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1.
Biochem Biophys Res Commun ; 525(4): 823-829, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32164940

RESUMO

Barnacles are notorious marine fouling organisms. Their successful attachment to a substrate requires that they search for an appropriate habitat during their cyprid stage. A chemical cue called SIPC (Settlement-Inducing Protein Complex) has been shown to play a key role in the induction of cyprid gregarious settlement; however, the underlying biochemical mechanism remains unclear. Here, RNA-seq was used to examine the gene expression profiles of Amphibalanus amphitrite cyprids in response to SIPC and to identify SIPC-activated intracellular signaling pathways. A total of 389 unigenes were differentially expressed in response to SIPC, and cement protein genes were not among them. KEGG enrichment analysis suggested that SNARE interactions in the vesicular transport pathway were significantly influenced by SIPC treatment, indicating a possible role for SIPC in triggering protein transportation and secretion. Several genes with specific functions in metamorphosis were found among the differentially expressed genes (DEGs). GO (Gene Ontology) enrichment analysis revealed that the DEGs were significantly enriched in enamel mineralization pathways, suggesting that SIPC may also be involved in the activation of mineralization.

2.
Theranostics ; 10(4): 1514-1530, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32042319

RESUMO

Intrinsic cardiogenic factor expression, a proxy for cardiomyogenic lineage commitment, may be an important determinant of donor cell cardiac reparative capacity in cell therapy applications; however, whether and how this contributes to their salutary effects remain largely ambiguous. Methods: The current study examined the consequences of enhanced cardiogenic factor expression, via lentiviral delivery of GMT (GATA4, MEF2C, and TBX5), on cardiac mesenchymal cell (CMC) anti-fibrogenic paracrine signaling dynamics, in vitro, and cardiac reparative capacity, in vivo. Proteome cytokine array analyses and in vitro cardiac fibroblast activation assays were performed using conditioned medium derived from either GMT- or GFP control-transduced CMCs, to respectively assess cardiotrophic factor secretion and anti-fibrogenic paracrine signaling aptitude. Results: Relative to GFP controls, GMT CMCs exhibited enhanced secretion of cytokines implicated to function in pathways associated with matrix remodeling and collagen catabolism, and more ably impeded activated cardiac fibroblast Col1A1 synthesis in vitro. Following their delivery in a rat model of chronic ischemic cardiomyopathy, conventional echocardiography was unable to detect a therapeutic advantage with either CMC population; however, hemodynamic analyses identified a modest, yet calculable supplemental benefit in surrogate measures of global left ventricular contractility with GMT CMCs relative to GFP controls. This phenomenon was neither associated with a decrease in infarct size nor an increase in viable myocardium, but with only a marginal decrease in regional myocardial collagen deposition. Conclusion: Overall, these results suggest that CMC cardiomyogenic lineage commitment biases cardiac repair and, further, that enhanced anti-fibrogenic paracrine signaling potency may underlie, in part, their improved therapeutic utility.

3.
Langmuir ; 36(10): 2673-2682, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32097553

RESUMO

The reflectin proteins have been extensively studied for their role in reflectance in cephalopods. In the recently evolved Loliginid squids, these proteins and the structural color they regulate are dynamically tunable, enhancing their effectiveness for camouflage and communication. In these species, the reflectins are found in highest concentrations within the structurally tunable, membrane enclosed, periodically stacked lamellae of subcellular Bragg reflectors and in the intracellular vesicles of specialized skin cells known as iridocytes and leuocophores, respectively. To better understand the interactions between the reflectins and the membrane structures that encompass them, we analyzed the interactions of two purified reflectins with synthetic phospholipid membrane vesicles similar in composition to cellular membranes, using confocal fluorescence microscopy and dynamic light scattering. The purified recombinant reflectins were found to drive multivalent vesicle agglomeration in a ratio-dependent and saturable manner. Extensive proteolytic digestion terminated with PMSF of the reflectin A1-vesicle complexes triggered energetic membrane rearrangement, resulting in vesicle fusion, fission, and tubulation. This behavior contrasted markedly with that of vesicles complexed with reflectin C, from which PMSF-terminated proteolysis only released the original size vesicles. Clues to the basis for this difference, residing in significant differences between the structures of the two reflectins, led to the suggestion that specific reflectin-membrane interactions may play a role in the ontogenetic formation, long-term maintenance, and/or dynamic behavior of their biophotonically active host membrane nanostructures. Similar energetic remodeling has been associated with osmotic stress in other membrane systems, suggesting a path to reconstitution of the biophotonic system in vitro.

