Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chin J Integr Med ; 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33515398

RESUMO

OBJECTIVE: To investigate whether blood-brain barrier (BBB) served a key role in the edema-relief effect of bloodletting puncture at hand twelve Jing-well points (HTWP) in traumatic brain injury (TBI) and the potential molecular signaling pathways. METHODS: Adult male Sprague-Dawley rats were assigned to the sham-operated (sham), TBI, and bloodletting puncture (bloodletting) groups (n=24 per group) using a randomized number table. The TBI model rats were induced by cortical contusion and then bloodletting puncture were performed at HTWP twice a day for 2 days. The neurological function and cerebral edema were evaluated by modified neurological severity score (mNSS), cerebral water content, magnetic resonance imaging and hematoxylin and eosin staining. Cerebral blood flow was measured by laser speckles. The protein levels of aquaporin 4 (AQP4), matrix metalloproteinases 9 (MMP9) and mitogen-activated protein kinase pathway (MAPK) signaling were detected by immunofluorescence staining and Western blot. RESULTS: Compared with TBI group, bloodletting puncture improved neurological function at 24 and 48 h, alleviated cerebral edema at 48 h, and reduced the permeability of BBB induced by TBI (all P<0.05). The AQP4 and MMP9 which would disrupt the integrity of BBB were downregulated by bloodletting puncture (P<0.05 or P<0.01). In addition, the extracellular signal-regulated kinase (ERK) and p38 signaling pathways were inhibited by bloodletting puncture (P<0.05). CONCLUSIONS: Bloodletting puncture at HTWP might play a significant role in protecting BBB through regulating the expressions of MMP9 and AQP4 as well as corresponding regulatory upstream ERK and p38 signaling pathways. Therefore, bloodletting puncture at HTWP may be a promising therapeutic strategy for TBI-induced cerebral edema.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33145737

RESUMO

The article Photocatalytic kinetics and cyclic stability of photocatalysts Fe-complex/TiO2 in the synergistic degradation of phenolic pollutants and reduction of Cr(VI), written by Tongtong Guo, Shuang Yang, Yunning Chen, Lu Yang, Yingnan Sun and Qingkun Shang, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 20 October 2020 with open access.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33079350

RESUMO

In this paper, the kinetic characteristics and cycle stability of Fe-complex/TiO2 in the process of degradation of phenolic pollutants and reduction of heavy metal Cr(VI) were studied systematically. First, the structural characteristics and photocatalytic activities of Fe(III)-(8-hydroxyquinoline-5-carboxylic acid)-TiO2 (Fe-HQC-TiO2) nanoparticle to degrade phenolic pollutants and reduce Cr(VI) simultaneously had been investigated. Compared with the single degradation, the efficiency of synergistic degradation/reduction had been improved and the degradation/reduction rate had been obviously accelerated. In particular, the cyclic stability of Fe-HQC-TiO2 photocatalyst decreased obviously when it was used to reduce Cr(VI) alone, but it could still keep above 90% after three cycles when it was used for reduction of Cr(VI) and degradation of phenol synergistically. Second, to Fe-HQS/TiO2 nanoparticle or Fe-HQS/TiO2 nanotube (HQS (8-hydroxyquinoline-5-sulfonic acid)), the synergistic degradation/reduction (2,4-dichlorophenol/Cr(VI)) efficiencies were always greater than those of a single degradation/reduction and the time was greatly reduced. All the results indicated that there were interactions between Cr(VI) and phenol or 2,4-dichlorophenol in the photocatalytic process. The possible mechanism of synergistic accelerated degradation of phenolic compounds and reduction of Cr(VI) was proposed by analyzing and testing the surface characteristics of photocatalyst and the properties of photocatalytic system during the synergistic degradation/reduction.

4.
Biosens Bioelectron ; 170: 112662, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33032198

RESUMO

Cancer cell enumeration and phenotyping can predict the prognosis and the therapy efficacy in patients, yet it remains challenging to detect the rare tumor cells. Herein, we report an octopus-inspired, bifunctional aptamer signal amplifier-based cytosensor (OApt-cytosensor) for sensitive cell analysis. By assembling high-affinity antibodies on an electrode surface, the target cells could be specifically captured and thus been sandwiched by the cell surface marker-specific DNA aptamers. These on-cell aptamers function as electrochemical signal amplifiers by base-selective electronic doping with methylene blue. Such a sandwich configuration enables highly sensitive cell detection down to 10 cells/mL (equal to ~1-2 cells at a sampling volume of 150 µL), even in a large excess of nontarget blood cells. This approach also reveals the cell-surface markers and tracks the cellular epithelial-to-mesenchymal transition induced by signaling regulators. Furthermore, the electron-doped aptamer shows remarkable cell fluorescent labeling that guides the release of the captured cells from electrode surface via electrochemistry. These features make OApt-cytosensor a promising tool in revealing the heterogeneous cancer cells and anticancer drug screening at the single-cell level.

5.
Plant Physiol ; 184(1): 487-505, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32661061

RESUMO

Cryptochromes are photolyase-like, blue-light (BL) photoreceptors found in various organisms. Arabidopsis (Arabidopsis thaliana) cryptochromes (CRYs; CRY1, and CRY2) mediate many light responses including photoperiodic floral initiation. Cryptochromes interact with COP1 and SPA1, causing the stabilization of CONSTANS (CO) and promotion of FLOWERING LOCUS T (FT) transcription and flowering. The AP2-like transcriptional factor TOE1 negatively regulates FT expression and flowering by indirectly inhibiting CO transcriptional activation activity and directly binding to FT Here, we demonstrate that CRY1 and CRY2 physically interact with TOE1 and TOE2 in a BL-dependent manner in flowering regulation. Genetic studies showed that mutation of TOE1 and TOE2 partially suppresses the late-flowering phenotype of cry1 cry2 mutant plants. BL-triggered interactions of CRY2 with TOE1 and TOE2 promote the dissociation of TOE1 and TOE2 from CO, resulting in alleviation of their inhibition of CO transcriptional activity and enhanced transcription of FT Furthermore, we show that CRY2 represses TOE1 binding to the regulatory element within the Block E enhancer of FT These results reveal that TOE1 and TOE2 act as downstream components of CRY2, thus partially mediating CRY2 regulation of photoperiodic flowering through modulation of CO activity and FT transcription.

6.
ACS Sens ; 5(8): 2514-2522, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32664724

RESUMO

MicroRNA (MiRNA)-based noninvasive diagnostics are hampered by the challenge in the quantification of circulating miRNAs using a general strategy. Here, we present a base-stacking effect-mediated ultrasensitive electrochemical miRNA sensor (BSee-miR) with a universal sandwich configuration. In the BSee-miR, a short DNA probe (10 nucleotides) self-assembled on a gold electrode surface could effectively capture the target miRNA synergizing with another sequence based on coaxial sandwich base-stacking, which rivals the fully complementary strength. Importantly, such a sandwich structure is flexible to incorporate signal amplification strategies (e.g., biotin-avidin) that are usually difficult to achieve in short sequence detection. Using this design, the BSee-miR achieves a broad dynamic range with a detection limit down to 7.5 fM. Furthermore, we found a high-curvature nanostructuring synergetic base-stacking effect that could improve the sensitivity of the BSee-miR by two orders of magnitude (79.3 aM). Our BSee-miR also has a single-base resolution to discriminate the highly homologous miRNAs. More importantly, this approach is universal and has been used to probe target miRNAs varying in sequences and secondary structures. Our ultrasensitive sensor could detect miRNA in cell lysates and human blood and distinguish cancer patients from normal individuals, promising a versatile tool to measure clinically relevant miRNAs for tumor diagnostics.

7.
New Phytol ; 225(2): 848-865, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514232

RESUMO

Arabidopsis CRY1 and phyB are the primary blue and red light photoreceptors mediating blue and red light inhibition of hypocotyl elongation, respectively. Auxin is a pivotal phytohormone involved in promoting hypocotyl elongation. CRY1 and phyB interact with and stabilize auxin/indole acetic acid proteins (Aux/IAAs) to inhibit auxin signaling. The present study investigated whether photoreceptors might interact directly with Auxin Response Factors (ARFs) to regulate auxin signaling. Protein-protein interaction studies demonstrated that CRY1 and phyB interact physically with ARF6 and ARF8 through their N-terminal domains in a blue and red light-dependent manner, respectively. Moreover, the N-terminal DNA-binding domain of ARF6 and ARF8 is involved in mediating their interactions with CRY1. Genetic studies showed that ARF6 and ARF8 act partially downstream from CRY1 and PHYB to regulate hypocotyl elongation under blue and red light, respectively. Chromatin immunoprecipitation-PCR assays demonstrated that CRY1 and phyB mediate blue and red light repression of the DNA-binding activity of ARF6 and ARF6-target gene expression, respectively. Altogether, the results herein suggest that the direct repression of auxin-responsive gene expression mediated by the interactions of CRY1 and phyB with ARFs constitutes a new layer of the regulatory mechanisms by which light inhibits auxin-induced hypocotyl elongation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , DNA de Plantas/metabolismo , Hipocótilo/crescimento & desenvolvimento , Ácidos Indolacéticos/farmacologia , Luz , Arabidopsis/efeitos dos fármacos , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/química , Criptocromos/química , Criptocromos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Hipocótilo/efeitos dos fármacos , Hipocótilo/metabolismo , Modelos Biológicos , Fitocromo B/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/efeitos da radiação , Domínios Proteicos , Fatores de Transcrição/metabolismo
8.
Food Sci Biotechnol ; 28(6): 1617-1625, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31807334

RESUMO

Tea catechins have attracted strong interests in pharmacological field for their extensive biological activities; however, their bioavailability in vivo is relatively low. Recent studies have shown tea catechins can modulate the composition of intestinal microbiota and help to improve hosts' health. Meanwhile, the gut flora plays a crucial role in regulating the production of the metabolites of tea catechins and their biological activity. Although the activities of tea catechins to promote intestinal micro-ecology have been extensively studied, little is known about the two-way phenol-microbial interactions. This review focuses on the modulatory effect of tea catechins on intestinal microbiota as well as the microbial degradation of tea catechins and the metabolites formed. Finally, the potential effects of tea catechins on chronic intestinal inflammation are emphasized.

9.
J Agric Food Chem ; 67(43): 11969-11976, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31583884

RESUMO

Our present study focused on the regulating effect of oolong tea polyphenols (OTPs) on the circadian rhythm of liver and intestinal microbiome. OTP significantly alleviated the disrupted diurnal oscillation and phase shift of the specific intestinal microbiota and liver clock genes in mice induced by constant dark (CD) treatment. Transcriptomics revealed that 1114 genes in the control group and 647 genes in the CD group showed circadian rhythm while 723 genes were rhythmic in the CD-OTP group. The Gene Ontology (GO) database provided significant differences in differentially expressed genes (DEGs) in response to OTP treatment. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched the most DEGs after OTP intervention including "Focal adhesion" (9 DEGs) and "PI3K-Akt signaling pathway" (9 DEGs). The present study provided a global view that OTP may alleviate the circadian rhythm disorder of the host, contributing to the improvement of microecology and health.


Assuntos
Camellia sinensis/química , Ritmo Circadiano/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/microbiologia , Fígado/metabolismo , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Adulto , Animais , Feminino , Ontologia Genética , Humanos , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transcriptoma/efeitos dos fármacos
10.
J Colloid Interface Sci ; 557: 825-836, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31580978

RESUMO

Measuring glucose in a convenient and economical manner is crucial for diabetes diagnostics and surveillance. Ongoing efforts are devoted to nonenzymatic sensors using functional nanomaterials. Drawbacks due to costly and cumbersome process, however, hamper the practicality. Here, we report the facile preparation of Cu/Ni bimetallic nanocatalyst toward glucose electrooxidation. Carboxylated multi-walled carbon nanotubes were chemically grafted onto indium tin oxide glass via silanization reaction and amide coupling reaction, providing distinct nucleation sites for Cu/Ni bimetallic electrocatalyst prepared by in-situ succinct electrodeposition, which synthetically created a three-dimensional electron transfer network. The surface morphology and chemical constituents were characterized by scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, infrared spectroscopy and atomic force microscopy. The prepared electrocatalyst displayed ultrahigh electrochemical activity; the catalytic current density for glucose oxidation was found to be over 6.7 mA mM-1 cm-2. The linear response spanned three orders of magnitude of glucose concentration ranging from 1 µM to 1 mM. Analytical parameters such as accuracy, reproducibility, specificity and stability have also been validated. Importantly, we reveal that Ni plays a dominant role over Cu in electrocatalytic oxidation of glucose, thus bettering our understanding and strategy for nonenzymatic glucose sensor design. Advantages of the glucose sensor presented include easy bulk preparation, low cost, and ready-to-use.


Assuntos
Ligas/química , Cobre/química , Glucose/análise , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Níquel/química , Técnicas Biossensoriais , Catálise , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , Oxirredução , Reprodutibilidade dos Testes , Propriedades de Superfície
11.
J Agric Food Chem ; 67(32): 8847-8854, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328515

RESUMO

Microbiome has been revealed as a key element involved in maintaining the circadian rhythms. Oolong tea polyphenols (OTP) has been shown to have potential prebiotic activity. Therefore, this study focused on the regulation mechanisms of OTP on host circadian rhythms. After 8 weeks of OTP administration, a large expansion in the relative abundance of Bacteroidetes with a decrease in Firmicutes was observed, which reflected the positive modulatory effect of OTP on gut flora. In addition, Kyoto Encyclopedia of Genes and Genomes pathways of ATP-binding cassette transporters, two-component system, and the biosynthesis of amino acids enriched the most differentially expressed genes after OTP treatment. Of the differentially expressed proteins identified, most were related to metabolism, genetic information processing, and environmental information processing. It underscores the ability of OTP to regulate circadian rhythm by enhancing beneficial intestinal microbiota and affecting metabolic pathways, contributing to the improvement of host microecology.


Assuntos
Camellia sinensis/química , Transtornos Cronobiológicos/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Transtornos Cronobiológicos/microbiologia , Transtornos Cronobiológicos/fisiopatologia , Modelos Animais de Doenças , Feminino , Humanos , Intestinos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chá/química
12.
Sci Total Environ ; 656: 1010-1020, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30625633

RESUMO

Photocatalysis is one of the effective strategies to eliminate various organic pollutants in water body. In this paper we have prepared a series of new composite photocatalysts to degrade phenol and norfloxacin under visible light irradiation. They were [FeII(dpbpy)2(H2O)2]/TiO2, [FeII(dpbpy)(phen)2]/TiO2 and [FeII(dpbpy)(bpy)2]/TiO2 (dpbpy: 2,2'-bipyridine-4,4'-diphosphoric acid, phen: 1,10-phenanthroline, bpy: 2,2-bipyridyl). The results show that their photocatalytic performance and cyclic stability are much better than that of pure TiO2 or P25. Phenol can be degraded almost completely and the active groups or substituents of norfloxacin (NOR) can be destroyed also, which greatly reduced the biological toxicity of phenol and norfloxacin in water. The possible mechanisms of improving the photocatalytic activity and stability of TiO2 by using Fe-complex are proposed based on free radical capture test and density functional theory calculation. It is clearly that the interfacial interaction between Fe-complex and titanium dioxide directly affects the photocatalytic activity and stability of the composite photocatalyst. The conjugated structure of the complexes plays a crucial role.


Assuntos
Ferro/química , Norfloxacino/análise , Fenol/análise , Fotólise , Titânio/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Antibacterianos/análise , Nanopartículas Metálicas/química
13.
Plant Cell ; 30(9): 1989-2005, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30131420

RESUMO

Cryptochromes (CRYs) are blue light photoreceptors that mediate a variety of light responses in plants and animals, including photomorphogenesis, flowering, and circadian rhythms. The signaling mechanism by which Arabidopsis thaliana cryptochromes CRY1 and CRY2 promote photomorphogenesis involves direct interactions with COP1, a RING motif-containing E3 ubiquitin ligase, and its enhancer SPA1. Brassinosteroid (BR) is a key phytohormone involved in the repression of photomorphogenesis, and here, we show that the signaling mechanism of Arabidopsis CRY1 involves the inhibition of BR signaling. CRY1 and CRY2 physically interact with BES1-INTERACTING MYC-LIKE1 (BIM1), a basic helix-loop-helix protein. BIM1, in turn, interacts with and enhances the activity of BRI1-EMS SUPPRESSOR1 (BES1), a master transcription factor in the BR signaling pathway. In addition, CRY1 and CRY2 interact specifically with dephosphorylated BES1, the physiologically active form of BES1 that is activated by BR in a blue light-dependent manner. The CRY1-BES1 interaction leads to both the inhibition of BES1 DNA binding activity and the repression of its target gene expression. Our study suggests that the blue light-dependent, BR-induced interaction of CRY1 with BES1 is a tightly regulated mechanism by which plants optimize photomorphogenesis according to the availability of external light and internal BR signals.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Criptocromos/metabolismo , Luz , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Criptocromos/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fosforilação/efeitos da radiação , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação
14.
Ecotoxicol Environ Saf ; 163: 172-179, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30053587

RESUMO

Hg contamination is a critical environmental problem, and its remediation using cost-effective and environmentally friendly methods is highly desirable. In this study, a multi-metal-resistant bacterium showing strong Hg(II) volatilization ability, Pseudomonas sp. DC-B1, was isolated from heavy metal-contaminated soils. DC-B1 volatilized 81.1%, 79.2% and 74.3% of the initial Hg2+ from culture solutions with initial Hg2+ concentrations of 5.1, 10.4, and 15.7 mg/L, respectively, within 24 h. Microcosm experiments were performed to investigate the remediation of Hg(II)-spiked soils inoculated with DC-B1 coupled with sawdust biochar amendment. The efficiency of Hg removal from two types of soil samples with different properties and an initial Hg(II) content of approximately 100 mg/kg was enhanced 5.7-13.1% by bio-augmentation with inoculation of the bacterial strain DC-B1, 5.4-10.7% by amendment of 4% (w/w) biochar, and 10.7-23.2% by the combination of DC-B1 and biochar amendments over an incubation period of 24 d over the efficiency in the control treatment under flooded conditions. Longer root lengths were observed in lettuce grown in the treated soils than in lettuce from the control soil, confirming the bioremediation efficacy of the two bioagents for soil Hg contamination.


Assuntos
Biodegradação Ambiental , Carvão Vegetal , Mercúrio/química , Pseudomonas/fisiologia , Poluentes do Solo/química , Solo/química , Recuperação e Remediação Ambiental/métodos , Alface/crescimento & desenvolvimento , Metais Pesados/química , Raízes de Plantas/crescimento & desenvolvimento , Pseudomonas/classificação , Especificidade da Espécie , Volatilização
15.
PLoS Genet ; 14(3): e1007247, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29522510

RESUMO

Light and microRNAs (miRNAs) are key external and internal signals for plant development, respectively. However, the relationship between the light signaling and miRNA biogenesis pathways remains unknown. Here we found that miRNA processer proteins DCL1 and HYL1 interact with a basic helix-loop-helix (bHLH) transcription factor, phytochrome-interacting factor 4 (PIF4), which mediates the destabilization of DCL1 during dark-to-red-light transition. PIF4 acts as a transcription factor for some miRNA genes and is necessary for the proper accumulation of miRNAs. DCL1, HYL1, and mature miRNAs play roles in the regulation of plant hypocotyl growth. These results uncovered a previously unknown crosstalk between miRNA biogenesis and red light signaling through the PIF4-dependent regulation of miRNA transcription and processing to affect red-light-directed plant photomorphogenesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ciclo Celular/metabolismo , MicroRNAs/metabolismo , Ribonuclease III/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Ciclo Celular/genética , Regulação da Expressão Gênica de Plantas , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Luz , MicroRNAs/genética , Plantas Geneticamente Modificadas , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/genética , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
J Orthop Surg Res ; 13(1): 19, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382342

RESUMO

BACKGROUND: It is difficult to repair cartilage damage when cartilage undergoes trauma or degeneration. Cartilage tissue engineering is an ideal treatment method to repair cartilage defects, but at present, there are still some uncertainties to be researched in cartilage tissue engineering including the mechanical properties of the repaired region. METHODS: In this study, using an agarose gel as artificial cartilage implanted into the cartilage defect and gluing the agarose gel to cartilage by using the medical bio-adhesive, the full-thickness and half-thickness defects models of articular cartilage in vitro repaired by tissue engineering were constructed. Strain behaviors of the repaired region were analyzed by the digital correlation technology under 5, 10, 15, and 20% compressive load. RESULTS: The axial normal strain (Ex) perpendicular to the surface of the cartilage and lateral normal strain (Ey) as well as shear strain (Exy) appeared obviously heterogeneous in the repaired region. In the full-defect model, Ex showed depth-dependent strain profiles where maximum Ex occurs at the low middle zone while in the half-defect mode, Ex showed heterogeneous strain profiles where maximum Ex occurs at the near deep zone. Ey and Exy at the interface site of both models present significantly differed from the host cartilage site. Ey and Exy exhibited region-specific change at the host, interface, and artificial cartilage sites in the superficial, middle, and deep zones due to the artificial cartilage implantation. CONCLUSION: Both defect models of cartilage exhibited a heterogeneous strain field due to the engineered cartilage tissue implant. The abnormal strain field can cause the cells within the repaired area to enter complex mechanical states which will affect the restoration of cartilage defects.


Assuntos
Cartilagem Articular/lesões , Engenharia Tecidual/métodos , Animais , Órgãos Bioartificiais , Cartilagem Articular/fisiopatologia , Cartilagem Articular/cirurgia , Força Compressiva , Sefarose , Estresse Mecânico , Sus scrofa , Adesivos Teciduais/uso terapêutico , Suporte de Carga
17.
Mol Plant ; 10(10): 1334-1348, 2017 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-28943325

RESUMO

Nuclear lamins are involved in multiple biological processes in metazoan cells. The proteins of the CROWDED NUCLEI (CRWN) family are considered lamin-like candidates in Arabidopsis, although the functions of these proteins are largely unknown. In this article we show that crwn1 crwn2 double mutant displays an enhanced resistance against virulent bacterial pathogens, and both virulent bacteria and salicylic acid (SA) induce transcription of CRWN1 gene as well as proteasome-mediated degradation of CRWN1 protein. We also show that CRWN1 interacts with NAC WITH TRANSMEMBRANE MOTIF1-LIKE9 (NTL9), a NAC transcription factor involved in plant immunity. The interaction between CRWN1 and NTL9 enhances the binding of NTL9 to the promoter of the PATHOGENESIS-RELATED1 (PR1) gene, and inhibits PR1 expression. Further genetic experiments indicated that the defense-related phenotypes of crwn1 crwn2 double mutant are dependent on NONEXPRESSOR OF PR GENES1 (NPR1), a transcriptional cofactor of PR1. These findings revealed a regulatory network composed of lamin-like protein CRWN1, NTL9, and NPR1 for the regulation of PR1 expression.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/imunologia , Laminas/fisiologia , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/microbiologia , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Laminas/química , Mutação , Proteínas Nucleares/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Pseudomonas syringae/fisiologia , Ácido Salicílico/metabolismo
18.
Sci Rep ; 6: 32630, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27586270

RESUMO

Nitric oxide synthase like enzyme (NOS-like enzyme), which produces nitric oxide, participates in many biological processes. However it remains unidentified and highly controversial that plants do possess a NOS-like enzyme. In this paper, a novel arginine analogue NP1 was designed and developed for the direct identification and real time tracking of NOS-like enzymes in plant by fluorescence sensing. It could bind NOS-like enzyme efficiently and enter the cell successfully. In vivo fluorescence response results directly proved that NOS-like enzymes did exist in tobacco leaf and would be stimulated by pathogen infection, which also provided a useful chemical tool for the study of the function of NOS-like enzyme in plants.


Assuntos
Arginina/análogos & derivados , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Imagem Molecular/métodos , Óxido Nítrico Sintase/metabolismo , Tabaco/enzimologia , Animais , Arginina/metabolismo , Fluorescência , Corantes Fluorescentes/síntese química , Camundongos , Epiderme Vegetal/citologia , Folhas de Planta/enzimologia
20.
PLoS Genet ; 11(10): e1005598, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26473486

RESUMO

The precise regulation of microRNA (miRNA) transcription and processing is important for eukaryotic development. Plant miRNAs are first transcribed as stem-loop primary miRNAs (pri-miRNAs) by RNA polymerase II,then cleaved in the nucleus into mature miRNAs by Dicer-like 1 (DCL1). We identified a cycling DOF transcription factor, CDF2, which interacts with DCL1 and regulates the accumulation of a population of miRNAs. CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes. CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs. Genetically, CDF2 works in the same pathway as miR156 or miR172 to control flowering. We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Ciclo Celular/genética , MicroRNAs/genética , Ribonuclease III/genética , Fatores de Transcrição/genética , Transcrição Genética , Arabidopsis/genética , Núcleo Celular/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/biossíntese , RNA Polimerase II/genética , Processamento Pós-Transcricional do RNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA