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1.
Anal Chem ; 94(11): 4610-4616, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35275492

RESUMO

The dark-field microscopy (DFM) imaging technology has the advantage of a high signal-to-noise ratio, and it is often used for real-time monitoring of plasmonic resonance scattering and biological imaging at the single-nanoparticle level. Due to the limitation of the optical diffraction limit, it is still a challenging task to accurately distinguish two or more nanoparticles whose distance is less than the diffraction limit. Here, we propose a computational strategy based on a deep learning framework (NanoNet), which will realize the effective segmentation of the scattered light spots in diffraction-limited DFM images and obtain high-resolution plasmonic light scattering imaging. A small data set of DFM and the corresponding scanning electron microscopy (SEM) image pairs are used to learn for obtaining a highly resolved semantic imaging model using NanoNet, and thus highly resolved DFM images matching the resolution of those acquired using SEM can be obtained. Our method has the ability to transform diffraction-limited DFM images to highly resolved ones without adding a complex optical system. As a proof of concept, a highly resolved DFM image of living cells through the NanoNet technique is successfully made, opening up a new avenue for high-resolution optical nanoscopic imaging.


Assuntos
Aprendizado Profundo , Nanopartículas , Microscopia/métodos , Imagem Óptica
2.
Anal Chem ; 93(4): 2619-2626, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33427440

RESUMO

Plasmonic nanoparticles, which have excellent local surface plasmon resonance (LSPR) optical and chemical properties, have been widely used in biology, chemistry, and photonics. The single-particle light scattering dark-field microscopy (DFM) imaging technique based on a color-coded analytical method is a promising approach for high-throughput plasmonic nanoparticle scatterometry. Due to the interference of high noise levels, accurately extracting real scattering light of plasmonic nanoparticles in living cells is still a challenging task, which hinders its application for intracellular analysis. Herein, we propose an automatic and high-throughput LSPR scatterometry technique using a U-Net convolutional deep learning neural network. We use the deep neural networks to recognize the scattering light of nanoparticles from background interference signals in living cells, which have a dynamic and complicated environment, and construct a DFM image semantic analytical model based on the U-Net convolutional neural network. Compared with traditional methods, this method can achieve higher accuracy, stronger generalization ability, and robustness. As a proof of concept, the change of intracellular cytochrome c in MCF-7 cells under UV light-induced apoptosis was monitored through the fast and high-throughput analysis of the plasmonic nanoparticle scattering light, providing a new strategy for scatterometry study and imaging analysis in chemistry.

3.
Angew Chem Int Ed Engl ; 60(34): 18721-18727, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34076954

RESUMO

This work presents a redox-mediated electrolytic nitrogen reduction reaction (RM-eNRR) using polyoxometalate (POM) as the electron and proton carrier which frees the TiO2 -based catalyst from the electrode and shifts the reduction of nitrogen to a reactor tank. The RM-eNRR process has achieved an ammonium production yield of 25.1 µg h-1 or 5.0 µg h-1 cm-2 at an ammonium concentration of 6.7 ppm. With high catalyst loading, 61.0 ppm ammonium was accumulated in the electrolyte upon continuous operation, which is the highest concentration detected for ambient eNRR so far. The mechanism underlying the RM-eNRR was scrutinized both experimentally and computationally to delineate the POM-mediated charge transfer and hydrogenation process of nitrogen molecule on the catalyst. RM-eNRR is expected to provide an implementable solution to overcome the limitations in the conventional eNRR process.

