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1.
Brief Bioinform ; 23(2)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35181793

RESUMO

Chromosome is composed of many distinct chromatin domains, referred to variably as topological domains or topologically associating domains (TADs). The domains are stable across different cell types and highly conserved across species, thus these chromatin domains have been considered as the basic units of chromosome folding and regarded as an important secondary structure in chromosome organization. However, the identification of TAD boundaries is still a great challenge due to the high cost and low resolution of Hi-C data or experiments. In this study, we propose a novel ensemble learning framework, termed as StackTADB, for predicting the boundaries of TADs. StackTADB integrates four base classifiers including Random Forest, Logistic Regression, K-NearestNeighbor and Support Vector Machine. From the analysis of a series of examinations on the data set in the previous study, it is concluded that StackTADB has optimal performance in six metrics, AUC, Accuracy, MCC, Precision, Recall and F1 score, and it is superior to the existing methods. In addition, the comparison of the performance of multiple features shows that Kmers-based features play an essential role in predicting TADs boundaries of fruit flies, and we also apply the SHapley Additive exPlanations (SHAP) framework to interpret the predictions of StackTADB to identify the reason why Kmers-based features are vital. The experimental results show that the subsequences matching the BEAF-32 motif play a crucial role in predicting the boundaries of TADs. The source code is freely available at https://github.com/HaoWuLab-Bioinformatics/StackTADB and the webserver of StackTADB is freely available at http://hwtad.sdu.edu.cn:8002/StackTADB.


Assuntos
Cromatina , Proteínas de Drosophila , Animais , Cromossomos , Proteínas de Ligação a DNA/genética , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas do Olho/genética , Aprendizado de Máquina , Software
2.
Brief Bioinform ; 23(1)2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34553746

RESUMO

Single-cell Hi-C data are a common data source for studying the differences in the three-dimensional structure of cell chromosomes. The development of single-cell Hi-C technology makes it possible to obtain batches of single-cell Hi-C data. How to quickly and effectively discriminate cell types has become one hot research field. However, the existing computational methods to predict cell types based on Hi-C data are found to be low in accuracy. Therefore, we propose a high accuracy cell classification algorithm, called scHiCStackL, based on single-cell Hi-C data. In our work, we first improve the existing data preprocessing method for single-cell Hi-C data, which allows the generated cell embedding better to represent cells. Then, we construct a two-layer stacking ensemble model for classifying cells. Experimental results show that the cell embedding generated by our data preprocessing method increases by 0.23, 1.22, 1.46 and 1.61$\%$ comparing with the cell embedding generated by the previously published method scHiCluster, in terms of the Acc, MCC, F1 and Precision confidence intervals, respectively, on the task of classifying human cells in the ML1 and ML3 datasets. When using the two-layer stacking ensemble framework with the cell embedding, scHiCStackL improves by 13.33, 19, 19.27 and 14.5 over the scHiCluster, in terms of the Acc, ARI, NMI and F1 confidence intervals, respectively. In summary, scHiCStackL achieves superior performance in predicting cell types using the single-cell Hi-C data. The webserver and source code of scHiCStackL are freely available at http://hww.sdu.edu.cn:8002/scHiCStackL/ and https://github.com/HaoWuLab-Bioinformatics/scHiCStackL, respectively.


Assuntos
Algoritmos , Software , Humanos , Aprendizado de Máquina
3.
Opt Express ; 32(11): 19252-19264, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38859064

RESUMO

Faced with growing demands for high-speed and reliable communication systems, optical intelligent reflecting surfaces (OIRS) have recently attracted a lot of interest in visible light communication (VLC). With potential applications in a variety of scenarios, including indoor wireless communications and the Internet of Things (IoT), OIRS is expected to have a transformative impact on optical wireless communications. However, current research is predominantly theoretical, and the hardware implementation of OIRS is insufficient. Therefore, this paper introduces an OIRS prototype based on a mirror array, which is capable of adjusting the reflected lightwave by manipulating the orientation of individual OIRS units to realize an adjustable optical wireless communication environment. Additionally, a hardware platform with a configurable control system for OIRS-based VLC has been developed in this paper. Finally, experimental results demonstrate significant improvements in the amplitude of the received signal and the signal-to-noise ratio of the developed prototype, thereby verifying the enhancement of communication efficiency and the potential of practical OIRS deployment.

4.
Opt Express ; 32(6): 8537-8554, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571111

RESUMO

A theoretical channel impulse response (CIR) model of short-range non-line-of-sight (NLOS) ultraviolet communications (UVC) in noncoplanar geometry under the single-scatter condition is proposed. Simulation results obtained from the widely accepted Monte-Carlo (MC)-based channel model of NLOS UVC are provided to verify corresponding theoretical results obtained from the proposed theoretical single-scatter CIR model. Additionally, an outdoor experiment with a light-emitting diode (LED) as the light source is first designed to measure the channel step response of NLOS UVC and to further validate the proposed theoretical single-scatter CIR model. By varying the different parameters of the transmitter and the receiver, such as the baseline range, the inclination angle, the azimuth angle, the beam divergence angle, and the field-of-view angle, the results of the proposed theoretical single-scatter CIR model and the MC-based channel model are exhibited and further analyzed in detail. Results indicate that the computational time cost by the proposed theoretical single-scatter CIR model is decreased to less than 0.6% of the MC-based one with comparable accuracy in assessing the temporal characteristics of NLOS UVC channels. Additionally, theoretical results obtained from the proposed theoretical single-scatter CIR model manifest satisfactory agreement with corresponding experimental measurements.

5.
Nucleic Acids Res ; 50(18): 10278-10289, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36161334

RESUMO

Promoters are consensus DNA sequences located near the transcription start sites and they play an important role in transcription initiation. Due to their importance in biological processes, the identification of promoters is significantly important for characterizing the expression of the genes. Numerous computational methods have been proposed to predict promoters. However, it is difficult for these methods to achieve satisfactory performance in multiple species. In this study, we propose a novel weighted average ensemble learning model, termed iPro-WAEL, for identifying promoters in multiple species, including Human, Mouse, E.coli, Arabidopsis, B.amyloliquefaciens, B.subtilis and R.capsulatus. Extensive benchmarking experiments illustrate that iPro-WAEL has optimal performance and is superior to the current methods in promoter prediction. The experimental results also demonstrate a satisfactory prediction ability of iPro-WAEL on cross-cell lines, promoters annotated by other methods and distinguishing between promoters and enhancers. Moreover, we identify the most important transcription factor binding site (TFBS) motif in promoter regions to facilitate the study of identifying important motifs in the promoter regions. The source code of iPro-WAEL is freely available at https://github.com/HaoWuLab-Bioinformatics/iPro-WAEL.


Assuntos
Arabidopsis , Biologia Computacional , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Biologia Computacional/métodos , Humanos , Camundongos , Regiões Promotoras Genéticas , Software , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Sítio de Iniciação de Transcrição
6.
J Craniofac Surg ; 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38299822

RESUMO

BACKGROUND: Implant surgery is a popular operation in craniomaxillofacial surgery, but the occurrence of peri-implantitis affects the success and survival rate of the implant. Research has found that Th-cell-related cytokines are associated with peri-implantitis. However, the distribution and proportions of Th-cell subsets in submandibular lymph nodes' immune environments during the progression of peri-implantitis remain unclear. METHODS: Forty-eight rats were randomly divided into 4 groups: the control group, the 1-week ligation peri-implantitis induction (Lig 1w) group, the Lig 2w group, and the Lig 4w group (n=12). Ligation was maintained for different times to induce peri-implantitis 4 weeks after implantation. Inflammation and bone resorption were examined by clinical probing and micro-CT. The submandibular lymph nodes were harvested for quantitative real-time polymerase chain reaction and flow cytometry to obtain the Th-cell profiles. RESULTS: With increasing ligation time, more redness and swelling in the gingiva and more bone resorption around the implant were observed (P<0.05). The proportions of Th1 and Th17 cells increased, the proportion of Th2 cells decreased, and the proportion of Treg cells first increased and then decreased in the lymph nodes (P<0.05). CONCLUSIONS: This study provided a preliminary characterization of the temporal distribution of Th cells in lymph nodes of peri-implantitis. Persistent elevation of Th1 and Th17 proportions and decrease of Treg proportion may be the cause of bone resorption in peri-implantitis. Lymphatic drainage may be a bridge between craniomaxillofacial diseases and systemic diseases. Early immune support against T cells may be a potential therapeutic idea for the prevention of implant failure and the potential risk of systemic disease.

7.
Bioinformatics ; 38(19): 4497-4504, 2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-35997565

RESUMO

MOTIVATION: Three-dimensional (3D) genome organization is of vital importance in gene regulation and disease mechanisms. Previous studies have shown that CTCF-mediated chromatin loops are crucial to studying the 3D structure of cells. Although various experimental techniques have been developed to detect chromatin loops, they have been found to be time-consuming and costly. Nowadays, various sequence-based computational methods can capture significant features of 3D genome organization and help predict chromatin loops. However, these methods have low performance and poor generalization ability in predicting chromatin loops. RESULTS: Here, we propose a novel deep learning model, called CLNN-loop, to predict chromatin loops in different cell lines and CTCF-binding sites (CBS) pair types by fusing multiple sequence-based features. The analysis of a series of examinations based on the datasets in the previous study shows that CLNN-loop has satisfactory performance and is superior to the existing methods in terms of predicting chromatin loops. In addition, we apply the SHAP framework to interpret the predictions of different models, and find that CTCF motif and sequence conservation are important signs of chromatin loops in different cell lines and CBS pair types. AVAILABILITY AND IMPLEMENTATION: The source code of CLNN-loop is freely available at https://github.com/HaoWuLab-Bioinformatics/CLNN-loop and the webserver of CLNN-loop is freely available at http://hwclnn.sdu.edu.cn. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Cromatina , Aprendizado Profundo , Fator de Ligação a CCCTC/metabolismo , Sítios de Ligação , Linhagem Celular
8.
J Nanobiotechnology ; 21(1): 485, 2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38105216

RESUMO

Although various new biomaterials have enriched the methods for peri-implant inflammation treatment, their efficacy is still debated, and secondary operations on the implant area have also caused pain for patients. Recently, strategies that regulate macrophage polarization to prevent or even treat peri-implantitis have attracted increasing attention. Here, we prepared a laser-drilled and covered with metal organic framework-miR-27a agomir nanomembrane (L-MOF-agomir) implant, which could load and sustain the release of miR-27a agomir. In vitro, the L-MOF-agomir titanium plate promoted the repolarization of LPS-stimulated macrophages from M1 to M2, and the macrophage culture supernatant promoted BMSCs osteogenesis. In a ligation-induced rat peri-implantitis model, the L-MOF-agomir implants featured strong immunomodulatory activity of macrophage polarization and alleviated ligation-induced bone resorption. The mechanism of repolarization function may be that the L-MOF-agomir implants promote the macrophage mitochondrial function and metabolism reprogramming from glycolysis to oxidative phosphorylation. Our study demonstrates the feasibility of targeting cell metabolism to regulate macrophage immunity for peri-implantitis inhibition and provides a new perspective for the development of novel multifunctional implants.


