Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Digestion ; : 1-14, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38663369

RESUMO

INTRODUCTION: This study attempted to investigate how proprotein convertase subtilisin/kexin type 9 (PCSK9) influences the stemness of stomach adenocarcinoma (STAD) cells. METHODS: CCK-8 and sphere-formation assays were used to detect cell viability and stemness. qRT-PCR and Western blot were used to detect PCSK9 and TEAD4 expression. The binding relationship was verified by dual-luciferase and chromatin immunoprecipitation assays. The effect of TEAD4 activating PCSK9 on the stemness of STAD cells was detected by bioinformatics, BODIPY 493/503, Oil red O, Western blot, and kits. In vivo experiments verified the role of the TEAD4/PCSK9 axis in tumor formation in nude mice. RESULTS: PCSK9 and TEAD4 were highly expressed in STAD. PCSK9 was enriched in the fatty acid metabolism (FAM) pathway. PCSK9 activated the fatty acid metabolism and promoted the proliferation and stemness of STAD cells. TEAD4 as a transcription factor upstream of PCSK9, cell experiments revealed that knockdown of PCSK9 inhibited STAD cell stemness, whereas further addition of fatty acid inhibitors could attenuate the promoting effect on STAD cell stemness brought by STAD overexpression. Rescue experiments showed overexpressed PCSK9 exerted an inhibitory effect on the stemness of STAD cells brought by TEAD4 knockdown. The hypothesis that TEAD4/PCSK9 axis can promote STAD cell growth was confirmed by in vivo experiments. CONCLUSION: Transcription factor TEAD4 could activate PCSK9 to promote the stemness of STAD cells through FAM. These results added weight to the assumption that TEAD4/PCSK9 axis has the potential to be the therapeutic target that inhibits cancer stem cell in STAD.

2.
Anal Chem ; 93(41): 13974-13980, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34612623

RESUMO

Dynamic information of intracellular transcripts is essential to understand their functional roles. Routine RNA-sequencing (RNA-seq) methods only measure RNA species at a steady state and do not provide RNA dynamic information. Here, we develop addition-elimination mechanism-activated nucleotide transition sequencing (AENT-seq) for transcriptome-wide profiling of RNA dynamics. In AENT-seq, nascent transcripts are metabolically labeled with 4-thiouridine (4sU). The total RNA is treated with N2H4·H2O under aqueous conditions. N2H4·H2O is demonstrated to convert 4sU to 4-hydrazino cytosine (C*) based on an addition-elimination chemistry. C* is regarded as cytosine (C) during the DNA extension process. This 4sU-to-C transition marks nascent transcripts, so it enables sequencing analysis of RNA dynamics. We apply our AENT-seq to investigate transcript dynamic information of several genes involved in cancer progression and metastasis. This method uses a simple chemical reaction in aqueous solutions and will be rapidly disseminated with extensive applications.


Assuntos
RNA , Tiouridina , Sequência de Bases , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Nucleotídeos , RNA/genética , Análise de Sequência de RNA
3.
Rapid Commun Mass Spectrom ; 35(24): e9203, 2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-34549468

RESUMO

RATIONALE: The interactions between proteins and ligands are involved in many biological processes and early stages of drug development. Native electrospray ionization mass spectrometry (native ESI-MS) has played an important role in the characterization of protein-ligand interactions. Herein, native ESI-MS combined with molecular docking was used for the characterization of ginsenoside-myoglobin (Mb) interactions. METHODS: The binding of ginsenosides (Rb3 , Rc, Rd, Re) to Mb was determined by native ESI-MS. Titration experiments were performed for the calculation of the dissociation constants (Kd ) of the complexes. Molecular docking was used to simulate the binding of ginsenosides with Mb by AutoDock. RESULTS: The ginsenoside-Mb complex with stoichiometric ratio 1:1 was observed by native ESI-MS. The Kd values determined by the direct calculation method were matched with those obtained by the curve fitting method. However, the relative standard deviations (RSDs) obtained by direct calculation were larger than those obtained by curve fitting. From the molecular docking, it was inferred that hydrophobic interactions, hydrogen bonding and Van der Waals forces participate in the binding of ginsenosides to proteins. CONCLUSIONS: The ginsenoside-Mb interactions can be characterized by ESI-MS combined with molecular docking. This approach can be helpful to investigate the interactions between natural drugs and proteins in various diseases.