4.
BMC Vet Res ; 15(1): 134, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064364

RESUMO

BACKGROUND: Duck viral hepatitis (DVH) is an acute disease of young ducklings with no effective veterinary drugs for treatment. Gynostemma pentaphyllum is a well-known traditional Chinese medicine that plays an important role in the treatment of various diseases. Gypenoside (GP), one of the main ingredients of Gynostemma pentaphyllum, was reported with good hepatoprotective effects. However, its low solubility limits its application in the clinics. To improve its solubility and bioactivity, a phosphorylated derivative of gypenoside (pGP) was prepared by the sodium trimetaphosphate-sodium tripolyphosphate (STMP-STPP) method. An infrared spectroscopy method was applied to analyse the structures of GP and pGP. Then, a methyl thiazolyl tetrazolium (MTT) colorimetric assay was applied to study the hepatocyte protective efficacy of these two drugs against duck hepatitis A virus type 1 (DHAV-1) infection, and qPCR, TUNEL labelling and flow cytometry methods were used to study the relevant hepatocyte protective in vitro. RESULTS: The infrared spectroscopy detection results showed that the phosphorylation modification of GP was successful. The MTT colorimetric assay results showed that both GP and pGP possessed good hepatocyte protective efficacy in vitro, and pGP performed better than GP when the drug was added before or after virus inoculation. Furthermore, the qPCR results revealed that both drugs could effectively inhibit the adsorption (when adding GP and pGP pre-virus inoculation), replication and release of DHAV-1, and the viral inhibition rate of pGP was greater than that of GP. The subsequent TUNEL labelling and flow cytometry assays showed that both GP and pGP could significantly inhibit duck embryo hepatocyte apoptosis induced by DHAV-1, and the inhibition effect of pGP was much stronger than that of GP. CONCLUSIONS: GP exerts good hepatocyte protective efficacy not only by inhibiting the proliferation of DHAV-1 but also by inhibiting duck embryonic hepatocyte apoptosis induced by DHAV-1, and phosphorylation modification significantly improves the antiviral and the anti-apoptotic effects of GP. Therefore, pGP has the potential to be developed into a novel drug against DHAV-1 infection.


Assuntos
Vírus da Hepatite do Pato/efeitos dos fármacos , Animais , Antivirais/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Patos , Gynostemma/química , Hepatite Viral Animal/tratamento farmacológico , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Fosforilação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Replicação Viral/efeitos dos fármacos
5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(2): 188-192, 2019 Mar.
Artigo em Zh | MEDLINE | ID: mdl-31106537

RESUMO

OBJECTIVE: To study the relationship between hypoxia and the hypoxia inducible factor-1α (HIF-1α) from lung cancer cells, to reveal the possible mechanism of brain metastases of lung cancer. METHODS: The hypoxia model of A549 lung cancer cells was established. After hypoxia culture of A549 cells for 0.5, 2, 4, 8, 12 and 24 h (normal oxygen culture at the same time point was set as the control group), the mass concentration of HIF-1α in A549 lung cancer cell culture medium were determined by ELISA. Transwell chamber was used to construct an in vitro blood brain barrier model, was treated with A549 lung cancer cell culture medium after different time points of hypoxia, Tran endothelial resistance (TER) change of blood-brain barrier model in instrument, to reflect the changes of blood-brain barrier permeability in vitro; A549 lung cancer cells in the culture medium were counted under Transwell room. A549 lung cancer cells with hypoxia at different time points injected into Wistar rats via tail vein, Western blot method was used to menstruate expression of tight junction associated protein Claudin-5 in the brain tissues, Evans blue to detect the change of blood brain barrier permeability in rats. RESULTS: Compared with the control group, the HIF-1α mass concentration in the cell culture solution of A549 increased, the in vitro blood-brain barrier model TER decreased, and the cell number of A549 that passed through transwell into the lower chamber increased (all P<0.05) after hypoxia 2 h, the above effect was most obvious when hypoxia 8 h (all P<0.01). After hypoxia 24 h, it was restored to the control group level. In the in vivo experiment of rats, compared with the control group, the mass percent of Evans blue in rat brain tissues increased after A549 cell culture solution with hypoxia 2 h was injected via caudal vein, meaning increased the permeability of rat blood brain barrier, while the expression of Claudin-5 protein in rat brain tissues decreased (all P<0.05). The effect was most obvious when A549 cell culture solution with hypoxia 8 h was injected into rat tail vein (P<0.01 ). Ejectionof hypoxia 24 h A549 cell culture solution yielded the same effects as those in the control group. CONCLUSION: Hypoxia can induce the increase of HIF-1α in lung cancer cells. The increase of HIF-1α results in the decrease of Claudin-5 expression and increase of blood-brain barrier permeability, leading to lung cancer cells metastasis into the brain.


