc-containing superoxide dismutase; FeZnSOD) was repressed. The changes in SOD activities were positively correlated with the amount of each enzyme as determined by immunoblotting, suggesting that metals do not modulate the activity per se but the amount of each protein.
- Published
- 1996
45. Programmed cell death-ligand 1 ameliorates psoriatic inflammation by inhibiting TCR-induced IL-17A production of T cells overexpressing PD-1
- Author
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Jong Hoon Kim, Young Joon Choi, Byung Ha Lee, Mi-Young Song, Chae Yeon Ban, Jihye Kim, Junsik Park, Song-Ee Kim, Tae-Gyun Kim, Su-Hyung Park, Hyoung-Pyo Kim, Young-Chul Sung, Soo-Chan Kim, and Eui-Cheol Shin
- Subjects
Immunology ,Immunology and Allergy - Abstract
Psoriasis is one of the most common chronic inflammatory diseases in the skin. Recently, IL-17-producing T cells have been shown to play a critical role in psoriatic inflammation. Programmed cell death-1 (PD-1) is a co-inhibitory receptor expressed on T cells in various chronic inflammatory diseases; however, it remains to be elucidated whether PD-1 is overexpressed on T cells in psoriasis and whether PD-1 agonist alleviates psoriatic inflammation. We examined PD-1 expression on IL-17A-producing T cells from Imiquimod (IMQ)-treated mice and psoriasis patients. Additionally, we investigated the therapeutic effect of recombinant programmed cell death ligand-1-Fc (PD-L1-Fc) protein on IMQ-induced psoriatic inflammation. During IMQ-induced psoriatic inflammation, PD-1 is overexpressed on CD27−Vγ1− γδ T cells. Further, PD-1 expression on IL-17A+ T cells was confirmed in tissue samples from patients with psoriatic skin. In the CD27−Vγ1−γδ T cell population, Vγ4−γδ T cells with Vγ6 mRNA expression showed a high level of PD-1 expression. Further, these PD-1hiVγ4−(Vγ6+) γδ T cells were specialized for T-cell receptor (TCR)-induced IL-17A production, which was inhibited by PD-L1-Fc protein treatment. In IMQ-treated mice, PD-L1-Fc protein reduced psoriatic inflammation when given alone and enhanced the therapeutic effect of anti-p40 when given in combination. In conclusion, PD-1 is overexpressed in IL-17A-producing T cells in both IMQ-treated mice and psoriasis patients, and recombinant PD-L1-Fc protein alleviates psoriatic inflammation in IMQ-treated mice.
- Published
- 2016
46. IL-21 Promotes the Pathologic Immune Response to Pneumovirus Infection
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Joseph B. Domachowske, Zu-Xi Yu, Hyoung-Pyo Kim, Cynthia A. Bonville, Chi-Keung Wan, Warren J. Leonard, Rosanne Spolski, and Lu Wang
- Subjects
CD4-Positive T-Lymphocytes ,medicine.medical_treatment ,T cell ,Chemokine CXCL1 ,Immunology ,Mice, Transgenic ,Biology ,CD8-Positive T-Lymphocytes ,Virus ,Article ,Mice ,Immune system ,parasitic diseases ,medicine ,Immunology and Allergy ,Animals ,Pneumovirus Infections ,Lung ,Mice, Knockout ,medicine.diagnostic_test ,Interleukin-6 ,Interleukins ,Mice, Inbred C57BL ,Cytokine ,medicine.anatomical_structure ,Bronchoalveolar lavage ,Respiratory virus ,Murine pneumonia virus ,Th17 Cells ,Receptors, Interleukin-21 ,Bronchoalveolar Lavage Fluid ,CD8 - Abstract
IL-21 is a cytokine with pleiotropic actions, promoting terminal differentiation of B cells, increased Ig production, and the development of Th17 and T follicular helper cells. IL-21 is also implicated in the development of autoimmune disease and has antitumor activity. In this study, we investigated the role of IL-21 in host defense to pneumonia virus of mice (PVM), which initiates an infection in mice resembling that of respiratory syncytial virus disease in humans. We found that PVM-infected mice expressed IL-21 in lung CD4+ T cells. Following infection, Il21r−/− mice exhibited less lung infiltration by neutrophils than did wild-type (WT) mice and correspondingly had lower levels of the chemokine CXCL1 in bronchoalveolar lavage fluid and lung parenchyma. CD8+, CD4+, and γδ T cell numbers were also lower in the lungs of PVM-infected Il21r−/− mice than in infected WT mice, with normal Th17 cytokines but diminished IL-6 production in PVM-infected Il21r−/− mice. Strikingly, Il21r−/− mice had enhanced survival following PVM infection, and moreover, treatment of WT mice with soluble IL-21R-Fc fusion protein enhanced their survival. These data reveal that IL-21 promotes the pathogenic inflammatory effect of PVM and indicate that manipulating IL-21 signaling may represent an immunomodulatory strategy for controlling PVM and potentially other respiratory virus infections.
