701 results on '"Young-Tae Chang"'
Search Results
52. Synthetic Monosaccharide Channels: Size-Selective Transmembrane Transport of Glucose and Fructose Mediated by Porphyrin Boxes
- Author
-
Hong‐Guen Lee, Avinash Dhamija, Chandan K. Das, Kyeng Min Park, Young‐Tae Chang, Lars V. Schäfer, and Kimoon Kim
- Subjects
Glucose ,Monosaccharide Transport Proteins ,Monosaccharides ,Glucose Transport Proteins, Facilitative ,Biological Transport ,General Chemistry ,General Medicine ,Fructose ,Catalysis - Abstract
Here we report synthetic monosaccharide channels built with shape-persistent organic cages, porphyrin boxes (PBs), that allow facile transmembrane transport of glucose and fructose through their windows. PBs show a much higher transport rate for glucose and fructose over disaccharides such as sucrose, as evidenced by intravesicular enzyme assays and molecular dynamics simulations. The transport rate can be modulated by changing the length of the alkyl chains decorating the cage windows. Insertion of a linear pillar ligand into the cavity of PBs blocks the monosaccharide transport. In vitro cell experiment shows that PBs transport glucose across the living-cell membrane and enhance cell viability when the natural glucose transporter GLUT1 is blocked. Time-dependent live-cell imaging and MTT assays confirm the cyto-compatibility of PBs. The monosaccharide-selective transport ability of PBs is reminiscent of natural glucose transporters (GLUTs), which are crucial for numerous biological functions.
- Published
- 2022
53. Target identification of mouse stem cell probe CDy1 as ALDH2 and Abcb1b through live-cell affinity-matrix and ABC CRISPRa library†
- Author
-
Young-Hyun Go, Naoki Miyamoto, Xuezhi Bi, Larissa Miasiro Ciaramicoli, Heon Seok Kim, Haw-Young Kwon, Young Hyun Yu, Nam-Young Kang, Hyung-Ho Ha, Jin-Soo Kim, Seong-Wook Yun, Beomsue Kim, Young-Tae Chang, and Hyuk-Jin Cha
- Subjects
Mechanism (biology) ,Regeneration (biology) ,Cell ,ATP-binding cassette transporter ,Biology ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Biochemistry ,Embryonic stem cell ,Cell biology ,Chemistry ,medicine.anatomical_structure ,Chemistry (miscellaneous) ,medicine ,Identification (biology) ,Stem cell ,Molecular Biology ,Reprogramming - Abstract
CDy1 is a powerful tool to distingusih embryonic stem cells for reprogramming studies and regeneration medicine. However, the stem cell selectivity mechanism of CDy1 has not been fully understood. Here, we report ALDH2 and ABCB1 as the molecular targets of CDy1, elucidated by live-cell affinity-matrix and ABC transporter CRISPRa library screening. The two unique orthogonal mechanisms provide the potential of multi-demensional cellular distinction of specific cell types., CDy1 is a powerful tool to distingusih embryonic stem cells for reprogramming studies and regeneration medicine.
- Published
- 2021
54. A SLC35C2 Transporter‐Targeting Fluorescent Probe for the Selective Detection of B Lymphocytes Identified by SLC‐CRISPRi and Unbiased Fluorescence Library Screening
- Author
-
Min Gao, Sun Hyeok Lee, Raj Kumar Das, Haw‐Young Kwon, Heon Seok Kim, and Young‐Tae Chang
- Subjects
B-Lymphocytes ,Nucleotide Transport Proteins ,Humans ,General Chemistry ,General Medicine ,Catalysis ,Fluorescent Dyes ,Gene Library ,Neoplasm Proteins - Abstract
T and B lymphocytes are two major adaptive immune cells in the human defense system. To real-time monitor their diverse functions, a live-cell-selective probe for only one cell type is need to investigate the complex interaction of the immune cells. Herein, a small-molecule probe CDyB for live B cells is developed by an unbiased fluorescence library screening. The cell selectivity was confirmed by multiparametric single-cell analysis using CyTOF. Through a systematic SLC-CRISPRi library screening, the molecular target of CDyB was identified as SLC35C2 transporter based on a gating-oriented live-cell distinction (GOLD) mechanism. The gene expression analysis and knock-out experiments validated that the SLC35C2 transporter was the target for CDyB distinction. Interestingly, when CDyB was applied to study B cell development, the CDyB fluorescence and SLC35C2 expression were positively correlated with the B cell maturation process, and not involved in the T cell development.
- Published
- 2022
55. Adoptive therapy with amyloid-β specific regulatory T cells alleviates Alzheimer's disease
- Author
-
HyeJin Yang, Seon-Young Park, Hyunjung Baek, Chanju Lee, Geehoon Chung, Xiao Liu, Ji Hwan Lee, Byungkyu Kim, Minjin Kwon, Hyojung Choi, Hyung Joon Kim, Jae Yoon Kim, Younsub Kim, Ye-Seul Lee, Gaheon Lee, Sun Kwang Kim, Jin Su Kim, Young-Tae Chang, Woo Sang Jung, Kyung Hwa Kim, and Hyunsu Bae
- Subjects
Inflammation ,Mice ,Amyloid beta-Peptides ,Alzheimer Disease ,Medicine (miscellaneous) ,Animals ,Cognitive Dysfunction ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,T-Lymphocytes, Regulatory - Published
- 2022
56. TRPV4 regulates mitochondrial Ca2+-status and physiology in primary murine T cells based on their immunological state
- Author
-
Tusar Kanta Acharya, Shamit Kumar, Tejas Pravin Rokade, Young-Tae Chang, and Chandan Goswami
- Subjects
General Medicine ,General Pharmacology, Toxicology and Pharmaceutics ,General Biochemistry, Genetics and Molecular Biology - Published
- 2023
57. Lipid-Oriented Live-Cell Distinction of B and T Lymphocytes
- Author
-
Young-Tae Chang, Stuart N. Berry, Jae Won Lee, Justin Kok Soon Tan, Yun-Kyu Choi, Kangkyun Baek, Solip Park, Jae-Seong Yang, Gun Tae Jung, Kwang Pyo Kim, Soohyun Park, H. W. Lee, Haw-Young Kwon, Sangho Kim, Ki Hean Kim, Raj Kumar Das, Kyeng Min Park, Kimoon Kim, Sun Hyeok Lee, Nam-Young Kang, National Research Foundation of Korea, Government of South Korea, Institute for Basic Science (South Korea), Pohang University of Science and Technology, and Ministry of Education (South Korea)
- Subjects
Cell type ,T-Lymphocytes ,Cell ,Bone Marrow Cells ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Cell membrane ,Mice ,Colloid and Surface Chemistry ,medicine ,Animals ,Progenitor cell ,Fluorescent Dyes ,B-Lymphocytes ,biology ,Chemistry ,Cell Membrane ,Lymphocyte differentiation ,Cell Differentiation ,General Chemistry ,Complex cell ,Flow Cytometry ,0104 chemical sciences ,Cell biology ,Multicellular organism ,medicine.anatomical_structure ,Lipidomics ,biology.protein ,Antibody - Abstract
The identification of each cell type is essential for understanding multicellular communities. Antibodies set as biomarkers have been the main toolbox for cell-type recognition, and chemical probes are emerging surrogates. Herein we report the first small-molecule probe, CDgB, to discriminate B lymphocytes from T lymphocytes, which was previously impossible without the help of antibodies. Through the study of the origin of cell specificity, we discovered an unexpected novel mechanism of membrane-oriented live-cell distinction. B cells maintain higher flexibility in their cell membrane than T cells and accumulate the lipid-like probe CDgB more preferably. Because B and T cells share common ancestors, we tracked the cell membrane changes of the progenitor cells and disclosed the dynamic reorganization of the membrane properties over the lymphocyte differentiation progress. This study casts an orthogonal strategy for the small-molecule cell identifier and enriches the toolbox for live-cell distinction from complex cell communities., This research was supported by the Institute for Basic Science (IBS) (IBS-R007-A1), the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (no. 2020R1A2C2009776), the Ministry of Education (no. 2020R1A6A1A03047902), and the intramural fund of POSTECH (Pohang University of Science and Technology).