Assuntos
Neoplasias Encefálicas/secundário , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pulmonares/patologia , Células A549 , Animais , Hipóxia Celular , Humanos , Transplante de Neoplasias , Ratos , Ratos Wistar
6.
Biochem Biophys Res Commun ; 492(3): 425-433, 2017 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-28842253

RESUMO

Transcriptional silencing of estrogen receptor α (ERα) expression is an important etiology contributing to the letrozole-resistance in ERα-positive breast cancer (BCa) cells, but the transcription factors responsible for this transcriptional repression remain largely unidentified. Here we report that the expression of the basic helix-loop-helix myogenic regulatory factor MYOD was abnormally up-regulated in letrozole-resistant BCa tissues and in experimentally-induced letrozole-resistant BCa cells. Overexpression of the exogenous MYOD impaired ERα expression and potentiated letrozole-resistance in letrozole-sensitive MCF7 cells, whereas MYOD knockdown could effectively restore ERα expression and thereby promote letrozole-sensitivity in letrozole-resistant MCF-7/LR cells. Mechanistically, MYOD was shown to be a potent corepressor of ESR1 transcription, and this transcriptional repression was significantly enhanced in the presence of letrozole treatment. Thus, targeted inhibition of MYOD may restore ERα level and lead to resensitization to letrozole-based hormone therapy, providing a novel therapeutic strategy for relapsed ERα-positive BCa patients. Our data also underscore an unexpected chemotherapeutic facet of MYOD, which may operate as a novel regulator of BCa biology.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteína MyoD/metabolismo , Nitrilas/farmacologia , Transcrição Gênica , Triazóis/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptor alfa de Estrogênio/biossíntese , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Letrozol , Proteína MyoD/genética , Transcrição Gênica/efeitos dos fármacos
7.
J Med Syst ; 41(8): 126, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28718051

RESUMO

Coronary heart disease preoperative diagnosis plays an important role in the treatment of vascular interventional surgery. Actually, most doctors are used to diagnosing the position of the vascular stenosis and then empirically estimating vascular stenosis by selective coronary angiography images instead of using mouse, keyboard and computer during preoperative diagnosis. The invasive diagnostic modality is short of intuitive and natural interaction and the results are not accurate enough. Aiming at above problems, the coronary heart disease preoperative gesture interactive diagnostic system based on Augmented Reality is proposed. The system uses Leap Motion Controller to capture hand gesture video sequences and extract the features which that are the position and orientation vector of the gesture motion trajectory and the change of the hand shape. The training planet is determined by K-means algorithm and then the effect of gesture training is improved by multi-features and multi-observation sequences for gesture training. The reusability of gesture is improved by establishing the state transition model. The algorithm efficiency is improved by gesture prejudgment which is used by threshold discriminating before recognition. The integrity of the trajectory is preserved and the gesture motion space is extended by employing space rotation transformation of gesture manipulation plane. Ultimately, the gesture recognition based on SRT-HMM is realized. The diagnosis and measurement of the vascular stenosis are intuitively and naturally realized by operating and measuring the coronary artery model with augmented reality and gesture interaction techniques. All of the gesture recognition experiments show the distinguish ability and generalization ability of the algorithm and gesture interaction experiments prove the availability and reliability of the system.


Assuntos
Doença das Coronárias , Gestos , Algoritmos , Mãos , Humanos , Reprodutibilidade dos Testes
8.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 48(6): 857-861, 2017 Nov.
Artigo em Zh | MEDLINE | ID: mdl-29260520

RESUMO

OBJECTIVE: To determine the effect of prostaglandin E2 (PGE2) on brain metastasis of lung cancer,and to explore the possible mechanism of aspirin (PGE2 inhibitor) reducing brain metastasis of lung cancer. METHODS: Radioimmunoassay was performed to measure the expression level of PGE2 in cell supernatant collected from cells treated with or without aspirin (8 mmol/L) at different time points. After establishing in vitro blood-brain barrier (BBB) model using Transwell, lung cancer cells was added to upper chamber of transwell and was then treated with aspirin (8 mmol/L). Western blot was used to examine the expression of occludin protein in brain microvascular endothelial cells. The permeability changes of BBB model in vitro were determined using horseradish peroxides. The number of lung cancer cells passing through BBB model in vitro was counted with Hemocytometer. Effect of aspirin on brain metastasis of lung cancer was observed in nude mice in the animal level. RESULTS: PGE2 level decreased and reached minimum level 120 min after aspirin treatment in lung cancer cells culture fluid. Occludin expression increased and reached maximum level 120 min after aspirin treatment in brain microvascular endothelial cells. At the same time,permeability of BBB and number of lung cancer cells passing through BBB also reached the lowest value 120 min after aspirin treatment. Aspirin significantly reduced the incidence of brain metastasis of lung cancer in animal model. CONCLUSION: Aspirin reduced occurrences of the brain metastasis of lung cancer in animal model,which may be caused by inhibition of PGE2 released by lung cancer cells and upregulation of occludin expression therefore leading to decrease in BBB permeability.


