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1.
Artigo em Inglês | MEDLINE | ID: mdl-32054269

RESUMO

Flexible electronics have gained considerable research concern due to their wide prospect for health monitoring, soft robotics and artificial intelligence, wherein flexible pressure sensors are necessary components of wearable devices. It is well known that the synergistic functions and multiscale structures of hybrid materials exert tremendous effects on the performance of flexible devices. Herein, inspired by the unique structure of the faceplate of sunflowers, we construct a hierarchical structure by in-situ grown vertically aligned molybdenum disulfide (MoS2) nanosheets on carbonized silk fabric (MoS2/CSilk), which is applied as the sensing material in flexible pressure sensors. The MoS2/CSilk pressure sen-sor showed high sensitivity and good stability. We demonstrated its applications in monitoring subtle physiology sig-nals, such as pulse wave and voice vibrations. In addition, they were used as electrodes in lithium ion batteries. The MoS2/CSilk electrode delivered ultra-high first-cycle discharge and charge capacities of 2895 and 1594 mA h g-1. The MoS2/CSilk electrode exhibited a high capacity of 810 mA h g-1 with a CE approaching 100% even after 300 cycles, sug-gesting a good high-rate stability. The excellent overall performances are attributed to the unique structure the MoS2/CSilk and the synergistic effect of CSilk and MoS2. The concept and strategy of this work can be extended to the design and fabrication of other multifunctional devices.

2.
Sci Adv ; 5(11): eaax0649, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31723600

RESUMO

Wearable sweat analysis devices for monitoring of multiple health-related biomarkers with high sensitivity are highly desired for noninvasive and real-time monitoring of human health. Here, we report a flexible sweat analysis patch based on a silk fabric-derived carbon textile for simultaneous detection of six health-related biomarkers. The intrinsically N-doped graphitic structure and the hierarchical woven, porous structure provided the carbon textile good electrical conductivity, rich active sites, and good water wettability for efficient electron transmission and abundant access to reactants, enabling it to serve as an excellent working electrode in electrochemical sensors. On the basis of the above, we fabricated a multiplex sweat analysis patch that is capable of simultaneous detection of glucose, lactate, ascorbic acid, uric acid, Na+, and K+. The integration of selective detectors with signal collection and transmission components in this device has enabled us to realize real-time analysis of sweat.

3.
ACS Appl Mater Interfaces ; 11(22): 20272-20280, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31083901

RESUMO

With the blooming of wearable technology, developing active materials that can be printed on a large scale has been attracting great attention. Particularly, there are abundant genius structure designs in nature that are endowed with superior performance, inspiring the design of materials for high-performance wearables. Herein, we report the controllable preparation of bionic carbon nanosheets decorated with in situ formed nanoparticles (NP-CNS) through the pyrolysis of calcium gluconate (CG), which are further used for printing high-performance humidity/pressure/strain sensors. The transformation from CG to NP-CNS had been studied in detail. Interestingly, papillae-like CaO NPs are formed on the carbon nanosheets, endowing NP-CNS with good dispersion in inks and rapid response to external stimuli. Particularly, the printed humidity sensor possesses a fast response time (1.7 s) and a broad detection range (0-96% RH), increasing from the high hydroscopicity of the CaO NPs and the thus induced expansion of the NP-CNS. Besides, the strain sensor and pressure sensor also show high sensitivity and broad detection range, which is derived from the unique bionic structure of the NP-CNS. We further showed their excellent performance in monitoring of pulse wave, breath, and human motion, indicating the wide potential applications of the bionic NP-CNS in smart wearables.

