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Cai Q, Tai HC. Super-Resolution Imaging of Tau Proteins in Isolated and Immobilized Brain Synaptosomes. Methods Mol Biol 2024; 2754:445-456. [PMID: 38512681 DOI: 10.1007/978-1-0716-3629-9_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Tau protein has important physiological functions at both presynaptic and postsynaptic terminals. Pathological tau species are also associated with synaptic dysfunctions in several neurodegenerative disorders, especially Alzheimer's disease. To understand tau distribution inside synaptic compartments, super-resolution imaging is required. Here, we describe a facile protocol to immobilize and image brain synaptosomes without aggregation artefacts, by substituting the standard fixative paraformaldehyde with ethylene glycol bis(succinimidyl succinate) (EGS). Super-resolution imaging of tau proteins is achieved through three-color direct stochastic optical reconstruction microscopy (dSTORM). Tau protein is found to colocalize with synaptic vesicles as well as postsynaptic densities.
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Affiliation(s)
- Qixu Cai
- State Key Laboratory of Vaccines for Infectious Diseases, School of Public Health, Xiamen University, Xiamen, People's Republic of China
| | - Hwan-Ching Tai
- State Key Laboratory of Vaccines for Infectious Diseases, School of Public Health, Xiamen University, Xiamen, People's Republic of China.
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2
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Tai HC, Chang CH, Cai W, Lin JH, Huang SJ, Lin QY, Yuan ECY, Li SL, Lin YCJ, Chan JCC, Tsao CS. Wood cellulose microfibrils have a 24-chain core-shell nanostructure in seed plants. Nat Plants 2023:10.1038/s41477-023-01430-z. [PMID: 37349550 DOI: 10.1038/s41477-023-01430-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/08/2023] [Indexed: 06/24/2023]
Abstract
Wood cellulose microfibril (CMF) is the most abundant organic substance on Earth but its nanostructure remains poorly understood. There are controversies regarding the glucan chain number (N) of CMFs during initial synthesis and whether they become fused afterward. Here, we combined small-angle X-ray scattering, solid-state nuclear magnetic resonance and X-ray diffraction analyses to resolve CMF nanostructures in native wood. We developed small-angle X-ray scattering measurement methods for the cross-section aspect ratio and area of the crystalline-ordered CMF core, which has a higher scattering length density than the semidisordered shell zone. The 1:1 aspect ratio suggested that CMFs remain mostly segregated, not fused. The area measurement reflected the chain number in the core zone (Ncore). To measure the ratio of ordered cellulose over total cellulose (Roc) by solid-state nuclear magnetic resonance, we developed a method termed global iterative fitting of T1ρ-edited decay (GIFTED), in addition to the conventional proton spin relaxation editing method. Using the formula N = Ncore/Roc, most wood CMFs were found to contain 24 glucan chains, conserved between gymnosperm and angiosperm trees. The average CMF has a crystalline-ordered core of ~2.2 nm diameter and a semidisordered shell of ~0.5 nm thickness. In naturally and artificially aged wood, we observed only CMF aggregation (contact without crystalline continuity) but not fusion (forming a conjoined crystalline unit). This further argued against the existence of partially fused CMFs in new wood, overturning the recently proposed 18-chain fusion hypothesis. Our findings are important for advancing wood structural knowledge and more efficient use of wood resources in sustainable bio-economies.
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Affiliation(s)
- Hwan-Ching Tai
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, School of Public Health, Xiamen University, Xiamen, People's Republic of China.
| | - Chih-Hui Chang
- Department of Chemistry, National Taiwan University, Taipei, Republic of China
| | - Wenjie Cai
- School of Cultural Industry and Tourism and Cultural Industry Research Center, Fujian Social Science Research Base, Xiamen University of Technology, Xiamen, People's Republic of China
| | - Jer-Horng Lin
- Department of Chemistry, National Taiwan University, Taipei, Republic of China
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei, Republic of China
| | - Qian-Yan Lin
- Department of Chemistry, National Taiwan University, Taipei, Republic of China
| | | | - Shu-Li Li
- Department of Chemistry, National Taiwan University, Taipei, Republic of China
| | - Ying-Chung Jimmy Lin
- Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei, Republic of China
| | | | - Cheng-Si Tsao
- Department of Materials Science and Engineering, National Taiwan University, Taipei, Republic of China.
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3
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Wu X, Guo LZ, Liu YH, Liu YC, Yang PL, Leung YS, Tai HC, Wang TD, Lin JCW, Lai CL, Chuang YH, Lin CH, Chou PT, Lai IR, Liu TM. Plasma riboflavin fluorescence as a diagnostic marker of mesenteric ischemia-reperfusion injury in rats. Thromb Res 2023; 223:146-154. [PMID: 36753876 DOI: 10.1016/j.thromres.2023.01.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/25/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
Due to the delayed and vague symptoms, it is difficult to early diagnose mesenteric ischemia injuries in the dynamics of acute illness, leading to a 60-80 % mortality rate. Here, we found plasma fluorescence spectra can rapidly assess the severity of mesenteric ischemia injury in animal models. Ischemia-reperfusion damage of the intestine leads to multiple times increase in NADH, flavins, and porphyrin auto-fluorescence of blood. The fluorescence intensity ratio between blue-fluorophores and flavins can reflect the occurrence of shock. Using liquid chromatography and mass spectroscopy, we confirm that riboflavin is primarily responsible for the increased flavin fluorescence. Since humans absorb riboflavin from the intestine, its increase in plasma may indicate intestinal mucosa injury. Our work suggests a self-calibrated and reagent-free approach to identifying the emergence of fatal mesenteric ischemia in emergency departments or intensive care units.
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Affiliation(s)
- Xueqin Wu
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau SAR, China; MOE Frontiers Science Center for Precision Oncology, University of Macau, Macau SAR, China
| | - Lun-Zhang Guo
- Department of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Hung Liu
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Yu-Cheng Liu
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau SAR, China; MOE Frontiers Science Center for Precision Oncology, University of Macau, Macau SAR, China
| | - Po-Lun Yang
- Department of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Shiuan Leung
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Hwan-Ching Tai
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen 361102, P. R. China.
| | - Tzung-Dau Wang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, Taipei 10002, Taiwan
| | - Jesse Chih-Wei Lin
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Chao-Lun Lai
- Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan; Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
| | - Yueh-Hsun Chuang
- Department of Anesthesiology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Chih-Hsueh Lin
- Department of Nutrition, College of Medical and Health Care, Hungkuang University, Taichung City 433304, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - I-Rue Lai
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; Department of Surgery, National Taiwan University Hospital, Taipei 100229, Taiwan.
| | - Tzu-Ming Liu
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau SAR, China; MOE Frontiers Science Center for Precision Oncology, University of Macau, Macau SAR, China.
