17 results on '"Zhan-Qi, Cao"'
Search Results
2. The roles of galectins in hepatic diseases
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Zhan-Qi Cao, Mei-Juan Sun, and Ping Leng
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0301 basic medicine ,Histology ,Cirrhosis ,Physiology ,Galectins ,Disease ,Hepatic Diseases ,Immunomodulation ,03 medical and health sciences ,medicine ,Extracellular ,Animals ,Humans ,Galectin ,Hepatitis ,030102 biochemistry & molecular biology ,business.industry ,Liver Diseases ,High mortality ,Cell Biology ,General Medicine ,medicine.disease ,030104 developmental biology ,Gene Expression Regulation ,Multigene Family ,Hepatocellular carcinoma ,Cancer research ,Disease Susceptibility ,business ,Signal Transduction - Abstract
Hepatic diseases include all diseases that occur in the liver, including hepatitis, cirrhosis, hepatocellular carcinoma, etc. Hepatic diseases worldwide are characterized by high incidences of digestive system diseases, which present with subtle symptoms, are difficult to treat and have high mortality. Galectins are β-galactoside-binding proteins that have been found to be aberrantly expressed during hepatic disease progression. An increasing number of studies have shown that abnormal expression of galectins is extensively involved in hepatic diseases, such as hepatocellular carcinoma (HCC), liver cirrhosis, hepatitis and liver fibrosis. Galectins function as intracellular and extracellular hepatic disease regulators mainly through the binding of their carbohydrate recognition domain to glycoconjugates expressed in hepatocytes. In this review, we summarize current research on the various roles of galectins in cirrhosis, hepatitis, liver fibrosis and HCC, which may provide a preliminary theoretical basis for the exploration of new targets for the treatment of hepatic diseases.
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- 2020
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3. Effects of 2,2',4'‑trihydroxychalcone on the proliferation, metastasis and apoptosis of A549 human lung cancer cells
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Jia-Lin, Sun, Zhan-Qi, Cao, Shi-Wei, Sun, Zhong-Hua, Sun, Shu-Hong, Sun, Jin-Feng, Ye, and Ping, Leng
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Cancer Research ,Oncology - Abstract
The aim of the present study was to evaluate the antitumor effects of 2,2',4'-trihydroxychalcone (7a) on the A549 human lung cancer cell line. A549 cells were treated with different concentrations of 7a for different time periods. Cells without 7a were used as the negative control group. Cell proliferation, invasion, vasculogenic mimicry (VM) formation, heterogeneous adhesion and apoptosis were measured using Cell Counting Kit-8, Transwell invasion, VM, adhesion and flow cytometric assays, respectively. In addition, the expression of related proteins was determined using western blot analysis or ELISA. The present study found that 7a had a significant inhibitory effect on the survival rate of the A549 lung cancer cells but almost no effect on BEAS-2B human lung epithelial cells or human venous endothelial cells. The migration rate, VM length, invasion rate and heterogeneous adhesion number of cells treated with 7a significantly decreased as the concentration increased, while the apoptosis rate increased. Western blot analysis showed that 7a treatment significantly increased the expression levels of E-cadherin, cleaved poly (ADP-ribose) polymerase, Bax and caspase-3 and simultaneously decreased the expression levels of metalloproteinase-2/9, Bcl-2, phosphorylated (p)-PI3K, p-AKT, p-mTOR, vascular endothelial growth factor (VEGF), E-selectin and N-cadherin. At the same time, the ELISA results showed that the level of the pro-angiogenic factor VEGF in the culture media was reduced in the presence of 7a. In addition, 7a could also reduce the nuclear NF-κB protein expression, which could inhibit the gene transcription of tumor apoptosis and metastasis-related proteins. Therefore, 7a may exert inhibitory effects on A549 cells by inhibiting cell proliferation, migration, VM formation and heterogeneous adhesion, as well as by inducing apoptosis through the suppression of the PI3K/AKT/NF-κB signaling pathway; these findings suggested that 7a may be a promising agent for the treatment of lung cancer.
