Browsing by Author "Wang, Yun-Ming"

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A N-(2-Aminophenyl)-5-(dimethylamino)-1-naphthalenesulfonic Amide (Ds-DAB) Based Fluorescent Chemosensor for Peroxynitrite
(2013-08-16)
Lin, Ku-Kuei
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Wu, Shou-Cheng
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Hsu, Kuang-Mei
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Hung, Chen-Hsiung
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Liaw, Wen-Feng
A dansyl derivative (Ds-DAB) was prepared and used as a fluorescent probe for peroxynitrite (ONOO-) detection. The results showed that the addition of peroxynitrite to the aqueous solution of Ds-DAB would result in obvious fluorescence enhancement. This probe is highly specific for peroxynitrite in aqueous solution, avoiding interference from other reactive oxygen species (ROS) and nitrogen species (RNS). The advantages of high selectivity, fast reaction rate, and peroxynitrite bioimaging render Ds-DAB suitable for peroxynitrite detection.
A regularly spaced and self-revealing protein ladder for anti-tag Western blot analysis
(2012-12-01)
Kao, Chien-Han
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Cheng, Chiu-Min
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Chuang, Kuo-Hsiang
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Chuang, Chih-Hung
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Tzou, Shey-Cherng
We designed a protein ladder (hereafter referred to as "Mega-tag") that contains 14 of the most commonly used epitope tags fused to molecular weight markers. The Mega-tag ladder can be simultaneously visualized when anti-tag antibodies are used to detect epitope-tagged recombinant proteins in Western blots. The logarithm of molecular weights and relative mobility of the Mega-tag protein ladder are highly correlated (R-2 = 0.997 +/- 0.00232), indicating that the dye-free Mega-tag protein ladder is accurate. It can also serve as a positive control for anti-epitope tag immunoblots. The Mega-tag protein ladder should provide a convenient and precise tool for Western blot analysis. (c) 2012 Elsevier Inc. All rights reserved.
A switch-on MRI contrast agent for noninvasive visualization of methylmercury
(2015-01-01)
Singh, Gyan
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Hsu, Kuang-Mei
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Chen, Yu-Jen
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Wu, Shou-Cheng
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Chen, Chiao-Yun
This communication presents the first Gd(III)-based T-1 MRI contrast agent, o-MeHgGad, for noninvasive visualization of CH3Hg+. o-MeHgGad showed a relaxivity enhancement of 62% in the presence of 1 equiv. of CH3Hg+. Moreover, a noticeable contrast enhancement was recorded in the liver, kidney, and intestine of mice exposed to CH3Hg+. Thus, the newly designed contrast agent has the potential to be used for in vivo bio-imaging of CH3Hg+ and could be useful for biomedical applications.
A water soluble and fast response fluorescent turn-on copper complex probe for H2S detection in zebra fish
(2016-01-15)
Palanisamy, Sathyadevi
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Lee, Lu-Ying
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Wang, Yu-Liang
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Chen, Yu-Jen
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Chen, Chiao-Yun
According to the displacement method, herein we reported a water soluble copper complex [Cu(MaT-cyclen)(2)] as a fluorescent probe for the detection of H2S. For this, 1((1-(10-methylanthracen-9-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1,4,7,10-tetraazacyclododecane (MaT-cyclen) was synthesized first To improve its solubility in aqueous media, sodium acetate group was introduced into 8-hydroxy-2-quinoline successfully. MaT-cyclen was chelated with Cu(II) to form [Cu(MaT-cyclen)2] complex, which displayed high sensitivity and selectivity for H2S over the other possible competitive substances on the basis of forming CuS. Meanwhile, [Cu(MaT-cyclen)(2)] displayed rapid response (< 1 min), well reversibility, lowest detection limit (205 nM), and high sensitivity for recognizing H2S in aqueous solution. Furthermore, its potential utility for biological applications was confirmed by fluorescence imaging of H2S in live cells as well as in zebra fish. (C) 2015 Elsevier B.V. All rights reserved.