Assuntos
Aspirina/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Metástase Neoplásica , Ocludina/metabolismo , Animais , Encéfalo , Neoplasias Encefálicas/secundário , Dinoprostona/antagonistas & inibidores , Camundongos , Camundongos Nus
9.
Molecules ; 21(12)2016 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-27983593

RESUMO

Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.


Assuntos
Medicina Tradicional Chinesa , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Animais , Humanos , Polissacarídeos/química
10.
J Med Syst ; 39(11): 133, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26319273

RESUMO

Preoperative path planning plays a critical role in vascular access surgery. Vascular access surgery has superior difficulties and requires long training periods as well as precise operation. Yet doctors are on different leves, thus bulky size of blood vessels is usually chosen to undergo surgery and other possible optimal path is not considered. Moreover, patients and surgeons will suffer from X-ray radiation during the surgical procedure. The study proposed an improved ant colony algorithm to plan a vascular optimal three-dimensional path with overall consideration of factors such as catheter diameter, vascular length, diameter as well as the curvature and torsion. To protect the doctor and patient from exposing to X-ray long-term, the paper adopted augmented reality technology to register the reconstructed vascular model and physical model meanwhile, locate catheter by the electromagnetic tracking system and used Head Mounted Display to show the planning path in real time and monitor catheter push procedure. The experiment manifests reasonableness of preoperative path planning and proves the reliability of the algorithm. The augmented reality experiment real time and accurately displays the vascular phantom model, planning path and the catheter trajectory and proves the feasibility of this method. The paper presented a useful and feasible surgical scheme which was based on the improved ant colony algorithm to plan vascular three-dimensional path in augmented reality. The study possessed practical guiding significance in preoperative path planning, intraoperative catheter guiding and surgical training, which provided a theoretical method of path planning for vascular access surgery. It was a safe and reliable path planning approach and possessed practical reference value.


Assuntos
Algoritmos , Procedimentos Clínicos/organização & administração , Período Pré-Operatório , Dispositivos de Acesso Vascular , Procedimentos Cirúrgicos Vasculares/métodos , Simulação por Computador , Humanos , Imageamento Tridimensional/métodos , Exposição à Radiação , Reprodutibilidade dos Testes , Fatores de Tempo
11.
Circulation ; 128(17): 1897-909, 2013 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-23995537

RESUMO

BACKGROUND: Although methods for generating cardiomyocytes from pluripotent stem cells have been reported, current methods produce heterogeneous mixtures of cardiomyocytes and noncardiomyocyte cells. Here, we report an entirely novel system in which pluripotent stem cell-derived cardiomyocytes are purified by cardiomyocyte-specific molecular beacons (MBs). MBs are nanoscale probes that emit a fluorescence signal when hybridized to target mRNAs. METHOD AND RESULTS: Five MBs targeting mRNAs of either cardiac troponin T or myosin heavy chain 6/7 were generated. Among 5 MBs, an MB that targeted myosin heavy chain 6/7 mRNA (MHC1-MB) identified up to 99% of HL-1 cardiomyocytes, a mouse cardiomyocyte cell line, but <3% of 4 noncardiomyocyte cell types in flow cytometry analysis, which indicates that MHC1-MB is specific for identifying cardiomyocytes. We delivered MHC1-MB into cardiomyogenically differentiated pluripotent stem cells through nucleofection. The detection rate of cardiomyocytes was similar to the percentages of cardiac troponin T- or cardiac troponin I-positive cardiomyocytes, which supports the specificity of MBs. Finally, MHC1-MB-positive cells were sorted by fluorescence-activated cell sorter from mouse and human pluripotent stem cell differentiating cultures, and ≈97% cells expressed cardiac troponin T or cardiac troponin I as determined by flow cytometry. These MB-based sorted cells maintained their cardiomyocyte characteristics, which was verified by spontaneous beating, electrophysiological studies, and expression of cardiac proteins. When transplanted in a myocardial infarction model, MB-based purified cardiomyocytes improved cardiac function and demonstrated significant engraftment for 4 weeks without forming tumors. CONCLUSIONS: We developed a novel cardiomyocyte selection system that allows production of highly purified cardiomyocytes. These purified cardiomyocytes and this system can be valuable for cell therapy and drug discovery.