- Published
- 2021
58. Application of Neuron‐Selective Fluorescent Probe, NeuA, To Identify Mouse Retinal Degeneration
- Author
-
Jun Cheng Er, Nam-Young Kang, David L. Silver, Bernice H. Wong, Veluchamy A Barathi, Young-Tae Chang, Sungjin Park, Xiao Liu, and Queenie Tan Shu Woon
- Subjects
Retinal degeneration ,genetic structures ,Mice, Inbred Strains ,010402 general chemistry ,01 natural sciences ,Biochemistry ,law.invention ,Mice ,chemistry.chemical_compound ,Confocal microscopy ,law ,In vivo ,Retinitis pigmentosa ,medicine ,Animals ,Molecular Biology ,Fluorescent Dyes ,Mice, Knockout ,Neurons ,Retina ,Symporters ,010405 organic chemistry ,Retinal Degeneration ,Organic Chemistry ,Retinal ,medicine.disease ,eye diseases ,0104 chemical sciences ,Cell biology ,medicine.anatomical_structure ,chemistry ,Molecular Medicine ,sense organs ,Neuron ,Ex vivo ,Photoreceptor Cells, Vertebrate - Abstract
The retina is part of the central nerve system (CNS) and has various interneurons and sensory neurons such as photoreceptor cells. Retinitis pigmentosa (RP) is an inherited condition that is characterized by photoreceptor degeneration. Herein, we developed a fluorescent probe - NeuA - for detecting retinal neuronal cells and applied NeuA to discriminate between healthy and RP retinas. The staining pattern of NeuA in the retinas of healthy and RP mouse models was examined in vitro , ex vivo and in vivo using confocal microscopy, the fluorescent fundus microscopy and optical coherent tomography (OCT). NeuA strongly stained the outer segment layer of photoreceptor cells and some bipolar cells in the healthy retina, but there was only weak staining in the photoreceptor degenerated retinas. Therefore, NeuA probe can be used as the detecting RP tools in the preclinical conditions.
- Published
- 2021
59. Prospecting for Live Cell Bioimaging Probes with Cheminformatic Assisted Image Array (caia).
- Author
-
Maria M. Posada, Kerby Shedden, Young Tae Chang, Qian Li, and Gustavo R. Rosania
- Published
- 2007
- Full Text
- View/download PDF
60. ABCB1 Can Actively Pump-out the Background-Free Tame Fluorescent Probe CO-1 From Live Cells
- Author
-
Larissa Miasiro Ciaramicoli, Heon Seok Kim, Samira Husen Alamudi, and Young‐Tae Chang
- Subjects
Mammals ,Staining and Labeling ,Organic Chemistry ,Animals ,Biological Transport ,General Chemistry ,Lysosomes ,Biochemistry ,Fluorescent Dyes - Abstract
Cell labelling using a small fluorescent probe is an important technique in biomedical sciences. We previously developed a biocompatible and membrane-permeable probe, CO-1, which has low nonspecific binding affinity towards nontarget molecules. Although this background-free tame probe has been utilized for labelling of various intracellular biomolecules in live cells, the probes' backgroung-free staining mechanism was not fully understood. Here, we propose that Gating-Oriented Live-cell Distinction (GOLD) mechanism occurs when ABCB1 transporter removes unbound CO-1 molecules from mammalian cells and, in a minor role, DIRC2 pumps CO-1 out from lysosomes. We also showed that solute carrier transporters were not involved in carrying CO-1 inside of cells. The role of reporters in assisting the probes' influx-efflux was analyzed by the combination of CRISPR library sceenings and inhibitors test. In summary, tame probe CO-1 cellular staining occurs in a dual mechanism where the probe moves freely through the cells membrane, but its washable property can be directly related to the action of ABCB1 transporter.
- Published
- 2022
61. Contagious Aggregation: Transmittable Protein Aggregation in Cellular Communities Initiated by Synthetic Cells
- Author
-
Hong-Guen Lee, Jin Hae Kim, Tumpa Gorai, Young Ho Ko, Haw-Young Kwon, Wooseong Chung, Ilha Hwang, Sungsu Lim, Yun Kyung Kim, Kwanwoo Shin, Young-Tae Chang, Kimoon Kim, and Kyeng Min Park
- Subjects
Protein Aggregates ,Colloid and Surface Chemistry ,Cell Membrane ,Humans ,Amyloidogenic Proteins ,Artificial Cells ,General Chemistry ,Biochemistry ,Lipids ,Protein Aggregation, Pathological ,Catalysis - Abstract
Aggregation of amyloidogenic proteins causing neurodegenerative diseases is an uncontrollable and contagious process that is often associated with lipid membranes in a highly complex physiological environment. Although several approaches using natural cells and membrane models have been reported, systematic investigations focusing on the association with the membranes are highly challenging, mostly because of the lack of proper molecular tools. Here, we report a new supramolecular approach using a synthetic cell system capable of controlling the initiation of protein aggregation and mimicking various conditions of lipid membranes, thereby enabling systematic investigations of membrane-dependent effects on protein aggregation by visualization. Extending this strategy through concurrent use of synthetic cells and natural cells, we demonstrate the potential of this approach for systematic and in-depth studies on interrogating inter- and intracellularly transmittable protein aggregation. Thus, this new approach offers opportunities for gaining insights into the pathological implications of contagious protein aggregation associated with membranes for neurotoxicity.
- Published
- 2022
62. Abstract GS3-10: Partitioning of cancer therapeutics in nuclear condensates
- Author
-
Arup K. Chakraborty, John Mantiega, Anthony A. Hyman, Ann Boija, Mrityunjoy Kar, Patrick M. McCall, Jesse M. Platt, Charles H. Li, Mengyang Fan, Victoria E. Clark, Tong Lee, Alessandra Dall’Agnese, Jonathan E. Henninger, Krishna Shrinivas, Ido Sagi, Phillip A. Sharp, Dylan J. Taatjes, Tim-Michael Decker, Tinghu Zhang, Jing-Ke Weng, Eliot L. Coffey, Lena K. Afeyan, Alicia V. Zamudio, Nathanael S. Gray, Benjamin R. Sabari, Isaac A. Klein, Richard A. Young, Nancy M. Hannett, Young-Tae Chang, Ozgur Oksuz, Yang Guo, and Susana Wilson Hawken
- Subjects
Cisplatin ,Cancer Research ,Chemistry ,Cell ,Small molecule ,In vitro ,MED1 ,Cell biology ,chemistry.chemical_compound ,medicine.anatomical_structure ,Oncology ,Live cell imaging ,In vivo ,medicine ,DNA ,medicine.drug - Abstract
The molecules of the cell are compartmentalized into membrane- and non-membrane-bound organelles. Many non-membrane-bound organelles are phase-separated biomolecular condensates with distinct physicochemical properties that can absorb and concentrate specific proteins and nucleic acids involved in discrete biochemical processes. We reasoned that selective condensate partitioning might also occur with small molecule drugs whose targets occur within condensates, and that the therapeutic index and efficacy of such compounds might therefore relate to their ability to partition into condensates. To test this idea, we focused our study on nuclear condensates reported in cell lines, demonstrated they occur in normal human and malignant breast cancer, and developed assays to test clinically active antineoplastic small molecule drugs relative to these condensates.To study the behavior of drugs within condensates, these were modeled in vitro with purified proteins and visualized by fluorescent confocal microscopy. We found that cisplatin, tamoxifen, JQ1, THZ1, and mitoxantrone are concentrated in specific protein condensates in vitro, and that this occurs through physicochemical properties independent of the drug target. For each drug, the small molecule partitioned into the same condensate in vitro in which its established target resides in vivo. A screen of a chemically diverse fluorescent probes and mutant-protein condensates demonstrated that pi-system interactions between aromatic moieties in the protein and small molecule govern concentration in condensates. These results show that clinically important drugs partition into specific protein condensates in vitro by virtue of defined chemical properties, thereby altering their local concentration.Alkylating agents are a class of commonly used antineoplastic compounds, of which cisplatin is a prominent example. In vitro droplet assays revealed that cisplatin is selectively concentrated in transcriptional condensates, and that this ability is required for efficient platination of target DNA. In cell studies revealed that cisplatin preferentially targets DNA contained within MED1 condensates, and disrupts the genetic regulatory elements that compose phase-separated transcriptional condensates. Live cell imaging demonstrated that transcriptional condensates are dissolved by cisplatin, whereas other condensates remain intact. Thus, we conclude that cisplatin preferentially modifies transcriptional condensate-associated DNA in cells, and that this causes selective condensate disruption. The mechanisms that produce drug resistance can provide clues to drug activity in the clinical setting. Investigating the behavior of tamoxifen within ER transcriptional condensates demonstrated that it disrupts these condensates in vitro and on oncogenes in cells; hormonal therapy resistant ESR1 mutations render these condensates resistant. MED1 overexpression, a poorly understood mechanism of tamoxifen resistance, increased the size of ER-MED1 condensates, thereby rending tamoxifen more dilute and ineffective when concentrated therein. This suggest that altering the size and nature of transcription condensates in breast cancer can mediate drug resistance in the clinical setting.Our results show that antineoplastic drugs partition selectively into condensates, that this can occur through physicochemical properties independent of their molecular targets, and that resistance to drugs may occur through condensate altering mechanisms. These results have implications for development of efficacious cancer therapeutics; effective target engagement will depend on factors such as drug partitioning in condensates. Assays of the type described here may thus help optimize condensate partitioning, target engagement, and the therapeutic index of drugs for cancer treatment. Citation Format: Isaac Klein, Ann Boija, Lena Afeyan, Susana Wilson Hawken, Mengyang Fan, Alessandra Dall'Agnese, Ozgur Oksuz, Jonathan Henninger, Krishna Shrinivas, Benjamin Sabari, Ido Sagi, Victoria Clark, Jesse Platt, Mrityunjoy Kar, Patrick McCall, Alicia Zamudio, John Mantiega, Eliot Coffey, Charles Li, Nancy Hannett, Yang Guo, Tim-Michael Decker, Tong Lee, Tinghu Zhang, Jing-Ke Weng, Dylan Taatjes, Arup Chakraborty, Phillip Sharp, Young Tae Chang, Anthony Hyman, Nathanael Gray, Richard Young. Partitioning of cancer therapeutics in nuclear condensates [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS3-10.