Assuntos
Ginsenosídeos/química , Simulação de Acoplamento Molecular/métodos , Mioglobina/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Sítios de Ligação , Cavalos , Ligantes , Músculo Esquelético/química , Ligação Proteica
4.
Phys Chem Chem Phys ; 23(17): 10448-10455, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33890604

RESUMO

Solar to hydrogen (H2) conversion systems based on carbon nanomaterials have shown great potentials in the clean energy field recently. However, for most systems, energy level alignments and light-induced redox processes are still unclear, which hinder artificial designing for higher efficiency of solar energy conversion and further applications. Here we report 77% enhancement in the light-driven H2 generation efficiency of N,S co-doped carbon quantum dot (N,S-CQD) aqueous system by adding TiO2 nanoparticles. Using steady-state and transient spectroscopy, four specific energy levels of CQDs are confirmed with the band gaps of 3.55 eV (X4), 2.99 eV (X3), 2.76 eV (X2) and 1.75 eV (X1), respectively. The X2 energy band is highly active for H+ reduction with a longer lifetime of 13.38 ns. Moreover, the observed low efficiency of intrinsic transition from X3 to X2 band of N,S-CQDs accounts for the poor performance of solar to H2 conversion for pure N,S-CQDs based on H2 generation and detailed time-resolved spectroscopic results. The mechanism of H2 generation enhancement can be explained by multiple electron transfer processes between N,S-CQDs and TiO2 NPs where TiO2 NPs act as electron intermediates that efficiently transfer electrons from the inert band (X3) to the active band (X2) for H2 generation. This study enriches the fundamental understanding of N,S-CQDs and provides a new pathway toward high-performance N,S-CQD-based solar to H2 conversion systems.

5.
Rapid Commun Mass Spectrom ; 34(18): e8853, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32511843

RESUMO

RATIONALE: Ginsenosides are considered to be the main functional components in ginseng and possess various important pharmacological activities. The study of the interactions between ginsenosides and proteins is indispensable for understanding the pharmacological activities of ginsenosides. In this work, the interactions of ginsenosides with cytochrome c (cyt c) were investigated by native mass spectrometry and molecular docking simulations. METHODS: The interactions of four ginsenosides (Rb1 , Rb3 , Rf, Rg1 ) and cyt c in NH4 OAc solution were investigated by electrospray ionization linear ion trap mass spectrometry (ESI-LTQ-MS). Molecular docking simulations of cyt c complexes were carried out by AutoDock. RESULTS: The native mass spectrometry results showed that the four ginsenosides were directly bound to cyt c, with stoichiometric ratios of 1:1 and 2:1 in NH4 OAc. The order of relative binding abilities of ginsenosides to cyt c obtained by ESI-MS was Rb1 > Rb3 > Rf > Rg1 , which was consistent with the docking results. Moreover, molecular docking simulations also indicated potential binding sites of cyt c and ginsenosides. Hydrogen-bond interaction played a very important role in cyt c binding with ginsenosides. CONCLUSIONS: It has been demonstrated that native MS is a useful tool to investigate the interactions of ginsenosides with cyt c. Molecular docking is a good complement to ESI analysis, and can provide information on potential binding sites of cyt c-ginsenoside complexess. This strategy will be helpful to further understand the interactions of proteins and small molecules.