4.
PLoS Biol ; 17(5): e3000277, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31107867

RESUMO

Chz1 is a specific chaperone for the histone variant H2A.Z in budding yeast. The ternary complex formed by Chz1 and H2A.Z-H2B dimer is the major in vivo substrate of Swi2/snif2-related 1 (SWR1), the ATP-dependent chromatin remodeling enzyme that deposits H2A.Z into chromatin. However, the structural basis for the binding preference of Chz1 for H2A.Z over H2A and the mechanism by which Chz1 modulates the histone replacement remain elusive. Here, we show that Chz1 utilizes 2 distinct structural domains to engage the H2A.Z-H2B dimer for optimal and specific recognition of H2A.Z. The middle region of Chz1 (Chz1-M) directly interacts with 2 highly conserved H2A.Z-specific residues (Gly98 and Ala57) and dictates a modest preference for H2A.Z-H2B. In addition, structural and biochemical analysis show that the C-terminal region of Chz1 (Chz1-C) harbors a conserved DEF/Y motif, which reflects the consecutive D/E residues followed by a single aromatic residue, to engage an arginine finger and a hydrophobic pocket in H2A.Z-H2B, enhancing the binding preference for H2A.Z-H2B. Furthermore, Chz1 facilitates SWR1-mediated H2A.Z deposition by alleviating inhibition caused by aggregation of excess free histones, providing insights into how Chz1 controls the bioavailability of H2A.Z to assist SWR1 in promoter-specific installation of a histone mark. Our study elucidates a novel H2A.Z-recognition mechanism and uncovers a molecular rationale for binding of free histone by specialized histone chaperones in vivo.


Assuntos
Chaperonas de Histonas/química , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Cromatina/metabolismo , Ligação Proteica , Multimerização Proteica
5.
Chemosphere ; 227: 109-116, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30986592

RESUMO

ZnO nanoparticles (NPs) are studied as a potential solution to alleviate Zn deficiency in human diet due to their special physicochemical properties. However, information for food quality and safety in NP-treated crops is limited. The effects of ZnO NPs and ZnSO4 on germination and growth of wheat (Triticum aestivum L.) were studied in germination and pot experiments. Zn content increased significantly, ZnO NPs were more effective than ZnSO4 at increasing grain Zn content, but less effective at increasing leaf Zn, and no ZnO NPs were detected in the wheat tissues by NP-treatments, indicated by XRD. Both ZnO NPs and ZnSO4 at moderate doses increased grain yield and biomass. Compared with control, the maximum grain yield and biomass of wheat treated with ZnO NPs and ZnSO4 were increased by 56%, 63% and 55%, 72%, respectively. ZnSO4 was more toxic than ZnO NPs at high doses as measured by the inhibitory effects in seed germination, root length, shoot length and dry biomass of seedlings. Structural damage in roots and variation in enzyme activities were greater with ZnSO4 than with ZnO NPs. ZnO NPs did not cause toxicity different from that of ZnSO4, which indicates that ZnO NPs used under the current experimental conditions did not cause Nano specific risks.


Assuntos
Nanopartículas Metálicas/análise , Triticum/crescimento & desenvolvimento , Sulfato de Zinco/metabolismo , Biofortificação , Biomassa , Grão Comestível/fisiologia , Germinação/fisiologia , Folhas de Planta/química , Raízes de Plantas/fisiologia , Plântula/efeitos dos fármacos , Zinco/análise , Óxido de Zinco/química
6.
J Pharm Biomed Anal ; 166: 379-386, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30711807

RESUMO

In this work, hypercrosslinked strong anion-exchange polymer resins (HXLPP-SAX) were synthesized and evaluated as solid-phase extraction (SPE) sorbents for extracting fluoroquinolones (FQs) in milk samples. These particles were prepared using a protocol that was facile and cost-effective by combining hypercrosslinking reactions and quaternisation reactions in one step. After the synthesis, the morphological properties and anion-exchange, adsorption, and selectivity performances of the HXLPP-SAX resins were characterized and evaluated. It was shown that the polymers were monodisperse microspheres, with the mean diameters of 2-4 µm, ion-exchange capacity (IEC) of 0.311 meq/g, and specific surface area more than 1000 m2/g. The resins applied as SPE sorbents possessed high selectivity in the extraction of amphoteric compounds (enoxacin and enrofloxacin as the representatives) followed by HPLC-UV analysis, as compared to commercially available strong anion-exchange sorbents (Oasis MAX). The SPE-HPLC-UV method was fully validated and exhibited good linearity (10-2000 ng/g, R2 ≥ 0.997), low limits of detection (2.8-5.1 ng/g), good recoveries (85.8%-117.9%, RSDs ≤ 7.1%) and precisions (intra-day RSDs ≤ 7.7% and inter-day RSDs ≤ 9.4%). Then the method was performed the selective enrichment of six FQs (enoxacin, norfloxacin, ciprofloxacin, lomefloxacin, enrofloxacin, and sparfloxacin) in milk samples. The present results demonstrated that the proposed resins exhibited a promising potential for the enrichment and determination of FQ residues in milk samples as well as in other samples with complex matrices.


Assuntos
Reagentes para Ligações Cruzadas/química , Fluoroquinolonas/análise , Resinas de Troca Iônica/química , Leite/química , Drogas Veterinárias/análise , Adsorção , Animais , Cromatografia Líquida de Alta Pressão , Resinas de Troca Iônica/síntese química , Limite de Detecção , Reprodutibilidade dos Testes , Extração em Fase Sólida , Espectrofotometria Ultravioleta
7.
Adv Mater ; 31(9): e1801072, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30300444

RESUMO

Flexible and wearable electronics are attracting wide attention due to their potential applications in wearable human health monitoring and care systems. Carbon materials have combined superiorities such as good electrical conductivity, intrinsic and structural flexibility, light weight, high chemical and thermal stability, ease of chemical functionalization, as well as potential mass production, enabling them to be promising candidate materials for flexible and wearable electronics. Consequently, great efforts are devoted to the controlled fabrication of carbon materials with rationally designed structures for applications in next-generation electronics. Herein, the latest advances in the rational design and controlled fabrication of carbon materials toward applications in flexible and wearable electronics are reviewed. Various carbon materials (carbon nanotubes, graphene, natural-biomaterial-derived carbon, etc.) with controlled micro/nanostructures and designed macroscopic morphologies for high-performance flexible electronics are introduced. The fabrication strategies, working mechanism, performance, and applications of carbon-based flexible devices are reviewed and discussed, including strain/pressure sensors, temperature/humidity sensors, electrochemical sensors, flexible conductive electrodes/wires, and flexible power devices. Furthermore, the integration of multiple devices toward multifunctional wearable systems is briefly reviewed. Finally, the existing challenges and future opportunities in this field are summarized.


Assuntos
Produtos Biológicos/química , Nanotubos de Carbono/química , Dispositivos Eletrônicos Vestíveis , Materiais Biocompatíveis/química , Técnicas Biossensoriais/métodos , Fontes de Energia Elétrica , Eletrodos , Eletrônica/métodos , Nanoestruturas/química
8.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 26(5): 1355-1359, 2018 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-30295250

RESUMO

OBJECTIVE: To study the soluble B7-H4 (sB7-H4) expression in serum and lymphoma tissues of patients with malignant lymphoma (ML) and its value for diagnosis and re-examination lymphoma. METHODS: The serum samples from 83 cases of ML were collected, among them 69 cases of newly diagnosed ML were enrolled in group A including 11 cases of Hodgkin's lymphoma (NHL group) and 58 cases of non-Hodgkin's lymphoma (NHL group), the serum samples from 14 cases of relapsed ML were enrolled in group B; at the same time the serum samples of 50 healthy persons conformed by physical examination were collected and enrolled in control group. The double antibody sandwich ELISA was used to detect the serum level of sB7-H4 in each group, and immunohistochemistry method was used to detect the expression of sB7-H4 in malignant lymphoma and reactive lymphoid hyperplasia tissues. RESULTS: The serum level of sB7-H4 in the group A was significantly increased in comparison with the group B and control group, and the level of group B was significantly higher than that in the control group (P<0.05); the serum level of sB7-H4 in the NHL group was significantly increased in comparison with HL group and control group, and the level of HL group was higher than that of control group (P<0.05). The expression of sB7-H4 in reactive lymphoid hyperplasia tissues was negative, but the positive expression rate in malignant lymphoma tissues was 47.50%, suggesting the positive rate of sB7-H4 in malignant lymphoma tissues was significantly higher than that of reactive lymphoid hyperplasia tissues (P<0.05). CONCLUSION: The high expression of sB7-H4 in serum and lymphoma tissues of patients with malignant lymphoma has a certain value for the diagnosis and re-examination of patients with malignant lymphoma.


Assuntos
Doença de Hodgkin , Linfoma não Hodgkin , Biomarcadores Tumorais , Ensaio de Imunoadsorção Enzimática , Humanos , Inibidor 1 da Ativação de Células T com Domínio V-Set
9.
Nano Lett ; 18(11): 7085-7091, 2018 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-30278140

RESUMO

Silk has outstanding mechanical properties and biocompatibility. It has been used to fabricate traditional textiles for thousands of years and can be produced in large scale. Silk materials are potentially attractive in modern textile electronics. However, silk is not electrically conductive, thus limiting its applications in electronics. Moreover, regenerated silk is generally rigid and brittle, which hinder post processing. Here we report the fabrication of conductive silk wire in which carbon nanotube (CNT) yarns are wrapped with fluffy and flexible silk nanofiber films. The silk nanofiber film was prepared by electrospinning and then wrapped around a rotating CNT yarn in situ. The obtained silk-sheathed CNT (CNT@Silk) wire has an insulating sheath, which protects the body against electrical shock. In addition, the fabricated wires exhibit a high electrical conductivity (3.1 × 104 S/m), good mechanical strength (16 cN/tex), excellent flexibility, and high durability. More importantly, the wires have an extremely low density (2.0-7.8 × 104 g/m3), which is 2 orders of magnitude lower than that of the traditional metal wire (for example, Cu). Moreover, the wires display a good resistance to humidity, and a simple post treatment can make the wires splash-resistant, thereby expanding its applications. On the basis of these features, we demonstrate the use of the lightweight CNT@Silk wires in smart clothes, including electrochromism and near-field communication.

10.
Neuron ; 99(3): 480-492.e5, 2018 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-30057206

RESUMO

The tip link, a filament formed by protocadherin 15 (PCDH15) and cadherin 23, conveys mechanical force from sound waves and head movement to open hair-cell mechanotransduction channels. Tip-link cadherins are thought to have acquired structural features critical for their role in mechanotransduction. Here, we biophysically and structurally characterize the unusual cis-homodimeric architecture of PCDH15. We show that PCDH15 molecules form double-helical assemblies through cis-dimerization interfaces in the extracellular cadherin EC2-EC3 domain region and in a unique membrane-proximal domain. Electron microscopy studies visualize the cis-dimeric PCDH15 assembly and reveal the PCDH15 extracellular domain as a parallel double helix with cis cross-bridges at the two locations we defined. The helical configuration suggests the potential for elasticity through helix winding and unwinding. Functional studies in hair cells show that mutations that perturb PCDH15 dimerization contacts affect mechanotransduction. Together, these data reveal the cis-dimeric architecture of PCDH15 and show that dimerization is critical for sensing mechanical stimuli.


Assuntos
Caderinas/química , Caderinas/fisiologia , Mecanotransdução Celular/fisiologia , Multimerização Proteica/fisiologia , Animais , Cristalização/métodos , Células HEK293 , Humanos , Camundongos , Camundongos Transgênicos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
11.
Vaccine ; 36(20): 2876-2885, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29599087

RESUMO

Respiratory syncytial virus (RSV) is the most common viral cause of bronchiolitis and pneumonia in children twelve months of age or younger and a significant cause of lower respiratory disease in older adults. As various clinical and preclinical candidates advance, cotton rats (Sigmodon hispidus) and non-human primates (NHP) continue to play a valuable role in RSV vaccine development, since both animals are semi-permissive to human RSV (HRSV). However, appropriate utilization of the models is critical to avoid mis-interpretation of the preclinical findings. Using a multimodality imaging approach; a fluorescence based optical imaging technique for the cotton rat and a nuclear medicine based positron emission tomography (PET) imaging technique for monkeys, we demonstrate that many common practices for intranasal immunization in both species result in inoculum delivery to the lower respiratory tract, which can result in poor translation of outcomes from the preclinical to the clinical setting. Using these technologies we define a method to limit the distribution of intranasally administered vaccines solely to the upper airway of each species, which includes volume restrictions in combination with injectable anesthesia. We show using our newly defined methods for strict intranasal immunization that these methods impact the immune responses and efficacy observed when compared to vaccination methods resulting in distribution to both the upper and lower respiratory tracts. These data emphasize the importance of well-characterized immunization methods in the preclinical assessment of intranasally delivered vaccine candidates.


Assuntos
Administração Intranasal , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Sigmodontinae , Animais , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Modelos Animais
12.
J Virol ; 91(19)2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28747497

RESUMO

Human respiratory syncytial virus (RSV) is the leading etiologic agent of lower respiratory tract infections in children, but no licensed vaccine exists. Previously, we developed two parainfluenza virus 5 (PIV5)-based RSV vaccine candidates that protect mice against RSV challenge. PIV5 was engineered to express either the RSV fusion protein (F) or the RSV major attachment glycoprotein (G) between the hemagglutinin-neuraminidase (HN) and RNA-dependent RNA polymerase (L) genes of the PIV5 genome [PIV5-RSV-F (HN-L) and PIV5-RSV-G (HN-L), respectively]. To investigate the stability of the vaccine candidates in vitro, they were passaged in Vero cells at high and low multiplicities of infection (MOIs) for 11 generations and the genome sequences, growth kinetics, and protein expression of the resulting viruses were compared with those of the parent viruses. Sporadic mutations were detected in the consensus sequences of the viruses after high-MOI passages, and mutation rates increased under low-MOI-passage conditions. None of the mutations abolished antigen expression. Increased numbers of mutations correlated with increased growth rates in vitro, indicating that the viruses evolved through the course of serial passages. We also examined the in vivo stability of the vaccine candidates after a single passage in African green monkeys. No mutations were detected in the consensus sequences of viruses collected from the bronchoalveolar lavage (BAL) fluid of the animals. In vivo, mutations in RSV G and PIV5 L were found in individual isolates of PIV5-RSV-G (HN-L), but plaque isolates of PIV5-RSV-F (HN-L) had no mutations. To improve upon the PIV5-RSV-F (HN-L) candidate, additional vaccine candidates were generated in which the gene for RSV F was inserted into earlier positions in the PIV5 genome. These insertions did not negatively impact the sequence stability of the vaccine candidates. The results suggest that the RSV F and G gene insertions are stable in the PIV5 genome. However, the function of the foreign gene insertion may need to be considered when designing PIV5-based vaccines.IMPORTANCE The genetic stability of live viral vaccines is important for safety and efficacy. PIV5 is a promising live viral vector and has been used to develop vaccines. In this work, we examined the genetic stability of a PIV5-based RSV vaccine in vitro and in vivo We found that insertions of foreign genes, such as the RSV F and G genes, were stably maintained in the PIV5 genome and there was no mutation that abolished the expression of RSV F or G. Interestingly, the function of the inserted gene may have an impact on PIV5 genome stability.


Assuntos
Glicoproteínas/genética , Proteína HN/genética , Vírus da Parainfluenza 5/genética , RNA Replicase/genética , Vírus Sincicial Respiratório Humano/genética , Proteínas Virais de Fusão/genética , Animais , Líquido da Lavagem Broncoalveolar/virologia , Linhagem Celular , Cricetinae , Instabilidade Genômica/genética , Glicoproteínas/imunologia , Vacinas contra Vírus Sincicial Respiratório/imunologia , Células Vero , Proteínas Virais de Fusão/imunologia
13.
J Virol ; 91(11)2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28298602

RESUMO

Human respiratory syncytial virus (RSV) is a common cause of severe respiratory disease among infants, immunocompromised individuals, and the elderly. No licensed vaccine is currently available. In this study, we evaluated two parainfluenza virus 5 (PIV5)-vectored vaccines expressing RSV F (PIV5/F) or G (PIV5/G) protein in the cotton rat and African green monkey models for their replication, immunogenicity, and efficacy of protection against RSV challenge. Following a single intranasal inoculation, both animal species shed the vaccine viruses for a limited time but without noticeable clinical symptoms. In cotton rats, the vaccines elicited RSV F- or G-specific serum antibodies and conferred complete lung protection against RSV challenge at doses as low as 103 PFU. Neither vaccine produced the enhanced lung pathology observed in animals immunized with formalin-inactivated RSV. In African green monkeys, vaccine-induced serum and mucosal antibody responses were readily detected, as well. PIV5/F provided nearly complete protection against RSV infection in the upper and lower respiratory tract at a dose of 106 PFU of vaccine. At the same dose levels, PIV5/G was less efficacious. Both PIV5/F and PIV5/G were also able to boost neutralization titers in RSV-preexposed African green monkeys. Overall, our data indicated that PIV5/F is a promising RSV vaccine candidate.IMPORTANCE A safe and efficacious respiratory syncytial virus (RSV) vaccine remains elusive. We tested the recombinant parainfluenza virus 5 (PIV5) vectors expressing RSV glycoproteins for their immunogenicity and protective efficacy in cotton rats and African green monkeys, which are among the best available animal models to study RSV infection. In both species, a single dose of intranasal immunization with PIV5-vectored vaccines was able to produce systemic and local immunity and to protect animals from RSV challenge. The vaccines could also boost RSV neutralization antibody titers in African green monkeys that had been infected previously. Our data suggest that PIV5-vectored vaccines could potentially protect both the pediatric and elderly populations and support continued development of the vector platform.


Assuntos
Vírus da Parainfluenza 5/genética , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Vetores Genéticos , Pulmão/virologia , Ratos , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/virologia , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vacinas contra Vírus Sincicial Respiratório/genética , Vírus Sincicial Respiratório Humano/genética , Sigmodontinae , Vacinação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Células Vero , Proteínas do Envelope Viral/genética , Proteínas Virais de Fusão/genética
14.
Mol Biosyst ; 12(7): 2257-64, 2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27156848

RESUMO

Hypoxia/re-oxygenation (H/R) injury is an important cause of heart failure and results in a critical metabolism dysfunction. In this paper, the cytoprotective effect of the nicotinamide adenine dinucleotide (NAD) precursor nicotinamide was evaluated using an in vitro model of cardiac H/R injury. Nicotinamide (0-20 mM) was applied to the myoblast cell line H9c2 which was subjected to hypoxia (12, 24, 36 h) followed by a re-oxygenation process (0, 4, 8, 12 h). Cell viability was measured, and mitochondrial metabolites were extracted and then measured by HPLC/MS/MS. The present study showed that nicotinamide could down-regulate the NADH/NAD ratio and then maintain the NAD-dependent metabolism processes. Furthermore, an aberrant decrease of fumarate levels and an increase of succinate levels were observed in the nicotinamide group, which was demonstrated to be caused by nicotinamide-induced succinate dehydrogenase (SDH) inhibition. These results suggest that nicotinamide exerts a protective effect on cardiomyoblasts against H/R-induced injury through both NADH/NAD regulation and reduction of reactive oxygen species generation via SDH inhibition.


Assuntos
Mioblastos Cardíacos/efeitos dos fármacos , Mioblastos Cardíacos/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Niacinamida/farmacologia , Substâncias Protetoras/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclo do Ácido Cítrico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Hipóxia , Metabolômica/métodos , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Modelos Biológicos , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Ratos , Espécies Reativas de Oxigênio
15.
Nat Struct Mol Biol ; 23(4): 317-23, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26974124

RESUMO

Histone variant H2A.Z, a universal mark of dynamic nucleosomes flanking gene promoters and enhancers, is incorporated into chromatin by SRCAP (SWR1), an ATP-dependent, multicomponent chromatin-remodeling complex. The YL1 (Swc2) subunit of SRCAP (SWR1) plays an essential role in H2A.Z recognition, but how it achieves this has been unclear. Here, we report the crystal structure of the H2A.Z-binding domain of Drosophila melanogaster YL1 (dYL1-Z) in complex with an H2A.Z-H2B dimer at 1.9-Å resolution. The dYL1-Z domain adopts a new whip-like structure that wraps over H2A.Z-H2B, and preferential recognition is largely conferred by three residues in loop 2, the hyperacidic patch and the extended αC helix of H2A.Z. Importantly, this domain is essential for deposition of budding yeast H2A.Z in vivo and SRCAP (SWR1)-catalyzed histone H2A.Z replacement in vitro. Our studies distinguish YL1-Z from known H2A.Z chaperones and suggest a hierarchical mechanism based on increasing binding affinity facilitating H2A.Z transfer from SRCAP (SWR1) to the nucleosome.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/química , Drosophila melanogaster/metabolismo , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Montagem e Desmontagem da Cromatina , Cristalografia por Raios X , Proteínas de Drosophila/química , Chaperonas de Histonas/química , Histonas/química , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Multimerização Proteica , Estrutura Terciária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Alinhamento de Sequência
16.
Front Immunol ; 6: 329, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26167164

RESUMO

Seasonal epidemics caused by influenza A (H1 and H3 subtypes) and B viruses are a major global health threat. The traditional, trivalent influenza vaccines have limited efficacy because of rapid antigenic evolution of the circulating viruses. This antigenic variability mediates viral escape from the host immune responses, necessitating annual vaccine updates. Influenza vaccines elicit a protective antibody response, primarily targeting the viral surface glycoprotein hemagglutinin (HA). However, the predominant humoral response is against the hypervariable head domain of HA, thereby restricting the breadth of protection. In contrast, the conserved, subdominant stem domain of HA is a potential "universal" vaccine candidate. We designed an HA stem-fragment immunogen from the 1968 pandemic H3N2 strain (A/Hong Kong/1/68) guided by a comprehensive H3 HA sequence conservation analysis. The biophysical properties of the designed immunogen were further improved by C-terminal fusion of a trimerization motif, "isoleucine-zipper", or "foldon". These immunogens elicited cross-reactive, antiviral antibodies and conferred partial protection against a lethal, homologous HK68 virus challenge in vivo. Furthermore, bacterial expression of these immunogens is economical and facilitates rapid scale-up.

17.
PLoS One ; 10(6): e0128068, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26030405

RESUMO

Valproate (VPA) has recently been shown to influence the behavioral effects of psycho-stimulants. Although glycogen synthase kinase 3ß (GSK3ß) signaling in the nucleus accumbens (NAc) plays a key role in mediating dopamine (DA)-dependent behaviors, there is less direct evidence that how VPA acts on the GSK3ß signaling in the functionally distinct sub-regions of the NAc, the NAc core (NAcC) and the NAc shell (NAcSh), during psycho-stimulant-induced hyperactivity. In the present study, we applied locomotion test after acute methamphetamine (MA) (2 mg/kg) injection to identify the locomotor activity of rats received repeated VPA (300 mg/kg) pretreatment. We next measured phosphor-GSK3ß at serine 9 and total GSK3ß levels in NAcC and NAcSh respectively to determine the relationship between the effect of VPA on MA-induced hyperlocomotor and changes in GSK3ß activity. We further investigated whether microinjection of VPA (300 µg/0.5 µl/side, once daily for 7 consecutive days) into NAcC or NAcSh could affect hyperactivity induced by MA. Our data indicated that repeated VPA treatment attenuated MA-induced hyperlocomotor, and the effect was associated with decreased levels of phosphorylated GSK3ß at Ser 9 in the NAcC. Moreover, repeated bilateral intra-NAcC, but not intra-NAcSh VPA treatment, significantly attenuated MA-induced hyperactivity. Our results suggested that GSK3ß activity in NAcC contributes to the inhibitory effects of VPA on MA-induced hyperactivity.


Assuntos
Quinase 3 da Glicogênio Sintase/metabolismo , Hipercinese/induzido quimicamente , Hipercinese/patologia , Metanfetamina/efeitos adversos , Núcleo Accumbens/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ácido Valproico/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/efeitos adversos , Estimulantes do Sistema Nervoso Central/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/química , Glicogênio Sintase Quinase 3 beta , Hipercinese/tratamento farmacológico , Hipercinese/fisiopatologia , Masculino , Metanfetamina/antagonistas & inibidores , Microinjeções , Atividade Motora/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Núcleo Accumbens/patologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Serina/metabolismo , Ácido Valproico/administração & dosagem , Ácido Valproico/uso terapêutico
18.
Proc Natl Acad Sci U S A ; 111(25): E2514-23, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24927560

RESUMO

Influenza hemagglutinin (HA) is the primary target of the humoral response during infection/vaccination. Current influenza vaccines typically fail to elicit/boost broadly neutralizing antibodies (bnAbs), thereby limiting their efficacy. Although several bnAbs bind to the conserved stem domain of HA, focusing the immune response to this conserved stem in the presence of the immunodominant, variable head domain of HA is challenging. We report the design of a thermotolerant, disulfide-free, and trimeric HA stem-fragment immunogen which mimics the native, prefusion conformation of HA and binds conformation specific bnAbs with high affinity. The immunogen elicited bnAbs that neutralized highly divergent group 1 (H1 and H5 subtypes) and 2 (H3 subtype) influenza virus strains in vitro. Stem immunogens designed from unmatched, highly drifted influenza strains conferred robust protection against a lethal heterologous A/Puerto Rico/8/34 virus challenge in vivo. Soluble, bacterial expression of such designed immunogens allows for rapid scale-up during pandemic outbreaks.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A Subtipo H1N1 , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Reações Cruzadas , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H1N1/química , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/imunologia , Estrutura Terciária de Proteína
19.
Cell Res ; 24(4): 389-99, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24613878

RESUMO

H2A.Z is a highly conserved histone variant in all species. The chromatin deposition of H2A.Z is specifically catalyzed by the yeast chromatin remodeling complex SWR1 and its mammalian counterpart SRCAP. However, the mechanism by which H2A.Z is preferentially recognized by non-histone proteins remains elusive. Here we identified Anp32e, a novel higher eukaryote-specific histone chaperone for H2A.Z. Anp32e preferentially associates with H2A.Z-H2B dimers rather than H2A-H2B dimers in vitro and in vivo and dissociates non-nucleosomal aggregates formed by DNA and H2A-H2B. We determined the crystal structure of the Anp32e chaperone domain (186-232) in complex with the H2A.Z-H2B dimer. In this structure, the region containing Anp32e residues 214-224, which is absent in other Anp32 family proteins, specifically interacts with the extended H2A.Z αC helix, which exhibits an unexpected conformational change. Genome-wide profiling of Anp32e revealed a remarkable co-occupancy between Anp32e and H2A.Z. Cells overexpressing Anp32e displayed a strong global H2A.Z loss at the +1 nucleosomes, whereas cells depleted of Anp32e displayed a moderate global H2A.Z increase at the +1 nucleosomes. This suggests that Anp32e may help to resolve the non-nucleosomal H2A.Z aggregates and also facilitate the removal of H2A.Z at the +1 nucleosomes, and the latter may help RNA polymerase II to pass the first nucleosomal barrier.


Assuntos
Células Eucarióticas/metabolismo , Histonas/metabolismo , Chaperonas Moleculares/fisiologia , Proteínas Nucleares/fisiologia , Fosfoproteínas/fisiologia , Sequência de Aminoácidos , Células HeLa , Histonas/química , Histonas/genética , Humanos , Modelos Moleculares , Chaperonas Moleculares/química , Simulação de Acoplamento Molecular , Proteínas Nucleares/química , Nucleossomos/metabolismo , Fosfoproteínas/química , Ligação Proteica , Estrutura Quaternária de Proteína , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
20.
Proteins ; 81(10): 1759-75, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23625724

RESUMO

The conserved "stem" domain of influenza virus hemagglutinin (HA) is a target for broadly neutralizing antibodies and a potential vaccine antigen for induction of hetero-subtypic protection. The epitope of 12D1, a previously reported bnAb neutralizing several H3 subtype influenza strains, was putatively mapped to residues 76-106 of the CD-helix, also referred to as long alpha helix (LAH) of the HA stem. A peptide derivative consisting of wt-LAH residues 76-130 conjugated to keyhole limpet hemocyanin was previously shown to confer robust protection in mice against challenge with influenza strains of subtypes H3, H1, and H5 which motivated the present study. We report the design of multiple peptide derivatives of LAH with or without heterologous trimerization sequences and show that several of these are better folded than wt-LAH. However, in contrast to the previous study immunization of mice with wt-LAH resulted in negligible protection against a lethal homologous virus challenge, while some of the newly designed immunogens could confer weak protection. Combined with structural analysis of HA, our data suggest that in addition to LAH, other regions of HA are likely to significantly contribute to the epitope for 12D1 and will be required to elicit robust protection. In addition, a dynamic, flexible conformation of isolated LAH peptide may be required for eliciting a functional anti-viral response.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H3N2 , Sequência de Aminoácidos , Animais , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vacinas contra Influenza/química , Vacinas contra Influenza/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Dados de Sequência Molecular , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Estrutura Secundária de Proteína , Subunidades Proteicas , Análise de Sobrevida
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