Assuntos
Transplante de Células/métodos , Infarto do Miocárdio/terapia , Miócitos Cardíacos/citologia , Células-Tronco Pluripotentes/citologia , RNA Mensageiro/isolamento & purificação , Potenciais de Ação/fisiologia , Animais , Biomarcadores , Diferenciação Celular/fisiologia , Linhagem Celular , Células Cultivadas , Citometria de Fluxo/métodos , Humanos , Camundongos , Miócitos Cardíacos/fisiologia , Cadeias Pesadas de Miosina/genética , Nanotecnologia , Conformação de Ácido Nucleico , Células-Tronco Pluripotentes/fisiologia , Sondas RNA/química , Sondas RNA/isolamento & purificação , RNA Mensageiro/química , Troponina I/genética , Troponina T/genética
12.
Planta ; 240(5): 1063-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25139277

RESUMO

MAIN CONCLUSION: Storage promotes carotenoid accumulation and converts amylochromoplasts into chromoplasts in winter squash. Such carotenoid enhancement is likely due to continuous biosynthesis along with reduced turnover and/or enhanced sequestration. Postharvest storage of fruits and vegetables is often required and frequently results in nutritional quality change. In this study, we investigated carotenoid storage plastids, carotenoid content, and its regulation during 3-month storage of winter squash butternut fruits. We showed that storage improved visual appearance of fruit flesh color from light to dark orange, and promoted continuous accumulation of carotenoids during the first 2-month storage. Such an increased carotenoid accumulation was found to be concomitant with starch breakdown, resulting in the conversion of amylochromoplasts into chromoplasts. The butternut fruits contained predominantly ß-carotene, lutein, and violaxanthin. Increased ratios of ß-carotene and violaxanthin to total carotenoids were noticed during the storage. Analysis of carotenoid metabolic gene expression and PSY protein level revealed a decreased expression of carotenogenic genes and PSY protein following the storage, indicating that the increased carotenoid level might not be due to increased biosynthesis. Instead, the increase likely resulted from a continuous biosynthesis with a possibly reduced turnover and/or enhanced sequestration, suggesting a complex regulation of carotenoid accumulation during fruit storage. This study provides important information to our understanding of carotenogenesis and its regulation during postharvest storage of fruits.


Assuntos
Carotenoides/metabolismo , Cucurbita/metabolismo , Armazenamento de Alimentos , Plastídeos/metabolismo , Vias Biossintéticas/genética , Western Blotting , Cor , Cucurbita/genética , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Hidrólise , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Amido/metabolismo , Fatores de Tempo , Xantofilas/metabolismo , beta Caroteno/metabolismo
13.
Int J Biol Macromol ; 257(Pt 1): 128666, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38070805

RESUMO

Staphylococcus enterotoxin B (SEB) interacts with MHC-II molecules to overactivate immune cells and thereby to produce excessive pro-inflammatory cytokines. Disrupting the interactions between SEB and MHC-II helps eliminate the lethal threat posed by SEB. In this study, a de novo computational approach was used to design protein binders targeting SEB. The MHC-II binding domain of SEB was selected as the target, and the possible promising binding mode was broadly explored. The obtained original binder was folded into triple-helix bundles and contained 56 amino acids with molecular weight 5.9 kDa. The interface of SEB and the binder was highly hydrophobic. ProteinMPNN optimization further enlarged the hydrophobic region of the binder and improved the stability of the binder-SEB complex. In vitro study demonstrated that the optimized binder significantly inhibited the inflammatory response induced by SEB. Overall, our research demonstrated the applicability of this approach in de novo designing protein binders against SEB, and thereby providing potential therapeutics for SEB induced diseases.


Assuntos
Enterotoxinas , Antígenos de Histocompatibilidade Classe II , Enterotoxinas/química , Citocinas/metabolismo
14.
Int J Biol Macromol ; : 133834, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39002899