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- 2022
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4. Research progress on the role of gal-3 in cardio/cerebrovascular diseases
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Zhan-Qi Cao, Xin Yu, and Ping Leng
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0301 basic medicine ,Acute coronary syndrome ,Galectins ,Aberrantly increased ,Disease ,RM1-950 ,Bioinformatics ,03 medical and health sciences ,High morbidity ,0302 clinical medicine ,Medicine ,Galectin-3 ,Animals ,Humans ,Molecular Targeted Therapy ,Galectin ,Pharmacology ,business.industry ,Inhibitors ,High mortality ,Cardiovascular Agents ,General Medicine ,Blood Proteins ,medicine.disease ,Up-Regulation ,Cerebrovascular Disorders ,030104 developmental biology ,Cardiovascular Diseases ,030220 oncology & carcinogenesis ,Heart failure ,Myocardial fibrosis ,Therapeutics. Pharmacology ,business ,Cardio/cerebrovascular diseases ,Signal Transduction - Abstract
Galectin-3 (gal-3), a member of the galectin family, is a glycoprotein with high affinity for β-galactoside. Gal-3 is a cytoplasmically synthesized protein that can shuttle between the cytoplasm and nucleus and can even be transported to the membrane and secreted into the extracellular environment. Cardio/cerebrovascular diseases generally refer to ischemic or hemorrhagic diseases occurring in the heart, brain and systemic tissues, which are characterized by high morbidity, high disability rates and high mortality rates. To date, considerable research has demonstrated that gal-3 expression is aberrantly increased and plays important roles in cardio/cerebrovascular diseases, such as acute ischemic stroke (AIS), myocardial fibrosis, acute coronary syndrome (ACS), and heart failure (HF). Hence, understanding the biological roles of gal-3 in these diseases may be essential for cardio/cerebrovascular disease treatment and diagnosis to improve patient quality of life. In this review, we summarize current research on the roles of gal-3 in human cardiovascular diseases and potential inhibitors of gal-3, which may provide new strategies for disease therapies.
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- 2020
5. Fluorescent photochromic donor-acceptor Stenhouse adduct controlled by visible light
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Jing Liu, Qianfu Luo, Da-Hui Qu, Shun Yang, Mingming Li, and Zhan-Qi Cao
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Barbituric acid ,Fluorophore ,Process Chemistry and Technology ,General Chemical Engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Acceptor ,Fluorescence ,0104 chemical sciences ,Adduct ,chemistry.chemical_compound ,Photochromism ,chemistry ,Indoline ,0210 nano-technology ,Visible spectrum - Abstract
A novel photochromic fluorescent DASA (donor-acceptor Stenhouse adduct) switch controlled by visible light was successfully designed and synthesized. Using 1,8-naphthalimide fluorophore in combination with indoline-based “donor” and barbituric acid “acceptor”, the DASA molecule exhibits two independent absorption bands at 440 nm and 616 nm. The physical and thermodynamic properties of fluorescent donor-acceptor Stenhouse adduct (DASA-NDI) have been investigated in different solvents. In accordance with the unique fluorescent properties under visible light/heat and H+/Cu2+, using fluorescence intensity at 604 nm (I604) as an output and visible light, H+ and Cu2+ as inputs, a combinatorial logic gate consisting of NOR and AND logics can be described and operated.
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- 2018
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6. Reversible switching of a supramolecular morphology driven by an amphiphilic bistable [2]rotaxane
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Chuan Gao, Ai-Hua Zou, Yi-Chuan Wang, Da-Hui Qu, Zhan-Qi Cao, Qi Zhang, and Gábor London
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Rotaxane ,Morphology (linguistics) ,Bistability ,Chemistry ,Vesicle ,Metals and Alloys ,Supramolecular chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Micelle ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Crystallography ,Transmission electron microscopy ,Amphiphile ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology - Abstract
An acid/base responsive amphiphilic [2]rotaxane switch containing a hydrophilic macrocycle component and a hydrophobic terminal bulky group was prepared and characterized. The morphology of the supramolecular assemblies formed by the rotaxanes could be switched between spherical vesicles and worm-like micelles using acid/base stimuli, as confirmed by transmission electron microscopy (TEM).