4.
Sci Total Environ ; 698: 134315, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31783453

RESUMO

Bioaerosol in the atmosphere plays a very important role in environment and public health. To forecast the bioaerosol concentration, the correlation between bioaerosol concentration and meteorological factors was discussed, and a Back Propagation (BP) neural network with Principal Component Analysis (PCA) method was utilized in this study. The proposed method works in three steps. The first step is to compute the correlation between bioaerosol concentration and meteorological factors, which consists of analyzing correlation and selecting meteorological factors applied to the study of forecast model. The second step is to use PCA analysis to reduce the dimensions of meteorological dataset. The third step is to use BP neural network, setting up, training BP neural network and proving the feasibility of forecast model included. The results of our model in forecasting bioaerosol concentration show 10.55% of average relative error, 2.80 pieces/L (pcs/L) of average absolute error, and 84.01 grade of forecast accuracy, providing a promising model for the forecasting of bioaerosol concentration.


Assuntos
Aerossóis/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Redes Neurais de Computação , Atmosfera , Conceitos Meteorológicos
5.
Small ; : e1902085, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31290615

RESUMO

2D MXene-based nanomaterials have attracted tremendous attention because of their unique physical/chemical properties and wide range of applications in energy storage, catalysis, electronics, optoelectronics, and photonics. However, MXenes and their derivatives have many inherent limitations in terms of energy storage applications. In order to further improve their performance for practical application, the nanoengineering of these 2D materials is extensively investigated. In this Review, the latest research and progress on 2D MXene-based nanostructures is introduced and discussed, focusing on their preparation methods, properties, and applications for energy storage such as lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, and supercapacitors. Finally, the critical challenges and perspectives required to be addressed for the future development of these 2D MXene-based materials for energy storage applications are presented.

6.
J Colloid Interface Sci ; 547: 291-298, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30959262

RESUMO

Two-dimensional (2D) molybdenum sulfide (MoS2) is considered as a promising catalyst for hydrogen evolution reaction (HER), originated from its abundant hydrogen evolution active sites. However, the HER performance of MoS2 is currently hindered by the limited exposed density of the active sites and low conductivity. Herein, we report a facile and scalable electrospinning technique to fabricate 2D MoS2 nanoplates doped with phosphorus within one-dimensional nitrogen doped-carbon nanofibers (NCNFs-MoS2|P) as a highly efficient HER catalyst. The space-confined growth with the presence of NCNFs avoided the stacking and aggregation of the MoS2 nanoplates, resulting in more exposed edge sites. The introduction of phosphorus atoms further activated the surface of MoS2 and enhanced the electron transfer. The overpotential of NCNFs-MoS2|P reached 98 mV at 10 mA cm-2, exhibiting excellent HER catalytic activity. Besides, almost no decay was observed after the stability test (5000 cycles or 20 h). The density functional calculations (DFT) elucidated that the incorporation of phosphorus atoms significantly improved the electrical conductivity and decreased the H adsorption energy barrier on MoS2, leading to a high catalytic performance of NCNFs-MoS2|P.

7.
Protein Expr Purif ; 159: 27-33, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30872132

RESUMO

Olfactory receptors (OR), a group of classic membrane proteins, plays a vital role in insect reproduction and acclimatization. Deciphering the molecular mechanism of insect olfaction could enhance pest control and environmental protection. Studies on ORs have faced a major bottleneck due to the notoriously strong hydrophobicity of ORs, which results in difficult expression in heterologous cell systems. Here, we demonstrated that insect ORs could be functionally produced using the E. coli cell-free protein synthesis system (CFPS), in which the highest yield of total ORs is 350 µg per 1 ml reaction. We tested the effects of detergent types and concentrations on soluble expression of ORs. The ORs showed a classic α-helical infrared spectrum. Quartz crystal microbalance (QCM) was used to demonstrate that ORs fold correctly and respond to their ligands. This is the first report that insect OR42a could be functionally produced in vitro. This approach may facilitate the development of biomimetic olfactory biosensors and may also be utilized for drug positioning and development, environmental protection and agriculture.

