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1.
Cell ; 166(3): 567-581, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27374329

RESUMO

Insulin signaling regulates many facets of animal physiology. Its dysregulation causes diabetes and other metabolic disorders. The spindle checkpoint proteins MAD2 and BUBR1 prevent precocious chromosome segregation and suppress aneuploidy. The MAD2 inhibitory protein p31(comet) promotes checkpoint inactivation and timely chromosome segregation. Here, we show that whole-body p31(comet) knockout mice die soon after birth and have reduced hepatic glycogen. Liver-specific ablation of p31(comet) causes insulin resistance, hyperinsulinemia, glucose intolerance, and hyperglycemia and diminishes the plasma membrane localization of the insulin receptor (IR) in hepatocytes. MAD2 directly binds to IR and facilitates BUBR1-dependent recruitment of the clathrin adaptor AP2 to IR. p31(comet) blocks the MAD2-BUBR1 interaction and prevents spontaneous clathrin-mediated IR endocytosis. BUBR1 deficiency enhances insulin sensitivity in mice. BUBR1 depletion in hepatocytes or the expression of MAD2-binding-deficient IR suppresses the metabolic phenotypes of p31(comet) ablation. Our findings establish a major IR regulatory mechanism and link guardians of chromosome stability to nutrient metabolism.


Assuntos
Pontos de Checagem do Ciclo Celular , Insulina/metabolismo , Mitose , Transdução de Sinais , Complexo 2 de Proteínas Adaptadoras/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Aneuploidia , Animais , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Segregação de Cromossomos , Clatrina/metabolismo , Endocitose , Células Hep G2 , Homeostase , Humanos , Resistência à Insulina , Fígado/metabolismo , Proteínas Mad2/metabolismo , Camundongos , Camundongos Knockout , Proteínas Nucleares , Proteínas Serina-Treonina Quinases/metabolismo , Receptor de Insulina/metabolismo
2.
Opt Express ; 32(9): 15444-15459, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38859194

RESUMO

The applications of rate-compatible low-density parity-check (RC-LDPC) codes are investigated for a 16 quadrature amplitude modulation (16QAM) signal and coherent detection system. With rate-compatible signals, we can provide the flexible net data rate between 135.5 Gb/s and 169.7 Gb/s in a passive optical network (PON) link. Based on the LDPC codes defined in the IEEE 802.3ca standard, we construct two sets of RC-LDPC codes with a fixed and variable information bit length. Since the puncturing operation may degrade the performance of LDPC codes, we apply the protograph-based extrinsic information transfer (PEXIT) technique to optimize the puncturing positions to mitigate the degradation. Additionally, we explore four low-complexity LDPC decoding algorithms (min sum, offset min sum, variable weight min sum, and relaxed min sum with 2nd min emulation) to investigate the relationship between the computational complexity and decoding performance. Simulation results indicate that the constructed codewords exhibit good performance in the waterfall region across a range of code rates. Finally, we conduct an experimental setup in a dual-polarization 25 GBaud 16QAM coherent PON to verify the effectiveness of the constructed LDPC codes with four decoding algorithms. The experimental results show maximal 4.8 dB receiver sensitivity differences, which demonstrate the feasibility of the method for constructing RC-LDPC codes in future high-speed flexible coherent PON.

3.
Crit Rev Eukaryot Gene Expr ; 33(2): 41-53, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36734856

RESUMO

This study aims to clarify molecular mechanisms and tumor-associated functions of LINC00312 in lung cancer. GEO database was used to acquire lung cancer-related expression microarrays. Then, relevant databases were applied to predict the downstream miRNA for LINC00312 and the target mRNA for the potential miRNA, with their associations deeply confirmed through dual-luciferase and RIP assays. The expression levels of epithelial-mesenchymal transition -related proteins (N-cadherin, Vimentin, MMP-2, and MMP-9) were examined by Western blot. The proliferation, migration, and invasion were evaluated through in vitro experiments including CCK-8 and Transwell assays and further validated by nude mouse xenograft tumor experiment. LINC00312, serving as a tumor suppressor, was down-regulated in lung cancer cells. RIP assay proved that miR-3175 bound LINC00312 and SEMA6A. The dual-luciferase assay showed that miR-3175 specifically targeted SEMA6A, suppressing the expression of SEMA6A. Overexpressing LINC00312 remarkably inhibited the binding between miR-3175 and SEMA6A. Overexpressing miR-3175 or silencing SEMA6A could hamper the effects of LINC00312 on lung cancer cells. LINC00312 inhibits lung cancer occurrence and progression via the miR-3175/SEMA6A axis.