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- 2017
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7. The role of galectin-4 in physiology and diseases
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Xiu-Li Guo and Zhan-Qi Cao
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0301 basic medicine ,Galectin 4 ,lcsh:Animal biochemistry ,tumor progression ,Peptide ,Review ,Endocytosis ,Biochemistry ,03 medical and health sciences ,Membrane Microdomains ,Neoplasms ,intestinal inflammation ,Drug Discovery ,galectin-4 ,Extracellular ,Animals ,Humans ,lcsh:QH573-671 ,crosslinker ,Cell adhesion ,lcsh:QP501-801 ,Peptide sequence ,Lipid raft ,Neurons ,chemistry.chemical_classification ,Wound Healing ,biology ,lcsh:Cytology ,Lectin ,Cell Biology ,Inflammatory Bowel Diseases ,Axons ,lipid raft ,Cell biology ,030104 developmental biology ,chemistry ,Tumor progression ,biology.protein ,Biotechnology - Abstract
Galectin-4, a tandem repeat member of the β-galactoside-binding proteins, possesses two carbohydrate-recognition domains (CRD) in a single peptide chain. This lectin is mostly expressed in epithelial cells of the intestinal tract and secreted to the extracellular. The two domains have 40% similarity in amino acid sequence, but distinctly binding to various ligands. Just because the two domains bind to different ligands simultaneously, galectin-4 can be a crosslinker and crucial regulator in a large number of biological processes. Recent evidence shows that galectin-4 plays an important role in lipid raft stabilization, protein apical trafficking, cell adhesion, wound healing, intestinal inflammation, tumor progression, etc. This article reviews the physiological and pathological features of galectin-4 and its important role in such processes.
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- 2016
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8. Discovery and Characterization of 4-Hydroxy-2-pyridone Derivative Sambutoxin as a Potent and Promising Anticancer Drug Candidate: Activity and Molecular Mechanism
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Xiu-Li Guo, Xin-Ke Zhang, Yan-Na Cheng, Lu-Ning Li, Zhan-Qi Cao, and Lei Wang
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0301 basic medicine ,Cell cycle checkpoint ,DNA damage ,Pyridines ,Pharmaceutical Science ,Mice, Nude ,Antineoplastic Agents ,Apoptosis ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Cell Line, Tumor ,Neoplasms ,Drug Discovery ,Animals ,Humans ,Viability assay ,Cyclin B1 ,Cell Proliferation ,chemistry.chemical_classification ,Cyclin-dependent kinase 1 ,Reactive oxygen species ,Mice, Inbred BALB C ,Basidiomycota ,Mycotoxins ,Xenograft Model Antitumor Assays ,Cell biology ,G2 Phase Cell Cycle Checkpoints ,030104 developmental biology ,Treatment Outcome ,chemistry ,030220 oncology & carcinogenesis ,Cancer cell ,Molecular Medicine ,DNA Damage ,Signal Transduction - Abstract
Sambutoxin, a representative derivative of 4-hydroxy-2-pyridone, was isolated from Hericium alpestre for the first time in this study. The possible correlation between the sambutoxin-induced suppression of tumor growth and its influence on cell-cycle arrest and apoptosis was investigated. The effects of sambutoxin on reactive oxygen species (ROS) production, DNA damage, mitochondrial transmembrane potential, cell apoptosis, and the expression of related proteins were evaluated. An in vitro cell viability study demonstrated that sambutoxin could inhibit the proliferation of various cancer cells. Treatment with sambutoxin induced the production of ROS, which caused DNA damage. Furthermore, the subsequent sambutoxin-induced activation of ATM and Chk2 resulted in G2/M arrest, accompanied by decreased expression of cdc25C, cdc2, and cyclin B1. Sambutoxin induced apoptosis by activating the mitochondrial apoptosis pathway through an increased Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (ΔΨm), cytochrome (Cyt) c release, caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) degradation. The ROS elevation induced the sustained phosphorylation of c-Jun N-terminal kinase (JNK), while SP600125, a JNK inhibitor, nearly completely reversed sambutoxin-induced apoptosis. Accordingly, an in vivo study showed that sambutoxin exhibited potential antitumor activity in a BALB/c nude mouse xenograft model without significant systemic toxicity. Moreover, the expression changes in proteins related to the G2/M phase, DNA damage, and apoptosis in vivo were consistent with those in vitro. Importantly, sambutoxin has remarkable antiproliferative effects and is a promising anticarcinogen candidate for cancer treatment.