Assuntos
Reabsorção Óssea , Implantes Dentários , MicroRNAs , Peri-Implantite , Humanos , Ratos , Animais , Peri-Implantite/prevenção & controle , Peri-Implantite/etiologia , Peri-Implantite/metabolismo , MicroRNAs/genética , Inflamação/complicações , Macrófagos/metabolismo , Titânio
9.
J Craniofac Surg ; 34(8): 2544-2550, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37427926

RESUMO

OBJECTIVES: To explore the use of immediate implant placement technique in peri-implantitis modeling, shorten the modeling period, and obtain similar effects. MATERIALS AND METHODS: Eighty rats were divided into 4 groups: immediate placement (IP), delayed placement (DP), IP-ligation (IP-L) and DP-ligation (DP-L). In the DP and DP-L groups, implants were placed 4 weeks after tooth extraction. In the IP and IP-L groups, implants were placed immediately. Four weeks later, the implants were ligated to induce peri-implantitis in the DP-L and IP-L groups. RESULTS: Nine implants were lost (3 in the IP-L and 2 each in the IP, DP, and DP-L group). The bone level decreased after ligation, and the buccal and lingual bone levels were lower in IP-L versus DP-L. The implant pullout strength was decreased after ligation. Micro-CT showed bone parameters were decreased after ligation, and the percent bone volume was higher in IP versus DP. Histology showed that the percent of CD4 + cells and IL-17 + cells was increased after ligation and higher in IP-L versus DP-L. CONCLUSIONS: We successfully introduced immediate implant placement into the modeling of peri-implantitis and observed similar bone resorption and more soft tissue inflammation in a shorter time.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Peri-Implantite , Ratos , Animais , Peri-Implantite/cirurgia , Peri-Implantite/patologia , Implantação Dentária Endóssea/métodos , Inflamação
10.
Angew Chem Int Ed Engl ; 62(24): e202301422, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37085464

RESUMO

Herein, a copper(I)-catalyzed asymmetric conjugate addition/protonation with selenols and α-substituted α,ß-unsaturated thioamides is disclosed, which affords a series of chiral selenides in high to excellent enantioselectivity. As for both selenols and α-substituted α,ß-unsaturated thioamides, the reaction enjoys broad substrate scopes. The present catalytic system is also successfully applied to asymmetric selenation of ß-substituted α,ß-unsaturated thioamides. A [Cu-(R,RP )-TANIAPHOS]-SePh species is characterized by its 77 Se NMR spectra, which gives a chemical shift at δ 462 ppm. Moreover, a {[Cu-(R)-TOL-BINAP]-SePh}2 species is characterized by X-ray analysis, which confirms the formation of Cu-Se bond in the reaction. Finally, the transformations of the thioamide group to amine and thioester are demonstrated to be straightforward.

11.
J Periodontal Res ; 57(5): 1043-1055, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35944133

RESUMO

OBJECTIVE: To compare miRNA expression levels and predict relevant target genes and signaling pathways in peri-implantitis and periodontitis. BACKGROUND: There are many differences between periodontitis and peri-implantitis. An understanding of the similarities and differences in the transcriptional patterns of these diseases, as well as the molecular mechanisms, is beneficial for the development of management strategies. MATERIALS AND METHODS: Rat models of periodontitis (PD, n = 6) and peri-implantitis (PI, n = 5) were established by ligation. Implantation without ligation (PIC, n = 5) and normal rats (PDC, n = 6) were used as controls. Micro-CT was used to confirm the successful establishment of the model. Gingiva was harvested for miRNA transcriptome sequencing, and the results were confirmed by qRT-PCR. miRNA target genes were predicted with miRTarBase. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. RESULTS: Sixty-nine miRNAs were differentially expressed in PI vs. PD, 105 were differentially expressed in PI vs. PIC, and 70 were differentially expressed in PD vs. PDC (log2 FC ≥1 and padj <0.05). The upregulated genes in all three comparisons were mostly involved in the biological process response to stimulus, whereas most of the downregulated genes were involved in nervous system development (p < .01). The upregulated genes in PI vs. PD and PI vs. PIC were involved in Toll-like receptor signaling and RIG-I-like signaling. The upregulated genes in PI vs. PD were involved in T- and B-cell receptor signaling, apoptosis, and osteoclast differentiation. Focal adhesion was downregulated in all three comparisons, and adherens junction was downregulated in PI vs. PD and PD vs. PDC (p < .1). CONCLUSION: This study showed differences in the miRNA expression profiles between peri-implantitis and periodontitis and annotated the possible target genes and molecular mechanisms; this study could lay a foundation for the development of management strategies.