- Published
- 2021
63. Novel live cell fluorescent probe for human-induced pluripotent stem cells highlights early reprogramming population
- Author
-
Subha Subramanian, Gerine Jin-Ling Tong, Yuin-Han Loh, Shigeki Sugii, Thekkeparambil Chandrabose Srijaya, Tannistha Nandi, Qiao Rui Xing, Nam-Young Kang, Sandhya Sriram, Allen Chen, Samydurai Sudhagar, Patrick Tan, and Young-Tae Chang
- Subjects
0301 basic medicine ,Cell type ,Induced Pluripotent Stem Cells ,Cell ,Population ,Adipose-derived stromal cell (ASC) ,Method ,Medicine (miscellaneous) ,Biology ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,lcsh:Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Human induced pluripotent stem cell (hiPSC) ,medicine ,Dental pulp stem cell (DPSC) ,Tra-1-60 ,Humans ,lcsh:QD415-436 ,Induced pluripotent stem cell ,education ,cAMP responsive element binding protein (CREB) ,Mesenchymal-epithelial transition (MET) ,Cells, Cultured ,Fluorescent Dyes ,DOFLA library fluorescence dye ,education.field_of_study ,lcsh:R5-920 ,Three-dimensional (3D) microcarrier-based culture system ,Golgi marker ,Cell Biology ,Cell sorting ,Cellular Reprogramming ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Cell culture ,Early stage pluripotency ,Molecular Medicine ,Stem cell ,Transcriptome ,lcsh:Medicine (General) ,Reprogramming ,030217 neurology & neurosurgery - Abstract
Background Despite recent rapid progress in method development and biological understanding of induced pluripotent stem (iPS) cells, there has been a relative shortage of tools that monitor the early reprogramming process into human iPS cells. Methods We screened the in-house built fluorescent library compounds that specifically bind human iPS cells. After tertiary screening, the selected probe was analyzed for its ability to detect reprogramming cells in the time-dependent manner using high-content imaging analysis. The probe was compared with conventional dyes in different reprogramming methods, cell types, and cell culture conditions. Cell sorting was performed with the fluorescent probe to analyze the early reprogramming cells for their pluripotent characteristics and genome-wide gene expression signatures by RNA-seq. Finally, the candidate reprogramming factor identified was investigated for its ability to modulate reprogramming efficiency. Results We identified a novel BODIPY-derived fluorescent probe, BDL-E5, which detects live human iPS cells at the early reprogramming stage. BDL-E5 can recognize authentic reprogramming cells around 7 days before iPS colonies are formed and stained positive with conventional pluripotent markers. Cell sorting of reprogrammed cells with BDL-E5 allowed generation of an increased number and higher quality of iPS cells. RNA sequencing analysis of BDL-E5-positive versus negative cells revealed early reprogramming patterns of gene expression, which notably included CREB1. Reprogramming efficiency was significantly increased by overexpression of CREB1 and decreased by knockdown of CREB1. Conclusion Collectively, BDL-E5 offers a valuable tool for delineating the early reprogramming pathway and clinically applicable commercial production of human iPS cells.
- Published
- 2021
64. Fluorescent Janus ring siloxanes for detection of Au(III) and l-cysteine
- Author
-
Thanawat Chaiprasert, Supphachok Chanmungkalakul, Yujia Liu, Teeraya Bureerug, Komthep Silpcharu, Masafumi Unno, Liu Xiaogang, Vuthichai Ervithayasuporn, Young-Tae Chang, and Paitoon Rashatasakhon
- Subjects
Process Chemistry and Technology ,General Chemical Engineering - Published
- 2022
65. A Systematic Study on the Relationship Between Viscosity Sensitivity and <scp>Temperature Dependency</scp> of <scp>BODIPY</scp> Rotors
- Author
-
Xiaogang Liu, Xiao Liu, Weijie Chi, Young-Tae Chang, Antonio de J Gómez-Infante, and Eduardo Peña-Cabrera
- Subjects
Viscosity ,chemistry.chemical_compound ,Dependency (UML) ,Chemistry ,Thermodynamics ,General Chemistry ,Sensitivity (control systems) ,BODIPY - Published
- 2020
66. Port efficiency and international trade in China
- Author
-
Suhyung Lee, Ahhyun Jo, Kyoung-Suk Choi, and Young-Tae Chang
- Subjects
050210 logistics & transportation ,Gravity model of trade ,business.industry ,0502 economics and business ,05 social sciences ,General Engineering ,Transportation ,Business ,Gateway (computer program) ,International trade ,050207 economics ,China ,Port (computer networking) - Abstract
The relationship between port infrastructure and international trade is linked inextricably since ports remain the main gateway for international trade. All international ports thus have as their g...
- Published
- 2020
67. Fluid-Matrix Interface Triggers a Heterogeneous Activation of Macrophages
- Author
-
YongKeun Park, Chungha Lee, Young-Tae Chang, Xiao Liu, Pilnam Kim, Hyoungsoo Kim, Jongbeom Lee, Herve Hugonnet, Youngmin Jo, and Hyo Min Kim
- Subjects
Innate immune system ,Chemistry ,Biochemistry (medical) ,Biomedical Engineering ,Inflammation ,General Chemistry ,Matrix (biology) ,Cell biology ,Biomaterials ,Extracellular matrix ,Heterogeneous population ,medicine ,Macrophage ,medicine.symptom ,Immune activation - Abstract
Spontaneous activation of macrophages in response to inflammation is a key part of innate immunity and host defense. Macrophages represent a heterogeneous population of cells with different phenotypic profiles performing distinct functions in host defense. Although a spectrum of macrophage activation stages exists in an inflamed region, the effect of local physical conditions on the heterotypic activation of macrophages is unknown. Here, we introduce an in vivo fluid-matrix interface analogous culture platform, an asymmetric microenvironment, facilitating the formation of macrophage aggregates (MAs). Macrophages were self-assembled to form MAs of ∼100 μm diameter at the collagen matrix-medium interface upon phorbol-12-myristate-13-acetate treatment. The macrophages within the half-embedded MAs into the matrix were heterogeneously activated, resulting in inhomogeneous cell-cell and cell-matrix interactions within the aggregates. Our demonstration may aid in a better understanding of the acquisition of macrophage heterogeneity in response to tissue-specific microenvironments.
- Published
- 2022
68. Analysis and Forecasting of the Dry Bulk Shipping Market:Structural VAR Models Using Ffa-Spot-Time Charter Rates
- Author
-
Byoung-Wook Ko and Young-Tae Chang
- Subjects
History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
69. SAMHD1 controls innate immunity by regulating condensation of immunogenic self RNA
- Author
-
Shovamayee Maharana, Stefanie Kretschmer, Susan Hunger, Xiao Yan, David Kuster, Sofia Traikov, Thomas Zillinger, Marc Gentzel, Nagaraja Chappidi, Nadja Lucas, Katharina Isabell Maser, Henrike Maatz, Alexander Rapp, Virginie Marchand, K. Venkatesan Iyer, Akshita Chhabra, Young-Tae Chang, Yuri Motorin, Norbert Hubner, Gunther Hartmann, Anthony Hyman, Simon Alberti, and Min Ae Lee-Kirsch
- Subjects
Exonucleases ,SAM Domain and HD Domain-Containing Protein 1 ,Autoimmune Diseases of the Nervous System ,Interferon Type I ,Humans ,Cell Biology ,Nervous System Malformations ,Molecular Biology ,Antiviral Agents ,Immunity, Innate ,RNA, Double-Stranded - Abstract
Recognition of pathogen-derived foreign nucleic acids is central to innate immune defense. This requires discrimination between structurally highly similar self and nonself nucleic acids to avoid aberrant inflammatory responses as in the autoinflammatory disorder Aicardi-Goutières syndrome (AGS). How vast amounts of self RNA are shielded from immune recognition to prevent autoinflammation is not fully understood. Here we show that SAM domain and HD domain-containing protein 1 (SAMHD1), one of the AGS-causing genes, functions as a single-stranded RNA (ssRNA) 3’exonuclease, the lack of which causes cellular RNA accumulation. Increased ssRNA in cells leads to dissolution of RNA-protein condensates, which sequester immunogenic double-stranded RNA (dsRNA). Release of sequestered dsRNA from condensates triggers activation of antiviral type I interferon via retinoic acid-inducible gene I-like receptors. Our results establish SAMHD1 as a key regulator of cellular RNA homeostasis and demonstrate that buffering of immunogenic self RNA by condensates regulates innate immune responses.