- Published
- 2012
47. Characterization of the major catalase from Streptomyces coelicolor ATCC 10147
- Author
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Jung-Hye Roe, Hyoung-pyo Kim, Jong-Soo Lee, and Yung Chil Hah
- Subjects
chemistry.chemical_classification ,biology ,Molecular mass ,Streptomyces coelicolor ,Substrate (chemistry) ,Catalase ,biology.organism_classification ,Microbiology ,Streptomyces ,Molecular Weight ,Enzyme ,Column chromatography ,chemistry ,Biochemistry ,Genes, Bacterial ,Mutagenesis ,Spectrophotometry ,Enzyme Stability ,Escherichia coli ,biology.protein ,Actinomycetales ,Polyacrylamide gel electrophoresis - Abstract
Streptomyces coelicolor ATCC 10147 produced catalases whose electrophoretic mobility varied depending on the growth phase in liquid culture. Polyacrylamide gel electrophoresis of cell extracts resulted in six catalase activity bands, which were designated Cat1 to Cat6. Of these. Cat4 appeared during all growth phases, whereas Cat1 appeared only during the stationary phase. Catalase-deficient mutants were screened by the H2O2 bubbling test following NTG mutagenesis. In all the non-bubbling mutants tested, the Cat4 activity band significantly decreased or disappeared, suggesting that Cat4 is the major catalase. Cat4 was purified to electrophoretic homogeneity and some of its properties analysed. The enzyme has a native molecular mass of 225 kDa, as determined by gel permeation column chromatography, and consists of four identical subunits of 57 kDa, as determined by SDS-PAGE. The enzyme contains 2.6 molecules of protohaem IX per tetramer, as indicated by the absorption spectrum. It was not reducible by sodium dithionite and exhibited no peroxidase activity with o-dianisidine as the substrate. All these characteristics, as well as inhibitor studies, indicate that the major vegetative catalase in S. coelicolor, unlike E. coli vegetative catalase, is a member of the typical monofunctional catalases found in eukaryotes and some bacteria.
- Published
- 1994
48. Key role for IL-21 in experimental autoimmune uveitis
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Warren J. Leonard, Wei Liao, William G. Telford, Lu Wang, Cheng-Rong Yu, Charles E. Egwuagu, and Hyoung-Pyo Kim
- Subjects
Interleukin 2 ,CD4-Positive T-Lymphocytes ,Adoptive cell transfer ,medicine.medical_treatment ,T-Lymphocytes ,Interleukin-1beta ,Mice, Transgenic ,Biology ,Retina ,Autoimmune Diseases ,Uveitis ,Mice ,medicine ,Animals ,Interleukin 6 ,Cells, Cultured ,Cell Proliferation ,Autoimmune disease ,Mice, Knockout ,Multidisciplinary ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Interleukins ,Interleukin-17 ,Biological Sciences ,medicine.disease ,Flow Cytometry ,Interleukin-10 ,Mice, Inbred C57BL ,Interleukin 10 ,Luminescent Proteins ,Cytokine ,Immunology ,biology.protein ,Interleukin-2 ,Receptors, Interleukin-21 ,Interleukin 17 ,Cytokine receptor ,medicine.drug - Abstract
IL-21 is a pleiotropic type 1 cytokine that shares the common cytokine receptor γ-chain, γ c , with IL-2, IL-4, IL-7, IL-9, and IL-15. IL-21 is most homologous to IL-2. These cytokines are encoded by adjacent genes, but they are functionally distinct. Whereas IL-2 promotes development of regulatory T cells and confers protection from autoimmune disease, IL-21 promotes differentiation of Th17 cells and is implicated in several autoimmune diseases, including type 1 diabetes and systemic lupus erythematosus. However, the roles of IL-21 and IL-2 in CNS autoimmune diseases such as multiple sclerosis and uveitis have been controversial. Here, we generated Il21 -mCherry/ Il2 -emGFP dual-reporter transgenic mice and showed that development of experimental autoimmune uveitis (EAU) correlated with the presence of T cells coexpressing IL-21 and IL-2 into the retina. Furthermore, Il21r −/− mice were more resistant to EAU development than wild-type mice, and adoptive transfer of Il21r −/− T cells induced much less severe EAU, underscoring the need for IL-21 in the development of this disease and suggesting that blocking IL-21/γ c –signaling pathways may provide a means for controlling CNS auto-inflammatory diseases.