Assuntos
Neoplasias Pulmonares , MicroRNAs , Semaforinas , Animais , Camundongos , Humanos , Linhagem Celular Tumoral , Proliferação de Células/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Pulmonares/metabolismo , Caderinas/genética , Caderinas/metabolismo , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Semaforinas/genética , Semaforinas/metabolismo
4.
J Anim Physiol Anim Nutr (Berl) ; 107(6): 1402-1418, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37391879

RESUMO

Zinc (Zn) plays a critical role in the growth of livestock, which depends on cell proliferation. In addition to modifying the growth associated with its effects on food intake, mitogenic hormones, signal transduction and gene transcription, Zn also regulates body weight gain through mediating cell proliferation. Zn deficiency in animals leads to growth inhibition, along with an arrest of cell cycle progression at G0/G1 and S phase due to depression in the expression of cyclin D/E and DNA synthesis. Therefore, in the present study, the interplay between Zn and cell proliferation and implications for the growth of livestock were reviewed, in which Zn regulates cell proliferation in several ways, especially cell cycle progression at the G0/G1 phase DNA synthesis and mitosis. During the cell cycle, the Zn transporters and major Zn binding proteins such as metallothioneins are altered with the requirements of cellular Zn level and nuclear translocation of Zn. In addition, calcium signaling, MAPK pathway and PI3K/Akt cascades are also involved in the process of Zn-interfering cell proliferation. The evidence collected over the last decade highlights the necessity of Zn for normal cell proliferation, which suggests Zn supplementation should be considered for the growth and health of poultry.


Assuntos
Gado , Zinco , Animais , Zinco/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proliferação de Células , DNA
5.
Molecules ; 27(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35744795

RESUMO

Irinotecan and Topotecan are two Camptothecin derivatives (CPTs) whose resistance is associated with the high expression of breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp). To reverse this resistance, two novel CPTs, FL77-28 (7-(3-Fluoro-4-methylphenyl)-10,11-methylenedioxy-20(S)-CPT) and FL77-29 (7-(4-Fluoro-3-methylphenyl)-10,11-methylenedioxy-20(S)-CPT), were synthesized by our group. In this study, the anti-tumor activities of FL77-28, FL77-29, and their parent, FL118 (10,11-methylenedioxy-20(S)-CPT), were evaluated and the results showed that FL77-28 and FL77-29 had stronger anti-tumor activities than FL118. The transport and uptake of FL118, FL77-28, and FL77-29 were investigated in Caco-2 cells for the preliminary prediction of intestinal absorption. The apparent permeability coefficient from apical to basolateral (Papp AP-BL) values of FL77-28 and FL77-29 were (2.32 ± 0.04) × 10-6 cm/s and (2.48 ± 0.18) × 10-6 cm/s, respectively, suggesting that the compounds had moderate absorption. Since the transport property of FL77-28 was passive diffusion and the efflux ratio (ER) was less than 2, two chemical inhibitors were added to further confirm the involvement of efflux proteins. The results showed that FL77-28 was not a substrate of P-gp or BCRP, but FL77-29 was mediated by P-gp. In conclusion, FL77-28 might be a promising candidate to overcome drug resistance induced by multiple efflux proteins.


Assuntos
Camptotecina , Proteínas de Neoplasias , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transporte Biológico , Células CACO-2 , Camptotecina/análogos & derivados , Camptotecina/metabolismo , Humanos , Proteínas de Neoplasias/metabolismo
6.
Chem Pharm Bull (Tokyo) ; 69(11): 1054-1060, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34719586