Activation of Angiogenesis and Wound Healing in Diabetic Mice Using NO-Delivery Dinitrosyl Iron Complexes
(2019-10-01)
Chen, Yu-Jen
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Wu, Shou-Cheng
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Wang, Hsiang-Ching
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Wu, Tung-Ho
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Yuan, Shyng-Shiou F.
In diabetes, abnormal angiogenesis due to hyperglycemia and endothelial dysfunction impairs wound healing and results in high risks of diabetic foot ulcers and mortality. Alternative therapeutic methods were attempted to prevent diabetic complications through the activation of endothelial nitric oxide synthase. In this study, direct application of nitric oxide using dinitrosyl iron complexes (DNICs) to promote angiogenesis and wound healing under physiological conditions and in diabetic mice is investigated. Based on in vitro and in vivo studies, DNIC [Fe-2(mu-SCH2CH2OH)(2)(NO)(4)] (DNIC-1) with a sustainable NO-release reactivity (t(1/2) = 27.4 +/- 0.5 h at 25 degrees C and 16.8 +/- 1.8 h at 37 degrees C) activates the NO-sGC-cGMP pathway and displays the best proangiogenesis activity overwhelming other NO donors and the vascular endothelial growth factor. Moreover, this pro-angiogenesis effect of DNIC-1 restores the impaired angiogenesis in the ischemic hind limb and accelerates the recovery rate of wound closure in diabetic mice. This study translates synthetic DNIC-1 into a novel therapeutic agent for the treatment of diabetes and highlights its sustainable (NO)-N-center dot-release reactivity on the activation of angiogenesis and wound healing.
Antiviral Activity of a Llama-Derived Single-Domain Antibody against Enterovirus A71
(2020-05-01)
Huang, Peng-Nien
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Wang, Hsiang-Ching
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Hung, Hui-Chen
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Tseng, Sung-Nien
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Chang, Teng-Yuan
In the past few decades, enterovirus A71 (EVA71) has caused devastating outbreaks in the Asia-Pacific region, resulting in serious sequelae in infected young children. No preventive or therapeutic interventions are currently available for curing EVA71 infection, highlighting a great unmet medical need for this disease. Here, we showed that one novel single-domain antibody (sdAb), F1, isolated from an immunized llama, could alleviate EVA71 infection both in vitro and in vivo. We also confirmed that the sdAb clone F1 recognizes EVA71 through a novel conformational epitope comprising the highly conserved region of VP3 capsid protein by using competitive-binding and overlapping-peptide enzyme-linked immunosorbent assays (ELISAs). Because of the virion's icosahedral structure, we reasoned that adjacent epitopes must be clustered within molecular ranges that may be simultaneously bound by an engineered antibody with multiple valency. Therefore, two singledomain binding modules (F1) were fused to generate an sdAb-in-tandem design so that the capture of viral antigens could be further increased by valency effects. We showed that the tetravalent construct F1xF1-hFc, containing two sdAb-intandem on a fragment crystallizable (Fc) scaffold, exhibits more potent neutralization activity against EVA71 than does the bivalent sdAb F1-hFc by at least 5.8-fold. We also demonstrated that, using a human scavenger receptor class B member 2 (hSCARB2) transgenic mouse model, a half dose of the F1xF1-hFc provided better protection against EVA71 infection than did the F1-hFc. Thus, our study furnishes important insights into multivalent sdAb engineering against viral infection and provides a novel strategic deployment approach for preparedness of emerging infectious diseases such as EVA71.