RESUMO

IL-2 regulates the immune response by interacting with different IL-2 receptor (IL-2R) subunits. High dose of IL-2 binds to IL-2Rßγc heterodimer, which induce various side effects while activating immune function. Disrupting IL-2 and IL-2R interactions can block IL-2 mediated immune response. Here, we used a computational approach to de novo design mini-binder proteins against IL-2R ß chain (IL-2Rß) to block IL-2 signaling. The hydrophobic region where IL-2 binds to IL-2Rß was selected and the promising binding mode was broadly explored. Three mini-binders with amino acid numbers ranging from 55 to 65 were obtained and binder 1 showed the best effects in inhibiting CTLL-2 cells proliferation and STAT5 phosphorylation. Molecular dynamics simulation showed that the binding of binder 1 to IL-2Rß was stable; the free energy of binder1/IL-2Rß complex was lower, indicating that the affinity of binder 1 to IL-2Rß was higher than that of IL-2. Free energy decomposition suggested that the ARG35 and ARG131 of IL-2Rß might be the key to improve the affinity of binder. Our efforts provided new insights in developing of IL-2R blocker, offering a potential strategy for ameliorating the side effects of IL-2 treatment.

15.
Int J Biol Macromol ; 259(Pt 2): 129208, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185298

RESUMO

The Staphylococcus aureus clumping factor A (ClfA) is a fibrinogen (Fg) binding protein that plays an important role in the clumping of S. aureus in blood plasma. The current anti-infective approaches targeting ClfA are mainly based on monoclonal antibodies but showed less impressive efficacy for clinical applications. Nanobodies offer advantages in enhanced tissue penetration and a propensity to bind small epitopes. However, there is no report on generating specific nanobodies for ClfA. Here, we constructed a synthetic nanobody library based on yeast surface display to isolate nanobodies against the Fg binding domain ClfA221-550. We firstly obtained a primary nanobody directed to ClfA221-550, and then employed error-prone mutagenesis to enhance its binding affinity. Finally, 18 variants were isolated with high affinities (EC50, 1.1 ± 0.1 nM to 4.8 ± 0.3 nM), in which CNb1 presented the highest inhibition efficiency in the adhesion of S. aureus to fibrinogen. Moreover, structural simulation analysis indicated that the epitope for CNb1 partially overlapped with the binding sites for fibrinogen, thus inhibiting ClfA binding to Fg. Overall, these results indicated that the specific nanobodies generated here could prevent the adhesion of S. aureus to fibrinogen, suggesting their potential capacities in the control of S. aureus infections.


Assuntos
Anticorpos de Domínio Único , Staphylococcus aureus , Staphylococcus aureus/metabolismo , Saccharomyces cerevisiae/metabolismo , Anticorpos de Domínio Único/metabolismo , Sítios de Ligação , Fibrinogênio/metabolismo
16.
World J Virol ; 13(2): 91286, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38984081

RESUMO

Severe acute respiratory syndrome coronavirus-2 is a highly contagious positive-sense, single-stranded RNA virus that has rapidly spread worldwide. As of December 17, 2023, 772838745 confirmed cases including 6988679 deaths have been reported globally. This virus primarily spreads through droplets, airborne transmission, and direct contact. Hospitals harbor a substantial number of confirmed coronavirus disease 2019 (COVID-19) patients and asymptomatic carriers, accompanied by high population density and a larger susceptible population. These factors serve as potential triggers for nosocomial infections, posing a threat during the COVID-19 pandemic. Nosocomial infections occur to varying degrees across different countries worldwide, emphasizing the urgent need for a practical approach to prevent and control the intra-hospital spread of COVID-19. This study primarily concentrated on a novel strategy combining preventive measures with treatment for combating COVID-19 nosocomial infections. It suggests preventive methods, such as vaccination, disinfection, and training of heathcare personnel to curb viral infections. Additionally, it explored therapeutic strategies targeting cellular inflammatory factors and certain new medications for COVID-19 patients. These methods hold promise in rapidly and effectively preventing and controlling nosocomial infections during the COVID-19 pandemic and provide a reliable reference for adopting preventive measures in the future pandemic.

17.
World J Virol ; 13(2): 90271, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38984085

RESUMO

Routine pediatric vaccination is one of the most effective public health inter-ventions for the control of a number of fatal diseases. However, during the coronavirus disease 2019 pandemic, routine pediatric vaccination rates were severely affected by disruptions of health services and vaccine confidence issues. Governments and the United Nations have taken measures to re-establish routine pediatric vaccination, while additional efforts are needed to catch up and develop plans to ensure routine vaccination services for the future pandemics.

18.
Artigo em Inglês | MEDLINE | ID: mdl-38952049

RESUMO

The E-proteinoid 3 receptor (PTGER3), a member of the prostaglandin E2 (PGE2) subtype receptor, belongs to the G-protein-coupled superfamily of receptors. Animal studies have demonstrated its involvement in salt sensitivity by regulating sodium reabsorption. This study aimed to investigate the association between genetic variants of PTGER3 and salt sensitivity, longitudinal blood pressure (BP) changes, and the incidence of hypertension in Chinese adults. A chronic salt intake intervention was conducted involving 514 adults from 124 families in the 2004 Baoji Salt-Sensitivity Study Cohort in northern China. These participants followed a 3-day regular baseline diet, followed by a 7-day low-salt diet (3.0 g/d) and a 7-day high-salt diet (18 g/d), and were subsequently followed for 14 years. The findings revealed a significant relationship between the single nucleotide polymorphism (SNP) rs17482751 of PTGER3 and diastolic blood pressure (DBP) response to high salt intervention. Additionally, SNPs rs11209733, rs3765894, and rs2268062 were significantly associated with longitudinal changes in systolic blood pressure (SBP), DBP, and mean arterial pressure (MAP) during the 14-year follow-up period. SNP rs6424414 was significantly associated with longitudinal changes in DBP over 14 years. Finally, SNP rs17482751 showed a significant correlation with the incidence of hypertension over 14 years. These results emphasize the significant role of PTGER3 gene polymorphism in salt sensitivity, longitudinal BP changes, and the development of hypertension in the Chinese population.

19.
Int J Mol Sci ; 14(7): 13346-59, 2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-23807498

RESUMO

Radish floral bud abortion (FBA) is an adverse biological phenomenon that occurs during reproduction. Although FBA is a frequent occurrence, its molecular mechanism remains unknown. A transcript-derived fragment (TDF72), which was obtained by cDNA amplified fragment length polymorphism (cDNA-AFLP), was up-regulated in the aborted buds and exhibited 89% sequence homology with the AtγVPE gene. In this study, TDF72 was used to clarify the role of VPE in FBA by isolation of the VPE gene RsVPE1 from radish flower buds. The full-length genomic DNA was 2346 bp including nine exons and eight introns. The full-length cDNA was 1825 bp, containing a complete open reading frame (ORF) of 1470 bp, which encoded a predicted protein containing 489 amino acid residues, with a calculated molecular mass of 53.735 kDa. Expression analysis demonstrated that RsVPE1 was expressed in all tested organs of radish at different levels. Highest expression was detected in aborted flower buds, suggesting that RsVPE1 has a role in FBA. In order to analyze the role of RsVPE1 in FBA, RsVPE1 was overexpressed in transgenic Arabidopsis thaliana plants. Aborted flower buds appeared in transgenic plants subjected to heat stress. In addition, RsVPE1 expression in the transgenic plants reached a maximum when subjected to heat stress for 24 h and increased by 2.1-fold to 2.8-fold in three homozygous transgenic lines. These results indicated that RsVPE1 led to FBA when its expression levels exceeded a particular threshold, and provided evidence for the involvement of RsVPE1 in promoting FBA under heat stress.


Assuntos
Cisteína Endopeptidases , Flores , Resposta ao Choque Térmico/fisiologia , Proteínas de Plantas , Raphanus , Arabidopsis/enzimologia , Arabidopsis/genética , Cisteína Endopeptidases/biossíntese , Cisteína Endopeptidases/genética , Flores/enzimologia , Flores/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Raphanus/enzimologia , Raphanus/genética
20.
Medicine (Baltimore) ; 102(16): e33527, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37083816

RESUMO

There are many factors that can cause portal hypertension and secondary symptoms such as ascites, splenomegaly, and variceal hemorrhage, can seriously affect patients' quality of life and even threaten their lives. In this paper, we summarize various causes of portal hypertension based on etiology and pathogenesis and give individualized treatment strategies in order to remind clinicians to pay attention to the identification of different causes and select corresponding treatment, so that patients are provided with the optimal treatment strategies and benefit from them.


Assuntos
Varizes Esofágicas e Gástricas , Hipertensão Portal , Humanos , Adulto , Varizes Esofágicas e Gástricas/terapia , Varizes Esofágicas e Gástricas/complicações , Qualidade de Vida , Hemorragia Gastrointestinal/terapia , Hemorragia Gastrointestinal/complicações , Hipertensão Portal/terapia , Hipertensão Portal/complicações , Ascite/terapia , Ascite/complicações , Cirrose Hepática/complicações
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