RESUMO

In the evaluation of the druggability of candidate compounds, it was vital to predict the oral bioavailability of compounds from apparent permeability (Papp) across Caco-2 cell-culture model of intestinal epithelium cultured on commercial transwell plate inserts. The study was to investigate the transport characteristics and permeability of FL118 (10, 11-Methylenedioxy-20(S)-camptothecin) derivatives 7-Q6 (7-(4-Ethylphenyl)-10, 11-methylenedioxy-20(S)-camptothecin) and 7-Q20 (7-(4-Trifluoromethylphenyl)-10, 11-methylenedioxy-20(S)-camptothecin). Transport characteristics and permeability of the tested compounds to the small intestine were assessed at different concentrations (0.5, 1 µM) via Caco-2 cell monolayers model in vitro. Uptake studies based on Caco-2 cells, including temperatures, concentrations, and the influence of efflux transporters, were combined to confirm the transport characteristics of the tested compounds. Furthermore, cytotoxicity results showed that the concentrations used in the experiments were non-toxic and harmless to cells. In addition, The Papp of 7-Q6 was (3.69 ± 1.07) × 10-6 cm/s with efflux ratio (ER) 0.98, while the Papp of 7-Q20 was (7.78 ± 0.89) × 10-6 cm/s with ER 1.05 for apical-to-basolateral (AP→BL) at 0.5 µM, suggesting that 7-Q20 might possess higher oral bioavailability in vivo. Furthermore, P-glycoprotein (P-gp) was proved to slightly affect the accumulations of 7-Q20, while the absorption of 7-Q6 was irrelevant with P-gp and breast cancer resistant protein (BCRP) based on the cellular uptake assays. Accordingly, 7-Q6 was completely absorbed by passive diffusion, and 7-Q20 was mainly dependent on passive diffusion with being effluxed by P-gp slightly. Meanwhile, both 7-Q6 and 7-Q20 were potential antitumor drugs that might exhibit high oral bioavailability in the body.


Assuntos
Antineoplásicos/química , Benzodioxóis/química , Membrana Celular/metabolismo , Indolizinas/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/administração & dosagem , Benzodioxóis/administração & dosagem , Disponibilidade Biológica , Transporte Biológico , Células CACO-2 , Camptotecina/química , Camptotecina/metabolismo , Membrana Celular/ultraestrutura , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Absorção Gastrointestinal , Humanos , Indolizinas/administração & dosagem , Mucosa Intestinal/metabolismo
7.
Opt Express ; 28(4): 5212-5220, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32121746

RESUMO

We investigate various patterns of vector solitons arising in a passively mode-locked fiber laser based on semiconductor saturable absorber mirror (SESAM). By properly adjusting the cavity parameters including the pump power and intra-cavity birefringence, the fundamental vector solitons, vector soliton molecules, and macroscopic vector solitons can be separately observed. In particular, both vector soliton molecule and macroscopic vector solitons exhibit multi-pulse structure along one polarization axis while there occurs single pulse profile at its orthogonal polarization component. Thus, they can be treated as "1 + 2" and "1+n" vector solitons. Moreover, the size of the macroscopic solitons can be manipulated from half of the cavity to even the whole cavity. The generation mechanisms of these vector soliton patterns are also investigated.

8.
Chem Pharm Bull (Tokyo) ; 67(10): 1082-1087, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31391385

RESUMO

Camptothecin (CPT), a natural alkaloid, possesses potent anticancer activity. However, its application was terminated due to its low bioavailability and high toxicity. This work evaluated the potential of deoxycholic acid-CPT conjugate (G2) to improve the oral absorption of CPT. Deoxycholic acid significantly reduced cytotoxicity and inhibited the uptake of G2, in vitro. And G2 showed sodium-dependent uptake. In addition, in vivo study in rats indicated that the oral bioavailability of G2 was 2.06-fold higher than that of CPT. The present study suggested that using bile acid as the conjugated moiety is a hopeful strategy to improve the oral bioavailability of CPT.


Assuntos
Ácidos e Sais Biliares/administração & dosagem , Ácidos e Sais Biliares/química , Camptotecina/administração & dosagem , Camptotecina/química , Absorção Fisiológica , Administração Oral , Animais , Ácidos e Sais Biliares/farmacologia , Células CACO-2 , Camptotecina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Masculino , Conformação Molecular , Ratos , Ratos Sprague-Dawley
9.
BMC Microbiol ; 16: 91, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-27215540