- Published
- 2021
70. Validation of CDr15 as a new dye for detecting neutrophil extracellular trap
- Author
-
Won Woo Lee, Xiao Liu, Young-Tae Chang, Sang Jin Kim, Jong Wan Park, Ji Young Kim, and Bonah Kim
- Subjects
0301 basic medicine ,Fluorescence-lifetime imaging microscopy ,Neutrophils ,Cell ,Biophysics ,Extracellular Traps ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Neoplasms ,medicine ,Extracellular ,Humans ,DAPI ,Molecular Biology ,Cells, Cultured ,Fluorescent Dyes ,Chemistry ,DNA ,Cell Biology ,Neutrophil extracellular traps ,Fluorescence ,030104 developmental biology ,Membrane ,medicine.anatomical_structure ,Microscopy, Fluorescence ,030220 oncology & carcinogenesis ,Cancer cell - Abstract
Neutrophil extracellular trap (NET) is one of the first-line defenses against microbes. Under certain circumstances, however, it also plays an aggravating factor in diverse inflammation-related diseases including cancers and vascular diseases. Our aim is to develop a new method to detect NET in cells and tissues using a DNA-specific fluorescence probe CDr15. CDr15 was characterized to be impermeable to the cell membranes and to emit a strong fluorescence in association with extracellular DNAs in NET. Due to these properties, CDr15 was successfully shown to quantify NETs in vitro and to be applicable for real-time monitoring NET formation in PMA-stimulated neutrophils. Even in formaldehyde-fixed tumor specimens, CDr15 could detect NETs spreading around cancer cells. Compared with DAPI and SYTOX DNA dyes, CDr15 showed a lower level of background fluorescence and a higher specificity in NET detection. Based on these results, we propose CDr15 as a novel marker of NET to be applicable in experimental and clinical studies.
- Published
- 2020
71. A General Descriptor ΔE Enables the Quantitative Development of Luminescent Materials Based on Photoinduced Electron Transfer
- Author
-
Qinglong Qiao, Qingkai Qi, Xiao Liu, Zhaochao Xu, Kangming Xiong, Wenjuan Liu, Jie Chen, Keegan Kang, Chao Wang, Xiaogang Liu, Weijie Chi, Tee Meng Tan, and Young-Tae Chang
- Subjects
Quantum yield ,Nanotechnology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Fluorescence ,Catalysis ,Photoinduced electron transfer ,0104 chemical sciences ,Rhodamine ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,BODIPY ,Luminescence ,Biosensor ,Quantum - Abstract
Photoinduced electron transfer (PET) is one of the most important mechanisms for developing fluorescent probes and biosensors. Quantitative prediction of the quantum yields of these probes and sensors is crucial to accelerate the rational development of novel PET-based functional materials. Herein, we developed a general descriptor (ΔE) for predicting the quantum yield of PET probes, with a threshold value of ∼0.6 eV. When ΔE ∼0.6 eV, the quantum yield is high because of the inhibition of PET. This simple yet effective descriptor is applicable to a wide range of fluorophores, such as BODIPY, fluorescein, rhodamine, and Si-rhodamine. This ΔE descriptor enables us not only to establish new applications for existing PET probes but also to quantitatively design novel PET-based fluorophores for wash-free bioimaging and AIEgen development.
- Published
- 2020
72. The screening of drug-induced nephrotoxicity using gold nanocluster-based ratiometric fluorescent probes
- Author
-
Qin Liu, Lingzhi Zhao, Juanjuan Peng, Lin Yuan, Young-Tae Chang, Junyao Li, Xiaogang Liu, and Xiao Liu
- Subjects
Drug ,media_common.quotation_subject ,Acute kidney injury ,Metal Nanoparticles ,Triptolide ,Pharmacology ,medicine.disease ,Fluorescence ,Nanoclusters ,Nephrotoxicity ,chemistry.chemical_compound ,Spectrometry, Fluorescence ,chemistry ,Renal injury ,Pharmaceutical Preparations ,medicine ,General Materials Science ,Gold ,Drug induced nephrotoxicity ,media_common ,Fluorescent Dyes - Abstract
Herbal medicines are potential candidates for the treatment of various diseases, but their medication safety remains poorly regulated. Current screening methods for the herbal medicine-induced nephrotoxic effects include histological and serological assessments, which often fail to reflect the kidney dysfunction instantly. Here we report a ratiometric fluorescence approach for the rapid and facile screening of drug-induced acute kidney injury using chromophore-modified gold nanoclusters. These gold nanoclusters are highly sensitive to reactive oxygen species (ROS), with a detection limit of 14 nM for ˙OH. After passing through the glomerular filtration barrier, the gold nanocluster-based probes can quantify the fluctuation of the ROS level in the kidneys and evaluate the risk of drug-induced nephrotoxicity. We further employed nephrotoxic triptolide as the model drug and the screening of drug-induced early renal injury was demonstrated using the nanoprobes, which is unattainable by conventional diagnostic approaches. Our fluorescent probes also allow the identification of other nephrotoxic components from herbal medicine such as aristolochine, providing a high-throughput strategy for the screening of herbal supplement-induced nephrotoxicity.
- Published
- 2021
73. Neutrophil-Selective Fluorescent Probe Development through Metabolism-Oriented Live-Cell Distinction
- Author
-
Haw-Young Kwon, Sun Hyeok Lee, Sang Hyuk Park, Joseph Jeong, Heewon Cho, Larissa Miasiro Ciaramicoli, Min Gao, and Young-Tae Chang
- Subjects
Innate immune system ,Blood Cells ,Molecular Structure ,Chemistry ,Neutrophils ,Cell ,Inflammation ,General Medicine ,General Chemistry ,Metabolism ,Lipid Droplets ,Fluorescence ,Catalysis ,Cell biology ,medicine.anatomical_structure ,Clinical diagnosis ,Lipid droplet ,medicine ,Humans ,medicine.symptom ,Biogenesis ,Fluorescent Dyes - Abstract
Human neutrophils are the most abundant leukocytes and have been considered as the first line of defence in the innate immune system. Selective imaging of live neutrophils will facilitate the in situ study of neutrophils in infection or inflammation events as well as clinical diagnosis. However, small-molecule-based probes for the discrimination of live neutrophils among different granulocytes in human blood have yet to be reported. Herein, we report the first fluorescent probe NeutropG for the specific distinction and imaging of active neutrophils. The selective staining mechanism of NeutropG is elucidated as metabolism-oriented live-cell distinction (MOLD) through lipid droplet biogenesis with the help of ACSL and DGAT. Finally, NeutropG is applied to accurately quantify neutrophil levels in fresh blood samples by showing a high correlation with the current clinical method.
- Published
- 2021
74. Neuroprotective Effects of Ex Vivo Expanded Regulatory T Cells on Trimethyltin Induced Neurodegeneration in Mice
- Author
-
HyeJin Yang, Insop Shim, Seon-Young Park, Hyunsu Bae, Xiao Liu, Young-Tae Chang, and Minsook Ye
- Subjects
nervous system ,Chemistry ,Neurodegeneration ,medicine ,Pharmacology ,medicine.disease ,Neuroprotection ,Ex vivo - Abstract
BackgroundTrimethyltin (TMT) is a potent neurotoxicant that leads to hippocampal neurodegeneration. Regulatory T cells (Tregs) play an important role in maintaining the immune balance in the central nervous system (CNS), but their activities are impaired in neurodegenerative diseases. In this study, we aimed to determine whether adoptive transfer of Tregs, as a living drug, ameliorates hippocampal neurodegeneration in TMT-intoxicated mice.MethodsCD4+CD25+ Tregs were expanded in vitro and adoptively transferred to TMT-treated mice. First, we explored the effects of Tregs on behavioral deficits using the Morris water maze and elevated plus maze tests. Biomarkers related to memory formation, such as cAMP response element-binding protein (CREB), protein kinase C (PKC), neuronal nuclear protein (NeuN), nerve growth factor (NGF), and ionized calcium binding adaptor molecule 1 (Iba1) in the hippocampus were examined by immunohistochemistry after mouse sacrifice. To investigate the neuroinflammatory responses, the polarization status of microglia was examined in vivo and in vitro using real-time reverse transcription polymerase chain reaction (rtPCR) and Enzyme-linked immunosorbent assy (ELISA). Additionally, the inhibitory effects of Tregs on TMT-induced microglial activation were examined using time-lapse live imaging in vitro with an activation-specific fluorescence probe, CDr20.ResultsAdoptive transfer of Tregs improved spatial learning and memory functions and reduced anxiety in TMT-intoxicated mice. Additionally, adoptive transfer of Tregs reduced neuronal loss and recovered the expression of neurogenesis enhancing molecules in the hippocampi of TMT-intoxicated mice. In particular, Tregs inhibited microglial activation and pro-inflammatory cytokine release in the hippocampi of TMT-intoxicated mice. The inhibitory effects of TMT were also confirmed via in vitro live time lapse imaging in a Treg/microglia co-culture system.ConclusionsThese data suggest that adoptive transfer of Tregs ameliorates disease progression in TMT-induced neurodegeneration by promoting neurogenesis and modulating microglial activation and polarization.