Assuntos
Citocromos c , Ginsenosídeos , Simulação de Acoplamento Molecular/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Sítios de Ligação , Citocromos c/análise , Citocromos c/química , Citocromos c/metabolismo , Ginsenosídeos/análise , Ginsenosídeos/química , Ginsenosídeos/metabolismo , Cavalos , Ligação Proteica
6.
Future Oncol ; 16(7): 293-306, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32067473

RESUMO

Colorectal cancer is the third most common cancer in the world and its incidence is on the rise. Dietary intervention has emerged as an attractive strategy to curtail its occurrence and progression. Diet is known to influence the gut microbiome, as dietary factors and gut bacteria can act in concert to cause or protect from colorectal cancer. Several studies have presented evidence for such interactions and have pointed out the different ways by which the diet and gut microbiome can be altered to produce beneficial effects. This review article aims to summarize the interrelationship between diet, gut flora and colorectal cancer so that a better preventive approach can be applied.


Assuntos
Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/etiologia , Dieta , Suscetibilidade a Doenças , Microbioma Gastrointestinal , Animais , Neoplasias Colorretais/prevenção & controle , Humanos , Prebióticos , Probióticos , Medição de Risco , Fatores de Risco , Simbióticos
7.
Oncologist ; 24(7): 883-e407, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30877190

RESUMO

LESSONS LEARNED: Patients with metastatic colorectal cancer with good performance status or no liver metastasis could benefit from apatinib.Circulating tumor DNA abundance may be a predictor in serial monitoring of tumor load. BACKGROUND: Apatinib, an oral vascular endothelial growth factor (VEGF) receptor-2 inhibitor, has been approved as third-line treatment for metastatic gastric cancer in China. The aim of this study was to evaluate the efficacy and safety of apatinib, in the treatment of patients with refractory metastatic colorectal cancer after failure of two or more lines of chemotherapy. METHODS: In this open-label, single-arm, phase II study, patients with histological documentation of adenocarcinoma of the colon or rectum were eligible if they had received at least two prior regimens of standard therapies including fluoropyrimidine, oxaliplatin, and irinotecan. These patients were treated with apatinib in a daily dose of 500 mg, p.o., in the third-line or higher setting. Capture sequencing was dynamically performed to identify somatic variants in circulating tumor DNA (ctDNA) with a panel of 1,021 cancer-related genes. The primary endpoint was progression-free survival (PFS) and the tumor response was determined according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Interim analysis was applied as predefined. RESULTS: From June 1, 2016 to December 31, 2017, 26 patients were enrolled. The median PFS of the whole group was 3.9 months (95% confidence interval [CI]: 2.1-5.9). The median overall survival (OS) was 7.9 months (95% CI: 4.6-10.1+). Patients with performance status (PS) 0-1 had longer PFS than those with PS 2 (4.17 months vs. 1.93 months, p = .0014). Patients without liver metastasis also had longer PFS than those who had live metastasis (5.87 months vs. 3.33 months, p = .0274). The common side effects of apatinib were hypertension, hand-foot syndrome, proteinuria, and diarrhea. The incidence of grade 3-4 hypertension, hand-foot syndrome, proteinuria, and diarrhea was 76.92%, 11.54%, 73.08%, and 23.08%, respectively. All of the patients received dose reduction because of adverse effect. Results of capture sequencing showed APC, TP53, and KRAS were most frequently mutant genes. ctDNA abundance increased before the radiographic assessment in ten patients. CONCLUSION: Apatinib monotherapy showed promising efficiency for patients with refractory colorectal cancer, especially in patients with PS 0-1 or no liver metastasis. ctDNA abundance may be a predictor in serial monitoring of tumor load.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Piridinas/uso terapêutico , Adulto , Idoso , Neoplasias Colorretais/patologia , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Terapia de Salvação , Taxa de Sobrevida
8.
J Am Chem Soc ; 140(37): 11726-11734, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30145886