RESUMO

BACKGROUND: Clostridium termitidis CT1112 is an anaerobic, Gram-positive, mesophilic, spore-forming, cellulolytic bacterium, originally isolated from the gut of a wood feeding termite Nasusitermes lujae. It has the ability to hydrolyze both cellulose and hemicellulose, and ferment the degradation products to acetate, formate, ethanol, lactate, H2, and CO2. It is therefore ges in gene and gene product expression during growth of C. termitidis on cellobiose, xylose, xylan, and α-cellulose. RESULTS: Correlation of transcriptome and proteome data with growth and fermentation profiles identified putative carbon-catabolism pathways in C. termitidis. The majority of the proteins associated with central metabolism were detected in high abundance. While major differences were not observed in gene and gene-product expression for enzymes associated with metabolic pathways under the different substrate conditions, xylulokinase and xylose isomerase of the pentose phosphate pathway were found to be highly up-regulated on five carbon sugars compared to hexoses. In addition, genes and gene-products associated with a variety of cellulosome and non-cellulosome associated CAZymes were found to be differentially expressed. Specifically, genes for cellulosomal enzymes and components were highly expressed on α-cellulose, while xylanases and glucosidases were up-regulated on 5 carbon sugars with respect to cellobiose. Chitinase and cellobiophosphorylases were the predominant CAZymes expressed on cellobiose. In addition to growth on xylan, the simultaneous consumption of two important lignocellulose constituents, cellobiose and xylose was also demonstrated. CONCLUSION: There are little changes in core-metabolic pathways under the different carbon sources compared. The most significant differences were found to be associated with the CAZymes, as well as specific up regulation of some key components of the pentose phosphate pathway in the presence of xylose and xylan. This study has enhanced our understanding of the physiology and metabolism of C. termitidis, and provides a foundation for future studies on metabolic engineering to optimize biofuel production from natural biomass.


Assuntos
Clostridium/crescimento & desenvolvimento , Perfilação da Expressão Gênica/métodos , Lignina/metabolismo , Proteômica/métodos , Análise de Sequência de RNA/métodos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Celobiose/metabolismo , Celulose/metabolismo , Clostridium/genética , Clostridium/metabolismo , Fermentação , Regulação Bacteriana da Expressão Gênica , Redes e Vias Metabólicas , Xilanos/metabolismo , Xilose/metabolismo
10.
Appl Microbiol Biotechnol ; 99(13): 5583-92, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26002633

RESUMO

Biodiesel production-derived waste glycerol (WG) was previously investigated as potential carbon source for medium chain length polyhydroxyalkanoate (mcl-PHA) production by Pseudomonas putida LS46. In this study, we evaluated the effect of impurities in the WG on P. putida LS46 physiology during exponential growth and corresponding changes in transcription and protein expression profiles compared with cells grown on pure, reagent grade glycerol. High concentration of metal ions, such as Na(+), and numbers of heavy metals ion, such as copper, ion, zinc, were detected in biodiesel-derived WG. Omics analysis from the corresponding cultures suggested altered expression of genes involved in transport and metabolism of ammonia and heavy metal ions. Expression of three groups of heavy metal homeostasis genes was significantly changed (mostly upregulated) in WG cultures and included the following: copper-responded cluster 1 and 2 genes, primarily containing cusABC; two copies of copAB and heavy metal translocating P-type ATPase; Fur-regulated, TonB-dependent siderophore receptor; and several cobalt/zinc/cadmium transporters. Expression of these genes suggests regulation of intracellular concentrations of heavy metals during growth on biodiesel-derived glycerol. Finally, a number of genes involved in adapting to, or metabolizing free fatty acids and other nonheavy metal contaminants, such as Na(+), were also upregulated in P. putida LS46 grown on biodiesel-derived glycerol.


Assuntos
Biocombustíveis , Poluentes Ambientais/metabolismo , Glicerol/metabolismo , Metais Pesados/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Pseudomonas putida/crescimento & desenvolvimento , Pseudomonas putida/genética , Amônia/metabolismo , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica , Proteoma/análise , Pseudomonas putida/metabolismo
11.
BMC Genomics ; 15: 567, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24998381