- Published
- 2021
75. The predicted bZIP transcription factor ZIP-1 promotes resistance to intracellular infection in Caenorhabditis elegans
- Author
-
Spencer S. Gang, Cohen Lb, Emily R. Troemel, Wu F, Kirthi C. Reddy, Lazetic, Gira Bhabha, and Young-Tae Chang
- Subjects
Orsay virus ,biology ,Intracellular parasite ,Gene expression ,medicine ,RNA virus ,biology.organism_classification ,medicine.disease_cause ,Gene ,Transcription factor ,Caenorhabditis elegans ,Intracellular ,Cell biology - Abstract
Defense against intracellular infection has been extensively studied in vertebrate hosts, but less is known about invertebrate hosts. For example, almost nothing is known about the transcription factors that induce defense against intracellular intestinal infection in the model nematode Caenorhabditis elegans. Two types of intracellular pathogens that naturally infect the C. elegans intestine are the Orsay virus, which is a positive-sense RNA virus, and microsporidia, which are fungal pathogens. Surprisingly, these molecularly distinct pathogens induce a common host transcriptional response called the Intracellular Pathogen Response (IPR). Here we describe zip-1 as an IPR regulator that functions downstream of all known IPR activating and regulatory pathways. zip-1 encodes a putative bZIP transcription factor of previously unknown function, and we show how zip-1 controls induction of a subset of genes upon IPR activation. ZIP-1 protein is expressed in the nuclei of intestinal cells, and is required in the intestine to upregulate IPR gene expression. Importantly, zip-1 promotes resistance to infection by the Orsay virus and by microsporidia in intestinal cells. Altogether, our results indicate that zip-1 represents a central hub for all triggers of the IPR, and that this transcription factor plays a protective role against intracellular pathogen infection in C. elegans.
- Published
- 2021
76. Chemoinformatic Analysis of a Supertargeted Combinatorial Library of Styryl Molecules.
- Author
-
Kerby Shedden, Julie Brumer, Young Tae Chang, and Gustavo R. Rosania
- Published
- 2003
- Full Text
- View/download PDF
77. Casting red light for bad oil by dual turning-on mechanisms of fluorescence and its application in the portable platform
- Author
-
Xiao Liu, Eun Gyeong Choi, Songbin Cui, Kapil Kumar, Myongji Cho, and Young-Tae Chang
- Subjects
Materials Chemistry ,Metals and Alloys ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Instrumentation ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2022
78. Nanomaterials-based imaging diagnosis and therapy of cardiovascular diseases
- Author
-
Yang Zhong, Xueping Zeng, Yuling Zeng, Lulu Yang, Juanjuan Peng, Lingzhi Zhao, and Young-tae Chang
- Subjects
Biomedical Engineering ,Pharmaceutical Science ,General Materials Science ,Bioengineering ,Biotechnology - Published
- 2022
79. A Near-Infrared Organic Fluorescent Probe for Broad Applications for Blood Vessels Imaging by High-Throughput Screening via 3D-Blood Vessel Models
- Author
-
Muhammad Asri Abdul Sisak, Sun Hyeok Lee, Ichio Aoki, Fiona Louis, Young-Tae Chang, and Michiya Matsusaki
- Subjects
Spectroscopy, Near-Infrared ,Chemistry ,High-throughput screening ,Near-infrared spectroscopy ,General Chemistry ,Fluorescence ,High-Throughput Screening Assays ,medicine.anatomical_structure ,medicine ,General Materials Science ,Preclinical imaging ,Biomedical engineering ,Blood vessel ,Fluorescent Dyes - Abstract
Blood vessels are present in all of the organs, reflecting their importance for oxygen and nutrient delivery to the cells. Until now, no organic fluorophore has been reported for the live imaging of endothelium although the layer is the key to blood vessel functions. Here, the discovery of a blood vessel organic probe at near-infrared (NIR) wavelength range (BV-NIR) through an engineered blood capillary-based screening system, which is a more physiological model than a conventional cell culture condition, is reported. This selected Cy5 based probe shows the highest specific adsorption property out of 240 candidates on the endothelium and is equivalent to an anti-CD31 antibody in terms of intensity. The BV-NIR probe indicating strong and stable in vitro, ex vivo, and in vivo imaging of the endothelium even after histological immunostaining processes shows potential as a convenient tool for live imaging as well as for covisualization with a specific antibody.
- Published
- 2021
80. High Content and High Throughout Phenotypic Assay for the Hourly Resolution of the Malaria Parasite Erythrocytic Cycle
- Author
-
A. P. Patel, D. Bell, Edgar Deu, S. Ridewood, S. H. Lee, and Young-Tae Chang
- Subjects
medicine.diagnostic_test ,Drug resistance ,Computational biology ,Biology ,medicine.disease ,Genome ,Phenotype ,Genetically modified organism ,Flow cytometry ,parasitic diseases ,medicine ,Parasite hosting ,Malaria ,Genetic screen - Abstract
Over the last 20 years increased funding for malaria research has resulted in very significant technical advances to study the biology ofPlasmodiumspecies. High throughput phenotypic assays have been developed to screen millions of compounds and identify small molecules with antiparasitic activity. At the same time, advances in malaria genetic have greatly facilitated the generation of genetically modified parasites, and whole genome genetic screens are now feasible inPlasmodiumspecies. Finally, there has been an increased interest to study malaria parasites at the population level, in particular in the area of drug resistance. Drug resistant field isolates have been collected around the world, and drug resistant strains are routinely generated in the lab to study the mechanisms of drug resistance. As a result, one of the current bottlenecks in malaria research is our ability to quickly characterize the phenotype associated with compound treatment or genetic modification, or to quickly compare differences in intracellular development between strains. Here, we present a high content/high throughput phenotypic assay that combines highly selective RNA, DNA, and RBC membrane dyes to provide hourly resolution of the full erythrocytic cycle for bothP. falciparumandP. knowlesi. A flow cytometry assay allows the analysis of samples in a 384-well format and a quick way to determine the parasite developmental stage. On the other hand, the fluorescence microscopy format allows for a detailed visualization of parasite morphology. Finally, using open source software we have developed protocols for the automated cluster analysis of microscopy images. This assay can be applied to anyPlasmodiumspecies, requires very little amount of sample, is performed with fixed cells, and is easily scalable. Overall, we believe this assay will be a great tool for the malaria community to studyPlasmodiumspecies.
- Published
- 2021
81. Cucurbitacin B induces neurogenesis in PC12 cells and protects memory in APP/PS1 mice
- Author
-
Jianhua Qi, Lijuan Gao, Jing Li, Hiroyuki Osada, Young-Tae Chang, Lan Xiang, Kaiyue Sun, and Makoto Muroi
- Subjects
0301 basic medicine ,MAPK/ERK pathway ,cucurbitacin B ,Neurite ,Neurogenesis ,Neuronal Outgrowth ,Tropomyosin receptor kinase B ,cofilin ,CREB ,PC12 Cells ,03 medical and health sciences ,Amyloid beta-Protein Precursor ,Mice ,0302 clinical medicine ,Memory ,Cell Line, Tumor ,glucocorticoid receptor ,Neurites ,Animals ,Protein kinase C ,Neurons ,Mice, Inbred ICR ,Phospholipase C ,biology ,Chemistry ,TrkA ,Cell Biology ,Original Articles ,Cofilin ,Alzheimer's disease ,Triterpenes ,Cell biology ,Rats ,030104 developmental biology ,Nerve growth factor ,Neuroprotective Agents ,nervous system ,030220 oncology & carcinogenesis ,biology.protein ,Molecular Medicine ,Original Article ,Oligopeptides ,Signal Transduction - Abstract
Cucurbitacin B (CuB) isolated from Cucumis melo by using a PC12 cell bioassay system exhibited significant nerve growth factor (NGF)‐mimic or NGF‐enhancing activity in PC12 and primary neuron cells. It was also demonstrated pro‐neurogenesis effects in ICR and APP/PS1 mice and improved memory deficit of APP/PS1 mice. Its possible mechanism includes significant induction of the phosphorylation of glucocorticoid receptor (GR), protein kinase C (PKC), phospholipase C (PLC) and inhibition of cofilin. ChemProteoBase profiling, binding assay and cellular thermal shift assay (CETSA) were used to determine the target protein. Results revealed that CuB could affect actin dynamics as an actin inhibitor but did not bind with GR. The protein level of cofilin in PC12 cells after treating 0.3 μM and different temperatures was significantly higher than that of control group. Other neurotrophic signalling pathways, such as TrkA/TrkB, were analysed with specific inhibitors and Western blot. The inhibitors of TrkA, PLC, PKC, Ras, Raf and ERK1/2 significantly decreased the percentage of PC12 cells with neurite outgrowth and shortened the length of neurite outgrowth induced by CuB. CuB significantly induced the phosphorylation of TrkA, ERK and CREB. The phosphorylation of these proteins was obviously decreased by their specific inhibitors. These results suggest that cofilin is a candidate target protein of CuB in PC12 cells and that the GR/PLC/PKC and TrkA/Ras/Raf/ERK signalling pathways play important roles in the neuroprotective effect of CuB.
