Gut commensal Parabacteroides distasonis alleviates inflammatory arthritis.

OBJECTIVE: Gut microbiota dysbiosis is closely linked to the pathogenesis of rheumatoid arthritis (RA). We aimed to identify potential probiotic gut microbes that can ameliorate the development of RA. DESIGN: Microbiota profiling in patients with RA and healthy individuals was investigated via 16S rDNA bacterial gene sequencing and shotgun metagenomics. Collagen-induced arthritic mice and TNF-α transgenic mice were used to evaluate the roles of the gut commensal Parabacteroides distasonis in RA. The effects of P. distasonis-derived microbial metabolites on the differentiation of CD4+ T cells and macrophage polarisation were also investigated. RESULTS: The relative abundance of P. distasonis in new-onset patients with RA and patients with RA with history of the disease was downregulated and this decrease was negatively correlated with Disease Activity Score-28 (DAS28). Oral treatment of arthritic mice with live P. distasonis (LPD) considerably ameliorated RA pathogenesis. LPD-derived lithocholic acid (LCA), deoxycholic acid (DCA), isolithocholic acid (isoLCA) and 3-oxolithocholic acid (3-oxoLCA) had similar and synergistic effects on the treatment of RA. In addition to directly inhibiting the differentiation of Th17 cells, 3-oxoLCA and isoLCA were identified as TGR5 agonists that promoted the M2 polarisation of macrophages. A specific synthetic inhibitor of bile salt hydrolase attenuated the antiarthritic effects of LPD by reducing the production of these four bile acids. The natural product ginsenoside Rg2 exhibited its anti-RA effects by promoting the growth of P. distasonis. CONCLUSIONS: P. distasonis and ginsenoside Rg2 might represent probiotic and prebiotic agents in the treatment of RA.

Synthesis and characterization of protocatechuic acid grafted carboxymethyl chitosan with oxidized sodium alginate hydrogel through the Schiff's base reaction.

Excessive accumulation of free radicals is closely related to the occurrence and development of various neurodegenerative diseases. In this study, a novel protocatechuic acid grafted carboxymethyl chitosan with oxidized sodium alginate (PCA-g-CMCS/OSA) hydrogel was developed to maintain the oxidation-antioxidation balance activities. By optimizing the pH-soluble range (pH > 6.4) of CMCS, PCA was grafted onto CMCS skeleton via EDC/NHS, and then conjugated with aldehyde group of OSA to form Schiff's base hydrogel at physiological temperature. The gelation time can be adjusted rapidly within 1-3 min by controlling the content of OSA. The shaped hydrogel exhibited porous network structure with high porosity (>90 %), swelling ratio (2000-3000 %) and rheological property, which is beneficial to cell growth and proliferation. The conjugates preserved excellent DPPH and ABTS radicals scavenging abilities and adequate biodegradability within 5 weeks. Moreover, with the release of PCA monomer due to degradation of the PCA-g-CMCS/OSA, the hydrogel also exhibited excellent biocompatibility and protective effect on H2O2-induced oxidative damage in PC12 cells. These results suggested that the PCA-g-CMCS/OSA hydrogel would appear to be a more attractive candidate for potential biomedical applications such as antioxidant drug release and tissue engineering implant material.

Polypyrrole-Coated K2Mn[Fe(CN)6] Stabilizing Its Interfaces and Inhibiting Irreversible Phase Transition during the Zinc Storage Process in Aqueous Batteries.

Prussian blue analogues (PBAs) have been considered as promising cathodes for aqueous zinc-ion batteries because of their open framework for accommodating large ions, tunable valence state, and facile synthesis. Among PBAs, potassium manganese hexacyanoferrate (KMHCF) is favored due to its high working voltage, high specific capacity, and low cost. However, it suffers from severe capacity decay and poor rate capability, which are mainly a result of poor intrinsic conductivity, irreversible phase transition, transition metal dissolution, and structural collapse during charge/discharge cycling. These issues extremely limit its practical application. In order to solve these problems, conductive polypyrrole (PPy) was used to coat KMHCF microcubes to form KMHCF@PPy composites to achieve superior rate capability and prolonged cycle life. With the PPy coating, the KMHCF@PPy composite delivers a discharge capacity of 107.6 mA h g-1 after 100 cycles at 100 mA g-1, and even at 500 mA g-1 after 500 cycles, 64.2 mA h g-1 still remained. The excellent electrochemical performance can be attributed to the effects from PPy. On the one hand, PPy supplies an effective electronic transmission network for KMHCF to enhance the electronic conductivity. On the other hand, it plays the role of a protective layer to effectively inhibit the dissolution of Mn and the phase transition during the cycling.