Azide-alkyne cycloaddition for universal post-synthetic modifications of nucleic acids and effective synthesis of bioactive nucleic acid conjugates
(2014)
Su, Yu-Chih
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Lo, Yu-Lun
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Hwang, Chi-Ching
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Wang, Li-Fang
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Wu, Min Hui
The regioselective post-synthetic modifications of nucleic acids are essential to studies of these molecules for science and applications. Here we report a facile universal approach by harnessing versatile phosphoramidation reactions to regioselectively incorporate alkynyl/azido groups into post-synthetic nucleic acids primed with phosphate at the 5\' termini. With and without the presence of copper, the modified nucleic acids were subjected to azide-alkyne cycloaddition to afford various nucleic acid conjugates including a peptide-oligonucleotide conjugate (POC) with high yield. The POC was inoculated with human A549 cells and demonstrated excellent cell-penetrating ability despite cell deformation caused by a small amount of residual copper chelated to the POC. The combination of phosphoramidation and azide-alkyne cycloaddition reactions thus provides a universal regioselective strategy to post-synthetically modify nucleic acids. This study also explicated the toxicity of residual copper in synthesized bioconjugates destined for biological systems.
Bioinorganic Chemistry of the Natural [Fe(NO)(2)] Motif: Evolution of a Functional Model for NO-Related Biomedical Application and Revolutionary Development of a Translational Model!
(2018-10-15)
Lu, Tsai-Te
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Wang, Yun-Ming
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Hung, Chen-Hsiung
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Chiou, Show-Jen
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Liaw, Wen-Feng
Identification of the distinctive electron paramagnetic resonance signal at g = 2.03 in the yeast cells and liver of mice treated with carcinogens opened the discovery and investigation of the natural [Fe(NO)(2)] motif in the form of dinitrosyliron complexes (DNICs). In this Viewpoint, a chronological collection of the benchmark for the study of DNIC demonstrates that the preceding study of its biological synthesis, storage, transport, transformation, and function related to NO physiology inspires the biomimetic study of structural and functional models supported by thiolate ligands to provide mechanistic insight at a molecular level. During the synthetic, spectroscopic, and theoretical investigations on the structure-to-reactivity relationship within DNICs, control of the Fe-NO bonding interaction and of the delivery of NO+/(NO)-N-center dot/HNO/NO- by the supporting ligands and nuclearity evolves into the "redesign of the natural [Fe(NO)(2)] motif" as a strategy to develop DNICs for NO-related biomedical application and therapeutic approach. The revolutionary transformation of covalent a [Fe(NO)(2)] motif into a translational model for hydrogenase, triggered by the discovery of redox interconversion among [{Fe(NO)(2)}(9)-L-center dot] <-> {Fe(NO)(2)}(9) <-> {Fe(NO)(2)}(10) <-> [{Fe(NO)(2)}(10)-L-center dot](-) echoes the preceding research journey on [Fe]/[NiFe]-hydrogenase and completes the development of an electrodeposited-film electrode for electrocatalytic water splitting. Through the 50-year journey, bioinorganic chemistry of DNIC containing the covalent [Fe(NO)(2)] motif and noninnocent/labile NO ligands highlights itself as a unique metallocofactor to join the longitudinal study between biology/chemistry/biomedical application and the lateral study toward multielectron (photo/electro)catalysis for industrial application. This Viewpoint discloses the potential [Fe(NO)(2)] motif awaiting continued contribution in order to emerge as a novel application in the next 50 years, whereas the parallel development of bioinorganic chemistry, guided by inspirational Nature, moves the science forward to the next stage in order to benefit the immediate needs for human activity.
Bispecific Antibody Conjugated Manganese-Based Magnetic Engineered Iron Oxide for Imaging of HER2/neu- and EGFR-Expressing Tumors
(2016-01-01)
Wu, Shou-Cheng
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Chen, Jen
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Wang, Hsiang-Ching
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Chou, Min-Yuan
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Chang, Teng-Yuan
The overexpression of HER2/neu and EGFR receptors plays important roles in tumorigenesis and tumor progression. Targeting these two receptors simultaneously can have a more widespread application in early diagnosis of cancers. In this study, a new multifunctional nanoparticles (MnMEIO-CyTE777-(Bis)-mPEG NPs) comprising a manganese-doped iron oxide nanoparticle core (MnMEIO), a silane-amino functionalized poly(ethylene glycol) copolymer shell, a near infrared fluorescence dye (CyTE777), and a covalently conjugated anti-HER2/neu and anti-EGFR receptors bispecific antibody (Bis) were successfully developed. In vitro T-2-weighted MR imaging studies in SKBR-3 and A431 tumor cells incubated with MnMEIO-CyTE777-(Bis)-mPEG NPs showed -94.8 +/- 3.8 and -84.1 +/- 2.8% negative contrast enhancement, respectively. Pharmacokinetics study showed that MnMEIO-CyTE777-(Bis)-mPEG NPs were eliminated from serum with the half-life of 21.3 mins. In vivo MR imaging showed that MnMEIO-CyTE777-(Bis)-mPEG NPs could specifically and effectively target to HER2/neu-and EGFR-expressing tumors in mice; the relative contrast enhancements were 11.8 (at 2 hrs post-injection) and 61.5 (at 24 hrs post-injection) fold higher in SKBR-3 tumors as compared to Colo-205 tumors. T2-weighted MR and optical imaging studies revealed that the new contrast agent (MnMEIO-CyTE777-(Bis)-mPEG NPs) could specifically and effectively target to HER2/neu-and/or EGFR-expressing tumors. Our results demonstrate that MnMEIO-CyTE777-(Bis)-mPEG NPs are able to recognize the tumors expressing both HER2/neu and/or EGFR, and may provide a novel molecular imaging tool for early diagnosis of cancers expressing HER2/neu and/or EGFR.
Comparison of Gd-Bz-TTDA, Gd-EOB-DTPA, and Gd-BOPTA for dynamic MR imaging of the liver in rat models
(2012-03-01)
Jaw, Twei-Shiun
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Chen, Shih-Hsien
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Wang, Yun-Ming
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Hsu, Jui-Sheng
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Kuo, Yu-Ting
To evaluate the competitive potential of a new lipophilic paramagnetic complex, Gd-Bz-TTDA [4-benzyl-3,6,10-tri (carboxymethyl)-3,6,10-triazado-decanedioic acid] compared with two other commercially available MR hepatobiliary contrast agents, gadobenate dimeglumine (Gd-BOPTA) and gadoxetic acid (Gd-EOB-DTPA), dynamic MR imaging studies were performed on normal and hepatocellular carcinoma (HCC) rat models using a 1.5-Tesla MR scanner. The results indicate that normal rats that were injected with 0.1 mmol/kg Gd-Bz-TTDA showed significantly more intense and persistent liver enhancement than those that were injected with the same dose of Gd-EOB-DTPA or Gd-BOPTA. All of these agents showed similar enhancement patterns in the implanted HCC. The liver-lesion contrast-to-noise ratios were higher and more persistent in rats that were injected with Gd-Bz-TTDA. These results indicate that Gd-Bz-TTDA is comparable with the commercially available hepatobiliary agents, Gd-EOB-DTPA and Gd-BOPTA, and can result in more intense and prolonged liver enhancement while still providing better liver-lesion discrimination. These results warrant further large-scale studies. Copyright (C) 2012, Elsevier Taiwan LLC. All rights reserved.
Cucumarioside A(2)-2 Causes Macrophage Activation in Mouse Spleen
(2017-11-01)
Pislyagin, Evgeny A.
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Manzhulo, Igor V.
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Gorpenchenko, Tatiana Y.
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Dmitrenok, Pavel S.
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Avilov, Sergey A.
The immunomodulatory effect of triterpene glycoside cucumarioside A(2)-2 (CA(2)-2), isolated from the Far Eastern sea cucumber Cucumaria japonica, was compared with lipopolysaccharide (LPS) on mouse spleen. It has been shown that the intraperitoneal (i.p.) glycoside administration leads to increased spleen macrophage activating markers iba-1, IL-1, iNOs, ROS and NO formation, with additional change of macrophage phenotype to M1. The mass spectrometry profiles of peptide/protein were obtained using MALDI-TOF-MS on the different parts of spleen sections isolated by laser mircodissection techniques. It was found that i.p. stimulation of animals with CA(2)-2 leads to marked changes in the intensity of the characteristic peaks of spleen peptides/proteins, primarily in red pulp.
Decision Support for the Optimization of Provider Staffing for Hospital Emergency Departments with a Queue-Based Approach
(2019-12-01)
Jiang, Fuu-Cheng
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Shih, Cheng-Min
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Wang, Yun-Ming
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Yang, Chao-Tung
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Chiang, Yi-Ju
Deployment or distribution of valuable medical resources has emerged as an increasing challenge to hospital administrators and health policy makers. The hospital emergency department (HED) census and workload can be highly variable. Improvement of emergency services is an important stage in the development of the healthcare system and research on the optimal deployment of medical resources appears to be an important issue for HED long-term management. HED performance, in terms of patient flow and available resources, can be studied using the queue-based approach. The kernel point of this research is to approach the optimal cost on logistics using queuing theory. To model the proposed approach for a qualitative profile, a generic HED system is mapped into the M/M/R/N queue-based model, which assumes an R-server queuing system with Poisson arrivals, exponentially distributed service times and a system capacity of N. A comprehensive quantitative mathematical analysis on the cost pattern was done, while relevant simulations were also conducted to validate the proposed optimization model. The design illustration is presented in this paper to demonstrate the application scenario in a HED platform. Hence, the proposed approach provides a feasibly cost-oriented decision support framework to adapt a HED management requirement.
Design of a Micro-Electrode Cell for Programmable Lab-on-CMOS Platform
(2016)
Ho, Yingchieh
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Wang, Gary
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Lai, Kelvin Yi-Tse
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Lug, Yi-Wen
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Liu, Keng-Ming
This paper presents a programmable lab-on-CMOS (LoCMOS) with micro-electrode cell array. Array structure is suitable for programmable like CMOS VLSIs. In order to improve the utilization, each micro-electrode cell is composed of actuation and sensing circuit. In addition, a CMOS-compatible extended drain MOSFET (EDMOS) is adopted under a 3V supply. This LoCMOS platform is composed of 1,800 microelectrodes with exploiting EDMOS to enable droplet actuations. Through its field programmability, the chip can successfully perform all microfluidic operations, droplet moving/cutting/mixing on a 2-dimenional microelectrode cell array. Implemented in 0.35um standard CMOS process, the LoCMOS platform demonstrates microfluidic functions and droplet detection. Measured results show successfully for actuation and real-time droplet location sensing.
Development of a Gd(III)-Based Receptor-Induced Magnetization Enhancement (RIME) Contrast Agent for beta-Glucuronidase Activity Profiling
(2012-11-19)
Chen, Shih-Hsien
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Kuo, Yu-Ting
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Singh, Gyan
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Cheng, Tian-Lu
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Su, Yu-Zheng
beta-Glucuronidase is a key lysosomal enzyme and is often overexpressed in necrotic tumor masses. We report here the synthesis of a pro receptor induced magnetization enhancement (pro RIME) magnetic resonance imaging (MRI) contrast agent ([Gd(DOTA-FP beta Gu)]) for molecular imaging of beta-glucuronidase activity in tumor tissues. The contrast agent consists of two parts, a gadolinium complex and a beta-glucuronidase substrate (beta-D-glucopyranuronic acid). The binding association constant (K-A) of [Gd(DOTA-FP beta Gu)] is 7.42 X 10(2), which is significantly lower than that of a commercially available MS-325 (K-A = 3.0 x 10(4)) RIME contrast agent. The low K-A value of [Gd(DOTA-FP beta Gu)] is due to the pendant beta-D-glucopyranuronic acid moiety. Therefore, [Gd(DOTA-FP beta Gu)] can be used for detection of beta-glucuronidase through RIME modulation. The detail mechanism of enzymatic activation of [Gd(DOTA-FP beta Gu)] was elucidated by LC-MS. The kinetics of beta-glucuronidase catalyzed hydrolysis of [Eu(DOTA-FP beta Gu)] at pH 7.4 best fit the Miechalis-Menten kinetic mode with K-m = 1.38 mM, K-cat = 3.76 x 10(3), and k(cat)/K-m = 2.72 x 10(3) M-1 s(-1). The low K-m value indicates high affinity of beta-glucuronidase for [Gd(DOTA-FP beta Gu)] FP beta Gu) at physiological pH. Relaxometric studies revealed that T-1 relaxivity of [Gd(DOTA-FP beta Gu)] changes in response to the concentration of beta-glucuronidase. Consistent with the relaxometric studies, [Gd(DOTA-FP beta Gu)] showed significant change in MR image signal in the presence of beta-glucuronidase and HSA. In vitro and in vivo MR images demonstrated appreciable differences in signal enhancement in the cell lines and tumor xenografts in accordance to their expression levels of beta-glucuronidase. [GRAPHICS] .
Development of a Mucin4-Targeting SPIO Contrast Agent for Effective Detection of Pancreatic Tumor Cells in Vitro and in Vivo
(2013-11-28)
Wu, Shou-Cheng
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Chen, Yu-Jen
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Lin, Yi-Jan
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Wu, Tung-Ho
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Wang, Yun-Ming
In search of a unique and reliable contrast agent targeting pancreatic adenocarcinoma, new multifunctional nanoparticles (MnMEIO-silane-NH2-(MUC4)-mPEG NPs) were successfully developed in this study. Mucin4-expression levels were determined through different imaging studies in a panel of pancreatic tumor cells (HPAC, BxPC-3, and Panc-1) both in vitro and in vivo studies. The in vitro T-2-weighted MR imaging study in HPAC and Panc-1 tumor cells treated with NPs showed -89.1 +/- 5.7% and -0.9 +/- 0.2% contrast enhancement, whereas in in vivo study, it is found to be -81.5 +/- 4.5% versus -19.6 +/- 5.2% (24 h postinjection, 7.0 T), respectively. The T-2-weighted MR and optical imaging studies revealed that the novel agent can specifically and effectively target to mucin4-expressing tumors in nude mice. Hence, it is suggested that MnMEIO-silane-NH2-(MUC4)-mPEG NPs are able to provide an efficient and targeted delivery of MUC4 antibodies to mucin4-expressing pancreatic tumors.
Development of a novel thermal-sensitive multifunctional liposome with antibody conjugation to target EGFR-expressing tumors
(2019-01-01)
Liu, Kuan-Chieh
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Arivajiagane, Arundhathi
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Wu, Shang-Jung
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Tzou, Shey-Cherng
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Chen, Chiao-Yun
A novel EGFR-targeting, thermal-sensitive multifunctional liposome (TSML) was developed based on manganese-doped magnetismengineered iron oxide nanoparticles (MnMEIOs) and gold nanorods (AuNRs) for efficient photothermal therapy and magnetic resonance (MR) imaging. An Erbitux-conjugated TSML (Erb-TSML) was encapsulated with doxorubicin and gold nanorods conjugated with manganese-doped magnetism-engineered iron oxide nanoparticles, for theranostic applications of EGFR-positive tumors. The Erb-TSML selectively targeted EGFRpositive tumors and promoted tumor destruction by laser activation. Using confocal microscopy, MR and optical imaging, we demonstrated that Erb-TSML specifically bound to A431 tumor cells. No signs of major morphological damages to the normal tissues were observed in mice treated with Erb-TSMLand laser, indicating this theranostic platform protected heart against doxorubicin-induced toxicity to normal tissues. These results indicate that the Erb-TSML may be a promising diagnostic and therapeutic platform for EGFR-overexpressing tumors. (C) 2018 Elsevier Inc. All rights reserved.
Development of an Anti-Methoxy Poly(ethylene glycol) (alpha-mPEG) Cell-Based Capture System to Measure mPEG and mPEGylated Molecules
(2014-10-14)
Chuang, Kuo-Hsiang
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Kao, Chien-Han
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Roffler, Steve R.
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Lu, Ssu-Jung
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Cheng, Ta-Chun
Quantitative pharmacokinetic analysis of methoxy-poly(ethylene glycol) (mPEG) and mPEGylated molecules is important for clinical drug development. Here we developed sensitive sandwich and competitive ELISAs by expressing an anti-mPEG antibody on the surface of fibroblasts for effective capture of mPEG molecules in biological samples. alpha-mPEG sandwich ELISA could quantify the higher-molecular-weight of mPEG (2, 5, and 20 kDa) and mPEGylated molecules. alpha-mPEG cell-based competitive ELISA was developed to measure the lower-molecular-weight of mPEG molecules (559, 750, and 1000 Da) at nanomolar levels. In addition, alpha-mPEG cell-based ELISA was unaffected by the presence of 10% human serum or murine serum. We further demonstrate that the alpha-mPEG cell-based ELISA determined similar pharmacokinetics of mPEG(5K) as traditional gamma counting of I-131-mPEG(5K). The alpha-mPEG cell-based ELISA may provide an accurate, high sensitivity and easy-to-use tool for directly measuring mPEG and mPEGylated molecules in complex biological samples to accelerate the clinical development of mPEG drugs.
Development of an inflammatory tissue-selective chimeric TNF receptor
(2019-01-01)
Lee, Chia-Jung
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Wang, Chao-Ching
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Chen, Michael
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Chuang, Kuo-Hsiang
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Cheng, Tian-Lu
Background: Inhibiting TNF-alpha is an effective therapy for inflammatory diseases such as rheumatoid arthritis. However, systemic, nondiscriminatory neutralization of TNF-alpha is associated with considerable adverse effects. Methods: Here, we developed a trimeric chimeric TNF receptor by linking an N-terminal mouse Acrp30 trimerization domain and an MMP-2/9 substrate sequence to the mouse extracellular domain of TNF receptor 2 followed by a C-terminal mouse tetranectin coiled-coil domain (mouse Acrp-MMP-TNFR-Tn). Results: Here, we show that the Acrp30 trimerization domain inhibited the binding activity of TNFR, possibly by closing the binding site of the trimeric receptor. Cleavage of the substrate sequence by MMP-9, an enzyme highly expressed in inflammatory sites, restored the binding activity of the mouse TNF receptor. We also constructed a recombinant human chimeric TNF receptor (human Acrp-MMP-TNFR-Tn) in which an MMP-13 substrate sequence was used to link the human Acrp and the human TNF receptor 2. Human Acrp-MMP-TNFR-Tn showed reduced binding activity, and MMP-13 digestion recovered its binding activity with TNF-alpha. Conclusion: Acrp-masked chimeric TNF receptors may be able to be used for inflammatory tissue-selective neutralization of TNF-alpha to reduce the adverse effects associated with systemic neutralization of TNF-alpha.
Development of Bifunctional Gadolinium-Labeled Superparamagnetic Nanoparticles (Gd-MnMEIO) for In Vivo MR Imaging of the Liver in an Animal Model
(2016-02-17)
Kuo, Yu-Ting
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Chen, Chiao-Yun
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Liu, Gin-Chung
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Wang, Yun-Ming
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生物科技學系
Liver tumors are common and imaging methods, particularly magnetic resonance imaging (MRI), play an important role in their non-invasive diagnosis. Previous studies have shown that detection of liver tumors can be improved by injection of two different MR contrast agents. Here, we developed a new contrast agent, Gd-manganese-doped magnetism-engineered iron oxide (Gd-MnMEIO), with enhancement effects on both T1-and T2-weighted MR images of the liver. A 3.0T clinical MR scanner equipped with transmit/receiver coil for mouse was used to obtain both T1-weighted spoiled gradient-echo and T2-weighted fast spin-echo axial images of the liver before and after intravenous contrast agent injection into Balb/c mice with and without tumors. After pre-contrast scanning, six mice per group were intravenously injected with 0.1 mmol/kg Gd-MnMEIO, or the control agents, i.e., Gd-DTPA or SPIO. The scanning time points for T1-weighted images were 0.5, 5, 10, 15, 20, 25, and 30 min after contrast administration. The post-enhanced T2-weighted images were then acquired immediately after T1-weighted acquisition. We found that T1-weighted images were positively enhanced by both Gd-DTPA and Gd-MnMEIO and negatively enhanced by SPIO. The enhancement by both Gd-DTPA and Gd-MnMEIO peaked at 0.5 min and gradually declined thereafter. Gd-MnMEIO (like Gd-DTPA) enhanced T1-weighted images and (like SPIO) T2-weighted images. Marked vascular enhancement was clearly visible on dynamic T1-weighted images with Gd-MnMEIO. In addition, the T2 signal was significantly decreased at 30 min after administration of Gd-MnMEIO. Whereas the effects of Gd-MnMEIO and SPIO on T2-weighted images were similar (p = 0.5824), those of Gd-MnMEIO and Gd-DTPA differed, with Gd-MnMEIO having a significant T2 contrast effect (p = 0.0086). Our study confirms the feasibility of synthesizing an MR contrast agent with both T1 and T2 shortening effects and using such an agent in vivo. This agent enables tumor detection and characterization in single liver MRI sections.
Dinitrosyliron Complex [(PMDTA)Fe(NO)(2)]: Intermediate for Nitric Oxide Monooxygenation Activity in Nonheme Iron Complex
(2020-06-15)
Lu, Shan
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Chiou, Tzung-Wen
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Li, Wei-Liang
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Wang, Chun-Chieh
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Wang, Yun-Ming
Despite a comprehensive study on the biosynthesis and function of nitric oxide, biological metabolism of nitric oxide, especially when its concentration exceeds the cytotoxic level, remains elusive. Oxidation of nitric oxide by O-2 in aqueous solution has been known to yield NO2. On the other hand, a biomimetic study on the metal-mediated conversion of NO to NO2/NO3- via O-2 reactivity disclosed a conceivable pathway for aerobic metabolism of NO. During the NO-to-NO2-/NO3- conversion, transient formation of metal-bound peroxynitrite and subsequent release of (NO2)-N-center dot via O-O bond cleavage were evidenced by nitration of tyrosine residue or 2,4-di-tert-butylphenol (DTBP). However, the synthetic/catalytic/enzymatic cycle for conversion of nitric oxide into a nitrite pool is not reported. In this study, sequential reaction of the ferrous complex [(PMDTA)Fe(kappa(2) -O,O'- NO2)(kappa(1) -O-NO2)] (3; PMDTA = pentamethyldiethylenetriamine) with NO(g), KC8, and O-2 established a synthetic cycle, complex 3 -> {Fe(NO)(2)}(9) DNIC [(PMDTA)Fe(NO)(2)][NO2] (4) -> {Fe(NO)(2)}(10) DNIC [(PMDTA)Fe(NO)(2)] (1) -> [(PMDTA)(NO)- Fe(kappa(2)-O,N-ONOO)] (2) -> complex 3, for the transformation of nitric oxide into nitrite. In contrast to the reported reactivity of metal-bound peroxynitrite toward nitration of DTBP, peroxynitrite-bound MNIC 2 lacks phenol nitration reactivity toward DTBP. Presumably, the [(PMDTA)Fe] core in {Fe(NO)}(8) MNIC 2 provides a mononuclear template for intramolecular interaction between Fe-bound peroxynitrite and Fe-bound NO , yielding Fe-bound nitrite stabilized in the form of complex 3. This [(PMDTA)Fe]-core-mediated concerted peroxynitrite homolytic O-O bond cleavage and combination of the O atom with Fe- bound NO - reveals a novel and effective pathway for NO-to-NO2- transformation. Regarding the reported assembly of the dinitrosyliron unit (DNIU) [Fe(NO)(2)] in the biological system, this synthetic cycle highlights DNIU as a potential intermediate for nitric oxide monooxygenation activity in a nonheme iron system.