Assuntos
MicroRNAs , Peri-Implantite , Periodontite , Animais , Gengiva/metabolismo , MicroRNAs/genética , Peri-Implantite/genética , Peri-Implantite/metabolismo , Periodontite/genética , Periodontite/metabolismo , Ratos , Transcriptoma/genética
12.
Environ Monit Assess ; 194(9): 630, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35920913

RESUMO

Water quality monitoring is very important in agricultural catchments. UV-Vis spectrometry is widely used in place of traditional analytical methods because it is cost effective and fast and there is no chemical waste. In recent years, artificial neural networks have been extensively studied and used in various areas. In this study, we plan to simplify water quality monitoring with UV-Vis spectrometry and artificial neural networks. Samples were collected and immediately taken back to a laboratory for analysis. The absorption spectra of the water sample were acquired within a wavelength range from 200 to 800 nm. Convolutional neural network (CNN) and partial least squares (PLS) methods are used to calculate water parameters and obtain accurate results. The experimental results of this study show that both PLS and CNN methods may obtain an accurate result: linear correlation coefficient (R2) between predicted value and true values of TOC concentrations is 0.927 with PLS model and 0.953 with CNN model, R2 between predicted value and true values of TSS concentrations is 0.827 with PLS model and 0.915 with CNN model. CNN method may obtain a better linear correlation coefficient (R2) even with small number of samples and can be used for online water quality monitoring combined with UV-Vis spectrometry in agricultural catchment.


Assuntos
Monitoramento Ambiental/métodos , Rios , Qualidade da Água , Agricultura/normas , Inglaterra , Análise dos Mínimos Quadrados , Redes Neurais de Computação , Espectrofotometria Ultravioleta/métodos
13.
J Cell Mol Med ; 25(1): 27-36, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33128338

RESUMO

The effects of long-term nitrate therapy are compromised due to protein S-Nitrosylation, which is mediated by nitric oxide (NO). This study is to determine the role of Akt S-Nitrosylation in the recovery of heart functions after ischaemia. In recombinant Akt protein and in HEK293 cells, NO donor decreased Akt activity and induced Akt S-Nitrosylation, but was abolished if Akt protein was mutated by replacing cysteine 296/344 with alanine (Akt-C296/344A). In endothelial cells, NO induced Akt S-Nitrosylation, reduced Akt activity and damaged multiple cellular functions including proliferation, migration and tube formation. These alterations were ablated if cells expressed Akt-C296/344A mutant. In Apoe-/- mice, nitroglycerine infusion increased both Akt S-Nitrosylation and infarct size, reduced Akt activity and capillary density, and delayed the recovery of cardiac function in ischaemic hearts, compared with mice infused with vehicle. Importantly, these in vivo effects of nitroglycerine in Apoe-/- mice were remarkably prevented by adenovirus-mediated enforced expression of Akt-C296/344A mutant. In conclusion, long-term usage of organic nitrate may inactivate Akt to delay ischaemia-induced revascularization and the recovery of cardiac function through NO-mediated S-Nitrosylation.


Assuntos
Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Revascularização Miocárdica , Nitratos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Adenoviridae/metabolismo , Sequência de Aminoácidos , Animais , Apolipoproteínas E/deficiência , Apolipoproteínas E/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisteína/metabolismo , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos , Mutação/genética , Neovascularização Fisiológica/efeitos dos fármacos , Óxido Nítrico/metabolismo , Nitroglicerina/farmacologia , Nitroprussiato/farmacologia , Nitrosação
14.
Arch Virol ; 166(1): 249-258, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33165649

RESUMO

The use of bacteriophage-encoded murein hydrolases (endolysins) is being actively explored as a means of controlling multidrug-resistant pathogens. Previously, we isolated and characterized one such enzyme, the phage ΦEf11 ORF28 lysin, which demonstrated profound antimicrobial activity against many strains of Enterococcus faecalis. Although the lysin is eminently active against many vancomycin-resistant enterococal (VRE) strains, and displays lower minimum inhibitory concentrations than vancomycin against vancomycin-sensitive strains, there is a subset of E. faecalis strains that is not affected by the lysin. Currently, there is no explanation for the disparate sensitivity to ORF28 lysin among E. faecalis strains. In the present investigation, we show that the intrinsic insensitivity of the insusceptible strains to the lysin is associated with the presence of a ΦEf11 prophage. Of the strains harboring phage ΦEf11 genes (N = 28), 68% were insensitive to the lysin, whereas 91% of the strains (N = 75) lacking detectable ΦEf11 genes demonstrated lysin sensitivity. Furthermore, curing a lysin-resistant, lysogenic E. faecalis strain resulted in a lysin-sensitive derivative, whereas lysogenizing a wild-type non-lysogenic strain converted it from lysin sensitivity to lysin resistance. Our results suggest that lysin resistance comes about through lysogenic conversion of non-lysogenic, lysin-sensitive strains.


Assuntos
Bacteriófagos/genética , Endopeptidases/genética , Enterococcus faecalis/virologia , Prófagos/genética , Proteínas Virais/genética , Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Lisogenia/genética , Testes de Sensibilidade Microbiana/métodos , Vancomicina/farmacologia
15.
J Periodontal Res ; 56(2): 219-225, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33296525

RESUMO

Inflammatory alveolar bone defects are caused by periodontal pathogens, are one of the most common oral diseases in the clinic, and are characterized by periodontal support tissue damage. MicroRNAs (miRNAs) can participate in a variety of inflammatory lesions and modulate bone metabolism through the posttranscriptional regulation of target genes. In recent years, studies have confirmed that some miRNAs play significant roles in the development of inflammatory alveolar bone defects. Therefore, we reviewed the correlation between miRNAs and inflammatory alveolar bone defects and elucidated the underlying mechanisms to provide new ideas for the prevention and treatment of inflammatory alveolar bone defects.


Assuntos
Perda do Osso Alveolar , MicroRNAs , Perda do Osso Alveolar/genética , Humanos , MicroRNAs/genética , Periodonto
16.
Nat Mater ; 18(5): 482-488, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886399

RESUMO

In two-dimensional (2D) systems, high mobility is typically achieved in low-carrier-density semiconductors and semimetals. Here, we discover that the nanobelts of Weyl semimetal NbAs maintain a high mobility even in the presence of a high sheet carrier density. We develop a growth scheme to synthesize single crystalline NbAs nanobelts with tunable Fermi levels. Owing to a large surface-to-bulk ratio, we argue that a 2D surface state gives rise to the high sheet carrier density, even though the bulk Fermi level is located near the Weyl nodes. A surface sheet conductance up to 5-100 S per □ is realized, exceeding that of conventional 2D electron gases, quasi-2D metal films, and topological insulator surface states. Corroborated by theory, we attribute the origin of the ultrahigh conductance to the disorder-tolerant Fermi arcs. The evidenced low-dissipation property of Fermi arcs has implications for both fundamental study and potential electronic applications.