RESUMO

Light-driven H2 generation using semiconductor nanocrystal heterostructures has attracted intense recent interest because of the ability to rationally improve their performance by tailoring their size, composition, and morphology. In zero- and one-dimensional nanomaterials, the lifetime of the photoinduced charge-separated state is still too short for H2 evolution reaction, limiting the solar-to-H2 conversion efficiency. Here we report that using two-dimensional (2D) CdS nanoplatelet (NPL)-Pt heterostructures, H2 generation internal quantum efficiency (IQE) can exceed 40% at pH 8.8-13 and approach unity at pH 14.7. The near unity IQE at pH 14.7 is similar to those reported for 1D nanorods and can be attributed to the irreversible hole removal by OH-. At pH < 13, the IQE of 2D NPL-Pt is significantly higher than those in 1D nanorods. Detailed time-resolved spectroscopic studies and modeling of the elementary charge separation and recombination processes show that, compared to 1D nanorods, 2D morphology extends charge-separated state lifetime and may play a dominant role in enhancing the H2 generation efficiency. This work provides a new approach for designing nanostructures for efficient light-driven H2 generation.

9.
Appl Microbiol Biotechnol ; 101(5): 1945-1952, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27830294

RESUMO

(1S)-2-chloro-1-(3, 4-difluorophenyl) ethanol ((S)-CFPL) is an intermediate for the drug ticagrelor, and is manufactured via chemical approaches. To develop a biocatalytic solution to (S)-CFPL, an inventory of ketoreductases from Chryseobacterium sp. CA49 were rescreened, and ChKRED20 was found to catalyze the reduction of the ketone precursor with excellent stereoselectivity (>99 % ee). After screening an error-prone PCR library of the wild-type ChKRED20, two mutants, each bearing a single amino acid substitution of H145L or L205M, were identified with significantly increased activity. Then, the two critical positions were each randomized by constructing saturation mutagenesis libraries, which delivered several mutants with further enhanced activity. Among them, the mutant L205A was the best performer with a specific activity of 178 µmol/min/mg, ten times of that of the wild-type. Its k cat/K m increased by 15 times and half-life at 50 °C increased by 70 %. The mutant catalyzed the complete conversion of 150 and 200 g/l substrate within 6 and 20 h, respectively, to yield enantiopure (S)-CFPL with an isolated yield of 95 %.


Assuntos
Adenosina/análogos & derivados , Chryseobacterium/enzimologia , Etanol/análogos & derivados , Etanol/síntese química , Cetonas/metabolismo , Oxirredutases/metabolismo , 2-Propanol/química , Adenosina/síntese química , Adenosina/química , Biocatálise , Chryseobacterium/metabolismo , Etanol/química , Biblioteca Gênica , Mutagênese , NAD/química , Oxirredução , Oxirredutases/genética , Especificidade por Substrato , Ticagrelor
10.
Appl Microbiol Biotechnol ; 101(23-24): 8395-8404, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29067484

RESUMO

ChKRED20 is an efficient and robust anti-Prelog ketoreductase that can catalyze the reduction of ketones to chiral alcohols as pharmaceutical intermediates with great industrial potential. To overcome its limitation on the bioreduction of ortho-substituted acetophenone derivatives, the X-ray crystal structure of the apo-enzyme of ChKRED20 was determined at a resolution of 1.85 Å and applied to the molecular modeling and reshaping of the catalytic cavity via three rounds of iterative saturation mutagenesis together with alanine scanning and recombination. The mutant Mut3B was achieved with expanded catalytic scope that covered all the nine substrates tested as compared with two substrates for the wild type. It exhibited 13-20-fold elevated k cat/K m values relative to the wild type or to the first gain-of-activity mutant, while retaining excellent stereoselectivity toward seven of the substrates (98-> 99% ee). Another mutant 29G10 displayed complementary selectivity for eight of the ortho-substituted acetophenone derivatives, with six of them delivering excellent stereoselectivity (90-99% ee). Its k cat/K m value toward 1-(2-fluorophenyl)ethanone was 5.6-fold of the wild type. The application of Mut3B in elevated substrate concentrations of 50-100 g/l was demonstrated in 50-ml reactions, achieving 75-> 99% conversion and > 99% ee.