- Published
- 2011
49. DNA methylation-dependent regulation of TrkA, TrkB, and TrkC genes in human hepatocellular carcinoma
- Author
-
Byung Ho Son, Min Soo Kim, Jong-Joo Lee, Hyoung-Pyo Kim, Yong Kyun Cho, and Wook Jin
- Subjects
Antimetabolites, Antineoplastic ,animal structures ,Carcinoma, Hepatocellular ,Molecular Sequence Data ,Biophysics ,Tropomyosin receptor kinase B ,Receptors, Nerve Growth Factor ,Tropomyosin receptor kinase A ,Biochemistry ,Tropomyosin receptor kinase C ,Gene Expression Regulation, Enzymologic ,Low-affinity nerve growth factor receptor ,Humans ,Receptor, trkB ,Receptor, trkC ,Receptor, trkA ,Promoter Regions, Genetic ,Molecular Biology ,Cell Proliferation ,biology ,Base Sequence ,Liver cell ,Liver Neoplasms ,Twist-Related Protein 1 ,Nuclear Proteins ,Cell Biology ,DNA Methylation ,Molecular biology ,Gene Expression Regulation, Neoplastic ,nervous system ,Trk receptor ,DNA methylation ,biology.protein ,Azacitidine ,Neurotrophin - Abstract
The tropomyosin-related kinase (Trk) family of neurotrophin receptors, TrkA, TrkB and TrkC, has been implicated in the growth and survival of human cancers. Here we report that Trks are frequently overexpressed in hepatocellular carcinoma (HCC) from patients and human liver cancer cell lines. To unravel the underlying molecular mechanism(s) for this phenomenon, DNA methylation patterns of CpG islands in TrkA, TrkB, and TrkC genes were examined in normal and cancer cell lines derived from liver. A good correlation was observed between promoter hypermethylation and lower expression of TrkA, TrkB, and TrkC genes, which was supported by the data that inhibiting DNA methylation with 5-azacytidine restored expression of those genes in normal liver cell lines. Furthermore, Trks promoted the proliferation of HepG2 and induced expression of the metastatic regulator, Twist. These results suggest that Trks may contribute to growth and metastasis of liver cancer.
- Published
- 2011
50. Analysis of interleukin-21-induced Prdm1 gene regulation reveals functional cooperation of STAT3 and IRF4 transcription factors
- Author
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Hyokjoon Kwon, Keiko Ozato, Kathryn Calame, Warren J. Leonard, Colleen E. Donovan, Chainarong Tunyaplin, David E. Levy, Matthew L. Goldman, Hyoung-Pyo Kim, Danielle Thierry-Mieg, Sebastian Carotta, Jean Thierry-Mieg, Jangsuk Oh, Stephen L. Nutt, and Prafullakumar Tailor
- Subjects
CD4-Positive T-Lymphocytes ,STAT3 Transcription Factor ,Cellular differentiation ,Response element ,Immunology ,Molecular Sequence Data ,Biology ,Article ,Mice ,Plasma cell differentiation ,PRDM1 ,Immunology and Allergy ,Animals ,Binding site ,STAT3 ,MOLIMMUNO ,Transcription factor ,Regulation of gene expression ,Mice, Knockout ,B-Lymphocytes ,Binding Sites ,Base Sequence ,Interleukins ,Cell Differentiation ,Molecular biology ,Introns ,Mice, Inbred C57BL ,Infectious Diseases ,Gene Expression Regulation ,CELLIMMUNO ,Interferon Regulatory Factors ,biology.protein ,Positive Regulatory Domain I-Binding Factor 1 ,Genome-Wide Association Study ,Transcription Factors - Abstract
SummaryInterleukin-21 (IL-21) is a pleiotropic cytokine that induces expression of transcription factor BLIMP1 (encoded by Prdm1), which regulates plasma cell differentiation and T cell homeostasis. We identified an IL-21 response element downstream of Prdm1 that binds the transcription factors STAT3 and IRF4, which are required for optimal Prdm1 expression. Genome-wide ChIP-Seq mapping of STAT3- and IRF4-binding sites showed that most regions with IL-21-induced STAT3 binding also bound IRF4 in vivo and furthermore revealed that the noncanonical TTCnnnTAA GAS motif critical in Prdm1 was broadly used for STAT3 binding. Comparing genome-wide expression array data to binding sites revealed that most IL-21-regulated genes were associated with combined STAT3-IRF4 sites rather than pure STAT3 sites. Correspondingly, ChIP-Seq analysis of Irf4−/− T cells showed greatly diminished STAT3 binding after IL-21 treatment, and Irf4−/− mice showed impaired IL-21-induced Tfh cell differentiation in vivo. These results reveal broad cooperative gene regulation by STAT3 and IRF4.
- Published
- 2008
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