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1.
Small ; 20(12): e2307467, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37940620

RESUMEN

The electrochemical reduction of carbon dioxide (CO2) to ethylene creates a carbon-neutral approach to converting carbon dioxide into intermittent renewable electricity. Exploring efficient electrocatalysts with potentially high ethylene selectivity is extremely desirable, but still challenging. In this report, a laboratory-designed catalyst HKUST-1@Cu2O/PTFE-1 is prepared, in which the high specific surface area of the composites with improved CO2 adsorption and the abundance of active sites contribute to the increased electrocatalytic activity. Furthermore, the hydrophobic interface constructed by the hydrophobic material polytetrafluoroethylene (PTFE) effectively inhibits the occurrence of hydrogen evolution reactions, providing a significant improvement in the efficiency of CO2 electroreduction. The distinctive structures result in the remarkable hydrocarbon fuels generation with high Faraday efficiency (FE) of 67.41%, particularly for ethylene with FE of 46.08% (-1.0 V vs RHE). The superior performance of the catalyst is verified by DFT calculation with lower Gibbs free energy of the intermediate interactions with improved proton migration and selectivity to emerge the polycarbon(C2+) product. In this work, a promising and effective strategy is presented to configure MOF-based materials with tailored hydrophobic interface, high adsorption selectivity and more exposed active sites for enhancing the efficiency of the electroreduction of CO2 to C2+ products with high added value.

2.
Nat Chem Biol ; 18(1): 47-55, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34782743

RESUMEN

Inducer-triggered therapeutic protein expression from designer cells is a promising strategy for disease treatment. However, as most inducer systems harness transcriptional machineries, protein expression timeframes are unsuitable for many therapeutic applications. Here, we engineered a genetic code expansion-based therapeutic system, termed noncanonical amino acids (ncAAs)-triggered therapeutic switch (NATS), to achieve fast therapeutic protein expression in response to cognate ncAAs at the translational level. The NATS system showed response within 2 hours of triggering, whereas no signal was detected in a transcription-machinery-based system. Moreover, NATS system is compatible with transcriptional switches for multi-regulatory-layer control. Diabetic mice with microencapsulated cell implants harboring the NATS system could alleviate hyperglycemia within 90 min on oral delivery of ncAA. We also prepared ncAA-containing 'cookies' and achieved long-term glycemic control in diabetic mice implanted with NATS cells. Our proof-of-concept study demonstrates the use of NATS system for the design of next-generation cell-based therapies to achieve fast orally induced protein expression.


Asunto(s)
Tratamiento Basado en Trasplante de Células y Tejidos , Diabetes Mellitus Experimental/terapia , Código Genético , Animales , Glucemia/metabolismo , Ratones , Prueba de Estudio Conceptual , Transcripción Genética
3.
Nano Lett ; 23(13): 6124-6131, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37347949

RESUMEN

Excitons in two-dimensional transition metal dichalcogenides have a valley degree of freedom that can be optically manipulated for quantum information processing. Here, we integrate MoS2 monolayers with achiral silicon disk array metasurfaces to enhance and control valley-specific absorption and emission. Through the coupling to the metasurface electric and magnetic Mie modes, the intensity and lifetime of the emission of neutral excitons, trions, and defect bound excitons can be enhanced and shortened, respectively, while the spectral shape can be modified. Additionally, the degree of polarization (DOP) of exciton and trion emission from the valley can be symmetrically enhanced at 100 K. The DOP increase is attributed to both the metasurface-enhanced chiral absorption of light and the metasurface-enhanced exciton emission from the Purcell effect. Combining Si-compatible photonic design with large-scale 2D materials integration, our work makes an important step toward on-chip valleytronic applications approaching room-temperature operation.