Assuntos
Chryseobacterium/enzimologia , Cetonas/metabolismo , Mutagênese , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Cristalografia por Raios X , Cinética , Modelos Moleculares , Proteínas Mutantes/química , Oxirredutases/química , Conformação Proteica , Especificidade por Substrato
11.
Appl Microbiol Biotechnol ; 100(8): 3567-75, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26658823

RESUMO

Ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE) is an important chiral intermediate for the synthesis of "blockbuster" drug statins. The carbonyl reductase ChKRED20 from Chryseobacterium sp. CA49 was found to catalyze the bio-reductive production of (S)-CHBE with excellent stereoselectivity (>99.5 % ee). Perceiving a capacity for improvement, we sought to increase the thermostability of ChKRED20 to allow a higher reaction temperature. After one round of error-prone PCR (epPCR) library screening followed by the combination of beneficial mutations, a triple-mutant MC135 was successfully achieved with substantially enhanced thermostablity. The activity of MC135 at 50 °C was similar to the wild type. However, at its temperature optima of 65 °C, the mutant displayed 63 % increase of activity compared to the wild type and remained >95 % activity after being incubated for 15 days, while the wild type had a half-life of 11.9 min at 65 °C. At a substrate/catalyst ratio of 100 (w/w), the mutant catalyzed the complete conversion of 300 g/l substrate within 1 h to yield enantiopure (S)-CHBE with an isolated yield of 95 %, corresponding to a space-time yield of 1824 mM/h.


Assuntos
Acetoacetatos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Chryseobacterium/enzimologia , Oxirredutases/genética , Oxirredutases/metabolismo , Acetoacetatos/química , Biocatálise , Chryseobacterium/química , Chryseobacterium/genética , Estabilidade Enzimática , Temperatura Alta , Isomerismo , Cinética , Mutação , Oxirredutases/química
12.
J Phys Chem A ; 119(50): 12579-85, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26562362

RESUMO

The effect of a hydrogen bond on the photochemical synthesis of silver nanoparticles has been investigated via experimental and theoretical methods. In a benzophenone system, the photochemical synthesis process includes two steps, which are that hydrogen abstraction reaction and the following reduction reaction. We found that for the first step, an intermolecular hydrogen bond enhances the proton transfer. The efficiency of hydrogen abstraction increases with the hydrogen bond strength. For the second step, the hydrogen-bonded ketyl radical complex shows higher reducibility than the ketyl radical. The inductively coupled plasma-optical emission spectroscopy (ICP-OES) measurement exhibits a 2.49 times higher yield of silver nanoparticles in the hydrogen bond ketyl radical complex system than that for the ketyl radical system. Theoretical calculations show that the hydrogen bond accelerates electron transfer from the ketyl radical to the silver ion by raising the SOMO energy of the ketyl radical; thus, the SOMO-LUMO interaction is more favorable.

13.
Int J Biol Macromol ; 271(Pt 2): 132412, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38754674

RESUMO

Acute myocardial infarction (AMI) causes acute cardiac cell death when oxygen supply is disrupted. Improving oxygen flow to the damaged area could potentially achieve the to prevent cell death and provide cardiac regeneration. Here, we describe the production of oxygen-producing injectable bio-macromolecular hydrogels from natural polymeric components including gelatin methacryloyl (GelMA), hyaluronic acid (HA) loaded with catalase (CAT). Under hypoxic conditions, the O2-generating hydrogels (O2 (+) hydrogel) encapsulated with Mesenchymal stem cells (MSCs)-derived-exosomes (Exo- O2 (+) hydrogel) released substantial amounts of oxygen for >5 days. We demonstrated that after 7 days of in vitro cell culture, exhibits identical production of paracrine factors compared to those of culture of rat cardiac fibroblasts (RCFs), rat neonatal cardiomyocytes (RNCs) and Human Umbilical Vein Endothelial Cells (HUVECs), demonstrating its ability to replicate the natural architecture and function of capillaries. Four weeks after treatment with Exo-O2 (+) hydrogel, cardiomyocytes in the peri-infarct area of an in vivo rat model of AMI displayed substantial mitotic activity. In contrast with infarcted hearts treated with O2 (-) hydrogel, Exo- O2 (+) hydrogel infarcted hearts showed a considerable increase in myocardial capillary density. The outstanding therapeutic advantages and quick, easy fabrication of Exo- O2 (+) hydrogel has provided promise favourably for potential cardiac treatment applications.