- Published
- 2019
82. A Photoexcitation‐Induced Twisted Intramolecular Charge Shuttle
- Author
-
Danning Gu, Zhaochao Xu, Yock Siong Teo, Qinglong Qiao, Young-Tae Chang, Wenjuan Liu, Weijie Chi, Matthew J. Lang, Xiaogang Liu, and Richmond Lee
- Subjects
Materials science ,Fluorophore ,010405 organic chemistry ,Charge (physics) ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Acceptor ,Catalysis ,0104 chemical sciences ,Separation process ,Photoexcitation ,chemistry.chemical_compound ,chemistry ,Chemical physics ,Excited state ,Intramolecular force ,BODIPY - Abstract
Charge transfer and separation are important processes governing numerous chemical reactions. Fundamental understanding of these processes and the underlying mechanisms is critical for photochemistry. Herein, we report the discovery of a new charge-transfer and separation process, namely the twisted intramolecular charge shuttle (TICS). In TICS systems, the donor and acceptor moieties dynamically switch roles in the excited state because of an approximately 90° intramolecular rotation. TICS systems thus exhibit charge shuttling. TICSs exist in several chemical families of fluorophores (such as coumarin, BODIPY, and oxygen/carbon/silicon-rhodamine), and could be utilized to construct functional fluorescent probes (i.e., viscosity- or biomolecule-sensing probes). The discovery of the TICS process expands the current perspectives of charge-transfer processes and will inspire future applications.
- Published
- 2019
83. Visualizing Microglia with a Fluorescence Turn‐On Ugt1a7c Substrate
- Author
-
Florent Ginhoux, Jin-Soo Kim, Young-Tae Chang, Aymeric Silvin, Sungjin Park, H. Shawn Je, Masahiro Fukuda, Audrey Tze Ting Khoo, Xiao Liu, Beomsue Kim, Sejong Choi, Taejoon Kwon, Jungyeol Lee, Xiaogang Liu, Dongdong Su, Weijie Chi, Diana S. Y. Wan, and Srikanta Sanu
- Subjects
Genetically modified mouse ,Brain development ,Microglia ,010405 organic chemistry ,Chemistry ,Optical Imaging ,Chemical probe ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Fluorescence ,Catalysis ,In vitro ,0104 chemical sciences ,Mice ,medicine.anatomical_structure ,nervous system ,In vivo ,medicine ,Animals ,Macrophage ,Glucuronosyltransferase ,Neuroscience ,Fluorescent Dyes - Abstract
Microglia, the brain-resident macrophage, are involved in brain development and contribute to the progression of neural disorders. Despite the importance of microglia, imaging of live microglia at a cellular resolution has been limited to transgenic mice. Efforts have therefore been dedicated to developing new methods for microglia detection and imaging. Using a thorough structure-activity relationships study, we developed CDr20, a high-performance fluorogenic chemical probe that enables the visualization of microglia both in vitro and in vivo. Using a genome-scale CRISPR-Cas9 knockout screen, the UDP-glucuronosyltransferase Ugt1a7c was identified as the target of CDr20. The glucuronidation of CDr20 by Ugt1a7c in microglia produces fluorescence.
- Published
- 2019
84. Visualizing Microglia with a Fluorescence Turn‐On Ugt1a7c Substrate
- Author
-
Beomsue Kim, Masahiro Fukuda, Jung‐Yeol Lee, Dongdong Su, Srikanta Sanu, Aymeric Silvin, Audrey T. T. Khoo, Taejoon Kwon, Xiao Liu, Weijie Chi, Xiaogang Liu, Sejong Choi, Diana S. Y. Wan, Sung‐Jin Park, Jin‐Soo Kim, Florent Ginhoux, H. Shawn Je, and Young‐Tae Chang
- Subjects
General Medicine - Published
- 2019
85. A Photoexcitation‐Induced Twisted Intramolecular Charge Shuttle
- Author
-
Weijie Chi, Qinglong Qiao, Richmond Lee, Wenjuan Liu, Yock Siong Teo, Danning Gu, Matthew John Lang, Young‐Tae Chang, Zhaochao Xu, and Xiaogang Liu
- Subjects
General Medicine - Published
- 2019
86. Korea Leading Scholars and Institutions in Maritime Research
- Author
-
Young-Tae Chang and Ahhyun Jo
- Subjects
Political science ,Regional science ,Ranking (information retrieval) - Published
- 2019
87. Imaging inflammation using an activated macrophage probe with Slc18b1 as the activation-selective gating target
- Author
-
Heon Seok Kim, Beomsue Kim, Jong-Jin Kim, Jun-Young Kim, Sungjin Park, Sivaraman Balasubramaniam, Sung-Chan Lee, Sejong Choi, Jin-Soo Kim, Jung Yeol Lee, Nam-Young Kang, Yong-An Lee, and Young-Tae Chang
- Subjects
0301 basic medicine ,Mice, Knockout, ApoE ,Science ,Molecular Probe Techniques ,General Physics and Astronomy ,Inflammation ,02 engineering and technology ,Gating ,Article ,General Biochemistry, Genetics and Molecular Biology ,Mice ,03 medical and health sciences ,In vivo ,medicine ,Animals ,Humans ,Macrophage ,lcsh:Science ,Cation Transport Proteins ,Multidisciplinary ,Chemistry ,Transporter ,General Chemistry ,Macrophage Activation ,021001 nanoscience & nanotechnology ,Small molecule ,Plaque, Atherosclerotic ,Cell biology ,RAW 264.7 Cells ,030104 developmental biology ,Molecular Probes ,Acridines ,lcsh:Q ,CRISPR-Cas Systems ,medicine.symptom ,0210 nano-technology ,Molecular probe ,HeLa Cells - Abstract
Activated macrophages have the potential to be ideal targets for imaging inflammation. However, probe selectivity over non-activated macrophages and probe delivery to target tissue have been challenging. Here, we report a small molecule probe specific for activated macrophages, called CDg16, and demonstrate its application to visualizing inflammatory atherosclerotic plaques in vivo. Through a systematic transporter screen using a CRISPR activation library, we identify the orphan transporter Slc18b1/SLC18B1 as the gating target of CDg16., Attempts to image activated macrophages in vivo have been hampered by selectivity and delivery problems. Here the authors develop a small molecule fluorescent probe specific to activated M1 and M2 macrophages, identify the orphan receptor Slc18b1/SLC18B1 as the mechanism of uptake, and use it to image atherosclerosis in mice.
- Published
- 2019
88. The impact of vessel speed reduction on port accidents
- Author
-
Hyosoo Park and Young-Tae Chang
- Subjects
0106 biological sciences ,Engineering ,Injury control ,Accident prevention ,Poison control ,Transportation ,Human Factors and Ergonomics ,01 natural sciences ,Accident Prevention ,0502 economics and business ,Forensic engineering ,Humans ,Speed reduction ,Safety, Risk, Reliability and Quality ,Ships ,050210 logistics & transportation ,business.industry ,010604 marine biology & hydrobiology ,05 social sciences ,Commerce ,Public Health, Environmental and Occupational Health ,Port (computer networking) ,United States ,Accidents ,business ,Program Evaluation ,Marine engineering ,Coast guard - Abstract
Reduced-speed zones (RSZs) have been designated across the world to control emissions from ships and prevent mammal strikes. While some studies have examined the effectiveness of speed reduction on emissions and mammal preservation, few have analyzed the effects of reduced ship speed on vessel safety. Those few studies have not yet measured the relationship between vessel speed and accidents by using real accident data. To fill this gap in the literature, this study estimates the impact of vessel speed reduction on vessel damages, casualties and frequency of vessel accidents. Accidents in RSZ ports were compared to non-RSZ ports by using U.S. Coast Guard data to capture the speed reduction effects. The results show that speed reduction influenced accident frequency as a result of two factors, the fuel price and the RSZ designation. Every $10 increase in the fuel price led to a 10.3% decrease in the number of accidents, and the RSZ designation reduced vessel accidents by 47.9%. However, the results do not clarify the exact impact of speed reduction on accident casualty.
- Published
- 2019
89. Port Competitiveness, Efficiency, and Supply Chains: A Literature Review
- Author
-
Wayne K. Talley and Young-Tae Chang
- Subjects
Competition (economics) ,Supply chain management ,Computer science ,Supply chain ,Transportation ,Port (computer networking) ,Productivity ,Industrial organization - Abstract
This article examines such port competitiveness from the perspective of port efficiency and supply chains. Specifically, studies are examined that investigate port competitiveness from the traditional perspective and from the chain perspective. In doing so, methodological problems of the literature in investigating port competitiveness are deduced.