8.
Biochem Genet ; 57(4): 571-582, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30737589

RESUMO

Mosquitoes transmit many harmful diseases that seriously threaten public health. The mosquito's olfactory system is of great significance for host selection. Inotropic receptors (IRs) and olfactory receptors (ORs) have been demonstrated to be capable of odorant molecular recognition. Analyzing the molecular principles of mosquito olfaction facilitates the development of prevention and therapy techniques. Advances in the understanding of IRs have been seriously inadequate compared to those of ORs. Here, we provide evidence that 35 Anopheles sinensis IR (AsIR) genes are expressed, 7 of which are in the antennae and 2 have expression levels that are upregulated with a blood meal. A homologous analysis of the sequences showed that AsIRs are a subfamily of ionotropic glutamate receptors (iGLURs). This is the first that time IRs have been identified in Anopheles sinensis in vitro. The ultrastructure of the antennae supports the theory that diverse sensilla are distributed in the antennae. The results here may facilitate the revelation of the regulation mechanism in AsIRs, which could mitigate the transmission of diseases by mosquitoes.


Assuntos
Anopheles/genética , Anopheles/metabolismo , Antenas de Artrópodes/metabolismo , Proteínas de Insetos/genética , Receptores Ionotrópicos de Glutamato/genética , Sequência de Aminoácidos , Animais , Anopheles/ultraestrutura , Antenas de Artrópodes/ultraestrutura , Feminino , Regulação da Expressão Gênica , Genes de Insetos , Proteínas de Insetos/metabolismo , Microscopia Eletrônica de Varredura , Filogenia , Receptores Ionotrópicos de Glutamato/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Olfato/genética
9.
J Mol Med (Berl) ; 97(1): 25-35, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30397790

RESUMO

Latent infection of Propionibacterium acnes was considered as a new pathogeny for low back pain (LBP); however, there is no credible animal evidence or mechanism hypothesis. This study proved that P. acnes is a causative pathogen of bacteria-induced LBP and investigated its underlying mechanism. For this, P. acnes was firstly identified in patients' degenerated intervertebral disc (IVDs) samples. The results of patients' Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Japanese Orthopaedic Association (JOA), and Oswestry Disability Index (ODI) scores indicated that P. acnes-positive patients showed more severe LBP and physical disability. Then, a P. acnes-inoculated lumbar IVDs model was established in rats. The results of paw/foot withdrawal threshold and qRT-PCR indicated that P. acnes-inoculated rats had obvious LBP in behavioral evaluation and over-expression of substance P (SP) and calcitonin gene-related peptide (CGRP) in IVDs. Subsequently, enzyme-linked immunosorbent assay (ELISA) results demonstrated that increased expression of IL-8 or CINC-1 (the homolog of IL-8 in rats) in the P. acnes-positive IVDs of human and rats. The CINC-1 injected animal model proved that the cytokines were able to induce LBP. Finally, the co-culture experiments showed that nucleus pulposus cells (NPCs) were able to respond to P. acnes and secreted IL-8/CINC-1 via TLR-2/NF-κB p65 pathway. In conclusion, P. acnes had strong association with LBP by stimulating NPCs to secrete pro-algesic factor of IL-8/CINC-1 via TLR2/NF-κBp65 pathway. The finding may provide a promising alternative therapy strategy for LBP in clinical. KEY MESSAGES: Patients with P. acnes-positive IVDs tended to have more severe LBP, physical disability, and increased IL-8 expressions. P. acnes can induce LBP via IL-8/CINC-1 in IVDs. P. acnes stimulate the NPCs to secrete pro-algesic factor of IL-8/CINC-1 via TLR2/NF-κBp65 pathway.

10.
BMC Bioinformatics ; 19(Suppl 20): 503, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30577759

RESUMO

BACKGROUND: Bacterial small non-coding RNAs (sRNAs) have emerged as important elements in diverse physiological processes, including growth, development, cell proliferation, differentiation, metabolic reactions and carbon metabolism, and attract great attention. Accurate prediction of sRNAs is important and challenging, and helps to explore functions and mechanism of sRNAs. RESULTS: In this paper, we utilize a variety of sRNA sequence-derived features to develop ensemble learning methods for the sRNA prediction. First, we compile a balanced dataset and four imbalanced datasets. Then, we investigate various sRNA sequence-derived features, such as spectrum profile, mismatch profile, reverse compliment k-mer and pseudo nucleotide composition. Finally, we consider two ensemble learning strategies to integrate all features for building ensemble learning models for the sRNA prediction. One is the weighted average ensemble method (WAEM), which uses the linear weighted sum of outputs from the individual feature-based predictors to predict sRNAs. The other is the neural network ensemble method (NNEM), which trains a deep neural network by combining diverse features. In the computational experiments, we evaluate our methods on these five datasets by using 5-fold cross validation. WAEM and NNEM can produce better results than existing state-of-the-art sRNA prediction methods. CONCLUSIONS: WAEM and NNEM have great potential for the sRNA prediction, and are helpful for understanding the biological mechanism of bacteria.


Assuntos
Algoritmos , Bactérias/genética , Biologia Computacional/métodos , RNA Bacteriano/genética , RNA não Traduzido/genética , Área Sob a Curva , Sequência de Bases , Benchmarking , Bases de Dados de Ácidos Nucleicos
11.
PLoS Comput Biol ; 14(12): e1006616, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30533006

RESUMO

LncRNA-protein interactions play important roles in post-transcriptional gene regulation, poly-adenylation, splicing and translation. Identification of lncRNA-protein interactions helps to understand lncRNA-related activities. Existing computational methods utilize multiple lncRNA features or multiple protein features to predict lncRNA-protein interactions, but features are not available for all lncRNAs or proteins; most of existing methods are not capable of predicting interacting proteins (or lncRNAs) for new lncRNAs (or proteins), which don't have known interactions. In this paper, we propose the sequence-based feature projection ensemble learning method, "SFPEL-LPI", to predict lncRNA-protein interactions. First, SFPEL-LPI extracts lncRNA sequence-based features and protein sequence-based features. Second, SFPEL-LPI calculates multiple lncRNA-lncRNA similarities and protein-protein similarities by using lncRNA sequences, protein sequences and known lncRNA-protein interactions. Then, SFPEL-LPI combines multiple similarities and multiple features with a feature projection ensemble learning frame. In computational experiments, SFPEL-LPI accurately predicts lncRNA-protein associations and outperforms other state-of-the-art methods. More importantly, SFPEL-LPI can be applied to new lncRNAs (or proteins). The case studies demonstrate that our method can find out novel lncRNA-protein interactions, which are confirmed by literature. Finally, we construct a user-friendly web server, available at http://www.bioinfotech.cn/SFPEL-LPI/.


Assuntos
Aprendizado de Máquina , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Algoritmos , Sequência de Aminoácidos , Sequência de Bases , Biologia Computacional , Bases de Dados de Ácidos Nucleicos , Bases de Dados de Proteínas , Humanos , Ligação Proteica/genética , Processamento Pós-Transcricional do RNA , RNA Longo não Codificante/química , Proteínas de Ligação a RNA/química
12.
Basic Res Cardiol ; 114(1): 3, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30446837

RESUMO

Preclinical investigations support the concept that donor cells more oriented towards a cardiovascular phenotype favor repair. In light of this philosophy, we previously identified HDAC1 as a mediator of cardiac mesenchymal cell (CMC) cardiomyogenic lineage commitment and paracrine signaling potency in vitro-suggesting HDAC1 as a potential therapeutically exploitable target to enhance CMC cardiac reparative capacity. In the current study, we examined the effects of pharmacologic HDAC1 inhibition, using the benzamide class 1 isoform-selective HDAC inhibitor entinostat (MS-275), on CMC cardiomyogenic lineage commitment and CMC-mediated myocardial repair in vivo. Human CMCs pre-treated with entinostat or DMSO diluent control were delivered intramyocardially in an athymic nude rat model of chronic ischemic cardiomyopathy 30 days after a reperfused myocardial infarction. Indices of cardiac function were assessed by echocardiography and left ventricular (LV) Millar conductance catheterization 35 days after treatment. Compared with naïve CMCs, entinostat-treated CMCs exhibited heightened capacity for myocyte-like differentiation in vitro and superior ability to attenuate LV remodeling and systolic dysfunction in vivo. The improvement in CMC therapeutic efficacy observed with entinostat pre-treatment was not associated with enhanced donor cell engraftment, cardiomyogenesis, or vasculogenesis, but instead with more efficient inhibition of myocardial fibrosis and greater increase in myocyte size. These results suggest that HDAC inhibition enhances the reparative capacity of CMCs, likely via a paracrine mechanism that improves ventricular compliance and contraction and augments myocyte growth and function.


Assuntos
Histona Desacetilase 1/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/patologia , Animais , Benzamidas/farmacologia , Fibrose , Xenoenxertos , Humanos , Células-Tronco Mesenquimais/metabolismo , Piridinas/farmacologia , Ratos , Ratos Nus , Recuperação de Função Fisiológica
13.
Appl Opt ; 57(33): 9798-9802, 2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30462013

RESUMO

In this paper, we report on the intracavity frequency doubling of the Pr:YLF laser with a LiB3O5 (LBO) crystal, which was pumped by a combined 1.4 W blue laser diode at 444 nm and 1.5 W blue laser diode at 469 nm. By optimizing the design of the resonator, using a 5-mm-long LBO crystal, the maximum output power of 5 mW at 302 nm was achieved with respect to the total pump power.

14.
Protein Pept Lett ; 25(11): 986-995, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30289060

RESUMO

BACKGROUND: Cryptochrome is a flavin-binding blue-light photoreceptor that functions in growth and development in plants, the circadian clock in animals and navigation in birds. However, a lack of purified cryptochrome has hindered studies of the structure and function of this protein. In this study, we obtained a substantial amount of the Columbia livia Cryptochrome1 (ClCry1) protein by using a prokaryotic expression system. In addition, we performed comprehensive experiments to assess the influence of several factors on the purification and yield of ClCry1, such as the inducer that was used, temperature, duration of expression and type of growth medium. These assays clearly indicated that such factors influenced the purification and yield of ClCry1. Moreover, Flavin Adenine Dinucleotide (FAD) was added during expression and purification of ClCry1, which resulted in production of large amounts of ClCry1 protein with the FAD cofactor from the Escherichia coli (E. coli) heterologous expression system. We believe that this study provides a novel avenue to acquire large amounts of ClCry1 that contains FAD and lays the foundation for studies of the geomagnetic navigation mechanism of Aves. OBJECTIVE: In this article, our motivation is to sufficiently acquire functional ClCry1 protein. METHOD: In this article, we performed series of experiments to optimize the yields of ClCry1 protein expression by conducting with expression-vectors, variable inducers, temperatures, medias and durations of induction, which also identified the most appropriate conditions for obtaining functional ClCry1. Moreover, we identified a solution for the FAD abscission of ClCry1 by adding additional FAD into the dialysis buffer during the purification. RESULTS: Following our performed series of experiments, we assessed several crucial parameters, such as inducer, temperature, duration of induction, culture medium and recombinant expression vector. The highest yields of ClCry1 were observed with 0.01 mM IPTG and expressing for 8 h with pET21a-ClCry1 as recombinant expression vectors. CONCLUSION: We demonstrated the feasibility of heterologous expression of ClCry1 in E. coli. In addition, we identified a solution for the low yield and FAD abscission of ClCry1 by conducting several experiments with variable inducers, temperatures, medias and durations of induction, which also identified the most appropriate conditions for obtaining functional ClCry1. Moreover, the typical yield was approximately 6 mg of ClCry1 from 2-liter culture, and 50% of the final protein contained the FAD cofactor. These results strongly suggest that our expression strategy is useful.


Assuntos
Columbidae/genética , Criptocromos/genética , Criptocromos/isolamento & purificação , Escherichia coli/genética , Animais , Expressão Gênica , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação
15.
Cell Mol Life Sci ; 75(24): 4629-4641, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30264181

RESUMO

Two types of vertebrate cryptochromes (Crys) are currently recognized. Type 2 Crys function in the molecular circadian clock as light-independent transcriptional repressors. Type 4 Crys are a newly discovered group with unknown function, although they are flavoproteins, and therefore, may function as photoreceptors. It has been postulated that Crys function in light-dependent magnetoreception, which is thought to contribute towards homing and migratory behaviors. Here we have cloned and annotated the full-length pigeon ClCry1, ClCry2, and ClCry4 genes, and characterized the full-length proteins and several site-directed mutants to investigate the roles of these proteins. ClCry1 and ClCry2 are phylogenetically grouped as Type 2 Crys and thus are expected to be core components of the pigeon circadian clock. Interestingly, we find that ClCry4 is properly annotated as a Type 4 Cry. It appears that many birds possess a Type 4 Cry which, as in pigeon, is misannotated. Like the Type 2 Crys, ClCry4 is widespread in pigeon tissues. However, unlike the Type 2 Crys, ClCry4 is cytosolic, and purified ClCry4 possesses FAD cofactor, which confers characteristic UV-Vis spectra as well as two photochemical activities. We find that ClCry4 undergoes light-dependent conformational change, which is a property of insect Type 1 Crys involved in the insect-specific pathway of photoentrainment of the biological clock. ClCry4 can also be photochemically reduced by a mechanism common to all FAD-containing Cry family members, and this mechanism is postulated to be influenced by the geomagnetic field. Thus pigeon Crys control circadian behavior and may also have photosensory function.


Assuntos
Proteínas Aviárias/genética , Columbidae/genética , Criptocromos/genética , Animais , Proteínas Aviárias/análise , Proteínas Aviárias/metabolismo , Ritmo Circadiano , Clonagem Molecular , Columbidae/fisiologia , Criptocromos/análise , Criptocromos/metabolismo , Transporte de Elétrons , Flavina-Adenina Dinucleotídeo/metabolismo , Expressão Gênica , Luz , Oxirredução , Filogenia , Conformação Proteica
16.
ACS Appl Mater Interfaces ; 10(30): 25017-25025, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29990429

RESUMO

Developing adhesives that can function underwater remains a major challenge for bioengineering, yet many marine creatures, exemplified as mussels and barnacles, have evolved their unique proteinaceous adhesives for strong wet adhesion. The mechanisms underlying the strong adhesion of these natural adhesive proteins provide rich information for biomimetic efforts. Here, combining atomic force microscopy (AFM) imaging and force spectroscopy, we examine the effects of pH on the self-assembly and adhesive properties of cp19k, a key barnacle underwater adhesive protein. For the first time, we confirm that the bacterial recombinant Balanus albicostatus cp19k (rBalcp19k), which contains no 3,4-dihydroxyphenylalanine (DOPA) or any other amino acids with post-translational modifications, can self-assemble into aggregated nanofibers at acidic pHs. Under moderately acidic conditions, the adhesion strength of unassembled monomeric rBalcp19k on mica is only slightly lower than that of a commercially available mussel adhesive protein mixture, yet the adhesion ability of rBalcp19k monomers decreases significantly at increased pH. In contrast, upon preassembly at acidic and low-salinity conditions, rBalcp19k nanofibers keep stable in basic and high-salinity seawater and display much stronger adhesion and thus show resistance to its adverse impacts. Besides, we find that the adhesion ability of Balcp19k is not impaired when it is combined with an N-terminal Thioredoxin (Trx) tag, yet whether the self-assembly property will be disrupted is not determined. Collectively, the self-assembly-enhanced adhesion presents a previously unexplored mechanism for the strong wet adhesion of barnacle cement proteins and may lead to the design of barnacle-inspired adhesive materials.


Assuntos
Nanofibras , Adesivos , Animais , Microscopia de Força Atômica , Thoracica
17.
BMC Bioinformatics ; 19(1): 233, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29914348

RESUMO

BACKGROUND: Drug-disease associations provide important information for the drug discovery. Wet experiments that identify drug-disease associations are time-consuming and expensive. However, many drug-disease associations are still unobserved or unknown. The development of computational methods for predicting unobserved drug-disease associations is an important and urgent task. RESULTS: In this paper, we proposed a similarity constrained matrix factorization method for the drug-disease association prediction (SCMFDD), which makes use of known drug-disease associations, drug features and disease semantic information. SCMFDD projects the drug-disease association relationship into two low-rank spaces, which uncover latent features for drugs and diseases, and then introduces drug feature-based similarities and disease semantic similarity as constraints for drugs and diseases in low-rank spaces. Different from the classic matrix factorization technique, SCMFDD takes the biological context of the problem into account. In computational experiments, the proposed method can produce high-accuracy performances on benchmark datasets, and outperform existing state-of-the-art prediction methods when evaluated by five-fold cross validation and independent testing. CONCLUSION: We developed a user-friendly web server by using known associations collected from the CTD database, available at http://www.bioinfotech.cn/SCMFDD/ . The case studies show that the server can find out novel associations, which are not included in the CTD database.