Assuntos
Modelos Animais de Doenças , Exossomos , Gelatina , Ácido Hialurônico , Hidrogéis , Infarto do Miocárdio , Miócitos Cardíacos , Oxigênio , Animais , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/terapia , Infarto do Miocárdio/patologia , Gelatina/química , Hidrogéis/química , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ratos , Exossomos/metabolismo , Humanos , Metacrilatos/química , Neovascularização Fisiológica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Injeções , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Ratos Sprague-Dawley , Masculino
14.
Clin Cardiol ; 47(2): e24243, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38402557

RESUMO

BACKGROUND: The ratio of nonhigh-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) has been shown associated with various metabolic diseases and atherosclerosis in primary prevention. However, there is limited evidence on the relationship between the non-HDL-C/HDL-C ratio and progression of nonculprit coronary lesion (NCCL) after percutaneous coronary intervention (PCI). HYPOTHESIS: Our study aimed to investigate the potential association between the non-HDL-C/HDL-C ratio and NCCL progression in patients with acute coronary syndrome (ACS) undergoing PCI. METHODS: We conducted a retrospective analysis of ACS patients who underwent coronary angiography twice at a single center from 2016 to 2022. Lipid measurements, demographic, clinical, and other laboratory data were collected from electronic medical records. NCCLs were evaluated using quantitative coronary angiography. The primary outcome was the progression of NCCL. Patients were categorized based on NCCL progression and tertiles of the non-HDL-C/HDL-C ratio. Associations were analyzed using univariate and multivariate logistic regression analysis. RESULTS: The study included 329 ACS patients who underwent PCI, with a median follow-up angiography of 1.09 years. We found NCCL progression in 95 (28.9%) patients with acceptable low-density lipoprotein cholesterol control (median: 1.81 mmol/L). Patients in the top tertile of the non-HDL-C/HDL-C ratio had a higher risk of NCCL progression. After adjusting for potential confounding factors, the non-HDL-C/HDL-C ratio remained a significant predictor for NCCL progression (adjusted odds ratio: 1.45; 95% confidence interval: 1.14-1.86; p < 0.05). CONCLUSIONS: The non-HDL-C/HDL-C ratio predicts NCCL progression in ACS patients following PCI, providing a valuable tool for risk assessment and enhancing secondary prevention of atherosclerotic cardiovascular disease.


Assuntos
Síndrome Coronariana Aguda , Aterosclerose , Intervenção Coronária Percutânea , Humanos , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/terapia , Intervenção Coronária Percutânea/efeitos adversos , Estudos Retrospectivos , Colesterol , Angiografia Coronária , Lipoproteínas
15.
J Am Soc Mass Spectrom ; 34(3): 366-373, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36735536

RESUMO

Flavonoids are polyphenolic secondary metabolites with extensive biological activities and pharmacological effects. Exploring the interactions of flavonoids with proteins may be helpful for understanding their biological processes. Electrospray ionization mass spectrometry (ESI-MS) is a powerful tool to characterize the noncovalent protein-ligand (PL) complexes. However, some protein-flavonoid complexes are labile during electrospray ionization. Here, the labile lysozyme-flavonoid (rutin, icariin, and naringin) complexes were determined by direct ESI-MS without derivation. It has been found that low amounts of N-methylpyrrolidinone and dimethylformamide can protect labile lysozyme-flavonoid complexes away from dissociation during electrospray ionization process. The intact lysozyme-flavonoid complexes were specifically observed in mass spectra, and the measured binding affinities by ESI-MS were matched with the fluorescence data. The effects of additives on the analysis of lysozyme-flavonoid complexes were investigated by ESI-MS, combined with the molecular docking and fluorescence. This strategy was helpful to investigate the labile PL interactions by direct ESI-MS.


Assuntos
Muramidase , Espectrometria de Massas por Ionização por Electrospray , Muramidase/química , Simulação de Acoplamento Molecular , Espectrometria de Massas por Ionização por Electrospray/métodos , Ligantes , Flavonoides/química
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 294: 122542, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-36848858

RESUMO

Modification of surficial functional groups among carbon quantum dots (CQDs) has been considered an efficient approach to regulate the fluorescence emission of CQDs. However, the mechanism of how surficial functional groups affect fluorescence is vague which fundamentally limits the further applications of CQDs. Here we report the concentration-dependent fluorescence and fluorescence quantum yield of nitrogen-dopped carbon quantum dots (N-CQDs). At high concentrations (≥0.188 g/L), fluorescence redshift occurs accompanied with decrease in fluorescence quantum yield. Fluorescence excitation spectra and HOMO-LUMO energy gaps calculations show that energy levels of excited states of N-CQDs are relocated via the coupling of surficial amino groups among N-CQDs. Furthermore, electron density difference maps and broadened fluorescence spectra obtained from both experimental measurement and theoretical calculation further confirm that the coupling of surficial amino groups dominates the fluorescence property and verify the formation of charge-transfer state of N-CQDs complex at high concentrations which provides pathways for efficient charge transfer. Given that charge-transfer state induced fluorescence loss and fluorescence spectra broadening are the typical characteristics of organic molecules, CQDs exhibit the optical properties of both quantum dots and organic molecules.

17.
Chem Commun (Camb) ; 58(9): 1322-1325, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-34985087

RESUMO

Both sequence enrichment and base resolution are essential for accurate sequencing analysis of low-abundance RNA. Yet they are hindered by the lack of molecular tools. Here we report a bifunctional chemical signature for RNA 4-thiouridine (4sU) enrichment sequencing with single-base resolution. This chemical signature is designed for specific 4sU labeling with two functional parts. One part is a distal alkynyl group for the biotin-assisted pulldown enrichment of target molecules via click chemistry crosslinking. The other part is a -NH group proximal to the pyrimidine ring of 4sU. It allows 4sU-to-cytosine transition during the polymerase-catalyzed extension reaction based on altering hydrogen-bonding patterns. Ultimately, the 4sU-containing RNA molecules can be enriched and accurately analyzed by single-base resolution sequencing. The proposed method also holds great potential to investigate transcriptome dynamics integrated with high-throughput sequencing.


Assuntos
RNA/química , Tiouridina/química , Química Click , Citosina/química , Sequenciamento de Nucleotídeos em Larga Escala , Espectrometria de Massas , Motivos de Nucleotídeos , Pirimidinas/química , Estabilidade de RNA , Análise de Sequência de RNA
18.
Technol Health Care ; 30(S1): 425-440, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35124617