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Wu CY, Chen HJ, Wu YC, Tsai SW, Liu YH, Bhattacharya U, Lin D, Tai HC, Kong KV. Highly Efficient Singlet Oxygen Generation by BODIPY-Ruthenium(II) Complexes for Promoting Neurite Outgrowth and Suppressing Tau Protein Aggregation. Inorg Chem 2023; 62:1102-1112. [PMID: 36622931 DOI: 10.1021/acs.inorgchem.2c03017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Singlet oxygen (1O2) has been recently identified as a key molecule against toxic Aβ aggregation, which is associated with the currently incurable Alzheimer's disease (AD). However, limited research has studied its efficiency against tau protein aggregation, the other major hallmark of AD. Herein, we designed and synthesized boron-dipyrromethene (BODIPY)-ruthenium conjugates and isolated three isomers. Under visible-light irradiation, the ε isomer can be photoactivated and efficiently generate singlet oxygen. Particularly, the complex demonstrated successful results in attenuating tauopathy─an appreciable decrease to 43 ± 2% at 100 nM. The photosensitizer was further found to remarkably promote neurite outgrowth and significantly increased the length and number of neurites in nerve cells. As a result of effective photoinduced singlet oxygen generation and proactive neurite outgrowth, the hybrid design has great potential for therapeutics for Alzheimer's disease.
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Affiliation(s)
- Cheng-Yun Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Hsin-Jou Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Chin Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shu-Wei Tsai
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Hung Liu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | | | - Duo Lin
- Key Laboratory of OptoElectronic Science and Technology for Medicine, Ministry of Education, Fujian Provincial Key Laboratory for Photonics Technology, Digital Fujian Internet-of-Things Laboratory of Environment Monitoring, Fujian Normal University, Fuzhou 350007, China
| | - Hwan-Ching Tai
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Kien Voon Kong
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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5
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Bhattacharya U, Jhou JF, Zou YF, Abrigo G, Lin SW, Chen YH, Chien FC, Tai HC. Surface charge manipulation and electrostatic immobilization of synaptosomes for super-resolution imaging: a study on tau compartmentalization. Sci Rep 2021; 11:18583. [PMID: 34545174 PMCID: PMC8452691 DOI: 10.1038/s41598-021-98142-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/30/2021] [Indexed: 12/31/2022] Open
Abstract
Synaptosomes are subcellular fractions prepared from brain tissues that are enriched in synaptic terminals, widely used for the study of neural transmission and synaptic dysfunction. Immunofluorescence imaging is increasingly applied to synaptosomes to investigate protein localization. However, conventional methods for imaging synaptosomes over glass coverslips suffer from formaldehyde-induced aggregation. Here, we developed a facile strategy to capture and image synaptosomes without aggregation artefacts. First, ethylene glycol bis(succinimidyl succinate) (EGS) is chosen as the chemical fixative to replace formaldehyde. EGS/glycine treatment makes the zeta potential of synaptosomes more negative. Second, we modified glass coverslips with 3-aminopropyltriethoxysilane (APTES) to impart positive charges. EGS-fixed synaptosomes spontaneously attach to modified glasses via electrostatic attraction while maintaining good dispersion. Individual synaptic terminals are imaged by conventional fluorescence microscopy or by super-resolution techniques such as direct stochastic optical reconstruction microscopy (dSTORM). We examined tau protein by two-color and three-color dSTORM to understand its spatial distribution within mouse cortical synapses, observing tau colocalization with synaptic vesicles as well postsynaptic densities.
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Affiliation(s)
| | - Jia-Fong Jhou
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Yi-Fong Zou
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Gerald Abrigo
- Department of Optics and Photonics, National Central University, Taoyuan, Taiwan
| | - Shu-Wei Lin
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Yun-Hsuan Chen
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan
| | - Fan-Ching Chien
- Department of Optics and Photonics, National Central University, Taoyuan, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
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Su CK, Chen SY, Chung JH, Li GC, Brandmair B, Huthwelker T, Fulton JL, Borca CN, Huang SJ, Nagyvary J, Tseng HH, Chang CH, Chung DT, Vescovi R, Tsai YS, Cai W, Lu BJ, Xu JW, Hsu CS, Wu JJ, Li HZ, Jheng YK, Lo SF, Chen HM, Hsieh YT, Chung PW, Chen CS, Sun YC, Chan JCC, Tai HC. Materials Engineering of Violin Soundboards by Stradivari and Guarneri. Angew Chem Int Ed Engl 2021; 60:19144-19154. [PMID: 34062043 PMCID: PMC8457145 DOI: 10.1002/anie.202105252] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/22/2021] [Indexed: 11/24/2022]
Abstract
We investigated the material properties of Cremonese soundboards using a wide range of spectroscopic, microscopic, and chemical techniques. We found similar types of spruce in Cremonese soundboards as in modern instruments, but Cremonese spruces exhibit unnatural elemental compositions and oxidation patterns that suggest artificial manipulation. Combining analytical data and historical information, we may deduce the minerals being added and their potential functions—borax and metal sulfates for fungal suppression, table salt for moisture control, alum for molecular crosslinking, and potash or quicklime for alkaline treatment. The overall purpose may have been wood preservation or acoustic tuning. Hemicellulose fragmentation and altered cellulose nanostructures are observed in heavily treated Stradivari specimens, which show diminished second‐harmonic generation signals. Guarneri's practice of crosslinking wood fibers via aluminum coordination may also affect mechanical and acoustic properties. Our data suggest that old masters undertook materials engineering experiments to produce soundboards with unique properties.
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Affiliation(s)
- Cheng-Kuan Su
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
| | - Szu-Yu Chen
- Department of Optics and Photonics, National Central University, Taoyuan, Taiwan
| | - Jen-Hsuan Chung
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | - Guo-Chian Li
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | | | | | - John L Fulton
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, USA
| | - Camelia N Borca
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Joseph Nagyvary
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, USA
| | - Hsiao-Han Tseng
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | - Chih-Hui Chang
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | | | | | | | - Wenjie Cai
- School of Cultural Industry and Tourism, Xiamen University of Technology, Xiamen, Fujian, China
| | - Bing-Jyun Lu
- Department of Chemistry, Soochow University, Taipei, Taiwan
| | - Jia-Wei Xu
- Department of Optics and Photonics, National Central University, Taoyuan, Taiwan
| | - Chia-Shuo Hsu
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | - Jun-Jie Wu
- Department of Chemistry, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hao-Zhi Li
- Department of Chemistry, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yu-Kai Jheng
- Department of Forestry and Natural Resources, National Ilan University, I-Lan, Taiwan
| | - Sheng-Fong Lo
- Department of Forestry and Natural Resources, National Ilan University, I-Lan, Taiwan
| | - Hao Ming Chen
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | - Yi-Ting Hsieh
- Department of Chemistry, Soochow University, Taipei, Taiwan
| | - Po-Wen Chung
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chien-Sheng Chen
- Department of Chemistry, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yuh-Chang Sun
- Department of Biomedical Engineering and Environmental Sciences, National Tsing-Hua University, Hsinchu, Taiwan
| | - Jerry Chun Chung Chan
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei, 106, Taiwan
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Yuan ECY, Huang SJ, Huang HC, Sinkkonen J, Oss A, Org ML, Samoson A, Tai HC, Chan JCC. Faster magic angle spinning reveals cellulose conformations in woods. Chem Commun (Camb) 2021; 57:4110-4113. [PMID: 33908496 DOI: 10.1039/d1cc01149a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a first report on the detection of three different C6 conformers of cellulose in spruce, as revealed by solid-state 1H-13C correlation spectra. The breakthrough in 1H resolution is achieved by magic-angle spinning in the regime of 150 kHz. The suppression of dense dipolar network of 1H provides inverse detected 13C spectra at a good sensitivity even in natural samples. We find that the glycosidic linkages are initially more ordered in spruce than maple, but a thermal treatment of spruce leads to a more heterogeneous packing order of the remaining cellulose fibrils.
