The Experts below are selected from a list of 951 Experts worldwide ranked by ideXlab platform
Bo Tang - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen Selenide a vital metabolite of sodium selenite uncouples the sulfilimine bond and promotes the reversal of liver fibrosis
Science China-life Sciences, 2020Co-Authors: Dongrui Luan, Xiaonan Gao, Zengteng Zhao, Dandan Xia, Qiuling Zheng, Bo TangAbstract:Sodium selenite has alleviating effects on liver fibrosis; however, its therapeutic molecular mechanism remains unclear. Herein, Hydrogen Selenide, a major metabolite of Na2SeO3, was tested to uncouple the sulfilimine bond in collagen IV, the biomarker of liver fibrosis. A mouse model of liver fibrosis was constructed via a CCl4-induced method, followed by the administration of 0.2 mg kg-1 Na2SeO3 via gavage three times per week for 4 weeks. Changes in H2Se, NADPH, and H2O2 levels were monitored in real time by using NIR-H2Se, DCI-MQ-NADPH, and H2O2 probes in vivo, respectively. H2Se continuously accumulated in the liver throughout the Na2SeO3 treatment period, but the levels of NADPH and H2O2 decreased. The expression of collagen IV was analyzed through Western blot and liquid chromatography-mass spectrometry. Results confirmed that the sulfilimine bond of collagen IV in the fibrotic mouse livers could be broken by H2Se with the Na2SeO3 treatment. Therefore, the therapeutic effect of Na2SeO3 on liver fibrosis could be mainly attributed to H2Se that uncoupled the sulfilimine bond to induce collagen IV degradation. This study provided a reasonable explanation for the molecular mechanism of the in vivo function of Na2SeO3 and the prevention of liver fibrosis by administering inorganic selenium.
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cyclic regulation of the sulfilimine bond in peptides and nc1 hexamers via the hobr h2se conjugated system
Analytical Chemistry, 2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Kehua Xu, Xiaoxiao Song, Bo TangAbstract:The sulfilimine bond (−S═N−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV.
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Cyclic Regulation of the Sulfilimine Bond in Peptides and NC1 Hexamers via the HOBr/H2Se Conjugated System
2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Xiaoxiao Song, Xiaojun Liu, Xiaonan Gao, Bo TangAbstract:The sulfilimine bond (−SN−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV
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Simultaneous Detection of Mitochondrial Hydrogen Selenide and Superoxide Anion in HepG2 Cells under Hypoxic Conditions
2018Co-Authors: Ranran Cheng, Fanpeng Kong, Xiaojun Liu, Lili Tong, Bo TangAbstract:Previous studies proposed that sodium selenite (Na2SeO3) was reduced to Hydrogen Selenide (H2Se) and that H2Se subsequently reacted with oxygen to generate superoxide anion (O2•–), resulting in tumor cell oxidative stress and apoptosis. However, under the hypoxic conditions of a solid tumor, the anticancer mechanism of sodium selenite remains unclear. To reveal the exact anticancer mechanism of selenite in the real tumor microenvironment, we developed a mitochondria-targeting fluorescent nanosensor, Mito-N-D-MSN, which was fabricated from mesoporous silica nanoparticles (MSNs) loaded with two small-molecule fluorescent probes and a triphenylphosphonium ion as a mitochondria-targeting moiety. With Mito-N-D-MSN, the fluctuations in the contents of mitochondrial Hydrogen Selenide (H2Se) and superoxide anion (O2•–) in HepG2 cells induced by Na2SeO3 were investigated in detail under normoxic and hypoxic conditions. The results showed that the mitochondrial H2Se content increased gradually, while the O2•– content remained unchanged in HepG2 cells under hypoxic conditions, which indicated that the anticancer mechanism of selenite involves nonoxidative stress in the real tumor microenvironment
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Targetable Mesoporous Silica Nanoprobes for Mapping the Subcellular Distribution of H2Se in Cancer Cells
2018Co-Authors: Ranran Cheng, Fanpeng Kong, Xiaojun Liu, Xiaonan Gao, Xiaohong Pan, Bo TangAbstract:Hydrogen Selenide, a highly active reductant, is believed as a key molecule in the cytotoxicity of inorganic selenium compounds. However, the detail mechanism has hardly been studied because the distribution of H2Se in the subcellular organelles remains unclear. Herein, we exploited a series of novel targetable mesoporous silica nanoplatforms to map the distribution of H2Se in cytoplasm, lysosome, and mitochondria of cancer cells. The subcellular targeting moiety-conjugated mesoporous silica nanoparticles were assembled with a near-infrared fluorescent probe (NIR-H2Se) for detecting endogenous H2Se in the corresponding organelles. The confocal fluorescence imaging of cancer cells induced by Na2SeO3 found out a higher concentration of H2Se accumulated only in mitochondria. Consequently, the H2Se burst in mitochondria-triggered mitochondrial collapse that led to cell apoptosis. Hence, the selenite-induced cytotoxicity in cancer cells associates with the alteration in mitochondrial function caused by high level of H2Se. These findings provide a new way to explore the tumor cell apoptosis signaling pathways induced by Na2SeO3, meanwhile, we propose a research strategy for tracking the biomolecules in the subcellular organelles and the correlative cellular function and related disease diagnosis
Dongrui Luan - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen Selenide a vital metabolite of sodium selenite uncouples the sulfilimine bond and promotes the reversal of liver fibrosis
Science China-life Sciences, 2020Co-Authors: Dongrui Luan, Xiaonan Gao, Zengteng Zhao, Dandan Xia, Qiuling Zheng, Bo TangAbstract:Sodium selenite has alleviating effects on liver fibrosis; however, its therapeutic molecular mechanism remains unclear. Herein, Hydrogen Selenide, a major metabolite of Na2SeO3, was tested to uncouple the sulfilimine bond in collagen IV, the biomarker of liver fibrosis. A mouse model of liver fibrosis was constructed via a CCl4-induced method, followed by the administration of 0.2 mg kg-1 Na2SeO3 via gavage three times per week for 4 weeks. Changes in H2Se, NADPH, and H2O2 levels were monitored in real time by using NIR-H2Se, DCI-MQ-NADPH, and H2O2 probes in vivo, respectively. H2Se continuously accumulated in the liver throughout the Na2SeO3 treatment period, but the levels of NADPH and H2O2 decreased. The expression of collagen IV was analyzed through Western blot and liquid chromatography-mass spectrometry. Results confirmed that the sulfilimine bond of collagen IV in the fibrotic mouse livers could be broken by H2Se with the Na2SeO3 treatment. Therefore, the therapeutic effect of Na2SeO3 on liver fibrosis could be mainly attributed to H2Se that uncoupled the sulfilimine bond to induce collagen IV degradation. This study provided a reasonable explanation for the molecular mechanism of the in vivo function of Na2SeO3 and the prevention of liver fibrosis by administering inorganic selenium.
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cyclic regulation of the sulfilimine bond in peptides and nc1 hexamers via the hobr h2se conjugated system
Analytical Chemistry, 2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Kehua Xu, Xiaoxiao Song, Bo TangAbstract:The sulfilimine bond (−S═N−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV.
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Cyclic Regulation of the Sulfilimine Bond in Peptides and NC1 Hexamers via the HOBr/H2Se Conjugated System
2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Xiaoxiao Song, Xiaojun Liu, Xiaonan Gao, Bo TangAbstract:The sulfilimine bond (−SN−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV
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Highly Selective Fluorescent Probe for Imaging H2Se in Living Cells and in Vivo Based on the Disulfide Bond
2016Co-Authors: Fanpeng Kong, Dongrui Luan, Xiaojun Liu, Yuehui Zhao, Ziye Liang, Xiaohong Pan, Bo TangAbstract:Hydrogen Selenide (H2Se) is an important metabolite of dietary Se compounds and has been implicated in various pathological and physiological processes. The development of highly sensitive and selective methods for the sensing of H2Se is therefore very important. Herein, we developed a fluorescent probe (hemicyanine (Hcy)-H2Se) for detecting H2Se based on a new H2Se-specific receptor unit, 1,2-dithiane-4,5-diol. Hcy-H2Se showed high selectivity toward H2Se over thiols (RSH), Hydrogen sulfide (H2S), and selenocysteine (Sec) and was further exploited for the fluorescence imaging of H2Se both in living cells and in vivo. Furthermore, with the aid of Hcy-H2Se, we demonstrated that H2Se can be generated and gradually accumulated in HepG2 cells under hypoxic conditions and in the solid tumor after treatment with Na2SeO3
Fanpeng Kong - One of the best experts on this subject based on the ideXlab platform.
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cyclic regulation of the sulfilimine bond in peptides and nc1 hexamers via the hobr h2se conjugated system
Analytical Chemistry, 2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Kehua Xu, Xiaoxiao Song, Bo TangAbstract:The sulfilimine bond (−S═N−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV.
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Cyclic Regulation of the Sulfilimine Bond in Peptides and NC1 Hexamers via the HOBr/H2Se Conjugated System
2018Co-Authors: Dongrui Luan, Aishan Zheng, Fanpeng Kong, Xiaoxiao Song, Xiaojun Liu, Xiaonan Gao, Bo TangAbstract:The sulfilimine bond (−SN−), found in the collagen IV scaffold, significantly stabilizes the architecture via the formation of sulfilimine cross-links. However, precisely governing the formation and breakup process of the sulfilimine bond in living organisms for better life functions still remains a challenge. Hence, we established a new way to regulate the breaking and formation of the sulfilimine bond through Hydrogen Selenide (H2Se) and hypobromous acid (HOBr), which can be easily controlled at simulated physiological conditions. This novel strategy provides a circulation regulation system to modulate the sulfilimine bond in peptides and NC1 hexamers, which can offer a substantial system for further study of the physiological function of collagen IV
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Simultaneous Detection of Mitochondrial Hydrogen Selenide and Superoxide Anion in HepG2 Cells under Hypoxic Conditions
2018Co-Authors: Ranran Cheng, Fanpeng Kong, Xiaojun Liu, Lili Tong, Bo TangAbstract:Previous studies proposed that sodium selenite (Na2SeO3) was reduced to Hydrogen Selenide (H2Se) and that H2Se subsequently reacted with oxygen to generate superoxide anion (O2•–), resulting in tumor cell oxidative stress and apoptosis. However, under the hypoxic conditions of a solid tumor, the anticancer mechanism of sodium selenite remains unclear. To reveal the exact anticancer mechanism of selenite in the real tumor microenvironment, we developed a mitochondria-targeting fluorescent nanosensor, Mito-N-D-MSN, which was fabricated from mesoporous silica nanoparticles (MSNs) loaded with two small-molecule fluorescent probes and a triphenylphosphonium ion as a mitochondria-targeting moiety. With Mito-N-D-MSN, the fluctuations in the contents of mitochondrial Hydrogen Selenide (H2Se) and superoxide anion (O2•–) in HepG2 cells induced by Na2SeO3 were investigated in detail under normoxic and hypoxic conditions. The results showed that the mitochondrial H2Se content increased gradually, while the O2•– content remained unchanged in HepG2 cells under hypoxic conditions, which indicated that the anticancer mechanism of selenite involves nonoxidative stress in the real tumor microenvironment
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Targetable Mesoporous Silica Nanoprobes for Mapping the Subcellular Distribution of H2Se in Cancer Cells
2018Co-Authors: Ranran Cheng, Fanpeng Kong, Xiaojun Liu, Xiaonan Gao, Xiaohong Pan, Bo TangAbstract:Hydrogen Selenide, a highly active reductant, is believed as a key molecule in the cytotoxicity of inorganic selenium compounds. However, the detail mechanism has hardly been studied because the distribution of H2Se in the subcellular organelles remains unclear. Herein, we exploited a series of novel targetable mesoporous silica nanoplatforms to map the distribution of H2Se in cytoplasm, lysosome, and mitochondria of cancer cells. The subcellular targeting moiety-conjugated mesoporous silica nanoparticles were assembled with a near-infrared fluorescent probe (NIR-H2Se) for detecting endogenous H2Se in the corresponding organelles. The confocal fluorescence imaging of cancer cells induced by Na2SeO3 found out a higher concentration of H2Se accumulated only in mitochondria. Consequently, the H2Se burst in mitochondria-triggered mitochondrial collapse that led to cell apoptosis. Hence, the selenite-induced cytotoxicity in cancer cells associates with the alteration in mitochondrial function caused by high level of H2Se. These findings provide a new way to explore the tumor cell apoptosis signaling pathways induced by Na2SeO3, meanwhile, we propose a research strategy for tracking the biomolecules in the subcellular organelles and the correlative cellular function and related disease diagnosis
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Highly Selective Fluorescent Probe for Imaging H2Se in Living Cells and in Vivo Based on the Disulfide Bond
2016Co-Authors: Fanpeng Kong, Dongrui Luan, Xiaojun Liu, Yuehui Zhao, Ziye Liang, Xiaohong Pan, Bo TangAbstract:Hydrogen Selenide (H2Se) is an important metabolite of dietary Se compounds and has been implicated in various pathological and physiological processes. The development of highly sensitive and selective methods for the sensing of H2Se is therefore very important. Herein, we developed a fluorescent probe (hemicyanine (Hcy)-H2Se) for detecting H2Se based on a new H2Se-specific receptor unit, 1,2-dithiane-4,5-diol. Hcy-H2Se showed high selectivity toward H2Se over thiols (RSH), Hydrogen sulfide (H2S), and selenocysteine (Sec) and was further exploited for the fluorescence imaging of H2Se both in living cells and in vivo. Furthermore, with the aid of Hcy-H2Se, we demonstrated that H2Se can be generated and gradually accumulated in HepG2 cells under hypoxic conditions and in the solid tumor after treatment with Na2SeO3
Moungi G Bawendi - One of the best experts on this subject based on the ideXlab platform.
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preparation of ii vi quantum dot composites by electrospray organometallic chemical vapor deposition
Journal of Crystal Growth, 1994Co-Authors: Michal Danek, Klavs F Jensen, Christopher B Murray, Moungi G BawendiAbstract:Abstract New thin film composites consisting of a ZnSe matrix and CdSe nanocrystals (NCs) have been prepared by a novel technique combining electrospray and organometallic chemical vapor deposition (OMCVD). CdSe NCs, synthesized in solution by controlled growth of CdSe nuclei, were derivatized with pyridine or overcoated with a thin ZnSe layer. The derivatized NCs were dispersed in a pyridine/acetonitrile mixture and transferred into the growth zone of an OMCVD reactor using an electrospray. The transferred NCs were co-deposited with ZnSe grown by OMCVD from Hydrogen Selenide and diethyl zinc at temperatures ranging from 150 to 250 °C. The absorption and emission spectra of the composites show characteristic transitions of the NCs. The emission wavelength can be tuned by selecting the size of the NCs. A pre-formed ZnSe passivation layer, also synthesized in solution, improves thermal stability of the NCs during the co-deposition, and enhances the photoluminescence emission efficiency of the composites. The elemental composition and microstructure of the materials are probed by Auger electron spectroscopy, X-ray fluorescence spectroscopy, and high-resolution transmission electron microscopy.
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electrospray organometallic chemical vapor deposition a novel technique for preparation of ii vi quantum dot composites
Applied Physics Letters, 1994Co-Authors: Michal Danek, Klavs F Jensen, Christopher B Murray, Moungi G BawendiAbstract:A novel technique combining electrospray and organometallic chemical vapor deposition (OMCVD) has been developed for the synthesis of new II–VI quantum dot composites. CdSe nanocrystals (quantum dots) of selected size are dispersed in a pyridine/acetonitrile mixture. The nanocrystals are transferred by electrospray into the growth zone of an OMCVD reactor and codeposited on a ZnSe matrix grown from Hydrogen Selenide and diethyl zinc. Composites consisting of CdSe nanocrystals and an amorphous or polycrystalline ZnSe matrix have been deposited on glass substrates at temperatures of 150–250 °C. Room‐temperature absorption and photoluminescence spectra show optical transitions characteristic of the initial nanocrystal dispersions. The emission wavelength may be tuned in a broad spectral region by incorporating nanocrystals of varying sizes. The composites have been characterized by Auger electron spectroscopy, high resolution transmission electron microscopy, and scanning transmission electron microscopy.
Pierre Plateau - One of the best experts on this subject based on the ideXlab platform.
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Sodium Selenide toxicity is mediated by O2-dependent DNA breaks.
PLoS ONE, 2012Co-Authors: Gerald Peyroche, Cosmin Saveanu, Marc Dauplais, Myriam Lazard, Francois Beuneu, Laurence Decourty, Christophe Malabat, Alain Jacquier, Sylvain Blanquet, Pierre PlateauAbstract:Hydrogen Selenide is a recurrent metabolite of selenium compounds. However, few experiments studied the direct link between this toxic agent and cell death. To address this question, we first screened a systematic collection of Saccharomyces cerevisiae haploid knockout strains for sensitivity to sodium Selenide, a donor for Hydrogen Selenide (H(2)Se/HSe(-/)Se(2-)). Among the genes whose deletion caused hypersensitivity, homologous recombination and DNA damage checkpoint genes were over-represented, suggesting that DNA double-strand breaks are a dominant cause of Hydrogen Selenide toxicity. Consistent with this hypothesis, treatment of S. cerevisiae cells with sodium Selenide triggered G2/M checkpoint activation and induced in vivo chromosome fragmentation. In vitro, sodium Selenide directly induced DNA phosphodiester-bond breaks via an O(2)-dependent reaction. The reaction was inhibited by mannitol, a hydroxyl radical quencher, but not by superoxide dismutase or catalase, strongly suggesting the involvement of hydroxyl radicals and ruling out participations of superoxide anions or Hydrogen peroxide. The (*)OH signature could indeed be detected by electron spin resonance upon exposure of a solution of sodium Selenide to O(2). Finally we showed that, in vivo, toxicity strictly depended on the presence of O(2). Therefore, by combining genome-wide and biochemical approaches, we demonstrated that, in yeast cells, Hydrogen Selenide induces toxic DNA breaks through an O(2)-dependent radical-based mechanism.