Assuntos
Biologia Computacional/métodos , Doença , Descoberta de Drogas , Modelos Teóricos , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Projetos de Pesquisa , Humanos
18.
J Am Heart Assoc ; 7(4)2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29440036

RESUMO

BACKGROUND: We have recently found that 3 repeated doses (12×106 each) of c-kitPOS cardiac progenitor cells (CPCs) were markedly more effective than a single dose of 12×106 cells in alleviating postinfarction left ventricular dysfunction and remodeling. However, since the single-dose group received only one third of the total number of CPCs given to the multiple-dose group, it is unknown whether the superior therapeutic efficacy was caused by repeated treatments per se or by administration of a higher total number of CPCs. This issue has major clinical implications because multiple cell injections in patients pose significant challenges, which would be obviated by using 1 large injection. Accordingly, we determined whether the beneficial effects of 3 repeated CPC doses can be recapitulated by 1 large dose containing the same total number of cells. METHODS AND RESULTS: Rats with a 30-day-old myocardial infarction received 3 echo-guided intraventricular infusions, 35 days apart, of vehicle-vehicle-vehicle, 36×106 CPCs-vehicle-vehicle, or 3 equal doses of 12×106 CPCs. Infusion of a single, large dose of CPCs (36×106 cells) produced an initial improvement in left ventricular function, but no further improvement was observed after the second and third infusions (both vehicle). In contrast, each of the 3 doses of CPCs (12×106) caused a progressive improvement in left ventricular function, the cumulative magnitude of which was greater than with a single dose. Unlike the single dose, repeated doses reduced collagen content and immune cell infiltration. CONCLUSIONS: Three repeated doses of CPCs are superior to 1 dose even though the total number of cells infused is the same, possibly because of greater antifibrotic and anti-inflammatory actions.


Assuntos
Infarto do Miocárdio/cirurgia , Miocárdio/patologia , Miócitos Cardíacos/transplante , Transplante de Células-Tronco/métodos , Função Ventricular Esquerda , Remodelação Ventricular , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Modelos Animais de Doenças , Feminino , Fibrose , Hemodinâmica , Masculino , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Fenótipo , Ratos Endogâmicos F344 , Recuperação de Função Fisiológica , Fatores de Tempo
19.
Biochem Biophys Res Commun ; 493(1): 654-659, 2017 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-28865959

RESUMO

Barnacles robustly adhere themselves to diverse submarine substrates through a proteinaceous complex termed the "barnacle cement". Previous studies have indicated that certain peptides derived from some barnacle cement proteins can self-assemble into amyloid fibrils. In this study, we assessed the self-assembly behavior of a full-length 19 kDa cement protein from Balanus albicostatus (Balcp19k) in different buffers. Results of Thioflavin T binding assay, transmission electron microscopy, and Fourier transform infrared spectroscopy suggested that the bacterial recombinant Balcp19k was able to aggregate into typical amyloid fibrils. The time required for the self-assembly process was close to that required for the complete curing of barnacle cement complex. Moreover, the solubility of Balcp19k amyloid deposits in guanidine hydrochloride and urea was same as that of the cured cement. These results indicated the inherent self-assembling nature of Balcp19k, implying that the amyloid fibril formation plays a critical role in barnacle cement curing procedure and its insolubility. Our results should be conducive to understanding barnacle underwater adhesion mechanisms and have implications in the development of new-generation antifouling techniques and in the designing of novel wet adhesives for biomedical and technical applications.


Assuntos
Amiloide/química , Amiloide/metabolismo , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Thoracica/química , Thoracica/metabolismo , Adesividade , Adesivos , Animais , Benzotiazóis , Ligação Proteica , Tiazóis/química
20.
Nanotechnology ; 28(38): 385602, 2017 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-28691923

RESUMO

Hybrid materials of metal nanoparticles and biopolymers with catalytic properties are very promising to be used as detectors in biochemical reactions. In this work, the catalytic properties and relevant in situ self-assembly abilities of hybrid films of gold nanoparticles (GNPs) and cellulose for the oxidation of benign chromogen 3,3',5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) are revealed for the first time. The peroxidase-like properties of hybrid films are inherited from those of colloidal GNPs and increase with their contents of GNPs. It is discovered that the oxidized products of TMB grow in situ and assemble into rod-like and tumbleweed-like nanofiber assemblies on hybrid films. The rod-like nanofibers show a magnificent polarizing phenomenon under polarized light because of polycrystalline globular nanoparticles inside. The in situ self-assembly of polarizing nanofibers of chromogen catalyzed with hybrid films creates an opportunity for the synthesis of novel organic nanomaterials and the enhanced detection of biochemical products under polarized light.

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