17.
Appl Environ Microbiol ; 85(13)2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30979842

RESUMO

ϕEf11 is a temperate Siphoviridae bacteriophage that infects strains of Enterococcus faecalis The ϕEf11 genome, encompassing 65 open reading frames (ORFs), is contained within 42,822 bp of DNA. Within this genome, a module of six lysis-related genes was identified. Based upon sequence homology, one of these six genes, ORF28, was predicted to code for an N-acetylmuramoyl-l-alanine amidase endolysin of 46.133 kDa, composed of 421 amino acids. The PCR-amplified ORF28 was cloned and expressed, and the resulting gene product was affinity purified to homogeneity. The purified protein was obtained from a fusion protein that exhibited a molecular mass of 72.5 kDa, consistent with a 46.1-kDa protein combined with a fused 26.5-kDa glutathione S-transferase tag. It produced rapid, profound lysis in E. faecalis populations and was active against 73 of 103 (71%) E. faecalis strains tested. In addition, it caused substantial destruction of E. faecalis biofilms. The lysin was quite stable, retaining its activity for three years in refrigerated storage, was stable over a wide range of pHs, and was unaffected by the presence of a reducing agent; however, it was inhibited by increasing concentrations of Ca2+ Liquid chromatography-mass spectrometry analysis of E. faecalis cell wall digestion products produced by the ORF28 endolysin indicated that the lysin acted as an N-acetylmuramidase, an endo-ß-N-acetylglucosaminidase, and an endopeptidase, rather than an N-acetylmuramoyl-l-alanine amidase. The ϕEf11 ORF28 lysin shared 10% to 37% amino acid identity with the lytic enzymes of all other characterized E. faecalis bacteriophages.IMPORTANCE The emergence of multidrug-resistant pathogenic microorganisms has brought increasing attention to the urgent need for the development of alternative antimicrobial strategies. One such alternative to conventional antibiotics employs lytic enzymes (endolysins) that are produced by bacteriophages in the course of lytic infection. During lytic infection by a bacteriophage, these enzymes hydrolyze the cell wall peptidoglycan, resulting in the lysis of the host cell. However, external endolysin application can result in lysis from without. In this study, we have cloned, expressed, purified, and characterized an endolysin produced by a bacteriophage infecting strains of Enterococcus faecalis The lysin is broadly active against most of the tested E. faecalis strains and exhibits multifunctional enzymatic specificities that differ from all other characterized endolysins produced by E. faecalis bacteriophages.


Assuntos
Endopeptidases/genética , Siphoviridae/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Endopeptidases/química , Endopeptidases/metabolismo , Alinhamento de Sequência , Siphoviridae/enzimologia , Proteínas Virais/química , Proteínas Virais/metabolismo
18.
Apoptosis ; 23(5-6): 356-374, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29777330

RESUMO

Recent studies have confirmed that IL-6/GP130 targets are closely associated with tumor growth, metastasis and drug resistance. 5-Fluorouracil (5-FU) is the most common chemotherapeutic agent for colon cancer but is limited due to chemoresistance and high cytotoxicity. Bazedoxifene (BZA), a third-generation selective estrogen receptor modulator, was discovered by multiple ligand simultaneous docking and drug repositioning approaches to have a novel function as an IL-6/GP130 target inhibitor. Thus, we speculated that in colon cancer, the anti-tumor efficacy of 5-FU might be increased in combination with IL-6/GP130 inhibitors. CCK8 assay and colony formation assay were used to detect the cell proliferation and colony formation. We measured the IC50 value of 5-FU alone and in combination with BZA by cell viability inhibition. Cell migration and invasion ability were tested by scratch migration assays and transwell invasion assays. Flow cytometric analysis for cell apoptosis and cell cycle. Quantitative real-time PCR was used to detect Bad, Bcl-2 and Ki-67 mRNA expression and western blotting (WB) assay analyzed protein expression of Bad/Bcl-2 signaling pathway. Further mechanism study, WB analysis detected the key proteins level in IL-6/GP130 targets and JAK/STAT3, Ras/Raf/MEK/ERK, and PI3K/AKT/mTOR signaling pathway. A colon cancer xenograft model was used to further confirm the efficacy of 5-FU and BZA in vivo. The GP130, P-STAT3, P-AKT, and P-ERK expression levels were detected by immunohistochemistry in the xenograft tumor. BZA markedly potentiates the anti-tumor function of 5-FU in vitro and in vivo. Conversely, 5-FU activation is reduced following exogenous IL-6 treatment in cells. Further mechanistic studies determined that BZA treatment enhanced 5-FU anti-tumor activation by inhibiting the IL-6/GP130 signaling pathway and the phosphorylation status of the downstream effectors AKT, ERK and STAT3. In contrast, IL-6 can attenuate 5-FU function via activating IL-6R/GP130 signaling and the P-AKT, P-ERK and P-STAT3 levels. This study firstly verifies that targeting IL-6/GP130 signaling can increase the anti-tumor function of 5-FU; in addition, this strategy can sensitize cancer cell drug sensitivity, implying that blocking IL-6/GP130 targets can reverse chemoresistance. Therefore, combining 5-FU and IL-6/GP130 target inhibitors may be a promising approach for cancer treatment.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Receptor gp130 de Citocina/antagonistas & inibidores , Fluoruracila/uso terapêutico , Indóis/uso terapêutico , Interleucina-6/antagonistas & inibidores , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Feminino , Fluoruracila/administração & dosagem , Humanos , Indóis/administração & dosagem , Camundongos , Camundongos Nus , Invasividade Neoplásica , Transdução de Sinais/efeitos dos fármacos , Ensaio Tumoral de Célula-Tronco , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Biochem Biophys Res Commun ; 496(4): 1069-1075, 2018 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-29366790