- Published
- 2019
90. A thermoresponsive nanocarrier for mitochondria-targeted drug delivery
- Author
-
Jimin Gao, Young-Tae Chang, Yi Hu, Mengxue Zhou, Dongqing Wang, Hui Huang, Zhifang Chai, Huiru Lu, and Jun Chen
- Subjects
Drug ,Paclitaxel ,Cell Survival ,media_common.quotation_subject ,Mitochondrion ,010402 general chemistry ,01 natural sciences ,Catalysis ,Cell Line ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,Neoplasms ,Materials Chemistry ,Animals ,Humans ,Structure–activity relationship ,Medicine ,Cell Proliferation ,media_common ,Drug Carriers ,Dose-Response Relationship, Drug ,010405 organic chemistry ,business.industry ,Temperature ,Metals and Alloys ,General Chemistry ,Antineoplastic Agents, Phytogenic ,Mitochondria ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Cell culture ,Cancer cell ,Drug delivery ,Ceramics and Composites ,Cancer research ,Nanoparticles ,Drug Screening Assays, Antitumor ,Nanocarriers ,business - Abstract
Mitochondria emerge as an important target for cancer therapy. Herein, by taking advantage of the recently reported high temperature of mitochondria, a well-tuned thermoresponsive nanocarrier was developed for specifically delivering the anticancer drug, paclitaxel (PTX), to mitochondria in cancer cells. The temperature-dependent delivery of drugs to mitochondria represents a novel anticancer strategy.
- Published
- 2019
91. A fluorescent chemical probe CDy9 selectively stains and enables the isolation of live naïve mouse embryonic stem cells
- Author
-
Seung-Ju Cho, Young-Hyun Go, Dong Wook Han, Keun-Tae Kim, Young-Tae Chang, Sung-Hwan Moon, Mirang Kim, Ok-Seon Kwon, Haejeong Heo, Nam-Young Kang, Hyuk-Jin Cha, and Jong Soo Kim
- Subjects
Boron Compounds ,0301 basic medicine ,Biophysics ,Bioengineering ,Biomaterials ,Mice ,03 medical and health sciences ,Chimera (genetics) ,0302 clinical medicine ,Animals ,Inner cell mass ,Cells, Cultured ,Embryonic Stem Cells ,Fluorescent Dyes ,Dicarboxylic Acid Transporters ,Symporters ,Chemistry ,Mouse Embryonic Stem Cells ,Embryo ,Cell sorting ,Embryonic stem cell ,Cell biology ,Staining ,030104 developmental biology ,Mechanics of Materials ,Epiblast ,Ceramics and Composites ,Stem cell ,Heterocyclic Compounds, 3-Ring ,Germ Layers ,030217 neurology & neurosurgery - Abstract
Human and mouse embryonic stem cells (ESCs) differ in terms of their pluripotency status, i.e., naive vs. primed. This affects various biological properties and leads to several technical hurdles for future clinical applications, such as difficulties in chimera formation, single-cell passaging, and gene editing. In terms of generating functional human tissues and organs via mammalian interspecies chimerism, a fluorescent chemical probe that specifically labels naive ESCs would help to isolate these cells and monitor their conversion. This study demonstrates that the fluorescent chemical probe compound of designation yellow 9 (CDy9) selectively stains naive, but not primed, mouse ESCs (mESCs). CDy9 entered cells via Slc13a5, a highly expressed membrane transporter in naive mESCs. Fluorescence-based cell sorting based on CDy9 staining successfully separated naive mESCs from primed mESCs. Mice generated using CDy9+ cells isolated during the conversion of mouse epiblast stem cells into naive mESCs exhibited coat color chimerism. Furthermore, CDy9 specifically stained cells in the inner cell mass of mouse embryos. These findings suggest that CDy9 is a useful tool to isolate functional naive mESCs.
- Published
- 2018
92. Overview of maritime research publications by the late Professor Richard O. Goss
- Author
-
Paul Tae-Woo Lee and Young-Tae Chang
- Subjects
050210 logistics & transportation ,Laissez-faire ,021103 operations research ,Political science ,0502 economics and business ,05 social sciences ,Geography, Planning and Development ,0211 other engineering and technologies ,Economic history ,Ocean Engineering ,Transportation ,02 engineering and technology ,Management, Monitoring, Policy and Law - Abstract
We lost one of the great maritime scholars in 2017—Professor Richard Goss, who is considered one of the founders of maritime economics. He was a pioneer and a most influential leader in establishin...
- Published
- 2018
93. Efficient and wash-free labeling of membrane proteins using engineered Npu DnaE split-inteins
- Author
-
Youngeun Kwon, Kyoungmi Min, Young-Tae Chang, and Euiyeon Lee
- Subjects
0301 basic medicine ,dnaE ,Chemistry ,Protein engineering ,Protein labeling ,Biochemistry ,Staining ,03 medical and health sciences ,030104 developmental biology ,Membrane protein ,Covalent bond ,Biophysics ,Molecular Biology ,Fluorescent tag ,Conjugate - Abstract
An efficient and wash-free method to conjugate a fluorescent tag to a target membrane protein is developed, using engineered Npu DnaE split-inteins. This approach allowed fast labeling while avoiding the strenuous synthesis of a long polypeptide. Two different modes of labeling, namely specific binding and covalent conjugation, are observed. The covalent labeling was monitored within 5 min, without background staining.
- Published
- 2018
94. Blue-conversion of organic dyes produces artifacts in multicolor fluorescence imaging
- Author
-
Jungeun Noh, Triet Minh Hong, Yeonho Chang, Yun-Kyu Choi, Min Gyu Jeong, Kai Zhou, Sung Ho Ryu, Do-Hyeon Kim, Yonghoon Kwon, Young-Tae Chang, and Soyeon Park
- Subjects
0301 basic medicine ,Fluorescence-lifetime imaging microscopy ,Materials science ,Colocalization ,Nanotechnology ,General Chemistry ,Superresolution ,Practical guideline ,03 medical and health sciences ,Chemistry ,030104 developmental biology ,0302 clinical medicine ,Microscopy ,embryonic structures ,030217 neurology & neurosurgery - Abstract
Multicolor fluorescence imaging is a powerful tool visualizing the spatiotemporal relationship among biomolecules. Here, we report that commonly employed organic dyes exhibit a blue-conversion phenomenon, which can produce severe multicolor image artifacts leading to false-positive colocalization by invading predefined spectral windows, as demonstrated in the case study using EGFR and Tensin2. These multicolor image artifacts become much critical in localization-based superresolution microscopy as the blue-converted dyes are photoactivatable. We provide a practical guideline for the use of organic dyes for multicolor imaging to prevent artifacts derived by blue-conversion., Blue-conversion, a photooxidative conversion leading to the hypsochromic shift of absorption and emission spectra, occurs in popular organic dyes under conventional laser illumination and produces severe artifacts in multicolor fluorescence imaging.
- Published
- 2021
95. Gynura divaricata Water Extract Presented the Possibility to Enhance Neuronal Regeneration
- Author
-
Jiang Nan, Jianming Wu, Phenphichar Wanachantararak, Fahsai Kantawong, Chanakarn Saisuwan, Pirakorn Soeratanapant, and Young-Tae Chang
- Subjects
Antioxidant ,Diabetic neuropathy ,Article Subject ,DPPH ,medicine.medical_treatment ,Pharmacology ,03 medical and health sciences ,chemistry.chemical_compound ,Other systems of medicine ,0302 clinical medicine ,Functional food ,medicine ,MTT assay ,Gallic acid ,Gynura ,Viability assay ,030304 developmental biology ,0303 health sciences ,biology ,biology.organism_classification ,medicine.disease ,Complementary and alternative medicine ,chemistry ,030220 oncology & carcinogenesis ,RZ201-999 ,Research Article - Abstract
Gynura divaricata (GD) is an Asian herb widely used as an alternative medicine and functional food for type 2 diabetes. Diabetic neuropathy is considered as an important complication of diabetic patients. This study focused on neuroregenerative effects of GD for use in the prevention of diabetic neuropathy. GD leaves were cut and boiled in water to mimic real-life cooking. The boiled content was filtered through white gauze and lyophilized to preserve as dried powder. Antioxidant assay was performed using DPPH assays. UHPLC-QTOF-MS/MS was employed to test for important compounds in the extract of these herbs. MTT assay was used to test for cell viability. The extracts at concentration of 250 μg/mL were tested with human gingival cell to observe the change of gene expression. The DPPH assay showed that GD water extract at the concentration of 5000 μg/mL could inhibit DPPH radical for 39.2%. The results showed that 5000 µg of GD water extract contained total phenolic content equivalent to 310.9 µg standard gallic acid. UHPLC-QTOF-MS/MS result found phenolic acids and flavonoids as the main components. Human gingival cells treated with 250 μg/mL of GD water extract for 10 days showed upregulation of some neuronal differentiation markers. Staining with Cdr3 dye confirmed the presentation of neuronal progenitors. The extract at the concentration of 250 μg/mL was also tested with apical papilla cells to screen for change of gene expression by RNA sequencing. The result also showed significant upregulation of alpha-internexin (INA). These results indicated that GD water extract might have an inductive effect for neural regeneration and could be used as functional food and supplementation for the prevention or treatment of diabetic neuropathy. This work provided the basic knowledge for further investigations into the benefits of GD for diabetic neuropathy.