RESUMO

BACKGROUND: Yes-associated protein (YAP) has been reported to act as a candidate human oncogene and played a critical role in the development of multiple cancer types. OBJECTIVE: We aimed to investigate the expression, function, and underlying mechanisms of YAP in gastric cancer (GC). METHODS: Expression levels of YAP in gastric tissues were tested. CCK8 assay, clonogenic assay, apoptosis assay, transwell assay, cell scratch assay and animal study were conducted to explore the function of YAP. Chromatin immunoprecipitation (ChIP) assay and luciferase reporter assay were performed to explore the underlying mechanism. Survival analysis was carried out to reveal the relationship between YAP and clinical outcome. RESULTS: YAP was upregulated in gastric cancer tissues and correlates with poor prognosis. YAP could promote GC cells proliferation, metastatic capacity, inhibit GC cells apoptosis in vitro and in vivo. Bothß-catenin and YAP were mainly localized withi the tumor cell nuclei. ß-catenincould upregulate YAP expression by binding to the promotor region of YAP. Patients with both YAP and ß-catenin negetive expression had a better prognosis than others. CONCLUSIONS: YAP overexpression is driven by aberrant Wnt ß-catenin signalingand then contributed to the GC tumorigenesis and progression. Thus, YAP might be a potential target for GC treatment.


Assuntos
Neoplasias Gástricas , beta Catenina , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Via de Sinalização Wnt , Proteínas de Sinalização YAP , beta Catenina/genética , beta Catenina/metabolismo
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 267(Pt 2): 120573, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34774435

RESUMO

The rare earth materials have attracted intensive attention due to their strong luminescent characteristic. However, the split fine Stark levels are difficult to be determined. Here we report a room-temperature detection for Stark levels of YNbO4: Er3+ using established laser-induced spectroscopy system with dye laser of superhigh resolution of wavelength at 0.005 nm. From excitation spectra, six split Stark levels of 4G11/2 (Er3+) were directly detected. Moreover, nonradiative relaxations of 4G9/2→4G11/2 and 4G11/2→2H11/2/ 4S3/2 have been observed with weighed lifetimes of 0.70 µs and 6.15 µs, and characteristic green emission of Er3+ (@555 nm) yields lifetime of 31.78 µs.


Assuntos
Luz , Metais Terras Raras , Lasers , Luminescência , Análise Espectral
20.
Front Oncol ; 12: 909035, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35712486

RESUMO

Purpose: Immune checkpoint inhibitors plus antiangiogenic tyrosine kinase inhibitors may offer a first-line treatment for advanced hepatocellular carcinoma (HCC). In this phase 2 trial [registered with clinicaltrials.gov (NCT04052152)], we investigated the safety and efficacy of first-line anti-PD-1 antibody sintilimab plus antiangiogenic TKI anlotinib for advanced HCC. Methods and Materials: Pathologically-proven advanced HCC patients received sintilimab (200 mg) on day 1 and anlotinib (12 mg) once daily on days 1 to 14 every 3 weeks, with a safety run-in for the first six participants to assess dose-limiting toxicities (DLTs). The primary endpoints were safety and objective response rate (ORR) per RECIST v1.1. Results: Twenty advanced HCC patients were enrolled. No DLTs occurred in the safety run-in. All patients had treatment-related adverse events (TRAEs). Grade 3 TRAEs occurred in 8 (40.0%) patients, the most common being decreased platelet count (10.0%) and increased γ-glutamyl transferase (10.0%). No grade 4/5 TRAEs occurred. Five (25%) patients developed immune-related AEs. The ORR was 35.0% (95%CI 15.4%-59.2%) per RECIST v1.1 and 55.0% (95%CI 31.5%-76.9%) per modified RECIST. At data cutoff (March 31, 2021), the median progression-free survival was 12.2 months (95%CI, 3.8 to not reached). The median PFS was significantly longer in patients with lower LDH levels (not reached [NR], 95% CI, 8.7 to NR vs. higher LDH levels 5.2 months, 95% CI 3.4 to NR; P=0.020) and a CONUT score ≤2 (NR, 95% CI 5.1 to NR vs. CONUT score >2 6.2 months, 95% CI 1.8 to NR; P=0.020). Furthermore, patients showing tumor response had a significantly higher median proportion of CD16+CD56+ NK cells than patients who had stable or progressive disease (21.6% vs. 14.6%; P=0.026). Conclusion: Sintilimab plus anlotinib showed promising clinical activities with manageable toxicity as first-line treatment of advanced HCC.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA