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Chilling injury has a negative impact on the quantity and quality of crops, especially subtropical and tropical plants. The plant cell wall is not only the main source of biomass production, but also the first barrier to various stresses. Therefore, improving the understanding of the alterations in cell wall architecture is of great significance for both biomass production and stress adaptation. Herein, we demonstrated that the cell wall principal component cellulose accumulated during chilling stress, which was caused by the activation of MaCESA proteins. The sequence-multiple comparisons show that a cold-inducible NAC transcriptional factor MaNAC1, a homologue of Secondary Wall NAC transcription factors, has high sequence similarity with Arabidopsis SND3. An increase in cell wall thickness and cellulosic glucan content was observed in MaNAC1-overexpressing Arabidopsis lines, indicating that MaNAC1 participates in cellulose biosynthesis. Over-expression of MaNAC1 in Arabidopsis mutant snd3 restored the defective secondary growth of thinner cell walls and increased cellulosic glucan content. Furthermore, the activation of MaCESA7 and MaCESA6B cellulose biosynthesis genes can be directly induced by MaNAC1 through binding to SNBE motifs within their promoters, leading to enhanced cellulose content during low-temperature stress. Ultimately, tomato fruit showed greater cold resistance in MaNAC1 overexpression lines with thickened cell walls and increased cellulosic glucan content. Our findings revealed that MaNAC1 performs a vital role as a positive modulator in modulating cell wall cellulose metabolism within banana fruit under chilling stress.
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Arabidopsis , Musa , Celulose/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Musa/genética , Musa/metabolismo , Frutas/genética , Frutas/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Integuments form important protective cell layers surrounding the developing ovules in gymno- and angiosperms. Although several genes have been shown to influence the development of integuments, the transcriptional regulatory mechanism is still poorly understood. In this work, we report that the Class II KNOTTED1-LIKE HOMEOBOX (KNOX II) transcription factors KNOTTED1-LIKE HOMEBOX GENE 3 (KNAT3) and KNAT4 regulate integument development in Arabidopsis (Arabidopsis thaliana). KNAT3 and KNAT4 were co-expressed in inflorescences and especially in young developing ovules. The loss-of-function double mutant knat3 knat4 showed an infertility phenotype, in which both inner and outer integuments of the ovule are arrested at an early stage and form an amorphous structure as in the bell1 (bel1) mutant. The expression of chimeric KNAT3- and KNAT4-EAR motif repression domain (SRDX repressors) resulted in severe seed abortion. Protein-protein interaction assays demonstrated that KNAT3 and KNAT4 interact with each other and also with INNER NO OUTER (INO), a key transcription factor required for the outer integument formation. Transcriptome analysis showed that the expression of genes related with integument development is influenced in the knat3 knat4 mutant. The knat3 knat4 mutant also had a lower indole-3-acetic acid (IAA) content, and some auxin signaling pathway genes were downregulated. Moreover, transactivation analysis indicated that KNAT3/4 and INO activate the auxin signaling gene IAA INDUCIBLE 14 (IAA14). Taken together, our study identified KNAT3 and KNAT4 as key factors in integument development in Arabidopsis.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Óvulo Vegetal , Ácidos Indolacéticos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas Nucleares/metabolismoRESUMO
The production of Arabidopsis seed mucilage involves complex polysaccharide biosynthetic pathways and developmental processes in seed epidermal cells. Although the polysaccharide components of Arabidopsis seed mucilage have been identified, their regulatory mechanism requires further investigation. Here, we show that Class II KNOX gene family members KNAT3 and KNAT7 play an essential role in regulating mucilage production in the early developmental stages of Arabidopsis seeds. Double mutant knat3knat7 resulted in defective seed mucilage production and columellae formation, whereas knat3 showed a normal phenotype compared with wild type, and the mucilage thickness in knat7 was slightly disturbed. Rhamnogalacturonan I (RG-I) and its biosynthetic substrates galacturonic acid and rhamnose were reduced in both the adherent and soluble mucilage of knat3knat7. Comparative transcriptome analysis on whole seeds suggested that polysaccharide, glucosinolate and anthocyanin biosynthetic pathways were specifically repressed in knat3knat7. Transient co-expression of KNAT3 and KNAT7 with promoter regions of candidate genes in Arabidopsis protoplasts revealed that both KNAT3 and KNAT7 act as positive regulators of the RG-I biosynthetic gene MUCILAGE-MODIFIED 4 (MUM4, AT1G53500). Collectively, our results demonstrate that KNAT3 and KNAT7 are multifunctional transcription factors in secondary cell wall development and redundantly modulate mucilage biosynthesis in Arabidopsis seeds.
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Proteínas de Arabidopsis , Arabidopsis , Mucilagem Vegetal , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Mucilagem Vegetal/metabolismo , Polissacarídeos/metabolismo , Proteínas Repressoras/metabolismo , Sementes/genética , Sementes/metabolismoRESUMO
BACKGROUND: In rare cases, intrahepatic cholangiocarcinoma can present as a pyogenic liver abscess and are often misdiagnosed. This study aimed to analyze the imaging features of intrahepatic cholangiocarcinoma mimicking a pyogenic liver abscess. METHODS: The clinical data and imaging results of eight patients with pathologically confirmed intrahepatic cholangiocarcinoma mimicking a liver abscess were retrospectively collected. RESULTS: The mean age was 58 years with a range of 46-68 years. Fever and leukocytosis were present in six patients. All the eight lesions were a single mass. Air-liquid levels were present in two patients. Only one patient showed hepatic lobar atrophy and hepatic capsule retraction. The double target sign of liver abscess was not noticed in the CT/MRI images of all eight patients. The inner wall of the lesion was rough and irregular, with multiple dot/patchy and wall nodule enhancements. The abscess wall and the marginal parenchyma were supplied by the hepatic artery in four patients, and the intralesional arteries were rough and disrupted. Bile duct dilatation was seen adjacent to the lesion. In seven patients, diffusion-weighted images showed irregular patchy restricted diffusion in the marginal parenchyma of the necrotic area in addition to the prominent restricted diffusion in the necrotic area. Two patients with cholangiolithiasis showed patchy slight CT hypodensity, slight T1 hypointensity, slight T2 hyperintensity, and patchy delayed enhancement. Multiple lymph nodes enlargement in the hepatic hilar area and the retroperitoneal space were seen in five patients. CONCLUSION: Intrahepatic cholangiocarcinoma mimicking a pyogenic liver abscess have unique imaging features and require careful image examination to avoid misdiagnosis.
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Neoplasias dos Ductos Biliares , Colangiocarcinoma , Abscesso Hepático Piogênico , Idoso , Neoplasias dos Ductos Biliares/diagnóstico por imagem , Ductos Biliares Intra-Hepáticos/diagnóstico por imagem , Colangiocarcinoma/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
The function of the transcription factor KNOTTED ARABIDOPSIS THALIANA7 (KNAT7) is still unclear since it appears to be either a negative or a positive regulator for secondary cell wall deposition with its loss-of-function mutant displaying thicker interfascicular and xylary fiber cell walls but thinner vessel cell walls in inflorescence stems. To explore the exact function of KNAT7, class II KNOTTED1-LIKE HOMEOBOX (KNOX II) genes in Arabidopsis including KNAT3, KNAT4, and KNAT5 were studied together. By chimeric repressor technology, we found that both KNAT3 and KNAT7 repressors exhibited a similar dwarf phenotype. Both KNAT3 and KNAT7 genes were expressed in the inflorescence stems and the knat3 knat7 double mutant exhibited a dwarf phenotype similar to the repressor lines. A stem cross-section of knat3 knat7 displayed an enhanced irregular xylem phenotype as compared with the single mutants, and its cell wall thickness in xylem vessels and interfascicular fibers was significantly reduced. Analysis of cell wall chemical composition revealed that syringyl lignin was significantly decreased while guaiacyl lignin was increased in the knat3 knat7 double mutant. Coincidently, the knat3 knat7 transcriptome showed that most lignin pathway genes were activated, whereas the syringyl lignin-related gene Ferulate 5-Hydroxylase (F5H) was down-regulated. Protein interaction analysis revealed that KNAT3 and KNAT7 can form a heterodimer, and KNAT3, but not KNAT7, can interact with the key secondary cell wall formation transcription factors NST1/2, which suggests that the KNAT3-NST1/2 heterodimer complex regulates F5H to promote syringyl lignin synthesis. These results indicate that KNAT3 and KNAT7 synergistically work together to promote secondary cell wall biosynthesis.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Lignina , Proteínas Nucleares , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Despite continuous changes in treatment methods, the survival rate for advanced hepatocellular carcinoma (HCC) patients remains low, highlighting the importance of diagnostic methods for HCC. AIM: To explore the efficacy of texture analysis based on multi-parametric magnetic resonance (MR) imaging (MRI) in predicting microvascular invasion (MVI) in preoperative HCC. METHODS: This study included 105 patients with pathologically confirmed HCC, categorized into MVI-positive and MVI-negative groups. We employed Original Data Analysis, Principal Component Analysis, Linear Discriminant Analysis (LDA), and Non-LDA (NDA) for texture analysis using multi-parametric MR images to predict preoperative MVI. The effectiveness of texture analysis was determined using the B11 program of the MaZda4.6 software, with results expressed as the misjudgment rate (MCR). RESULTS: Texture analysis using multi-parametric MRI, particularly the MI + PA + F dimensionality reduction method combined with NDA discrimination, demonstrated the most effective prediction of MVI in HCC. Prediction accuracy in the pulse and equilibrium phases was 83.81%. MCRs for the combination of T2-weighted imaging (T2WI), arterial phase, portal venous phase, and equilibrium phase were 22.86%, 16.19%, 20.95%, and 20.95%, respectively. The area under the curve for predicting MVI positivity was 0.844, with a sensitivity of 77.19% and specificity of 91.67%. CONCLUSION: Texture analysis of arterial phase images demonstrated superior predictive efficacy for MVI in HCC compared to T2WI, portal venous, and equilibrium phases. This study provides an objective, non-invasive method for preoperative prediction of MVI, offering a theoretical foundation for the selection of clinical therapy.
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Diabetic wound healing remains a worldwide challenge for both clinicians and researchers. The high expression of matrix metalloproteinase 9 (MMP9) and a high inflammatory response are indicative of poor diabetic wound healing. H8, a curcumin analogue, is able to treat diabetes and is anti-inflammatory, and our pretest showed that it has the potential to treat diabetic wound healing. However, H8 is highly expressed in organs such as the liver and kidney, resulting in its unfocused use in diabetic wound targeting. (These data were not published, see Table S1 in the Supporting Information.) Accordingly, it is important to pursue effective carrier vehicles to facilitate the therapeutic uses of H8. The use of H8 delivered by macrophage membrane-derived nanovesicles provides a potential strategy for repairing diabetic wounds with improved drug efficacy and fast healing. In this study, we fabricated an injectable gelatin microsphere (GM) with sustained MMP9-responsive H8 macrophage membrane-derived nanovesicles (H8NVs) with a targeted release to promote angiogenesis that also reduces oxidative stress damage and inflammation, promoting diabetic wound healing. Gelatin microspheres loaded with H8NV (GMH8NV) stimulated by MMP9 can significantly facilitate the migration of NIH-3T3 cells and facilitate the development of tubular structures by HUVEC in vitro. In addition, our results demonstrated that GMH8NV stimulated by MMP9 protected cells from oxidative damage and polarized macrophages to the M2 phenotype, leading to an inflammation inhibition. By stimulating angiogenesis and collagen deposition, inhibiting inflammation, and reducing MMP9 expression, GMH8NV accelerated wound healing. This study showed that GMH8NVs were targeted to release H8NV after MMP9 stimulation, suggesting promising potential in achieving satisfactory healing in diabetic treatment.
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Diabetes Mellitus Experimental , Gelatina , Camundongos , Animais , Gelatina/farmacologia , Gelatina/química , Microesferas , Metaloproteinase 9 da Matriz/farmacologia , Metaloproteinase 9 da Matriz/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Cicatrização , Inflamação , MacrófagosRESUMO
Polysaccharide-based soft colloidal particles mediated by the dynamic bonding-engineered interfacial self-assembly can regulate the properties of oil-water interfacial films, availing the stability of emulsions under a wide pH range. The amphiphilic phenylboronic alginate soft colloidal particles (Alg-PBA) were designed to stabilize pH-responsive Pickering emulsions (PEs). Combining stability analysis with quartz crystal microbalance and dissipation monitoring (QCM-D), the microstructure and viscoelasticity of Alg-PBA at the oil-water interface were determined. The results showed that PEs stabilized by Alg-PBA due to a thicker and stronger viscoelastic interface film induced by BO bonds and hydrogen bonds. The structure-function relationship of the Alg-PBA emulsifier driven by dynamic bonds was further elaborated at multiple scales by laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Meanwhile, the microstructure of aerogels templated by emulsion could be tuned by adjusting dynamic bonds, which provides a new idea for polysaccharide soft material engineering.
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The soft interfacial template-assisted confined self-assembly of block copolymers (BCPs) guiding colloidal aggregates has been extensively investigated by interfacial instability. Whether the macromolecular polymer architectonics possessed stimulus-responsive self-regulated structural controllability more readily implement the morphological diversity of colloidal aggregates. Herein, we in-situ constructed the alginate-modified ß-cyclodextrin/azobenzene-functionalized alkyl chains (Alg-ß-CD/AzoC12) system by supramolecular host-guest interfacial recognition-engineered strategy, in which possessed photo-stimulated responsive structural reconfigurability by modulating assembly/disassembly behaviors between CD and Azo at oil/water interface. The host-guest droplet interfaces acted as soft templates managing interfacial instability by synergistically integrating supra-amphiphilic host-guest polymers with cosurfactants, further constructing various soft supracolloidal aggregates, including soft nanoaggregates, microspheres with tunable degrees of surface roughness. Additionally, the stimuli-altering structural reconfigurability of supramolecular host-guest polymers was regulated by ultraviolet/visible irradiation, endowing soft aggregates with structural diversity. It's highly anticipated that the supramolecular host-guest interfacial recognition self-assembly establishes great bridge between supramolecular host-guest chemistry and colloid interface science.
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Significant challenges remain in designing sufficient viscoelasticity polysaccharide-based high internal phase Pickering emulsions (HIPPEs) as soft materials for 3D printing. Herein, taking advantage of the interfacial covalent bond interaction between modified alginate (Ugi-OA) dissolved in the aqueous phase and aminated silica nanoparticles (ASNs) dispersed in oil, HIPPEs with printability were obtained. Using multitechniques coupling a conventional rheometer with a quartz crystal microbalance with dissipation monitoring, the correlation between interfacial recognition coassembly on the molecular scale and the stability of whole bulk HIPPEs on the macroscopic scale can be clarified. The results showed that Ugi-OA/ASNs assemblies (NPSs) were strongly retargeted into the oil-water interface due to the specific Schiff base-binding between ASNs and Ugi-OA, further forming thicker and more rigid interfacial films on the microscopic scale compared with that of the Ugi-OA/SNs (bared silica nanoparticles) system. Meanwhile, flexible polysaccharides also formed a 3D network that suppressed the motion of the droplets and particles in the continuous phase, endowing the emulsion with appropriately viscoelasticity to manufacture a sophisticated "snowflake" architecture. In addition, this study opens a novel pathway for the construction of structured all-liquid systems by introducing an interfacial covalent recognition-mediated coassembly strategy, showing promising applications.
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The traditional radiation air conditioning system has some problems, such as easy condensation, insufficient refrigeration capacity, complex structure, and control system. Therefore, this study proposes a new type of finned metal radiant plate with large heat flow per unit area, sufficient cooling capacity, and simplified heat exchange system, in order to realize large temperature difference between cooling and heating. The temperature field uniformity and thermal comfort test of a novel type of finned ceiling radiant panel and independent fresh air linked air conditioning system under summer cooling and winter heating circumstances are accomplished through artificially generated climate environments. The study's findings demonstrate that in the radiation and fresh air modes, the maximum interior temperature differential under cooling conditions does not rise over 2.1°C. The maximum temperature differential in the space at any one moment in the radiation and fresh air modes cannot be greater than 3°C when heating conditions are present. The fresh air's cooling and dehumidifying effects are clear. The dehumidification efficiency may reach 50%, and the moisture content ranges from 5.48 to 9.63 g/kg. With PMV ranging from -0.34 to 0.54, the enhanced air conditioning system in this research provides exceptionally good thermal comfort. Additionally, the finned radiant panel's installation area occupies just 14% of the ceiling, which is sufficient to fulfill the room's cooling and heating load needs as well as provide high thermal comfort and consistent indoor temperature. The theoretical investigation and practical implementation of the direct expansion radiant air conditioning system are both strongly supported by this research.
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Diabetic wounds are one of the most challenging public health issues of the 21st century due to their inadequate vascular supply, bacterial infections, high levels of oxidative stress, and abnormalities in antioxidant defenses, whereas there is no effective treatment for diabetic wounds. Due to the distinct properties of nanoparticles, such as their small particle size, elevated cellular uptake, low cytotoxicity, antibacterial activity, good biocompatibility, and biodegradability. The application of nanoparticles has been widely used in the treatment of diabetic wound healing due to their superior anti-inflammatory, antibacterial, and antioxidant activities. These nanoparticles can also be loaded with various agents, such as organic molecules (eg, exosomes, small molecule compounds, etc.), inorganic molecules (metals, nonmetals, etc.), or complexed with various biomaterials, such as smart hydrogels (HG), chitosan (CS), and hyaluronic acid (HA), to augment their therapeutic potential in diabetic wounds. This paper reviews the therapeutic potential and future perspective of nanoparticles in the treatment of diabetic wounds. Together, nanoparticles represent a promising strategy in the treatment of diabetic wound healing. The future direction may be to develop novel nanoparticles with multiple effects that not only act in wound healing at all stages of diabetes but also provide a stable physiological environment throughout the wound-healing process.
Assuntos
Quitosana , Diabetes Mellitus , Nanopartículas , Humanos , Cicatrização , Hidrogéis , Diabetes Mellitus/tratamento farmacológico , Antibacterianos , Antioxidantes/farmacologia , Antioxidantes/uso terapêuticoRESUMO
Increases in recorded high temperatures around the world are causing plant thermomorphogenesis and decreasing crop productivity. PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is a central positive regulator of plant thermomorphogenesis. However, the molecular mechanisms underlying PIF4-regulated thermomorphogenesis remain largely unclear. In this study, we identified ABNORMAL THERMOMORPHOGENESIS 1 (ABT1) as an important negative regulator of PIF4 and plant thermomorphogenesis. Overexpression of ABT1 in the activation tagging mutant abt1-D caused shorter hypocotyls and petioles under moderately high temperature (HT). ABT1 encodes WRKY14, which belongs to subgroup II of the WRKY transcription factors. Overexpression of ABT1/WRKY14 or its close homologs, including ABT2/WRKY35, ABT3/WRKY65, and ABT4/WRKY69in transgenic plants caused insensitivity to HT, whereas the quadruple mutant abt1 abt2 abt3 abt4 exhibited greater sensitivity to HT. ABTs were expressed in hypocotyls, cotyledons, shoot apical meristems, and leaves, but their expression were suppressed by HT. Biochemical assays showed that ABT1 can interact with TCP5, a known positive regulator of PIF4, and interrupt the formation of the TCP5-PIF4 complex and repress its transcriptional activation activity. Genetic analysis showed that ABT1 functioned antagonistically with TCP5, BZR1, and PIF4 in plant thermomorphogenesis. Taken together, our results identify ABT1/WRKY14 as a critical repressor of plant thermomorphogenesis and suggest that ABT1/WRKY14, TCP5, and PIF4 may form a sophisticated regulatory module to fine-tune PIF4 activity and temperature-dependent plant growth.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Plantas Geneticamente Modificadas/metabolismo , TemperaturaRESUMO
The regulation of the magnitude of the depletion effect is necessary for accurately predicting and explaining the emulsion stabilization mechanism. Herein, the bacterial cellulose/carboxymethyl chitosan (BC/CCS) complexes with tunable assembled behaviors were prepared and designed via electrostatic interaction. Specially, the emulsions stabilized by BC/CCS complexes exhibited excellent stability as compared with that stabilized by BC polymers alone. At pH 9.6, BC/CCS complexes in the continuous phase induced long-range depletion-stabilization effect to stabilize emulsions. Additionally, the magnitude of depletion effect of BC/CCS complexes could be improved by increasing BC concentration, and effectively stabilized emulsions. Furthermore, with the decrease to pH 7.0, the interfacial adsorption layers at the oil-water interface prevented oil droplets from agglomerating, but did not show better emulsion stability. These results clarified that the magnitude of the depletion effect could be controlled by altering BC-based complexes particles, which would be useful for the applications of emulsions in numerous fields.
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Quitosana , Adsorção , Bactérias , Celulose/química , Quitosana/química , Emulsões/química , Água/químicaRESUMO
We investigated the effect of an 11ß-HSD1 inhibitor (H8) on hepatic steatosis and its mechanism of action. Although H8, a curcumin derivative, has been shown to alleviate insulin resistance, its effect on non-alcoholic fatty liver disease (NAFLD) remains unknown. Rats were fed a high-fat diet (HFD) for 8 weeks, intraperitoneally injected with streptozotocin (STZ) to induce NAFLD, and, then, treated with H8 (3 or 6 mg/kg/day) or curcumin (6 mg/kg/day) for 4 weeks, to evaluate the effects of H8 on NAFLD. H8 significantly alleviated HFD+STZ-induced lipid accumulation, fibrosis, and inflammation as well as improved liver function. Moreover, 11ß-HSD1 overexpression was established by transfecting animals and HepG2 cells with lentivirus, carrying the 11ß-HSD1 gene, to confirm that H8 improved NAFLD, by reducing 11ß-HSD1. An AMP-activated protein kinase (AMPK) inhibitor (Compound C, 10 µM for 2 h) was used to confirm that H8 increased AMPK, by inhibiting 11ß-HSD1, thereby restoring lipid metabolic homeostasis. A silencing-related enzyme 1 (SIRT1) inhibitor (EX572, 10 µM for 4 h) and a SIRT1 activator (SRT1720, 1 µM for 4 h) were used to confirm that H8 exerted anti-inflammatory effects, by elevating SIRT1 expression. Our findings demonstrate that H8 alleviates hepatic steatosis, by inhibiting 11ß-HSD1, which activates the AMPK/SIRT1 signaling pathway.
Assuntos
Curcumina , Hepatopatia Gordurosa não Alcoólica , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Curcumina/farmacologia , Inibidores Enzimáticos/farmacologia , Lipídeos/farmacologia , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Transdução de Sinais , Sirtuína 1/genética , Sirtuína 1/metabolismoRESUMO
Hemicellulose is entangled with cellulose through hydrogen bonds and meanwhile acts as a bridge for the deposition of lignin monomer in the secondary wall. Therefore, hemicellulose plays a vital role in the utilization of cell wall biomass. Many advances in hemicellulose research have recently been made, and a large number of genes and their functions have been identified and verified. However, due to the diversity and complexity of hemicellulose, the biosynthesis and regulatory mechanisms are yet unknown. In this review, we summarized the types of plant hemicellulose, hemicellulose-specific nucleotide sugar substrates, key transporters, and biosynthesis pathways. This review will contribute to a better understanding of substrate-level regulation of hemicellulose synthesis.
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Soft emulsifiers with relatively suitable structural controllability are necessarily required for the preparation of multifunctional Pickering emulsions. Herein, a ß-cyclodextrin-grafted alginate/azobenzene-functionalized dodecyl (Alg-ß-CD/AzoC. 12) polymeric supra-amphiphile was designed based on the host-guest interfacial self-assembly. As compared with Alg-ß-CD amphiphilic polymers, the interfacial tension of Alg-ß-CD/AzoC12 supra-amphiphilic assemblies reduced from 29.57 mN/m to 0.18 mN/m, indicating the great amphiphilicity derived from Alg-ß-CD/AzoC12 supra-amphiphilic assemblies. With the increase of pH, the interfacial microstructures transformed from flocculated structures, spherical structures into deformed structures. Especially, the spherical microstructures with the highest interfacial viscoelasticity and thickness demonstrated the highest emulsifying efficiency due to the steric hindrance mechanism. Moreover, the interfacial elastic modulus of adsorbed layers exhibited ~4 times of that upon the ultraviolet illumination. These results disclosed that the interfacial microstructures could be readily regulated by the tunable amphiphilicity of Alg-ß-CD/AzoC12 assemblies, which would be useful for the applications of Pickering emulsions in numerous fields.
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Supramolecular host-guest chemistry bridging the adjustable amphiphilicity and macromolecular self-assembly is well advanced in aqueous media. However, the interfacial self-assembled behaviors have not been further exploited. Herein, we designed a ß-cyclodextrin-grafted alginate/azobenzene-functionalized dodecyl (Alg-ß-CD/AzoC12) supra-amphiphilic system that possessed tunable amphiphilicity by host-guest interfacial self-assembly. Especially, supra-amphiphilic aggregates could be utilized as highly efficient soft colloidal emulsifiers for stabilizing water-in-oil-water (W/O/W) Pickering emulsions due to the excellent interfacial activity. Meanwhile, the assembled particle structures could be modulated by adjusting the oil-water ratio, resulting from the tunable aggregation behavior of supra-amphiphilic macromolecules. Additionally, the interfacial adsorption films could be partially destroyed/reconstructed upon ultraviolet/visible irradiation due to the stimuli-altering balance of amphiphilicity of Alg-ß-CD/AzoC12 polymers, further constructing the stimulus-responsive Pickering emulsions. Therefore, the supramolecular interfacial self-assembly-mediated approach not only technologically advances the continued development of creative templates to construct multifunctional soft materials with anisotropic structures but also serves as a creative bridge between supramolecular host-guest chemistry, colloidal interface science, and soft material technology.
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Most structural self-healing materials were developed based on either reversible supramolecular interaction or dynamic covalent bonding. It seems a good idea to incorporate self-healing properties into high-performance materials. In this study, we fabricated the alginate-based cyclodextrin and polyacrylamide azobenzene highly stretchable and tough interpenetrating composite hydrogel with self-repairing behavior under light irradiation. Initially, the alginate-based cyclodextrin and polyacrylamide azobenzene were designed and synthesized. The corresponding structural, thermal, and morphological properties of hydrogels were characterized. The reversible transformation of the sol-gel can be achieved by the irradiation upon ultraviolet light and visible light. The self-healing behavior of this composited gel is based on the host-guest interaction between cyclodextrin and azobenzene. The recovery gel elongation at 48 h healing in the dark condition was is 0.04 MPa, with an elongation of 1140 %. Therefore, this gel can achieve self-healing ability while maintaining highly stretchable and tough performance.
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Acrilamidas/química , Resinas Acrílicas/química , Compostos Azo/química , Ciclodextrinas/química , Hidrogéis/química , Alginatos/química , Luz , Teste de Materiais , Estrutura Molecular , Peso Molecular , Transição de Fase , Polímeros/química , Pressão , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Raios Ultravioleta , beta-Ciclodextrinas/químicaRESUMO
OBJECTIVE: To explore the relationship between physiological parameters changes and severe heatstroke induced by 5-km armed cross-country training. METHODS: A total of 521 male officers and soldiers from a special team who participated in the summer training of 5-km armed cross-country training from year 2016 to 2017 were enrolled. All trainees participated in 5-km armed cross-country training in high temperature and humidity environment of ambient temperature > 32 centigradeand (or) relative humidity > 65%. The trainees were divided into two groups according to the incidence of severe heatstroke in the course of training. The age, enlistment time, constitution score, body mass index (BMI), external environment (ambient temperature, relative humidity, wind speed, heat index) of trainees of the two groups, and the change rates of arterial blood oxygen saturation (SaO2), body temperature, pulse and blood pressure within 5 minutes after the 5-km armed cross-country training were compared between the two groups. The risk factors of severe heatstroke were screened by two classified Logistic regression analysis, and the predictive value of various risk factors of severe heatstroke was analyzed by the receiver operator characteristic curve (ROC). RESULTS: In 521 trainees of 5-km armed cross-country training, 29 trainees suffered from severe heatstroke accounting for 5.57%. There was no significant difference in the age, enlistment time, constitution score, BMI, or external environment during 5-km armed cross-country training between severe heatstroke group and non-severe heatstroke group. Compared with those without severe heatstroke, the descending rates of body temperature, pulse, blood pressure and SaO2 increased rate within 5 minutes after 5-km armed cross-country training of severe heatstroke trainees were significantly decreased [temperature descending rate: (0.67±0.30)% vs. (1.43±1.28)%, pulse descending rate: (7.53±5.21)% vs. (13.48±8.07)%, blood pressure descending rate: (9.28±6.84)% vs. (19.42±7.73)%, SaO2 increased rate: (0.51±0.39)% vs. (1.50±1.43)%, all P < 0.01]. Two classification Logistic regression analysis showed that the temperature descending rate [odds ratio (OR) = 0.485, 95% confidence interval (95%CI) = 0.289-0.817], pulse descending rate (OR = 0.903, 95%CI = 0.845-0.965), blood pressure descending rate (OR = 0.841, 95%CI = 0.790-0.896), and SaO2 increased rate (OR = 0.421, 95%CI = 0.250-0.711) were the risk factors for severe heatstroke during 5-km armed cross-country training (all P < 0.01). ROC curve analysis showed that temperature descending rate [area under ROC curve (AUC) = 0.659, 95%CI = 0.604-0.714], pulse descending rate (AUC = 0.730, 95%CI = 0.762-0.900), blood pressure descending rate (AUC = 0.831, 95%CI = 0.659-0.801), SaO2 increased rate (AUC = 0.711, 95%CI = 0.655-0.767) could be used for the incidence of severe heatstroke prediction during 5-km armed cross-country training (all P < 0.01), and the predicted value was the same. CONCLUSIONS: Under the same conditions, the severe heatstroke during 5-km cross-country training is closely related to the descending rates of body temperature, pulse, and blood pressure as well as SaO2 increased rate within 5 minutes after the training, whose predictive values for severe heatstroke were the same.