4.
Ecotoxicol Environ Saf ; 252: 114619, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36753967

RESUMEN

The development of agriculture and industry has led to a gradual increase in the levels of cadmium (Cd) in the soil, which, due to its high mobility in soil, makes Cd deposition in plants a serious threat to the health of animals and humans. The important role of melatonin (MT) in regulating plant growth and adaptation to environmental stress has become a pertinent research topic, but the mechanisms of action of MT in Cd-stressed Platycladus orientalis seedlings are unclear. Here, we investigated the mitigation mechanism of exogenous MT application on P. orientalis seedlings under Cd stress. Cd stress significantly inhibited the growth of P. orientalis seedlings by disrupting photosynthetic pigments, mineral balance, osmotic balance, and oxidative balance. In contrast, the application of exogenous MT significantly increased the growth parameters of P. orientalis seedlings, reduced Cd accumulation and transfer in the seedlings, increased the content of iron, manganese, zinc, copper, chlorophyll, soluble protein, soluble sugar, and proline, reduced the content of glutathione, increased the activities of superoxide dismutase and peroxidase, and significantly enhanced the expression of antioxidant-related genes (POD, GST, and APX). It also effectively reduced the content of hydrogen peroxide and malondialdehyde to inhibit the production of reactive oxygen species, thus alleviating Cd-induced oxidative stress. In addition, MT significantly upregulated the expression of the ethanol dehydrogenase (ADH) gene, which is effective in removing the acetaldehyde produced by anaerobic respiration in seedlings under stress, thereby reducing the toxic effects on P. orientalis. The results showed that exogenous MT enhanced the tolerance of P. orientalis seedlings to Cd stress by regulating photosynthesis, mineral balance, osmotic balance, and the antioxidant system and that the optimal concentration of MT was 200 µmol·L-1.


Asunto(s)
Antioxidantes , Melatonina , Humanos , Antioxidantes/metabolismo , Melatonina/farmacología , Melatonina/metabolismo , Cadmio/metabolismo , Plantones , Estrés Oxidativo , Minerales/metabolismo , Nutrientes , Suelo , Peróxido de Hidrógeno/metabolismo
5.
Int J Mol Sci ; 24(18)2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37762261

RESUMEN

The CCD gene family plays a crucial role in the cleavage of carotenoids, converting them into apocarotenoids. This process not only impacts the physiology and development of plants but also enhances their tolerance toward different stresses. However, the character of the PmCCD gene family and its role in ornamental woody Prunus mume remain unclear. Here, ten non-redundant PmCCD genes were identified from the P. mume genome, and their physicochemical characteristics were predicted. According to the phylogenetic tree, PmCCD proteins were classified into six subfamilies: CCD1, CCD4, CCD7, CCD8, NCED and CCD-like. The same subfamily possessed similar gene structural patterns and numbers of conserved motifs. Ten PmCCD genes were concentrated on three chromosomes. PmCCD genes exhibited interspecific collinearity with P. armeniaca and P. persica. Additionally, PmCCD genes had obvious specificity in different tissues and varieties. Compared with white-flowered 'ZLE', PmCCD1 and PmCCD4 genes were low-expressed in 'HJH' with yellow petals, which suggested PmCCD1 and PmCCD4 might be related to the formation of yellow flowers in P. mume. Nine PmCCD genes could respond to NaCl or PEG treatments. These genes might play a crucial role in salt and drought resistance in P. mume. Moreover, PmVAR3 and PmSAT3/5 interacted with PmCCD4 protein in yeast and tobacco leaf cells. This study laid a foundation for exploring the role of the PmCCD gene family in flower coloration and stress response in P. mume.


Asunto(s)
Prunus , Filogenia , Prunus/metabolismo , Genes de Plantas , Flores , Regulación de la Expresión Génica de las Plantas
6.
Int J Mol Sci ; 23(18)2022 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-36142832

RESUMEN

The Gibberellic Acid Stimulated Arabidopsis/Gibberellin Stimulated Transcript (GASA/GAST) gene family is a group of plant-specific genes encoding cysteine-rich peptides essential to plant growth, development, and stress responses. Although GASA family genes have been identified in various plant species, their functional roles in Prunus mume are still unknown. In this study, a total of 16 PmGASA genes were identified via a genome-wide scan in Prunus mume and were grouped into three major gene clades based on the phylogenetic tree. All PmGASA proteins possessed the conserved GASA domain, consisting of 12-cysteine residues, but varied slightly in protein physiochemical properties and motif composition. With evolutionary analysis, we observed that duplications and purifying selection are major forces driving PmGASA family gene evolution. By analyzing PmGASA promoters, we detected a number of hormonal-response related cis-elements and constructed a putative transcriptional regulatory network for PmGASAs. To further understand the functional role of PmGASA genes, we analyzed the expression patterns of PmGASAs across different organs and during various biological processes. The expression analysis revealed the functional implication of PmGASA gene members in gibberellic acid-, abscisic acid-, and auxin-signaling, and during the progression of floral bud break in P. mume. To summarize, these findings provide a comprehensive understanding of GASA family genes in P. mume and offer a theoretical basis for future research on the functional characterization of GASA genes in other woody perennials.


Asunto(s)
Arabidopsis , Prunus , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Cisteína/metabolismo , Evolución Molecular , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Familia de Multigenes , Filogenia , Proteínas de Plantas/metabolismo , Prunus/metabolismo
7.
Nat Mater ; 19(12): 1312-1318, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32719510

RESUMEN

A fundamental understanding of hot-carrier dynamics in photo-excited metal nanostructures is needed to unlock their potential for photodetection and photocatalysis. Despite numerous studies on the ultrafast dynamics of hot electrons, so far, the temporal evolution of hot holes in metal-semiconductor heterostructures remains unknown. Here, we report ultrafast (t < 200 fs) hot-hole injection from Au nanoparticles into the valence band of p-type GaN. The removal of hot holes from below the Au Fermi level is observed to substantially alter the thermalization dynamics of hot electrons, reducing the peak electronic temperature and the electron-phonon coupling time of the Au nanoparticles. First-principles calculations reveal that hot-hole injection modifies the relaxation dynamics of hot electrons in Au nanoparticles by modulating the electronic structure of the metal on timescales commensurate with electron-electron scattering. These results advance our understanding of hot-hole dynamics in metal-semiconductor heterostructures and offer additional strategies for manipulating the dynamics of hot carriers on ultrafast timescales.

8.
Proc Natl Acad Sci U S A ; 115(34): E8027-E8036, 2018 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-30087184

RESUMEN

Activated T cells undergo metabolic reprogramming and effector-cell differentiation but the factors involved are unclear. Utilizing mice lacking DUSP6 (DUSP6-/-), we show that this phosphatase regulates T cell receptor (TCR) signaling to influence follicular helper T (TFH) cell differentiation and T cell metabolism. In vitro, DUSP6-/- CD4+ TFH cells produced elevated IL-21. In vivo, TFH cells were increased in DUSP6-/- mice and in transgenic OTII-DUSP6-/- mice at steady state. After immunization, DUSP6-/- and OTII-DUSP6-/- mice generated more TFH cells and produced more antigen-specific IgG2 than controls. Activated DUSP6-/- T cells showed enhanced JNK and p38 phosphorylation but impaired glycolysis. JNK or p38 inhibitors significantly reduced IL-21 production but did not restore glycolysis. TCR-stimulated DUSP6-/- T cells could not induce phosphofructokinase activity and relied on glucose-independent fueling of mitochondrial respiration. Upon CD28 costimulation, activated DUSP6-/- T cells did not undergo the metabolic commitment to glycolysis pathway to maintain viability. Unexpectedly, inhibition of fatty acid oxidation drastically lowered IL-21 production in DUSP6-/- TFH cells. Our findings suggest that DUSP6 connects TCR signaling to activation-induced metabolic commitment toward glycolysis and restrains TFH cell differentiation via inhibiting IL-21 production.


Asunto(s)
Diferenciación Celular/fisiología , Fosfatasa 6 de Especificidad Dual , Glucólisis/fisiología , Receptores de Antígenos de Linfocitos T , Transducción de Señal/fisiología , Linfocitos T Colaboradores-Inductores , Animales , Formación de Anticuerpos/fisiología , Antígenos CD28/genética , Antígenos CD28/inmunología , Antígenos CD28/metabolismo , Fosfatasa 6 de Especificidad Dual/genética , Fosfatasa 6 de Especificidad Dual/inmunología , Fosfatasa 6 de Especificidad Dual/metabolismo , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Interleucinas/genética , Interleucinas/inmunología , Interleucinas/metabolismo , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/inmunología , MAP Quinasa Quinasa 4/metabolismo , Ratones , Ratones Noqueados , Mitocondrias/genética , Mitocondrias/inmunología , Mitocondrias/metabolismo , Consumo de Oxígeno/fisiología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T Colaboradores-Inductores/citología , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/inmunología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Nano Lett ; 20(4): 2348-2358, 2020 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-32134672

RESUMEN

We report the light-induced modification of catalytic selectivity for photoelectrochemical CO2 reduction in aqueous media using copper (Cu) nanoparticles dispersed onto p-type nickel oxide (p-NiO) photocathodes. Optical excitation of Cu nanoparticles generates hot electrons available for driving CO2 reduction on the Cu surface, while charge separation is accomplished by hot-hole injection from the Cu nanoparticles into the underlying p-NiO support. Photoelectrochemical studies demonstrate that optical excitation of plasmonic Cu/p-NiO photocathodes imparts increased selectivity for CO2 reduction over hydrogen evolution in aqueous electrolytes. Specifically, we observed that plasmon-driven CO2 reduction increased the production of carbon monoxide and formate, while simultaneously reducing the evolution of hydrogen. Our results demonstrate an optical route toward steering the selectivity of artificial photosynthetic systems with plasmon-driven photocathodes for photoelectrochemical CO2 reduction in aqueous media.

10.
Nano Lett ; 20(1): 502-508, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31821762

RESUMEN

We describe the fabrication and use of arrays of TiO2 nanocones to yield high optical transmission into semiconductor photoelectrodes covered with high surface loadings of light-absorbing electrocatalysts. Covering over 50% of the surface of a light absorber with an array of high-refractive-index TiO2 nanocones imparted antireflective behavior (<5% reflectance) to the surface and allowed >85% transmission of broadband light to the underlying Si, even when thick metal contacts or opaque catalyst coatings were deposited on areas of the light-facing surface that were not directly beneath a nanocone. Three-dimensional full-field electromagnetic simulations for the 400-1100 nm spectral range showed that incident broadband illumination couples to multiple waveguide modes in the TiO2 nanocones, reducing interactions of the light with the metal layer. A proof-of-concept experimental demonstration of light-driven water oxidation was performed using a p+n-Si photoanode decorated with an array of TiO2 nanocones additionally having a Ni catalyst layer electrodeposited onto the areas of the p+n-Si surface left uncovered by the TiO2 nanocones. This photoanode produced a light-limited photocurrent density of ∼28 mA cm-2 under 100 mW cm-2 of simulated air mass 1.5 illumination, equivalent to the photocurrent density expected for a bare planar Si surface even though 54% of the front surface of the Si was covered by an ∼70 nm thick Ni metal layer.

11.
J Am Chem Soc ; 141(47): 18658-18661, 2019 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-31697074

RESUMEN

Photoelectrochemical deposition of Se-Te on isolated Au islands using an unstructured, incoherent beam of light produces growth of Se-Te alloy toward the direction of the incident light beam. Full-wave electromagnetic simulations of light absorption indicated that the induced spatial growth anisotropy was a function of asymmetric absorption in the evolving deposit. Inorganic phototropic growth is analogous to biological systems such as palm trees that exhibit phototropic growth wherein physical extension of the plant guides the crown toward the time-averaged position of the sun, to maximize solar harvesting.


Asunto(s)
Galvanoplastia , Selenio/química , Telurio/química , Electroquímica , Procesos Fotoquímicos
12.
Nano Lett ; 18(4): 2545-2550, 2018 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-29522350

RESUMEN

Harvesting nonequilibrium hot carriers from plasmonic-metal nanostructures offers unique opportunities for driving photochemical reactions at the nanoscale. Despite numerous examples of hot electron-driven processes, the realization of plasmonic systems capable of harvesting hot holes from metal nanostructures has eluded the nascent field of plasmonic photocatalysis. Here, we fabricate gold/p-type gallium nitride (Au/p-GaN) Schottky junctions tailored for photoelectrochemical studies of plasmon-induced hot-hole capture and conversion. Despite the presence of an interfacial Schottky barrier to hot-hole injection of more than 1 eV across the Au/p-GaN heterojunction, plasmonic Au/p-GaN photocathodes exhibit photoelectrochemical properties consistent with the injection of hot holes from Au nanoparticles into p-GaN upon plasmon excitation. The photocurrent action spectrum of the plasmonic photocathodes faithfully follows the surface plasmon resonance absorption spectrum of the Au nanoparticles and open-circuit voltage studies demonstrate a sustained photovoltage during plasmon excitation. Comparison with Ohmic Au/p-NiO heterojunctions confirms that the vast majority of hot holes generated via interband transitions in Au are sufficiently hot to inject above the 1.1 eV interfacial Schottky barrier at the Au/p-GaN heterojunction. We further investigated plasmon-driven photoelectrochemical CO2 reduction with the Au/p-GaN photocathodes and observed improved selectivity for CO production over H2 evolution in aqueous electrolytes. Taken together, our results offer experimental validation of photoexcited hot holes more than 1 eV below the Au Fermi level and demonstrate a photoelectrochemical platform for harvesting hot carriers to drive solar-to-fuel energy conversion.

13.
Int J Mol Sci ; 20(2)2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30650528

RESUMEN

Repairing damaged articular cartilage is challenging due to the limited regenerative capacity of hyaline cartilage. In this study, we fabricated a bilayered poly (lactic-co-glycolic acid) (PLGA) scaffold with small (200⁻300 µm) and large (200⁻500 µm) pores by salt leaching to stimulate chondrocyte differentiation, cartilage formation, and endochondral ossification. The scaffold surface was treated with tyramine to promote scaffold integration into native tissue. Porcine chondrocytes retained a round shape during differentiation when grown on the small pore size scaffold, and had a fibroblast-like morphology during transdifferentiation in the large pore size scaffold after five days of culture. Tyramine-treated scaffolds with mixed pore sizes seeded with chondrocytes were pressed into three-mm porcine osteochondral defects; tyramine treatment enhanced the adhesion of the small pore size scaffold to osteochondral tissue and increased glycosaminoglycan and collagen type II (Col II) contents, while reducing collagen type X (Col X) production in the cartilage layer. Col X content was higher for scaffolds with a large pore size, which was accompanied by the enhanced generation of subchondral bone. Thus, chondrocytes seeded in tyramine-treated bilayered scaffolds with small and large pores in the upper and lower parts, respectively, can promote osteochondral regeneration and integration for articular cartilage repair.


Asunto(s)
Cartílago Articular/citología , Condrocitos/citología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Regeneración , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Tiramina/química , Animales , Materiales Biocompatibles/química , Colágeno/metabolismo , Fuerza Compresiva , Modelos Animales , Espectroscopía de Fotoelectrones , Porosidad , Propiedades de Superficie , Porcinos , Agua/química
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 315: 124304, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38636424

RESUMEN

A ratiometric sensor with ultralow background is highly desired due to its low environmental influence and high sensitivity. Herein, inspired by the solubility difference of carboxylate in aqueous and organic solvents, we prepared a core-shell structure porous zirconia-covalent organic framework (COF) composite through thermal hydrolysis of UiO-66-COF precursors in organic alkali solution. The ligand 2-aminoterephthalic acids (H2BDC-NH2) of UiO-66 were transformed into 2-aminoterephthalate salts (ATA salts) that existed in zirconium-oxo clusters building units. The composites emitted only yellow emission (597 nm) from the COF in organic solvent due to the insolubility of ATA salts that induce aggregation-caused quenching (ACQ) and the protection of the COF shell. Contrarily, when water was added into mixture, the ATA salts were released into solution and its fluorescence recovered at 446 nm, while the fluorescence of COF was quenched due to the blockage of the intramolecular charge transfer (ICT) process by water. Thus, a high-sensitivity ratiometric fluorescence method is obtained with ultralow background signal and fast response (less than 1 min) for sensing water in organic solvent. We believe that the proposed ratiometric fluorescence sensor based on the zirconia-COF composite will provide the guidance for detection with wide applications.

17.
Microbiol Spectr ; 12(3): e0384623, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38299831

RESUMEN

Acidovorax citrulli is the main pathogen causing bacterial fruit blotch, which seriously threatens the global watermelon industry. At present, rapid, sensitive, and low-cost detection methods are urgently needed. The established CRISPR/LbCas12a visual detection method can specifically detect A. citrulli and does not cross-react with other pathogenic bacteria such as Erwinia tracheiphila, Pseudomonas syringae, and Xanthomonas campestris. The sensitivity of this method for genomic DNA detection is as low as 0.7 copies/µL, which is higher than conventional PCR and real-time PCR. In addition, this method only takes 2.5 h from DNA extraction to quantitative detection and does not require complex operation and sample treatment. Additionally, the technique was applied to test real watermelon seed samples for A. citrulli, and the results were contrasted with those of real-time fluorescence quantitative PCR and conventional PCR. The high sensitivity and specificity have broad application prospects in the rapid detection of bacterial fruit blotch bacterial pathogens of watermelon.IMPORTANCEBacterial fruit blotch, Acidovorax citrulli, is an important seed-borne bacterial disease of watermelon, melon, and other cucurbits. The lack of rapid, sensitive, and reliable pathogen detection methods has hampered research on fruit spot disease prevention and control. Here, we demonstrate the CRISPR/Cas12a system to analyze aspects of the specificity and sensitivity of A. citrulli and to test actual watermelon seed samples. The results showed that the CRISPR/Cas12a-based free-amplification method for detecting bacterial fruit blotch pathogens of watermelons was specific for A. citrulli target genes and 100-fold more sensitive than conventional PCR with quantitative real-time PCR. This method provides a new technical tool for the detection of A. citrulli.


Asunto(s)
Citrullus , Comamonadaceae , Citrullus/genética , Citrullus/microbiología , Frutas/microbiología , Enfermedades de las Plantas/microbiología , Comamonadaceae/genética , ADN
18.
Funct Plant Biol ; 512024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39298655

RESUMEN

Breeding abiotic stress-tolerant varieties of Rosa chinensis is a paramount goal in horticulture. WRKY transcription factors, pivotal in plant responses to diverse stressors, offer potential targets for enhancing stress resilience in R. chinensis . Using bioinformatics and genomic data, we identified RcWRKY transcription factor genes, characterised their chromosomal distribution, phylogenetic relationships, structural attributes, collinearity, and expression patterns in response to saline stress. Leveraging bidirectional database searches, we pinpointed 66 RcWRKY genes, categorised into three groups. All except RcWRKY60 encoded DNA Binding Domain and Zinc Finger Motif regions of the WRKY domain. Expansion of the RcWRKY gene family was propelled by 19 segmental, and 2 tandem, duplications. We unveiled 41 and 15 RcWRKY genes corresponding to 50 AtWRKY and 17 OsWRKY orthologs respectively, indicating postdivergence expansion. Expression analyses under alkaline stress pinpointed significant alterations in 54 RcWRKY genes. Integration of functional roles from their Arabidopsis orthologs and cis -acting elements within their promoters, along with quantitative reverse transcription PCR validation, underscored the importance of RcWRKY27 and 29 in R. chinensis ' alkaline stress response. These findings offer insights into the biological roles of RcWRKY transcription factors, as well as the regulatory dynamics governing R. chinensis ' growth, development, and stress resilience.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Filogenia , Proteínas de Plantas , Rosa , Estrés Fisiológico , Factores de Transcripción , Rosa/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico/genética , Álcalis/farmacología
19.
Acta Biomater ; 184: 210-225, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38969078

RESUMEN

Osteocytes perceive and process mechanical stimuli in the lacuno-canalicular network in bone. As a result, they secrete signaling molecules that mediate bone formation and resorption. To date, few three-dimensional (3D) models exist to study the response of mature osteocytes to biophysical stimuli that mimic fluid shear stress and substrate strain in a mineralized, biomimetic bone-like environment. Here we established a biomimetic 3D bone model by utilizing a state-of-art perfusion bioreactor platform where immortomouse/Dmp1-GFP-derived osteoblastic IDG-SW3 cells were differentiated into mature osteocytes. We evaluated proliferation and differentiation properties of the cells on 3D microporous scaffolds of decellularized bone (dBone), poly(L-lactide-co-trimethylene carbonate) lactide (LTMC), and beta-tricalcium phosphate (ß-TCP) under physiological fluid flow conditions over 21 days. Osteocyte viability and proliferation were similar on the scaffolds with equal distribution of IDG-SW3 cells on dBone and LTMC scaffolds. After seven days, the differentiation marker alkaline phosphatase (Alpl), dentin matrix acidic phosphoprotein 1 (Dmp1), and sclerostin (Sost) were significantly upregulated in IDG-SW3 cells (p = 0.05) on LTMC scaffolds under fluid flow conditions at 1.7 ml/min, indicating rapid and efficient maturation into osteocytes. Osteocytes responded by inducing the mechanoresponsive genes FBJ osteosarcoma oncogene (Fos) and prostaglandin-endoperoxide synthase 2 (Ptgs2) under perfusion and dynamic compressive loading at 1 Hz with 5 % strain. Together, we successfully created a 3D biomimetic platform as a robust tool to evaluate osteocyte differentiation and mechanobiology in vitro while recapitulating in vivo mechanical cues such as fluid flow within the lacuno-canalicular network. STATEMENT OF SIGNIFICANCE: This study highlights the importance of creating a three-dimensional (3D) in vitro model to study osteocyte differentiation and mechanobiology, as cellular functions are limited in two-dimensional (2D) models lacking in vivo tissue organization. By using a perfusion bioreactor platform, physiological conditions of fluid flow and compressive loading were mimicked to which osteocytes are exposed in vivo. Microporous poly(L-lactide-co-trimethylene carbonate) lactide (LTMC) scaffolds in 3D are identified as a valuable tool to create a favorable environment for osteocyte differentiation and to enable mechanical stimulation of osteocytes by perfusion and compressive loading. The LTMC platform imitates the mechanical bone environment of osteocytes, allowing the analysis of the interaction with other cell types in bone under in vivo biophysical stimuli.


Asunto(s)
Reactores Biológicos , Diferenciación Celular , Osteocitos , Osteocitos/citología , Osteocitos/metabolismo , Animales , Andamios del Tejido/química , Ratones , Perfusión , Estrés Mecánico , Línea Celular , Proliferación Celular , Fuerza Compresiva , Modelos Biológicos
20.
Mol Cell Biochem ; 381(1-2): 127-37, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23703028

RESUMEN

Endoplasmic reticulum stress (ERS) has been found in non-alcoholic fatty liver disease. The study was to further explore the mechanistic relationship between ERS and lipid accumulation. To induce ERS, the hepatoblastoma cell line HepG2 and the normal human L02 cell line were exposed to Tg for 48 h. RT-PCR and Western blot were performed to evaluate glucose-regulated protein (GRP-78) expression as a marker of ERS. ER ultrastructure was assessed by electron microscopy. Triglyceride content was examined by Oil Red O staining and quantitative intracellular triglyceride assay. The hepatic nuclear sterol regulatory element-binding protein (SREBP-1c), liver X receptor (LXRs), fatty acid synthase (FAS), and acetyl-coA carboxylase (ACC1) expressions were examined by real-time PCR and Western blot. 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF) was used to inhibit S1P serine protease inhibitor, and SREBP-1c cleavage was evaluated under ERS. SREBP-1c was knockdown and its effect on lipid metabolism was observed. Tg treatment upregulated GRP-78 expression and severely damaged the ER structure in L02 and HepG2 cells. ERS increased triglyceride deposition and enhanced the expression of SREBP-1c, FAS, and ACC1, but have no influence on LXR. AEBSF pretreatment abolished Tg-induced SREBP-1c cleavage. Moreover, SREBP-1c silencing reduced triglycerides and downregulated FAS expression. Pharmacological ERS induced by Tg leads to lipid accumulation through upregulation of SREBP-1c in L02 and HepG2 cells.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Estrés del Retículo Endoplásmico , Metabolismo de los Lípidos , Neoplasias Hepáticas/metabolismo , Hígado/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Regulación hacia Arriba , Acetil-CoA Carboxilasa/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/ultraestructura , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/ultraestructura , Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/genética , Ácido Graso Sintasas/metabolismo , Hígado Graso/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Proteínas de Choque Térmico/metabolismo , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Hígado/efectos de los fármacos , Hígado/patología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/ultraestructura , Receptores X del Hígado , Receptores Nucleares Huérfanos/genética , Receptores Nucleares Huérfanos/metabolismo , Proteolisis/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Sulfonas/farmacología , Tapsigargina/farmacología , Triglicéridos/metabolismo , Regulación hacia Arriba/efectos de los fármacos
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