RESUMO

Recent reports have indicated that circular RNA (circRNA) may regulate Lung adenocarcinoma (LAC) development. Our previous studies showed that hsa_circ_0012673 was up-regulated in a circRNA microarray. However, its expression level in LAC has not been verified, and the underlying molecular mechanisms in LAC are unknown. In this study, we found that the expression of hsa_circ_0012673 was up-regulated in LAC tissues compared to pair-matched adjacent non-tumor tissues (P = 0.0079), and that the expression level was associated with tumour size (P = 0.015). Furthermore, hsa_circ_0012673 was primarily localized in the cytoplasm and promoted cell proliferation of LAC cells by sponging miR-22, which targeted erb-b2 receptor tyrosine kinase 3 (ErbB3) in LAC. Hsa_circ_0012673 promotes LAC proliferation by suppressing miR-22, which targets ErbB3.


Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Proliferação de Células , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , MicroRNAs/metabolismo , RNA/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Ligação Proteica , RNA Circular , Receptor ErbB-3/metabolismo , Regulação para Cima
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(1): 162-5, 2017 01.
Artigo em Zh | MEDLINE | ID: mdl-30195286

RESUMO

Tongue coat information extraction plays an important role in disease diagnosis for the traditional Chinese medicine. For the purpose of quantifying the tongue coat properties in traditional Chinese medicine, most of the existing methods are based on computerized image analysis, carrying out RGB color space in a tongue imaging captured with digital camera. However, those methods cannot meet the requirements of clinical medicine. To explore more information about the tongue objectively, a new approach to analyze tongue information based on hyperspectral images is presented. Hyperspectral images are acquired using the hyperspectral imaging system in the spectral range of 370.200 0 to 992.956 0 nm (343bands), and the traditional Chinese medicine clinical diagnosis information is recorded. The main region of interest (ROI) in the samples is extracted while the background is removed from the tongue image, then tongue information of ROI is analyzed. The largest different spectral characteristics between tongue proper and tongue coat are found in the wavelength range of about 525 to 600 nm. Nine wavelengths tongue spectral images from 382.108 0 to 963.668 0 nm are extracted, then comparing with the actual tongue situation, we find that the spectral image at 527.548 0 nm band can better reflect the actual tongue situation than others. The experiment results show that hyperspectral imaging technique is very helpful for tongue coat information extraction of the traditional Chinese medicine, and this new analysis approach can provide a fast and simple non-invasive detection method for tongue coat segmentation and tongue coat information extraction.


Assuntos
Medicina Tradicional Chinesa , Língua , Cor , Armazenamento e Recuperação da Informação
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