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- 2018
9. An acid/base responsive side-chain polyrotaxane system with a fluorescent signal
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Da-Hui Qu, Zhan-Qi Cao, Zhou-Lin Luan, Qi Zhang, Jun Ren, and Rui-Rui Gu
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chemistry.chemical_classification ,Molecular switch ,Rotaxane ,Polymers and Plastics ,Bistability ,010405 organic chemistry ,Organic Chemistry ,Bioengineering ,Polymer ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Fluorescence ,Signal ,0104 chemical sciences ,chemistry ,Polymer chemistry ,Side chain ,Click chemistry ,Biophysics - Abstract
An acid/base-responsive polyrotaxane system was constructed, in which the side chain was modified with a diferrocene-functionalized bistable rotaxane molecular switch via the “CuAAC” click reaction. The reversible subunit shuttling movement of the rotaxane unit in the polymer system in response to external acid/base stimuli was accompanied by visual fluorescence changes.
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- 2016
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10. Two functional [2]rotaxanes featuring efficient intercomponent interactions between chromophores
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Da-Hui Qu, Xin Fu, Zhan-Qi Cao, Jian Yao, and Xiu-Li Zheng
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Rotaxane ,Process Chemistry and Technology ,General Chemical Engineering ,Electron donor ,Chromophore ,Photochemistry ,Combinatorial chemistry ,Acceptor ,Photoinduced electron transfer ,chemistry.chemical_compound ,Ferrocene ,chemistry ,Click chemistry ,Molecule - Abstract
Two functional [2]rotaxanes, with a 4-morpholin-naphthalimide fluorophore as one of the two stoppers and a difluoroboradiaza-s-indacene functionalized dibenzo[24]crown-8 as macrocycle, were designed, synthesized and well characterized. [2]Rotaxane 1 and 2 had almost the same structural skeleton, and a ferrocene unit was introduced in [2]rotaxane 1 as the other stopper, while a 3,5-dimethoxybenzene stopper in [2]rotaxane 2. It has shown that efficient energy transfer process in both two [2]rotaxanes occurred from the 4-morpholin-naphthalimide donor to the difluoroboradiaza-s-indacene acceptor. Moreover, [2]rotaxane 1 exhibited a remarkable fluorescence increase in response to the addition of base that can drive the shuttling motion because of the introduction of ferrocene electron donor. This work can pave the way for the design and construction of complex and functional molecular systems based on the mechanically interlocked molecules.
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- 2015
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11. A fluorescent bistable [2]rotaxane molecular switch on SiO2 nanoparticles
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Qi Zhang, Hong Li, Da-Hui Qu, Qi Miao, He Tian, and Zhan-Qi Cao
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Molecular switch ,chemistry.chemical_classification ,Rotaxane ,Bistability ,Metals and Alloys ,Alkyne ,General Chemistry ,Photochemistry ,Fluorescence ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Sio2 nanoparticles ,Functional group ,Materials Chemistry ,Ceramics and Composites ,Click chemistry - Abstract
A fluorescent bistable [2]rotaxane terminated with an alkyne functional group was constructed and immobilized onto the surface of SiO2 nanoparticles through click reaction. The shuttling motion of the macrocycle component between two different stations was driven by external acid–base stimuli both in solution and on SiO2 nanoparticles, accompanied by visual fluorescence changes.
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- 2015
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12. Metformin incombination with curcumin inhibits the growth, metastasis, and angiogenesis of hepatocellular carcinoma in vitro and in vivo
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Hui-Hui Zhang, Fu-Lian Gong, Xiu-Li Guo, Yan-Na Cheng, Lu-Gang Yu, Zhan-Qi Cao, and Ying Zhang
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0301 basic medicine ,Cancer Research ,MMP2 ,Carcinoma, Hepatocellular ,Curcumin ,Angiogenesis ,Mice, Nude ,Biology ,Metastasis ,Cell Line ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Animals ,Humans ,Neoplasm Metastasis ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cells, Cultured ,Cell Proliferation ,Mice, Inbred BALB C ,Neovascularization, Pathologic ,Liver Neoplasms ,Hep G2 Cells ,medicine.disease ,Xenograft Model Antitumor Assays ,digestive system diseases ,Metformin ,Tumor Burden ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,Female ,medicine.drug ,Signal Transduction - Abstract
Hepatocellular carcinoma (HCC) has poor prognosis due to the advanced disease stages by the time it is diagnosed, high recurrence rates and metastasis. In the present study, we investigated the effects of metformin (a safe anti-diabetic drug) and curcumin (a turmeric polyphenol extracted from rhizome of Curcuma longa Linn.) on proliferation, apoptosis, invasion, metastasis, and angiogenesis of HCC in vitro and in vivo. It was found that co-treatment of metformin and curcumin could not only induce tumor cells into apoptosis through activating the mitochondria pathways, but also suppress the invasion, metastasis of HCC cells and angiogenesis of HUVECs. These effects were associated with downregulation of the expression of MMP2/9, VEGF, and VEGFR-2, up-regulation of PTEN, P53 and suppression of PI3K/Akt/mTOR/NF-κB and EGFR/STAT3 signaling. Co-administration of metformin and curcumin significantly inhibited HCC tumor growth than administration with metformin or curcumin alone in a xenograft mouse model. Thus, metformin and curcumin in combination showed a better anti-tumor effects in hepatoma cells than either metformin or curcumin presence alone and might represent an effective therapeutic strategy for HCC treatment.
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- 2017
13. A Perylene-Bridged Switchable [3]Rotaxane Molecular Shuttle with a Fluorescence Output
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Hong Li, Lei Zou, Da-Hui Qu, Zhan-Qi Cao, Jian Yao, and He Tian
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chemistry.chemical_compound ,Rotaxane ,Fluorophore ,Molecular shuttle ,chemistry ,Ferrocene ,Organic Chemistry ,Molecule ,Chromophore ,Photochemistry ,Photoinduced electron transfer ,Perylene - Abstract
A bistable bis-branched [3]rotaxane with a perylene bisimide (PBI) chromophore that separates two mechanically interlocked [2]rotaxane arms including a diferrocene-functionalized dibenzo-24-crown-8 ring, was designed, prepared, and characterized by 1H NMR and 13C NMR spectroscopy and HR-ESI mass spectrometry. The uniform relative shuttling movement of target [3]rotaxane in response to external acid-base stimuli was confirmed by 1H NMR spectroscopy. Furthermore, the shuttling motion of the macrocycles in the system was accompanied by a remarkably visual fluorescence change due to the distance-dependent photoinduced electron transfer process from the ferrocene units to the PBI fluorophore. This kind of rotaxane has important potential for designing more sophisticated mechanically interlocked molecules with controllable functions.
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- 2014
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14. Photo-powered stretchable nano-containers based on well-defined vesicles formed by an overcrowded alkene switch
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Da-Hui Qu, Jing-Jing Yu, Qi Zhang, Shun Yang, Zhan-Qi Cao, and He Tian
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chemistry.chemical_classification ,Materials science ,010405 organic chemistry ,Alkene ,Vesicle ,technology, industry, and agriculture ,Metals and Alloys ,Nanotechnology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Amphiphile ,Drug delivery ,Nano ,Materials Chemistry ,Ceramics and Composites ,sense organs ,Well-defined - Abstract
A novel photo-responsive nano-container was successfully constructed based on well-defined vesicles formed by an amphiphilic overcrowded alkene switch. The nano-container could adjust its inner volume in reversible photo/heat controlled mode, which could show potential in remote drug delivery systems.
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- 2016
15. A fluorescent bistable [2]rotaxane molecular switch on SiO₂ nanoparticles
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Zhan-Qi, Cao, Qi, Miao, Qi, Zhang, Hong, Li, Da-Hui, Qu, and He, Tian
- Abstract
A fluorescent bistable [2]rotaxane terminated with an alkyne functional group was constructed and immobilized onto the surface of SiO2 nanoparticles through click reaction. The shuttling motion of the macrocycle component between two different stations was driven by external acid-base stimuli both in solution and on SiO2 nanoparticles, accompanied by visual fluorescence changes.
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- 2015
16. The anti-inflammatory effects of Morin hydrate in atherosclerosis is associated with autophagy induction through cAMP signaling
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Yue Zhou, Yan-Na Cheng, Xinke Zhang, Xiu-Li Guo, Lu-Gang Yu, Yan Sun, Hong-Yuan Wang, and Zhan-Qi Cao
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Male ,0301 basic medicine ,Cell signaling ,ATG5 ,Anti-Inflammatory Agents ,Inflammation ,Pharmacology ,Proinflammatory cytokine ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Sequestosome 1 ,Autophagy ,Cyclic AMP ,medicine ,Animals ,education ,Cells, Cultured ,Flavonoids ,education.field_of_study ,Tumor Necrosis Factor-alpha ,Chemistry ,BECN1 ,Atherosclerosis ,Lipids ,Mice, Inbred C57BL ,030104 developmental biology ,Immunology ,medicine.symptom ,Signal transduction ,030217 neurology & neurosurgery ,Signal Transduction ,Food Science ,Biotechnology - Abstract
cope Although the previous trials of inflammation have indicated that morin hydrate (MO) hold considerable promise, understanding the distinct mechanism of MO against inflammation remains a challenge. Methods and results This study investigated the effect of MO in atherosclerosis in ApoE−/− mice and underlying cell signaling of MO effect in inflammation in human umbilical vein endothelial cells (HUVECs). Administration of MO significantly reduced serum lipid level, inflammatory cytokines (TNF-α and ICAM-1), and atherosclerotic plaque formation in vivo. MO presence attenuated the expression of TNF-α-induced inflammatory cytokines (ICAM-1, COX-2, and MMP-9), and remarkably enhanced microtubule associated protein 1 light chain 3 beta 2 (MAP1LC3B2) expression and sequestosome 1 (SQSTM1/p62) degradation in HUVECs. These MO effects were significantly prevented by the presence of autophagic inhibitors, 3-methyladenine (3-MA), or chloroquine (CQ), as well as siRNA suppression of ATG5 and BECN1. MO increased intracellular cAMP levels and activated cAMP-PKA-AMPK-SIRT1 signaling in vivo and in vitro. These changes resulted in increased expression of autophagy-related protein MAP1LC3B2 and decreased secretion of inflammatory cytokines (ICAM-1, COX-2, and MMP-9). Conclusion Our results suggest that anti-AS and anti-inflammatory effects of MO are largely associated with its induction of autophagy through stimulation of cAMP-PKA-AMPK-SIRT1 signaling pathway.
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- 2017
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17. A switchable bis-branched [1]rotaxane featuring dual-mode molecular motions and tunable molecular aggregation
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Da-Hui Qu, Hong Li, Hans Ågren, Xin Li, Zhan-Qi Cao, and He Tian
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Rotaxane ,Materials science ,Fluorophore ,Rotaxanes ,Molecular Conformation ,Carbon-13 NMR ,Molecular Dynamics Simulation ,Photochemistry ,Imides ,Photoinduced electron transfer ,chemistry.chemical_compound ,Molecular dynamics ,Computers, Molecular ,Motion ,Zinc ,Ferrocene ,chemistry ,Proton NMR ,General Materials Science ,Perylene ,Fluorescent Dyes - Abstract
A multifunctional bis-branched [1]rotaxane containing a perylene bisimide (PBI) core and two identical bistable[1]rotaxane arms terminated with ferrocene units was prepared and characterized by (1)H NMR, (13)C NMR, and 2D ROESY NMR spectroscopies and by HR-ESI spectrometry. The system is shown to possess several key features: (1) In acetone solution, external acid-base stimuli can result in relative mechanical movements of its ring and thread, which can induce extension and contraction movements of the whole system accompanied by a rotational movement of the ferrocene units, thus realizing dual-mode molecular motions, and the optimized conformations at different states are obtained through molecular dynamics simulations employing the general Amber force field. (2) The introduction of PBI enables the system fluorescence encoding through distance-dependent photoinduced electron transfer process from the ferrocene units to the PBI fluorophore. (3) The addition of Zn(2+) can increase the degree of aggregation of the system, while adding base hinders aggregation because of the movement of the macrocycle. The tunable aggregated nanostructural morphologies of [1]rotaxane were examined by scanning electron microscopy. These results can pave the way to achieve precise control of integrated and coupling nanomechanical motions at a single-molecule level and provide more insight into controlling the aggregate behavior of switchable mechanically interlocked molecules.
- Published
- 2014
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