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Affiliation(s)
- Eric Chung-Yueh Yuan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Hung-Chia Huang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
| | - Jari Sinkkonen
- Innovation Centre for Biomaterials, Stora Enso AB, Nacka 13154, Sweden
| | - Andres Oss
- Tallinn University of Technology, Estonia.
| | | | | | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
| | - Jerry Chun Chung Chan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan, Republic of China.
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Tai HC, Chen PL, Xu JW, Chen SY. Two-photon fluorescence and second harmonic generation hyperspectral imaging of old and modern spruce woods. Opt Express 2020; 28:38831-38841. [PMID: 33379443 DOI: 10.1364/oe.410856] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
Spruce is the commonly-used tonewood for the top plate of violin-family instruments, such as violins and cellos. The wood properties can critically determine the acoustic quality. It's been shown the wood of famous old instruments differ from modern ones due to chemical treatment and aging. To reveal the differences microscopically in both spatial and spectral domains, a two-photon hyperspectral system has been applied to investigate the autofluorescence and second harmonic generation within wood samples. Not only the cellular structures were observed through optical sectioning, but the spectral variations were revealed among different age wood samples and different cellular structures.
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Lkhagva A, Shen CC, Leung YS, Tai HC. Comparative study of five different amine-derivatization methods for metabolite analyses by liquid chromatography-tandem mass spectrometry. J Chromatogr A 2020; 1610:460536. [PMID: 31563299 DOI: 10.1016/j.chroma.2019.460536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 08/17/2019] [Accepted: 09/09/2019] [Indexed: 01/21/2023]
Abstract
Current metabolomics research utilizes liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses to handle biological samples that contain thousands of quantifiable metabolites. However, no LC-MS/MS condition is suitable for directly analyzing all metabolites. An alternative approach is to derivatize metabolites to impart desirable properties such as better chromatographic separation, enhanced ionization efficiency, or fluorescence detection. An important category of metabolites is amine-containing compounds, which includes amino acids, neurotransmitters, alkaloids, biogenic amines, etc. Various derivatization methods have been developed for amine groups, but few studies have compared their relative strengths and weaknesses. We chose Dansyl-Cl, o-phthalaldehyde (OPA), Fmoc-Cl, Dabsyl-Cl, and Marfey's reagent to systematically compare their reactivity, absorbance, fluorescence, chromatographic separation, and ionization efficiencies under three pH conditions-2.6, 5.0, and 8.0. Their MS/MS fragmentation patterns were also examined under different collision energies. Overall, Dansyl-Cl is a very versatile derivatization method, generating products with fluorescence and high ionization efficiency. Fmoc-Cl is similarly useful under highly acidic chromatography conditions. Dabsyl-Cl may be a good alternative at weakly acidic and weakly basic conditions. OPA is a versatile fluorogenic reagent and its chemistry may be fine-tuned by incorporating different thiol molecules. Marfey's reagent is suboptimal in general, but its chiral property is useful for the separation of enantiomers. All five were applied to the analyses of Coptis chinensis, a Chinese medical herb, identifying hundreds of amine-containing metabolites through MS/MS analyses. None of the five methods is clearly superior, and their compound coverage profiles are rather distinct. A combination of multiple derivatization reagents is required for comprehensive coverage. Our comparative data provide useful guidelines for designing more efficient metabolomics experiments for different analytical goals.
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Affiliation(s)
- Ankhbayar Lkhagva
- Department of Chemistry, National Taiwan University, Taipei, Taiwan; Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
| | - Ching-Chieh Shen
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yun-Shiuan Leung
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei, Taiwan.
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10
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Wu HY, Kuo PC, Wang YT, Lin HT, Roe AD, Wang BY, Han CL, Hyman BT, Chen YJ, Tai HC. β-Amyloid Induces Pathology-Related Patterns of Tau Hyperphosphorylation at Synaptic Terminals. J Neuropathol Exp Neurol 2019; 77:814-826. [PMID: 30016458 DOI: 10.1093/jnen/nly059] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A synergy between β-amyloid (Aβ) and tau appears to occur in Alzheimer disease (AD), but the mechanisms of interaction, and potential locations, are little understood. This study investigates the possibility of such interactions within the cortical synaptic compartments of APP/PS1 mice. We used label-free quantitative mass spectrometry to study the phosphoproteome of synaptosomes, covering 2400 phosphopeptides and providing an unbiased survey of phosphorylation changes associated with amyloid pathology. Hyperphosphorylation was detected on 36 synaptic proteins, many of which are associated with the cytoskeleton. Importantly, tau is one of the most hyperphosphorylated proteins at the synapse, upregulated at both proline-directed kinase (PDK) sites (S199/S202, S396/S404) and nonPDK sites (S400). These PDK sites correspond to well-known pathological tau epitopes in AD patients, recognized by AT8 and PHF-1 antibodies, respectively. Hyperphosphorylation at S199/S202, a rarely examined combination, was further validated in patient-derived human synaptosomes by immunoblotting. Global surveys of upregulated phosphosites revealed 2 potential kinase motifs, which resemble those of cyclin-dependent kinase 5 (CDK5, a PDK) and casein kinase II (CK2, a nonPDK). Our data demonstrate that, within synaptic compartments, amyloid pathology is associated with tau hyperphosphorylation at disease-relevant epitopes. This provides a plausible mechanism by which Aβ promotes the spreading of tauopathy.
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Affiliation(s)
- Hsin-Yi Wu
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Po-Cheng Kuo
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Wang
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hao-Tai Lin
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Allyson D Roe
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Bo Y Wang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Chia-Li Han
- Master Program for Clinical Pharmacogenomics and Pharmacoproteomics, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yu-Ju Chen
- Department of Chemistry, National Taiwan University, Taipei, Taiwan.,Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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11
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Pei JC, Hung WL, Lin BX, Shih MH, Lu LY, Luo DZ, Tai HC, Studer V, Min MY, Lai WS. Therapeutic potential and underlying mechanism of sarcosine (N-methylglycine) in N-methyl-D-aspartate (NMDA) receptor hypofunction models of schizophrenia. J Psychopharmacol 2019; 33:1288-1302. [PMID: 31294644 DOI: 10.1177/0269881119856558] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Compelling animal and clinical studies support the N-methyl-D-aspartate receptor (NMDAR) hypofunction hypothesis of schizophrenia and suggest promising pharmacological agents to ameliorate negative and cognitive symptoms of schizophrenia, including sarcosine, a glycine transporter-1 inhibitor. AIMS AND METHODS It is imperative to evaluate the therapeutic potential of sarcosine in animal models, which provide indispensable tools for testing drug effects in detail and elucidating the underlying mechanisms. In this study, a series of seven experiments was conducted to investigate the effect of sarcosine in ameliorating behavioral deficits and the underlying mechanism in pharmacological (i.e., MK-801-induced) and genetic (i.e., serine racemase-null mutant (SR-/-) mice) NMDAR hypofunction models. RESULTS In Experiment 1, the acute administration of 500/1000 mg/kg sarcosine (i.p.) had no adverse effects on motor function and serum biochemical responses. In Experiments 2-4, sarcosine significantly alleviated MK-801-induced (0.2 mg/kg) brain abnormalities and behavioral deficits in MK-801-induced and SR-/- mouse models. In Experiment 5, the injection of sarcosine enhanced CSF levels of glycine and serine in rat brain. In Experiments 6-7, we show for the first time that sarcosine facilitated NMDAR-mediated hippocampal field excitatory postsynaptic potentials and influenced the movement of surface NMDARs at extrasynaptic sites. CONCLUSIONS Sarcosine effectively regulated the surface trafficking of NMDARs, NMDAR-evoked electrophysiological activity, brain glycine levels and MK-801-induced abnormalities in the brain, which contributed to the amelioration of behavioral deficits in mouse models of NMDAR hypofunction.
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Affiliation(s)
- Ju-Chun Pei
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Wei-Li Hung
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Bei-Xuan Lin
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Min-Han Shih
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Liang-Yin Lu
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Da-Zhong Luo
- Department of Psychology, National Taiwan University, Taipei, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Vincent Studer
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France.,French National Center for Scientific Research (CNRS), Bordeaux, France
| | - Ming-Yuan Min
- Institute of Zoology, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Wen-Sung Lai
- Department of Psychology, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
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12
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Chen MN, Ho KY, Hung YN, Su CC, Kuan CH, Tai HC, Cheng NC, Lin CC. Pre-treatment quality of life as a predictor of distant metastasis-free survival and overall survival in patients with head and neck cancer who underwent free flap reconstruction. Eur J Oncol Nurs 2019; 41:1-6. [PMID: 31358241 DOI: 10.1016/j.ejon.2019.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE This study examined the prognostic associations of pre-treatment quality of life (QoL) with overall survival (OS) and distant metastasis-free survival (DFMS) among patients with head and neck cancer (HNC) who underwent free flap reconstruction. METHODS A cohort of 127 HNC patients who received free flap reconstruction between November 2010 and June 2014 at a hospital were recruited. Pre-treatment QoL was measured by the University of Washington Quality of Life Questionnaire, which contains six physical domains, including speech, swallowing, appearance, saliva, taste and chewing, as well as the six social-emotional domains of pain, activity, recreation, shoulder, mood, and anxiety. Cox regression analyses were performed. RESULTS Results showed that pre-treatment QoL was predictive of OS and DMFS. Of the domains, swallowing, chewing, speech, taste, saliva, pain and shoulder were demonstrated to be significant predictors of OS. Additionally, swallowing, chewing, speech, pain and activity were demonstrated making significant contributions to DMFS. CONCLUSION Our data supported that physical domains of pre-treatment QoL were predictors for OS and DFMS in HNC patients with free-flap reconstruction. Longitudinal studies are warranted to clarify the prognostic abilities of social-emotional domains. Information on pre-treatment QoL should be taken into account to individualize care plan for these patients, and hence prolong their survival.
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Affiliation(s)
- M N Chen
- Department of Nursing, National Taiwan University Hospital, Taipei, Taiwan; School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan.
| | - K Y Ho
- School of Nursing, The University of Hong Kong, HKSAR, China.
| | - Y N Hung
- School of Gerontology and Health Management, College of Nursing, Taipei Medical University, Taipei, Taiwan.
| | - C C Su
- Department of Nursing, Chang Gung University of Science and Technology, Chiayi, Taiwan.
| | - C H Kuan
- Graduate Institute of Clinical Research, College of Medicine, National Taiwan University, Taipei, Taiwan; Division of Plastic Surgery, Department of Surgery, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
| | - H C Tai
- Division of Plastic Surgery, Department of Surgery, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
| | - N C Cheng
- Division of Plastic Surgery, Department of Surgery, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
| | - C C Lin
- School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan; School of Nursing, The University of Hong Kong, HKSAR, China; Alice Ho Miu Ling Nethersole Charity Foundation Professor in Nursing, Hong Kong.
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13
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Guo ZH, Yang CI, Ho CI, Huang SJ, Chen YC, Tai HC, Chan JCC. Fibrillization of β-Amyloid Peptides via Chemically Modulated Pathway. Chemistry 2018; 24:4939-4943. [PMID: 29380450 DOI: 10.1002/chem.201706001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 11/11/2022]
Abstract
The aggregation of β-amyloid peptides is closely associated with Alzheimer's disease. We have used liposomes to modulate the early aggregation events of 40-residue β-amyloid peptides. The spatial confinement provided by liposomes leads to the formation of nonfibrillar aggregates of β-amyloid peptides. These on-pathway β-sheet intermediates were used to seed the fibrillization of the monomer peptides. Solid-state NMR spectroscopy revealed that the resultant fibrils have a more uniform structure than those formed in liposome-free solution.
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Affiliation(s)
- Zhong-Hong Guo
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Chien-I Yang
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Cheng-I Ho
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Yin-Chung Chen
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Jerry Chun Chung Chan
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
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14
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Chen YH, Hsu HY, Yeh MT, Chen CC, Huang CY, Chung YH, Chang ZF, Kuo WC, Chan NL, Weng JH, Chung BC, Chen YJ, Jian CB, Shen CC, Tai HC, Sheu SY, Fang JM. Chemical Inhibition of Human Thymidylate Kinase and Structural Insights into the Phosphate Binding Loop and Ligand-Induced Degradation. J Med Chem 2016; 59:9906-9918. [DOI: 10.1021/acs.jmedchem.6b01280] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yi-Hsuan Chen
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Hua-Yi Hsu
- Department
of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan
| | - Ming-Tyng Yeh
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Chen-Cheng Chen
- Graduate
Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Chang-Yu Huang
- Graduate
Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Ying-Hsuan Chung
- Graduate
Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Zee-Fen Chang
- Graduate
Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Wei-Chen Kuo
- Institute
of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Nei-Li Chan
- Institute
of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Jui-Hsia Weng
- Institute
of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Bon-chu Chung
- Institute
of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Ju Chen
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
- Institute
of Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - Cheng-Bang Jian
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Ching-Chieh Shen
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Hwan-Ching Tai
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Sheh-Yi Sheu
- Department
of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan
- Institute
of Biomedical Informatics, National Yang-Ming University, Taipei 112, Taiwan
| | - Jim-Min Fang
- Department
of Chemistry, National Taiwan University, Taipei 106, Taiwan
- The
Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
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15
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Lin JM, Tsai YT, Liu YH, Lin Y, Tai HC, Chen CS. Identification of 2-oxohistidine Interacting Proteins Using E. coli Proteome Chips. Mol Cell Proteomics 2016; 15:3581-3593. [PMID: 27644758 DOI: 10.1074/mcp.m116.060806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 08/26/2016] [Indexed: 11/06/2022] Open
Abstract
Cellular proteins are constantly damaged by reactive oxygen species generated by cellular respiration. Because of its metal-chelating property, the histidine residue is easily oxidized in the presence of Cu/Fe ions and H2O2 via metal-catalyzed oxidation, usually converted to 2-oxohistidine. We hypothesized that cells may have evolved antioxidant defenses against the generation of 2-oxohistidine residues on proteins, and therefore there would be cellular proteins which specifically interact with this oxidized side chain. Using two chemically synthesized peptide probes containing 2-oxohistidine, high-throughput interactome screening was conducted using the E. coli K12 proteome microarray containing >4200 proteins. Ten interacting proteins were identified, and successfully validated using a third peptide probe, fluorescence polarization assays, as well as binding constant measurements. We discovered that 9 out of 10 identified proteins seemed to be involved in redox-related cellular functions. We also built the functional interaction network to reveal their interacting proteins. The network showed that our interacting proteins were enriched in oxido-reduction processes, ion binding, and carbon metabolism. A consensus motif was identified among these 10 bacterial interacting proteins based on bioinformatic analysis, which also appeared to be present on human S100A1 protein. Besides, we found that the consensus binding motif among our identified proteins, including bacteria and human, were located within α-helices and faced the outside of proteins. The combination of chemically engineered peptide probes with proteome microarrays proves to be an efficient discovery platform for protein interactomes of unusual post-translational modifications, and sensitive enough to detect even the insertion of a single oxygen atom in this case.
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Affiliation(s)
- Jun-Mu Lin
- From the ‡Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan.,§Department of Biomedical Sciences and Engineering, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan
| | - Yu-Ting Tsai
- ¶Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Yu-Hsuan Liu
- ¶Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Yun Lin
- ¶Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Hwan-Ching Tai
- ¶Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Chien-Sheng Chen
- From the ‡Graduate Institute of Systems Biology and Bioinformatics, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan; .,§Department of Biomedical Sciences and Engineering, National Central University, No. 300, Jhongda Rd., Jhongli 32001, Taiwan
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16
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Yang CI, Tsai BNF, Huang SJ, Wang TY, Tai HC, Chan JCC. Aggregation of Beta-Amyloid Peptides Proximal to Zwitterionic Lipid Bilayers. Chem Asian J 2015; 10:1967-71. [DOI: 10.1002/asia.201500482] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 06/01/2015] [Indexed: 01/05/2023]
Affiliation(s)
- Chien-I Yang
- Department of Chemistry; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
| | - Brook N. F. Tsai
- Department of Chemistry; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
| | - Shing-Jong Huang
- Instrumentation Center; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
| | - Ting-Yu Wang
- Instrumentation Center; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
| | - Hwan-Ching Tai
- Department of Chemistry; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
| | - Jerry C. C. Chan
- Department of Chemistry; National Taiwan University; No. 1, Section 4, Roosevelt Road Taipei 106 Taiwan
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17
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Huang CF, Liu YH, Tai HC. Synthesis of peptides containing 2-oxohistidine residues and their characterization by liquid chromatography-tandem mass spectrometry. J Pept Sci 2015; 21:114-9. [PMID: 25557961 DOI: 10.1002/psc.2735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/09/2014] [Accepted: 12/05/2014] [Indexed: 11/06/2022]
Abstract
Protein oxidation by reactive oxygen species has been associated with aging and neurodegenerative disorders, and histidine is one of the major oxidation targets due to its metal-chelating property and susceptibility to metal-catalyzed oxidation. 2-Oxohistidine, the major product of histidine oxidation, has been recently identified as a stable marker of oxidative damage in biological systems, but its biophysical and biochemical properties are understudied, partly because of difficulties in its chemical synthesis. We developed an efficient method to generate a 2-oxohistidine side chain using metal-catalyzed oxidation, applicable to both monomers and peptides. By optimizing reagent ratios and pH buffering in Cu(2+) /ascorbate/O2 reaction system, we improved the yield more than tenfold compared to reported conditions, which allowed us to obtain homogeneously modified 2-oxohisidine peptides for further studies. Analysis of 2-oxohistidine-containing model peptides by liquid chromatography-tandem mass spectrometry demonstrated increased retention time in reverse-phase chromatography and general stability of 2-oxohistidine under electrospray ionization and collision-induced dissociation. Thus, large-scale analysis of 2-oxohistidine-modified proteome should be feasible using shotgun protein mass spectrometry, and we were able to observe such peptides in proteomics datasets. The feasibility of acquiring purified peptide probes and peptide antigens containing 2-oxohistidine will help advance the study of this non-enzymatic posttranslational modification.
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Affiliation(s)
- Che-Fan Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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18
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Affiliation(s)
- Hwan-Ching Tai
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
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19
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Chen CC, Su WC, Huang BY, Chen YJ, Tai HC, Obena RP. Interaction modes and approaches to glycopeptide and glycoprotein enrichment. Analyst 2014; 139:688-704. [DOI: 10.1039/c3an01813j] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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20
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Tai HC, Wang BY, Serrano¿Pozo A, Frosch MP, Spires-Jones TL, Hyman BT. Frequent and symmetric deposition of misfolded tau oligomers within presynaptic and postsynaptic terminals in Alzheimer¿s disease. Acta Neuropathol Commun 2014. [DOI: 10.1186/preaccept-9134577561374599] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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21
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Kopeikina KJ, Polydoro M, Tai HC, Yaeger E, Carlson GA, Pitstick R, Hyman BT, Spires-Jones TL. Synaptic alterations in the rTg4510 mouse model of tauopathy. J Comp Neurol 2013; 521:1334-53. [PMID: 23047530 DOI: 10.1002/cne.23234] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/07/2012] [Accepted: 10/02/2012] [Indexed: 01/01/2023]
Abstract
Synapse loss, rather than the hallmark amyloid-β (Aβ) plaques or tau-filled neurofibrillary tangles (NFT), is considered the most predictive pathological feature associated with cognitive status in the Alzheimer's disease (AD) brain. The role of Aβ in synapse loss is well established, but despite data linking tau to synaptic function, the role of tau in synapse loss remains largely undetermined. Here we test the hypothesis that human mutant P301L tau overexpression in a mouse model (rTg4510) will lead to age-dependent synaptic loss and dysfunction. Using array tomography and two methods of quantification (automated, threshold-based counting and a manual stereology-based technique) we demonstrate that overall synapse density is maintained in the neuropil, implicating synapse loss commensurate with the cortical atrophy known to occur in this model. Multiphoton in vivo imaging reveals close to 30% loss of apical dendritic spines of individual pyramidal neurons, suggesting these cells may be particularly vulnerable to tau-induced degeneration. Postmortem, we confirm the presence of tau in dendritic spines of rTg4510-YFP mouse brain by array tomography. These data implicate tau-induced loss of a subset of synapses that may be accompanied by compensatory increases in other synaptic subtypes, thereby preserving overall synapse density. Biochemical fractionation of synaptosomes from rTg4510 brain demonstrates a significant decrease in expression of several synaptic proteins, suggesting a functional deficit of remaining synapses in the rTg4510 brain. Together, these data show morphological and biochemical synaptic consequences in response to tau overexpression in the rTg4510 mouse model.
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Affiliation(s)
- Katherine J Kopeikina
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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22
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Perez-Nievas BG, Stein TD, Tai HC, Dols-Icardo O, Scotton TC, Barroeta-Espar I, Fernandez-Carballo L, de Munain EL, Perez J, Marquie M, Serrano-Pozo A, Frosch MP, Lowe V, Parisi JE, Petersen RC, Ikonomovic MD, López OL, Klunk W, Hyman BT, Gómez-Isla T. Dissecting phenotypic traits linked to human resilience to Alzheimer's pathology. ACTA ACUST UNITED AC 2013; 136:2510-26. [PMID: 23824488 DOI: 10.1093/brain/awt171] [Citation(s) in RCA: 252] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Clinico-pathological correlation studies and positron emission tomography amyloid imaging studies have shown that some individuals can tolerate substantial amounts of Alzheimer's pathology in their brains without experiencing dementia. Few details are known about the neuropathological phenotype of these unique cases that might prove relevant to understanding human resilience to Alzheimer's pathology. We conducted detailed quantitative histopathological and biochemical assessments on brains from non-demented individuals before death whose brains were free of substantial Alzheimer's pathology, non-demented individuals before death but whose post-mortem examination demonstrated significant amounts of Alzheimer's changes ('mismatches'), and demented Alzheimer's cases. Quantification of amyloid-β plaque burden, stereologically-based counts of neurofibrillary tangles, neurons and reactive glia, and morphological analyses of axons were performed in the multimodal association cortex lining the superior temporal sulcus. Levels of synaptic integrity markers, and soluble monomeric and multimeric amyloid-β and tau species were measured. Our results indicate that some individuals can accumulate equivalent loads of amyloid-β plaques and tangles to those found in demented Alzheimer's cases without experiencing dementia. Analyses revealed four main phenotypic differences among these two groups: (i) mismatches had striking preservation of neuron numbers, synaptic markers and axonal geometry compared to demented cases; (ii) demented cases had significantly higher burdens of fibrillar thioflavin-S-positive plaques and of oligomeric amyloid-β deposits reactive to conformer-specific antibody NAB61 than mismatches; (iii) strong and selective accumulation of hyperphosphorylated soluble tau multimers into the synaptic compartment was noted in demented cases compared with controls but not in mismatches; and (iv) the robust glial activation accompanying amyloid-β and tau pathologies in demented cases was remarkably reduced in mismatches. Further biochemical measurements of soluble amyloid-β species-monomers, dimers and higher molecular weight oligomers-in total brain homogenates and synaptoneurosomal preparations failed to demonstrate significant differences between mismatches and demented cases. Together, these data suggest that amyloid-β plaques and tangles do not inevitably result in neural system derangement and dementia in all individuals. We identified distinct phenotypic characteristics in the profile of brain fibrillar and soluble amyloid-β and tau accrual and in the glial response that discriminated demented and non-demented individuals with high loads of Alzheimer's pathology. Amyloid-β deposition in the form of fibrillar plaques and intimately related oligomeric amyloid-β assemblies, hyperphosphorylated soluble tau species localized in synapses, and glial activation emerged in this series as likely mediators of neurotoxicity and altered cognition, providing further insight into factors and pathways potentially involved in human susceptibility or resilience to Alzheimer's pathological changes.
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Tai HC, Serrano-Pozo A, Hashimoto T, Frosch MP, Spires-Jones TL, Hyman BT. The synaptic accumulation of hyperphosphorylated tau oligomers in Alzheimer disease is associated with dysfunction of the ubiquitin-proteasome system. Am J Pathol 2012; 181:1426-35. [PMID: 22867711 DOI: 10.1016/j.ajpath.2012.06.033] [Citation(s) in RCA: 316] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 12/13/2022]
Abstract
In Alzheimer disease (AD), deposition of neurofibrillary tangles and loss of synapses in the neocortex and limbic system each correlate strongly with cognitive impairment. Tangles are composed of misfolded hyperphosphorylated tau proteins; however, the link between tau abnormalities and synaptic dysfunction remains unclear. We examined the location of tau in control and AD cortices using biochemical and morphologic methods. We found that, in addition to its well-described axonal localization, normal tau is present at both presynaptic and postsynaptic terminals in control human brains. In AD, tau becomes hyperphosphorylated and misfolded at both presynaptic and postsynaptic terminals, and this abnormally posttranslationally modified tau is enriched in synaptoneurosomal fractions. Synaptic tau seems to be hyperphosphorylated and ubiquitinated, and forms stable oligomers resistant to SDS denaturation. The accumulation of hyperphosphorylated tau oligomers at human AD synapses is associated with increased ubiquitinated substrates and increased proteasome components, consistent with dysfunction of the ubiquitin-proteasome system. Our findings suggest that synaptic hyperphosphorylated tau oligomers may be an important mediator of the proteotoxicity that disrupts synapses in AD.
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Affiliation(s)
- Hwan-Ching Tai
- MassGeneral Institute of Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Koffie RM, Hashimoto T, Tai HC, Kay KR, Serrano-Pozo A, Joyner D, Hou S, Kopeikina KJ, Frosch MP, Lee VM, Holtzman DM, Hyman BT, Spires-Jones TL. Apolipoprotein E4 effects in Alzheimer's disease are mediated by synaptotoxic oligomeric amyloid-β. ACTA ACUST UNITED AC 2012; 135:2155-68. [PMID: 22637583 DOI: 10.1093/brain/aws127] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The apolipoprotein E ε4 gene is the most important genetic risk factor for sporadic Alzheimer's disease, but the link between this gene and neurodegeneration remains unclear. Using array tomography, we analysed >50000 synapses in brains of 11 patients with Alzheimer's disease and five non-demented control subjects and found that synapse loss around senile plaques in Alzheimer's disease correlates with the burden of oligomeric amyloid-β in the neuropil and that this synaptotoxic oligomerized peptide is present at a subset of synapses. Further analysis reveals apolipoprotein E ε4 patients with Alzheimer's disease have significantly higher oligomeric amyloid-β burden and exacerbated synapse loss around plaques compared with apolipoprotein E ε3 patients. Apolipoprotein E4 protein colocalizes with oligomeric amyloid-β and enhances synaptic localization of oligomeric amyloid-β by >5-fold. Biochemical characterization shows that the amyloid-β enriched at synapses by apolipoprotein E4 includes sodium dodecyl sulphate-stable dimers and trimers. In mouse primary neuronal culture, lipidated apolipoprotein E4 enhances oligomeric amyloid-β association with synapses via a mechanism involving apolipoprotein E receptors. Together, these data suggest that apolipoprotein E4 is a co-factor that enhances the toxicity of oligomeric amyloid-β both by increasing its levels and directing it to synapses, providing a link between apolipoprotein E ε4 genotype and synapse loss, a major correlate of cognitive decline in Alzheimer's disease.
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Affiliation(s)
- Robert M Koffie
- Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, MA 02129, USA
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Tai HC, Besche H, Goldberg AL, Schuman EM. Characterization of the Brain 26S Proteasome and its Interacting Proteins. Front Mol Neurosci 2010; 3. [PMID: 20717473 PMCID: PMC2901091 DOI: 10.3389/fnmol.2010.00012] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 04/21/2010] [Indexed: 11/30/2022] Open
Abstract
Proteasome-mediated proteolysis is important for synaptic plasticity, neuronal development, protein quality control, and many other processes in neurons. To define proteasome composition in brain, we affinity purified 26S proteasomes from cytosolic and synaptic compartments of the rat cortex. Using tandem mass spectrometry, we identified the standard 26S subunits and a set of 28 proteasome-interacting proteins that associated substoichiometrically and may serve as regulators or cofactors. This set differed from those in other tissues and we also found several proteins that associated only with either the cytosolic or the synaptic proteasome. The latter included the ubiquitin-binding factor TAX1BP1 and synaptic vesicle protein SNAP-25. Native gel electrophoresis revealed a higher proportion of doubly-capped 26S proteasome (19S-20S-19S) in the cortex than in the liver or kidney. To investigate the interplay between proteasome regulation and synaptic plasticity, we exposed cultured neurons to glutamate receptor agonist NMDA. Within 4 h, this agent caused a prolonged decrease in the activity of the ubiquitin-proteasome system as shown by disassembly of 26S proteasomes, decrease in ubiquitin-protein conjugates, and dissociation of the ubiquitin ligases UBE3A (E6-AP) and HUWE1 from the proteasome. Surprisingly, the regulatory 19S particles were rapidly degraded by proteasomal, not lysosomal degradation, and the dissociated E3 enzymes also degraded. Thus the content of proteasomes and their set of associated proteins can be altered by neuronal activity, in a manner likely to influence synaptic plasticity and learning.
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Affiliation(s)
- Hwan-Ching Tai
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, CA, USA
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27
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Wang SM, Lai MK, Chueh SC, Tai HC, Chung SD. Optimal C2 concentration of cyclosporin corrected with good efficacy and safety in Asian kidney transplant recipients. Transplant Proc 2008; 40:2243-4. [PMID: 18790204 DOI: 10.1016/j.transproceed.2008.06.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Calcineurin inhibitors (CNI) are known for their renal toxicity. Lower CNI exposure is a reasonable option to mitigate potential CNI-induced renal toxicity. Herein we have presented our long-term results after lower cyclosporine (CsA) exposure in the first year. MATERIALS AND METHODS Between 1997 and 2004, 63 renal transplant recipients received CsA-based immunosuppression. CsA dosing was adjusted according to the 2-hour whole blood concentration (C2) level. We retrospectively reviewed acute rejection and graft survivals rates, as well as whole blood C2 levels. RESULTS Review of serial mean C2 concentrations at 1, 2, 3, 6, and 12 months after transplantation were 1341, 1241, 1191, 1059, and 927 ng/mL, respectively. These levels were slightly lower than those suggested by the Consensus for C2 levels by Levy et al in 2002, namely, 1600 to 2000 ng/mL (mean, 1700); 1400 to 1600 ng/mL (mean, 1500); 1200 to 1400 ng/mL (mean, 1300); 1000 to 1200 ng/mL (mean, 1100), and 800 to 1000 ng/mL (mean, 900), respectively. Acute rejection rate at 3 months and 1 year are 17.5% and 23.8%. Graft survival at 1 year was 97% and at 5 years, 89%. Two patient were lost to fulminant hepatitis and acute myocardial infarction during the first year, which were not associated with underimmunosuppression. CONCLUSION Appropriate CsA C2 levels may be lower among Taiwanese. Our C2 dosing strategy resulted in good outcomes with acceptable side effects in our single-center experience. Appropriate CsA C2 levels for Asians deserve more attention in trials of larger scale; most reference levels are presently concluded from studies of Caucasians.
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Affiliation(s)
- S M Wang
- Department of Urology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
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28
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Abstract
Eukaryotic protein degradation by the proteasome and the lysosome is a dynamic and complex process in which ubiquitin has a key regulatory role. The distinctive morphology of the postmitotic neuron creates unique challenges for protein degradation systems with respect to cell-surface protein turnover and substrate delivery to proteolytic machineries that are required for both synaptic plasticity and self-renewal. Moreover, the discovery of ubiquitin-positive protein aggregates in a wide spectrum of neurodegenerative diseases underlines the importance and vulnerability of the degradative system in neurons. In this article, we discuss the molecular mechanism of protein degradation in the neuron with respect to both its function and its dysfunction.
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Affiliation(s)
- Hwan-Ching Tai
- Division of Chemistry of Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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29
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Tai HC, Yang PJ, Lee PH, Chung SD, Chueh SC, Yu HJ. Acute lobar nephronia in a renal allograft: a case report and literature review. Transplant Proc 2008; 40:1737-40. [PMID: 18589182 DOI: 10.1016/j.transproceed.2007.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Accepted: 10/17/2007] [Indexed: 01/20/2023]
Abstract
We report a diabetic renal transplant recipient who presented with fever and right lower quadrant abdominal pain. Acute appendicitis was considered initially and she underwent emergent appendectomy. However, persistent symptoms postoperatively made us perform an imaging study to identify the problems. Abdominal and pelvic computed tomography disclosed several focal wedge-shaped lesions of low attenuation in the renal allograft. Acute lobar nephronia was successfully managed with parenteral antibiotics. The patient recovered without any sequela. A renal allograft in the right iliac fossa complicates the diagnosis among acute renal infection, malignancy, acute rejection, and even acute appendicitis. Biopsy of the renal allograft is sometimes needed due to clinically ambiguous imaging results. In this report, we not only detail the clinical course of such a rare case, but also review the previous 3 cases of acute lobar nephronia in renal allografts in the literature.
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Affiliation(s)
- H C Tai
- Department of Urology, National Taiwan University Hospital, Taipei, Taiwan
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30
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Lee JM, Tu CF, Tai HC, Chou NK, Weng CN, Lee YC, Lee PH. The impact of human ABO blood groups on human xenoreactive antibody-mediated cytotoxicity and the protective effect of human decay-accelerating factors exogene on swine endothelium. Transplant Proc 2008; 40:551-3. [PMID: 18374126 DOI: 10.1016/j.transproceed.2008.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
UNLABELLED Swine tissue can express antigens similar to human A/B blood types. We evaluated whether the variation in human blood type influences the human xenoreactive antibody-mediated cytotoxicity and modifies the protective effect of human decay-accelerating factor (hDAF) exogene, a complement activation regulator, on swine endothelium. METHODS Pig aortic endothelial cells were harvested form normal and hDAF transgenic pigs. Cellular viability was evaluated with an MTT assay. RESULTS As compared with that of other human blood types, human serum from blood type O donors induced more prominent cytotoxicity on swine endothelial cells both from hDAF transgenic or normal pigs (P < .05). In addition, this difference of xenoreactive antibody-induced cytotoxicity between treatment with O and other human blood type sera was more evident in hDAF transgenic swine endothelial cells than those of normal pigs (P < .05). The hDAF exogene can significantly protect the endothelial cells from human xenoreactive antibody-mediated cytotoxicty when treated with human serum from AB blood type (P < .05). Our data demonstrated that human ABO blood type significantly affected human xenoreactive antibody-induced cytotoxicity, which may modulate the protective effect of hDAF exogene expression on swine endothelial cells.
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Affiliation(s)
- J M Lee
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
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31
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Abstract
A recent study has shown that miR-134, a brain-specific microRNA, is present in dendrites where it represses the local synthesis of the protein kinase LimK1; this is a novel form of translational regulation in dendrites and may have important physiological implications.
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Affiliation(s)
- Hwan-Ching Tai
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 164-30, Pasadena, California 91125, USA
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32
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Lin WY, Murugesh MG, Sudhakar S, Yang HC, Tai HC, Chang CS, Liu YH, Wang Y, Chen IWP, Chen CH, Luh TY. On the Rigidity of Polynorbornenes with Dipolar Pendant Groups. Chemistry 2006; 12:324-30. [PMID: 16278915 DOI: 10.1002/chem.200500770] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A range of polynorbornenes (PNBs) with fused dipolar pendant groups at C-5,6 positions was synthesized by ring-opening metathesis polymerization catalyzed by a ruthenium carbene complex (Grubbs I). Photophysical studies, EFISH measurements, and atomic force microscopy images have been used to investigate the structures and morphology of these polymers. These results suggest that the polymers may adopt rigid rod-like structures. The presence of the double bonds in PNBs appeared to be indispensable for the rigidity of the polymers. Interaction between unsaturated pendant groups may result in coherent alignment leading to a rod-like structure.
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Affiliation(s)
- Wei-Yu Lin
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
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33
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Abstract
We report a new strategy for the parallel identification of O-GlcNAc-glycosylated proteins from cell lysates. The approach permits specific proteins of interest to be rapidly interrogated for the modification in any tissue or cell type and can be extended to peptides to facilitate the mapping of glycosylation sites. As an illustration of the approach, we identified four new O-GlcNAc-glycosylated proteins of low cellular abundance (c-Fos, c-Jun, ATF-1, and CBP) and two short regions of glycosylation in the enzyme O-GlcNAc transferase (OGT). The ability to target specific proteins across various tissue or cell types complements emerging proteomic technologies and should advance our understanding of this important posttranslational modification.
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Affiliation(s)
- Hwan-Ching Tai
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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34
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Lee JM, Tu CF, Huang SC, Tsuji K, Chen RJ, Hu CY, Hsieh RP, Tai HC, Weng CN, Lee YC, Lee CJ. Attenuation of human-to-pig xenogenic cellular proliferation and Th1 response by expressing the human MHC II DQ exogenes on porcine cells. Transplant Proc 2003; 35:527-8. [PMID: 12591516 DOI: 10.1016/s0041-1345(02)03858-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- J M Lee
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
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35
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Kong CW, Shih CJ, Hsiao HC, Chang HY, Tai HC, Lee KH, Hu HY, Tzeng CH. Acute and chronic phase platelet aggregability studies in Chinese patients after implantation of a permanent transvenous pacemaker. Int J Cardiol 1999; 69:83-6. [PMID: 10362377 DOI: 10.1016/s0167-5273(99)00012-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
It has been suggested that the incidence of thromboembolic events always increases in patients after insertion of a transvenous pacemaker. Blood samples from twenty consecutive patients (fifteen males and five females) before and after pacemaker implantation was retained for platelet aggregability studies which were analyzed separately with ADP, collagen, epinephrine and arachidonic acid. The maximal amplitude of platelet aggregatory curve was detected by an aggregometer. The samples collected the day before pacemaker implantation (day 0) were used as self-control. Day 1 and day 3 after pacemaker implantation were defined as the acute phase, while day 30 was defined as the chronic phase. The maximal amplitude of platelet aggregatory curve was observed to be lowest on day 1 and then return to normal on day 3 and day 30. The results of platelet aggregability, however, showed no significant difference (P>0.05) between self-control and post-implantation samples. In conclusion, there was no significant change in platelet aggregability for either acute or chronic phases after pacemaker implantation. Antiplatelet medications may not be necessary for the prevention of thromboembolic events after the implantation of a pacemaker.
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Affiliation(s)
- C W Kong
- Division of Cardiology, Veterans General Hospital, Taipei, Taiwan. ROC
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36
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Abstract
The quantitative effects of micropatterned laminin surfaces on neurite outgrowth and growth cone morphology were investigated. Using microlithography, 20- or 30-micron-wide laminin stripes were applied to the surface of a glass coverslip, alternating with BSA-coated glass stripes of the same dimension. Growth on these surfaces was strongly biased in the direction parallel to the stripes, but the mean length of outgrowth was reduced relative to that on uniform laminin surfaces. Growth cones were slightly more elongated on micropatterned surfaces than on controls and were aligned with the pattern. These results provide a starting point for examining the fundamental effects of micropatterned surfaces on neurite outgrowth and ways in which these may be useful in controlling and guiding neurite outgrowth for biotechnological applications.
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Affiliation(s)
- H C Tai
- Department of Chemical and Biochemical Engineering, Rutgers-The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854, USA
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37
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Abstract
Over the past decade, a large number of biomaterials have been proposed as artificial bone fillers for repairing bone defects. The material most widely used in clinical medicine is hydroxyapatite. The aim of our investigation was to study the effect of hydroxyapatite size mechanism on osteoblasts. The osteoblasts were cultured in vitro with 0.1% (1 mg/mL) of various sized hydroxyapatite particles (0.5-3.0, 37-63, 177-250, and 420-841 microm) for 1 h, 3 h, 1 day, 3 days, and 7 days. The results showed that adding hydroxyapatite particles to osteoblast cultures can significantly affect osteoblast cell count. Osteoblast populations decreased significantly. Osteoblast mean surface areas also changed significantly. Transforming growth factor-beta1 (TGF-beta1) concentrations in culture medium decreased significantly with the addition of hydroxyapatite particles. Prostaglandin E2 (PGE2) concentrations in medium increased significantly. The changes in TGF-beta1 and PGE2 concentration were more significant and persisted longer in smaller-particle groups. The inhibitory effects of hydroxyapatite particles on osteoblast cell cultures were mediated by the increased synthesis of PGE2. Caution should be exercised before using a hydroxyapatite product which could easily break down into fine particles.
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Affiliation(s)
- J S Sun
- Department of Orthopedic Surgery, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, ROC
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Tsuang YH, Lin FH, Tai HC, Sun JS, Liu HC, Hang YS. Biocompatibility and osteoconductivity of the pyrost bone substitutes. Histol Histopathol 1997; 12:19-24. [PMID: 9046039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The purpose of this study was to re-evaluate the bone regeneration power and the in vitro biocompatibility of the Pyrost bone substitute. Twenty-four adult New Zealand White rabbits were used. Bony defect over both iliac crest and mid-diaphyseal portion of the ulna bone were created. Appropriate sized-block of Pyrost bone substitute were implanted. Four of the animals were killed at each postoperative month to evaluate its bone regeneration power by histologic study. The Pyrost bones were co-cultured with osteoblasts to evaluate its biocompatibility. The results showed that Pyrost bone substitute was quite stable and incorporated well with active bone regeneration. The Pyrost heal better at the iliac crest than at the ulnar defect. The Pyrost was compatible to the osteoblasts. Osteoblasts had successfully seeded and mitotically expanded on the porous surface of the Pyrost bone graft. The result showed that Pyrost bone obviously exerts an intense stimulus on osteo-regeneration in the presence of osteoblasts. We consider Pyrost to be an alternate to the conventional preserved allografts that is occasionally necessary.
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Affiliation(s)
- Y H Tsuang
- Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, R.O.C
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Ti CT, Tai HC, Fang HC. Results of debridement treatment for spinal paralysis due to tuberculosis in children. Chin Med J 1965; 84:160-5. [PMID: 5295424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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