- Published
- 2021
- Full Text
- View/download PDF
96. Diversity-Oriented Fluorescence Library Approach (DOFLA) for Discovery of Cell-Permeable Probes for Applications in Live Cell Imaging
- Author
-
Dongdong Su and Young-Tae Chang
- Subjects
medicine.anatomical_structure ,Chemistry ,Live cell imaging ,Cell ,medicine ,Fluorescence ,Cell biology - Published
- 2021
97. Pitfalls in Monitoring Mitochondrial Temperature Using Charged Thermosensitive Fluorophores
- Author
-
Paule Bénit, Sunyou Park, Guy Lenaers, Jung Yeol Lee, Young-Tae Chang, Christine Leroy, Malgorzata Rak, Dominique Chretien, Riyad El-Khoury, Pierre Rustin, Maladies neurodéveloppementales et neurovasculaires (NeuroDiderot (UMR_S_1141 / U1141)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP), Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Neuromuscular Diagnostic Laboratory [Beyrouth, Liban], Department of Pathology & Laboratory Medicine [Beyrouth, Liban], American University of Beirut Medical Center [Beyrouth, Liban] (AUBMC), American University of Beirut [Beyrouth] (AUB)-American University of Beirut [Beyrouth] (AUB)-American University of Beirut Medical Center [Beyrouth, Liban] (AUBMC), American University of Beirut [Beyrouth] (AUB)-American University of Beirut [Beyrouth] (AUB), Department of Chemistry [Pohang, Corée du Sud], Pohang University of Science and Technology (POSTECH), Physiopathologie Cardiovasculaire et Mitochondriale (MITOVASC), and Université d'Angers (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,Cell physiology ,Cell type ,[SDV]Life Sciences [q-bio] ,MitoThermo Yellow ,Mitochondrion ,Analytical Chemistry ,HeLa ,lcsh:Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,lcsh:QD415-436 ,Physical and Theoretical Chemistry ,ComputingMilieux_MISCELLANEOUS ,Membrane potential ,biology ,Chemistry ,HEK 293 cells ,temperature ,biology.organism_classification ,Fluorescence ,mitochondria ,030104 developmental biology ,thermosensitive fluorescent probes ,Cell culture ,Biophysics ,human activities ,030217 neurology & neurosurgery - Abstract
Mitochondria are the source of internal heat which influences all cellular processes. Hence, monitoring mitochondrial temperature provides a unique insight into cell physiology. Using a thermosensitive fluorescent probe MitoThermo Yellow (MTY), we have shown recently that mitochondria within human cells are maintained at close to 50 °, C when active, increasing their temperature locally by about 10 °, C. Initially reported in the HEK293 cell line, we confirmed this finding in the HeLa cell line. Delving deeper, using MTY and MTX (MitoThermo X), a modified version of MTY, we unraveled some caveats related to the nature of these charged fluorophores. While enabling the assessment of mitochondrial temperature in HEK and HeLa cell lines, the reactivity of MTY to membrane potential variations in human primary skin fibroblasts precluded local temperature monitoring in these cells. Chemical modification of MTY into MTX did not result in a temperature probe unresponsive to membrane potential variations that could be universally used in any cell type to determine mitochondrial temperature. Thus, the cell-type dependence of MTY in measuring mitochondrial temperature, which is likely due to the variable binding of this dye to specific internal mitochondrial components, should imply cautiousness while using these nanothermometers for mitochondrial temperature analysis.
- Published
- 2020
98. Target identification of a macrocyclic hexaoxazole G-quadruplex ligand using post-target-binding visualization
- Author
-
Young-Tae Chang, Yuki Wakabayashi, Kazuo Nagasawa, Yue Ma, Hiroyuki Seimiya, Sachiko Okabe, Dongdong Su, Mizuho Yasuda, and Masayuki Tera
- Subjects
Fluorophore ,Macrocyclic Compounds ,Stereochemistry ,Alkyne ,010402 general chemistry ,G-quadruplex ,Ligands ,01 natural sciences ,Catalysis ,03 medical and health sciences ,chemistry.chemical_compound ,Cell Line, Tumor ,Materials Chemistry ,Moiety ,Humans ,Oxazoles ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Binding Sites ,Molecular Structure ,Chemistry ,Ligand ,Metals and Alloys ,General Chemistry ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,G-Quadruplexes ,Ceramics and Composites ,Click chemistry ,Azide ,BODIPY - Abstract
Macrocyclic hexaoxazoles (6OTDs) are G-quadruplex (G4) ligands, and some derivatives, such as L2H2-6OTD (1a) bearing two aminobutyl side chains, show cytotoxicity towards cancer cells. To identify the cellular target of 1a, we employed a post-target-binding strategy utilizing click reaction (Huisgen cyclization) between the azide-conjugated ligand L2H2-6OTD-Az (1b) and the cell-permeable dye CO-1 bearing a strained alkyne moiety and the BODIPY fluorophore under Cu-free conditions. We confirmed that introduction of the small azide group did not alter the physical or biological properties, including anti-cancer activity, of 1a, and we also demonstrated bias-free localization of CO-1. The post-binding visualization strategy suggested that L2H2-6OTD (1a) colocalized with RNA G4 in living cells.
- Published
- 2020
99. Diversification of reprogramming trajectories revealed by parallel single-cell transcriptome and chromatin accessibility sequencing
- Author
-
Li-Feng Zhang, Jian Xu, Cheng Xu Delon Toh, Y. S. Chuah, Nam-Young Kang, Young-Tae Chang, Pradeep Gautam, Hu Li, George Q. Daley, C. A. El Farran, Yuin-Han Loh, Qiao Rui Xing, Tushar Warrier, James J. Collins, Shigeki Sugii, and School of Biological Sciences
- Subjects
Molecular Plant Physiology ,Muscle Proteins ,Computational biology ,Biology ,Chromosomes ,03 medical and health sciences ,0302 clinical medicine ,Machinery ,Single cell transcriptome ,Humans ,Transcription factor ,Research Articles ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Systems Biology ,TEA Domain Transcription Factors ,Biological sciences [Science] ,RNA ,SciAdv r-articles ,Cellular Reprogramming ,Chromatin ,DNA-Binding Proteins ,Single-Cell Analysis ,Stem cell ,Transcriptome ,Reprogramming ,030217 neurology & neurosurgery ,Transcription Factors ,Research Article ,Developmental Biology - Abstract
Integrative single-cell analysis de-constructs the heterogeneity of human reprogramming and uncovers its stage-specific GRNs., Cellular reprogramming suffers from low efficiency especially for the human cells. To deconstruct the heterogeneity and unravel the mechanisms for successful reprogramming, we adopted single-cell RNA sequencing (scRNA-Seq) and single-cell assay for transposase-accessible chromatin (scATAC-Seq) to profile reprogramming cells across various time points. Our analysis revealed that reprogramming cells proceed in an asynchronous trajectory and diversify into heterogeneous subpopulations. We identified fluorescent probes and surface markers to enrich for the early reprogrammed human cells. Furthermore, combinatory usage of the surface markers enabled the fine segregation of the early-intermediate cells with diverse reprogramming propensities. scATAC-Seq analysis further uncovered the genomic partitions and transcription factors responsible for the regulatory phasing of reprogramming process. Binary choice between a FOSL1 and a TEAD4-centric regulatory network determines the outcome of a successful reprogramming. Together, our study illuminates the multitude of diverse routes transversed by individual reprogramming cells and presents an integrative roadmap for identifying the mechanistic part list of the reprogramming machinery.
- Published
- 2020
100. Partitioning of cancer therapeutics in nuclear condensates
- Author
-
Arup K. Chakraborty, Jesse M. Platt, Ozgur Oksuz, Tim-Michael Decker, Nathanael S. Gray, Richard A. Young, Yang Eric Guo, Jonathan E. Henninger, John C. Manteiga, Mengyang Fan, Patrick M. McCall, Alicia V. Zamudio, Eliot L. Coffey, Alessandra Dall’Agnese, Phillip A. Sharp, Lena K. Afeyan, Isaac A. Klein, Nancy M. Hannett, Krishna Shrinivas, Victoria E. Clark, Benjamin R. Sabari, Ann Boija, Mrityunjoy Kar, Charles H. Li, Anthony A. Hyman, Dylan J. Taatjes, Jing-Ke Weng, Susana Wilson Hawken, Ido Sagi, Tinghu Zhang, Young-Tae Chang, and Tong Ihn Lee
- Subjects
chemistry.chemical_classification ,Drug ,Multidisciplinary ,Chemistry ,SARS-CoV-2 ,Biomolecule ,media_common.quotation_subject ,Cancer ,COVID-19 ,Nucleocapsid Proteins ,medicine.disease ,Phosphoproteins ,Small molecule ,In vitro ,Article ,Disease therapy ,Drug activity ,medicine ,Biophysics ,Antineoplastic Drugs ,Coronavirus Nucleocapsid Proteins ,Humans ,media_common - Abstract
Drug partitioning in nuclear condensates There is increasing interest in the function of phase-separated biomolecular condensates in cells because of their distinct properties and expanding roles in important biological processes. Klein et al. considered the fate of small-molecule therapeutics in the context of nuclear condensates (see the Perspective by Viny and Levine). They show that certain antineoplastic drugs have physicochemical properties that cause them to concentrate preferentially in condensates, both in vitro and in cancer cells. This property influences drug activity, and protein mutations that alter condensate formation can lead to drug resistance. Optimizing condensate partitioning may be valuable in developing improved therapeutics. Science , this issue p. 1386 ; see also p. 1314
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.