Exfoliation and stabilization mechanism of graphene in carbon dioxide expanded organic solvents: molecular dynamics simulations.

CO2 expanded organic solvents possess significant advantages in liquid-phase exfoliation to obtain monolayer/few-layer graphene from graphite. Further insights into the mechanism of graphene exfoliation in such solvents are essential to explore liquid-phase dispersion of graphene as a more potent alternative to chemical vapor deposition. In this study, dynamic processes of exfoliation and stabilization of graphene in CO2-N,N-dimethylformamide (DMF), CO2-N-methylpyrrolidone (NMP), CO2-dimethyl sulfoxide (DMSO), and CO2-ethanol (EtOH) were investigated using molecular dynamics simulations. The origin of the effect of each solvent on graphene exfoliation was analyzed quantitatively through potential mean force simulations. It has been found that the organic solvent in a CO2 expanded solvent should be chosen with proper surface tension, and there exist two different graphene exfoliation processes in the effective solvents, which can be described as "burger dissociation" and "extrusion-taking away" processes, respectively. In the former process, a characteristic "super-burger-like" conformation with a semi-exfoliated structure was formed, which was the deciding factor to obtain high ratio of monolayer/few-layer graphene in dispersion product. A theoretical explanation has also been provided at the molecular level to the earlier experimental phenomena. A predicted simulation of the CO2-3,3'-iminobis(N,N-dimethylpropylamine) (DMPA) system is also calculated. This investigation helps to avoid incompatible CO2 expanded organic solvents employed in the experimental studies and provides theoretical clues to understand the mechanism of exfoliation and stabilization of graphene in such solvents.

[Preparation and formulation investigation of gastric retention calcium alginate microspheres containing Brucea javanica oil].

OBJECTIVE: To investigate the preparation technologies of gastric retention calcium alginate microsphere containing Brucea javanica oil, and to evaluate its formulations. METHODS: The formulations of gastric retention calcium alginate microspheres were optimized with G/M ration and concentration of sodium alginate,use level of iron calcium solution and pore-forming agent, cross-link time and pH value of cross-link solution, which had shown a great effect on microspheres morphology, drug release behavior, drug loaded and encapsulation efficiency. RESULTS: Brucea javanica oil alginate microspheres looked spherical, homogeneous and well distributive. And the drug loaded of Brucea javanica oil was over 40%, encapsulation efficiency was over 70%. CONCLUSION: The prepared gastric retention calcium alginate microspheres have a great sustained release and floating capability, which can provide a strong topical therapy for gastric diseases.

Transcript assembly and quantification by RNA-Seq reveals differentially expressed genes between soft-endocarp and hard-endocarp hawthorns.

Hawthorn (Crataegus spp.) is an important pome with a long history as a fruit, an ornamental, and a source of medicine. Fruits of hawthorn are marked by hard stony endocarps, but a hawthorn germplasm with soft and thin endocarp was found in Liaoning province of China. To elucidate the molecular mechanism underlying the soft endocarp of hawthorn, we conducted a de novo assembly of the fruit transcriptome of Crataegus pinnatifida and compared gene expression profiles between the soft-endocarp and the hard-endocarp hawthorn varieties. De novo assembly yielded 52,673 putative unigenes, 20.4% of which are longer than 1,000 bp. Among the high-quality unique sequences, 35,979 (68.3%) had at least one significant match to an existing gene model. A total of 1,218 genes, represented 2.31% total putative unigenes, were differentially expressed between the soft-endocarp hawthorn and the hard-endocarp hawthorn. Among these differentially expressed genes, a number of lignin biosynthetic pathway genes were down-regulated while almost all the flavonoid biosynthetic pathway genes were strongly up-regulated, concomitant with the formation of soft endocarp. In addition, we have identified some MYB and NAC transcription factors that could potentially control lignin and flavonoid biosynthesis. The altered expression levels of the genes encoding lignin biosynthetic enzymes, MYB and NAC transcription factors were confirmed by quantitative RT-PCR. This is the first transcriptome analysis of Crataegus genus. The high quality ESTs generated in this study will aid future gene cloning from hawthorn. Our study provides important insights into the molecular mechanisms underlying soft endocarp formation in hawthorn.