RESUMO
Covalent organic frameworks (COFs), at the forefront of porous materials, hold tremendous potential in membrane separation; however, achieving high continuity in COF membranes remains crucial for efficient gas separation. Here, we present a unique approach termed assembly-dissociation-reconstruction for fabricating COF membranes tailored for CO2/N2 separation. A parent COF is designed from two-node aldehyde and three-node amine monomers and dissociated to high-aspect-ratio nanosheets. Subsequently, COF nanosheets are orderly reconstructed into a crack-free membrane by surface reaction under water evaporation. The membrane exhibits high crystallinity, open pores and a strong affinity for CO2 adsorption over N2, resulting in CO2 permeance exceeding 1060 GPU and CO2/N2 selectivity surpassing 30.6. The efficacy of this strategy offers valuable guidance for the precise fabrication of gas-separation membranes.
RESUMO
Osteoarthritis (OA) is a joint disease caused by inflammation of cartilage and synovial tissue. Suppressing the process of inflammatory reaction and the generation of oxidative stress is an effective strategy to alleviate the progression of OA. Liensinine is one of the main components of lotus seeds, which has anti-hypertensive and anti-arrhythmia activities. In this study, we aimed to determine the anti-inflammatory effect of liensinine in an OA. Here, we found that liensinine significantly inhibited the inflammatory response of SW1353 cells and primary chondrocytes by inhibiting the release of inflammatory cytokines and oxidative stress. Moreover, we showed that liensinine was able to inhibit the activation of the NF-κB signaling pathway in IL-1ß-induced SW1353 cells. Lastly, we found that liensinine significantly ameliorated cartilage damage and inflammatory response in papain-induced rats. Our study demonstrated a significant protective effect of liensinine against OA, which might be by inhibiting the activation of the NF-κB signaling pathway, and provide a new insight for the treatment of OA using liensinine.
Assuntos
Anti-Inflamatórios , Condrócitos , Interleucina-1beta , NF-kappa B , Osteoartrite , Animais , Humanos , Masculino , Ratos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Células Cultivadas , Condrócitos/efeitos dos fármacos , Citocinas/metabolismo , Interleucina-1beta/metabolismo , Isoquinolinas , NF-kappa B/metabolismo , Osteoartrite/tratamento farmacológico , Osteoartrite/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Papaína , Fenóis , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: As a potent mediator of hypothermic neuroprotection, the cold-inducible protein RBM3 is characterized with one RNA-recognition motifs (RRM) and one arginine-glycine-rich (RGG) domain. It is known that these conserved domains are required for nuclear localization in some RNA-binding proteins. However, little is known about the actual role of RRM and RGG domains in subcellular localization of RBM3. METHODS: To clarify it, various mutants of human Rbm3 gene were constructed. Plasmids were transfected into cells and the localization of RBM3 protein and its varias mutants in cells and role in neuroprotection. RESULTS: In human neuroblastoma SH-SY5Y cells, either a truncation of RRM domain (aa 1-86) or RGG domain (aa 87-157) led to an obvious cytoplasmic distribution, compared to a predominant nuclear localization of whole RBM3 protein (aa 1-157). In contrast, mutants in several potential phosphorylated sites of RBM3, including Ser102, Tyr129, Ser147, and Tyr155, did not alter the nuclear localization of RBM3. Similarly, mutants in two Di-RGG motif sites also did not affect the subcellular distribution of RBM3. Lastly, the role of Di-RGG motif in RGG domains was further investigated. The mutant of double arginines in either Di-RGG motif-1 (Arg87/90) or -2 (Arg99/105) exhibited a higher cytoplasmic localization, indicating that both Di-RGG motifs are required for nucleic localization of RBM3. CONCLUSIONS: Our data suggest that RRM and RGG domains are both required for the nuclear localization of RBM3, with two Di-RGG domain being crucial for nucleocytoplasmic shuttling of RBM3.
Assuntos
Neuroproteção , Proteínas de Ligação a RNA , Humanos , Arginina , Citoplasma , Proteínas de Ligação a RNA/genética , Linhagem Celular TumoralRESUMO
In this study, a mutant xylanase of high thermostability was obtained by site-directed mutagenesis. The homologous 3D structure of xylanase was successfully modeled and the mutation sites were predicted using bioinformatics software. Two amino acids of XynZF-2 were respectively substituted by cysteines (T205C and A52C) and a disulfide bridge was introduced into the C-terminal of XynZF-2. The mutant gene xynZFTA was cloned into pPIC9K and expressed in P. pastoris. The optimum temperature of the variant XynZFTA was improved from 45°C to 60°C, and XynZFTA retained greater than 90.0% activity (XynZF-2 retained only 50.0% activity) after treatment at 50°C for 5 min. The optimum pH of mutant xylanase was similar to XynZF-2 (pH = 5.0). The pH stability span (5.0~7.0) of the mutant xylanase was increased to 3.0~9.0. Overall, the results implied that the introduction of a disulfide bridge in the C-terminal structure improved the thermostability and pH stability of XynZF-2.