RESUMO

BACKGROUND: Growing interest in cellulolytic clostridia with potential for consolidated biofuels production is mitigated by low conversion of raw substrates to desired end products. Strategies to improve conversion are likely to benefit from emerging techniques to define molecular systems biology of these organisms. Clostridium stercorarium DSM8532T is an anaerobic thermophile with demonstrated high ethanol production on cellulose and hemicellulose. Although several lignocellulolytic enzymes in this organism have been well-characterized, details concerning carbohydrate transporters and central metabolism have not been described. Therefore, the goal of this study is to define an improved whole genome sequence (WGS) for this organism using in-depth molecular profiling by RNA-seq transcriptomics and tandem mass spectrometry-based proteomics. RESULTS: A paired-end Roche/454 WGS assembly was closed through application of an in silico algorithm designed to resolve repetitive sequence regions, resulting in a circular replicon with one gap and a region of 2 kilobases with 10 ambiguous bases. RNA-seq transcriptomics resulted in nearly complete coverage of the genome, identifying errors in homopolymer length attributable to 454 sequencing. Peptide sequences resulting from high-throughput tandem mass spectrometry of trypsin-digested protein extracts were mapped to 1,755 annotated proteins (68% of all protein-coding regions). Proteogenomic analysis confirmed the quality of annotation and improvement pipelines, identifying a missing gene and an alternative reading frame. Peptide coverage of genes hypothetically involved in substrate hydrolysis, transport and utilization confirmed multiple pathways for glycolysis, pyruvate conversion and recycling of intermediates. No sequences homologous to transaldolase, a central enzyme in the pentose phosphate pathway, were observed by any method, despite demonstrated growth of this organism on xylose and xylan hemicellulose. CONCLUSIONS: Complementary omics techniques confirm the quality of genome sequence assembly, annotation and error-reporting. Nearly complete genome coverage by RNA-seq likely indicates background DNA in RNA extracts, however these preps resulted in WGS enhancement and transcriptome profiling in a single Illumina run. No detection of transaldolase by any method despite xylose utilization by this organism indicates an alternative pathway for sedoheptulose-7-phosphate degradation. This report combines next-generation omics techniques to elucidate previously undefined features of substrate transport and central metabolism for this organism and its potential for consolidated biofuels production from lignocellulose.


Assuntos
Proteínas de Bactérias/genética , Clostridium/metabolismo , Transcriptoma , Proteínas de Bactérias/metabolismo , Metabolismo dos Carboidratos/genética , Clostridium/genética , Perfilação da Expressão Gênica , Genoma Bacteriano , Anotação de Sequência Molecular , Proteômica , Pseudogenes , Análise de Sequência de RNA , Espectrometria de Massas em Tandem
12.
Appl Environ Microbiol ; 80(5): 1602-15, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24362431

RESUMO

Thermoanaerobacter spp. have long been considered suitable Clostridium thermocellum coculture partners for improving lignocellulosic biofuel production through consolidated bioprocessing. However, studies using "omic"-based profiling to better understand carbon utilization and biofuel producing pathways have been limited to only a few strains thus far. To better characterize carbon and electron flux pathways in the recently isolated, xylanolytic strain, Thermoanaerobacter thermohydrosulfuricus WC1, label-free quantitative proteomic analyses were combined with metabolic profiling. SWATH-MS proteomic analysis quantified 832 proteins in each of six proteomes isolated from mid-exponential-phase cells grown on xylose, cellobiose, or a mixture of both. Despite encoding genes consistent with a carbon catabolite repression network observed in other Gram-positive organisms, simultaneous consumption of both substrates was observed. Lactate was the major end product of fermentation under all conditions despite the high expression of gene products involved with ethanol and/or acetate synthesis, suggesting that carbon flux in this strain may be controlled via metabolite-based (allosteric) regulation or is constrained by metabolic bottlenecks. Cross-species "omic" comparative analyses confirmed similar expression patterns for end-product-forming gene products across diverse Thermoanaerobacter spp. It also identified differences in cofactor metabolism, which potentially contribute to differences in end-product distribution patterns between the strains analyzed. The analyses presented here improve our understanding of T. thermohydrosulfuricus WC1 metabolism and identify important physiological limitations to be addressed in its development as a biotechnologically relevant strain in ethanologenic designer cocultures through consolidated bioprocessing.


Assuntos
Proteínas de Bactérias/metabolismo , Lignina/metabolismo , Thermoanaerobacter/metabolismo , Fermentação , Análise do Fluxo Metabólico , Metaboloma , Proteoma/análise
13.
ScientificWorldJournal ; 2014: 465702, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25254244

RESUMO

Aiming at the static task scheduling problems in heterogeneous environment, a heuristic task scheduling algorithm named HCPPEFT is proposed. In task prioritizing phase, there are three levels of priority in the algorithm to choose task. First, the critical tasks have the highest priority, secondly the tasks with longer path to exit task will be selected, and then algorithm will choose tasks with less predecessors to schedule. In resource selection phase, the algorithm is selected task duplication to reduce the interresource communication cost, besides forecasting the impact of an assignment for all children of the current task permits better decisions to be made in selecting resources. The algorithm proposed is compared with STDH, PEFT, and HEFT algorithms through randomly generated graphs and sets of task graphs. The experimental results show that the new algorithm can achieve better scheduling performance.


Assuntos
Algoritmos , Sistemas Computacionais/normas , Armazenamento e Recuperação da Informação/normas , Modelos Teóricos , Simulação por Computador , Reprodutibilidade dos Testes , Fatores de Tempo
14.
Sheng Li Xue Bao ; 65(4): 417-32, 2013 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-23963074

RESUMO

Fungal pathogens represent major problems for human health and agriculture. As eukaryotic organisms, fungi share some important features with mammalian cells. Therefore, current anti-fungal antibiotics often can not distinguish between fungi and mammalian cells, resulting in serious side effects in mammalian cells. Accordingly, there is strong impetus to develop antifungal alternatives that are both safe and effective. The E1 family of colicin are channel-forming bacteriocins produced by Escherichia coli, which are bactericidal only to E. coli and related species. To target the channel-forming domain of colicin to fungal cell membrane, we engineered a sexual mating pheromone of Candida albicans, α-factor pheromone to colicin Ia. A peptide was constructed consisting of an α mating pheromone of C. albicans fused to the channel-forming domain of colicin Ia to create a new fusion protein, pheromonicin-CA (PMC-CA). Indirect immunolabeling showed that the PMC-CA bound to fungal cells and inhibited growth in the laboratory and field. In the field, the protective activity of pheromonicin against rice blast disease was significantly greater, on a molar basis, than that of triazoles, tricyclazole or isoprothiolane. These results suggest that fusion peptides may be of value as fungicidal agents under agricultural conditions.


Assuntos
Colicinas/química , Fungicidas Industriais/química , Peptídeos/química , Candida albicans/química , Fator de Acasalamento , Engenharia de Proteínas
15.
Adv Healthc Mater ; 12(31): e2301729, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37531233

RESUMO

Peripheral nerve defects, particularly those of a larger size, pose a significant challenge in clinical practice due to their limited regenerative capacity. To tackle this challenge, an advanced self-powered enzyme-linked microneedle (MN) nerve conduit is designed and fabricated. This innovative conduit is composed of anodic and cathodic MN arrays, which contain glucose oxidase (GOx) and horseradish peroxidase (HRP) encapsulated in ZIF-8 nanoparticles, respectively. Through an enzymatic cascade reaction, this MN nerve conduit generates microcurrents that stimulate the regeneration of muscles, blood vessels, and nerve fibers innervated by the sciatic nerve, eventually accelerating the repair of sciatic nerve injury. It is clear that this self-powered MN nerve conduit will revolutionize traditional treatment methods for sciatic nerve injury and find widespread application in the field of nerve tissue repair.


Assuntos
Tecido Nervoso , Traumatismos dos Nervos Periféricos , Ratos , Animais , Ratos Sprague-Dawley , Nervo Isquiático/fisiologia , Traumatismos dos Nervos Periféricos/terapia , Próteses e Implantes , Regeneração Nervosa/fisiologia
16.
Microbiol Spectr ; 11(1): e0120022, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36475882

RESUMO

ppGpp is a ubiquitous small nucleotide messenger that mediates cellular self-protective responses under environmental stress. However, the mechanisms of ppGpp that control transcription and other metabolic processes depend on the species, and ppGpp regulates the same process via different mechanisms. The level of ppGpp is regulated by RelA/SpoT homolog (RSH) enzymes that synthesize and hydrolyze the alarmone. Here, we constructed a ppGpp0 strain and monitored the effects of ppGpp on the transcriptional level, physiology, and secondary metabiotic production in the antibiotic producer Streptomyces diastatochromogenes 1628. The results showed the cell division and growth of ppGpp0 increased by measurement of gene transcription and DCWs. The utilization of nitrogen was affected depending on the nitrogen type with a significantly higher DCW of the ppGpp0 mutant in the medium supplied with the yeast extract and a lower growth rate in the inorganic nitrogen ammonium salt. The ppGpp-mediated stringent response could not affect the usage of carbon resources. More importantly, ppGpp0 inhibited the expression of antibiotic clusters and the production of toyocamycin and tetramycin P. The antibiotic resistance was also significantly downregulated in the ppGpp0 mutant. In conclusion, this study showed detailed changes in ppGpp-mediated stringent responses on S. diastatochromogenes 1628 cell growth, nutrient utilization, morphological characteristics, antibiotic production, and resistance, which will provide insights into the role of ppGpp in Streptomyces. IMPORTANCE The ppGpp-mediated stringent response is widely distributed in Escherichia coli, Bacillus subtilis, Streptomyces, Staphylococcus aureus, etc. Stringent responses give strains the ability to resist environmental stresses, and survival from nutrition starvation, virulence, long-term persistence, biofilm formation, and gut colonization. ppGpp has many targets in cells and can reprogram DNA replication, transcription, ribosome biogenesis and function, and lipid metabolism. However, the mechanism of ppGpp to control transcription and other metabolic processes depends on the bacterial species and regulates the same process via a different mechanism. In Streptomyces, how ppGpp regulates the transcription remains to be elucidated. However, because ppGpp regulates many genes involved in primary and secondary metabolism, we compared the transcription and cell division, cell growth, morphological differentiation, antibiotic resistance, and secondary synthesis in the wild-type S. diastatochromogenes and ppGpp0 strains.


Assuntos
Guanosina Tetrafosfato , Streptomyces , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Antibacterianos , Escherichia coli/genética , Nitrogênio/metabolismo , Regulação Bacteriana da Expressão Gênica
17.
Sci Adv ; 9(28): eadh1415, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37450590

RESUMO

Diabetic wounds with complex pathological features and a difficult-to-heal nature remain a formidable challenge. To address this challenge, we design and fabricate a self-powered enzyme-linked microneedle (MN) patch composed of anode and cathode MN arrays, which respectively contain glucose oxidase (GOx) and horseradish peroxidase (HRP) encapsulated in ZIF-8 nanoparticles. The enzymatic cascade reaction in the MN patch can effectively reduce local hyperglycemia in diabetic wounds while generating stable microcurrents to promote rapid healing of diabetic wounds. Therefore, the diabetic wounds treated with this MN patch exhibit rapid, complete, and scar-preventative healing, which can be attributed to the synergistic actions of hypoglycemic, antibacterial, anti-inflammatory, and bioelectrical stimulation. In brief, the self-powered MN patch is an effective method to rapidly promote diabetic wound healing and prevent scar formation.


Assuntos
Diabetes Mellitus , Hiperglicemia , Humanos , Cicatriz , Cicatrização/fisiologia
18.
Anim Nutr ; 13: 261-269, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37168446

RESUMO

The glucose metabolism of poultry draws wide attention as they have nearly twice the fasting blood glucose than that of mammals. To define the relationship between glucose metabolism and breed of chicken, the outcomes from different growth rate chickens showed that Arbor Acres (AA) broilers, a well-known fast-growing breed, had a lower fasting blood glucose concentration and glucose clearance rate when compared to Silky chickens, a Chinese traditional medicinal chicken with black skin and a slow growth rate. Moreover, AA broilers had a relatively slow rise in blood glucose in response to oral glucose solution than the Silky chickens on 21 and 42 d (P < 0.05), which is probably attributed to downregulated expression of pancreatic insulin (INS), and upregulated transcription of phosphoenolpyruvate carboxy kinase 1 (PCK1) and glucose transporter 2 (GLUT2) in the liver of AA broilers (P < 0.05). In response to feeding restriction from 7 to 21 d, both the fasting blood glucose and the response speed of AA broilers to oral glucose were increased on d 21 (P < 0.05), and the serum glucose concentrations after 3 weeks compensatory growth were improved by early feed restriction in AA broilers. Feed restriction could also upregulate the mRNA level of pancreatic INS on d 21 and 42, as well as decrease the expressions of PCK1, glucose-6-phosphatase catalytic (G6PC), and GLUT2 in the liver on d 21 (P < 0.05) when compared to the free feeding group. These results revealed that Silky chickens have a stronger capability to regulate glucose homeostasis than AA broilers, and feed restriction could improve the fasting blood glucose and the response to oral glucose of AA broilers.

19.
Int Immunopharmacol ; 118: 110144, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37030120

RESUMO

The aims of the present study were to examine the signaling mechanisms for transforming growth factor-ß1 (TGF-ß1)-induced rat airway smooth muscle cells (ASMCs) proliferation and migration and to determine the effect of lipoxin A4 (LXA4) on TGF-ß1-induced rat ASMCs proliferation and migration and its underlying mechanisms. TGF-ß1 upregulated transcriptional coactivator Yes-associated protein (YAP) expression by activating Smad2/3 and then upregulated cyclin D1, leading to rat ASMCs proliferation and migration. This effect was reversed after treatment with the TGF-ß1 receptor inhibitor SB431542. YAP is a critical mediator of TGF-ß1-induced ASMCs proliferation and migration. Knockdown of YAP disrupted the pro-airway remodeling function of TGF-ß1. Preincubation of rat ASMCs with LXA4 blocked TGF-ß1-induced activation of Smad2/3 and changed its downstream targets, YAP and cyclin D1, resulting in the inhibition of rat ASMCs proliferation and migration. Our study suggests that LXA4 suppresses Smad/YAP signaling to inhibit rat ASMCs proliferation and migration and therefore has potential value in the prevention and treatment of asthma by negatively modulating airway remodeling.


Assuntos
Ciclina D1 , Fator de Crescimento Transformador beta1 , Animais , Ratos , Remodelação das Vias Aéreas , Proliferação de Células , Ciclina D1/genética , Ciclina D1/metabolismo , Miócitos de Músculo Liso/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
20.
Quant Imaging Med Surg ; 13(4): 2426-2440, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37064370

RESUMO

Background: The sensitivity and correlation of coronary computed tomography angiography (CTA) as compared with histopathology are unknown in evaluating coronary arterial calcification. In this study, we retrospectively evaluated qualitatively and quantitatively the sensitivity and correlation of coronary CTA compared with histopathology in assessing coronary arterial calcification. Methods: This study was conducted on 12 randomly selected cadavers aged over 40 years at the time of death, and 53 segments of coronary arteries from these 12 cadavers were obtained from the Human Anatomy Laboratory of Tianjin Medical University. The artery segments were scanned using contrasted-enhanced dual-source computed tomography (DSCT) with an axial slice thickness of 0.6 mm. Coronary artery calcification in a coronary segment was defined as the presence of 1 or more voxels with a CT density >130 Hounsfield units. According to the arc of calcification in the cross section of the coronary artery wall, calcified plaques were divided into three categories: mild, moderate, and severe calcification. The coronary artery stenosis caused by calcified plaque was observed and calculated with multiplanar reconstruction (MPR), maximum density projection, volume rendering (VR), and cross-sectional reconstruction. After CT enhancement scanning, the coronary artery specimens were cut into 4-mm long segments and embedded in paraffin for pathological staining. Pathological classification and coronary artery stenosis measured with pathological analysis were used as comparison criteria. Results: Histopathology detected 69 Vb-type plaques, while DSCT detected 57 calcified plaques. The sensitivity of CT for detecting mild, moderate, and severe calcified plaques were 88.3% [95% confidence interval (CI): 74.1-95.6%], 100% (95% CI: 69.8-100%), and 100% (95% CI: 73.2-100%), respectively. DSCT had a significant (P<0.001) correlation with histopathology in quantifying coronary artery stenosis caused by mild, moderate, and severe calcified plaques (R2=0.9278, R2=0.9158, R2=0.7923, respectively). Compared with histopathology, DSCT overestimated coronary artery stenosis caused by mild, moderate, and severe calcified plaques (3.2%±2.0%, 4.9%±4.7%, and 14.7%±8.2%, respectively; P<0.05). Conclusions: DSCT contrast enhancement scanning can detect and characterize coronary artery calcification with a good correlation with histopathologic quantification of coronary artery stenosis caused by different types of calcified plaques, even though coronary CTA may overestimate the stenosis.

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