GPR35-mediated kynurenic acid sensing contributes to maintenance of gut microbiota homeostasis in ulcerative colitis.

Ulcerative colitis (UC) is a recurrent inflammatory disease related to gut microbiota disorder. Metabolites and their sensors play an important role in the communication between gut microbes and their host. Our previous study revealed that G protein-coupled receptor 35 (GPR35) is a key guardian of kynurenic acid (KA) and a core element of the defense responses against gut damage. However, the mechanism remains unknown. In this study, a DSS-induced rat colitis model was established and 16S rRNA sequencing was applied to explore the influence of GPR35-mediated KA sensing on gut microbiota homeostasis. Our results demonstrated that GPR35-mediated KA sensing is a necessary component in maintaining gut barrier integrity against DSS-induced damage. Furthermore, we provide compelling evidence suggesting that GPR35-mediated KA sensing plays a crucial role in maintaining gut microbiota homeostasis, which contributes to alleviation of DSS-induced colitis. In addition, five classes (Actinobacteria, Beta-/Gamma-proteobacteria, Erysipelotrichi, and Coriobacteriia) and six genera (Corynebacterium, Allobaculum, Parabacteroides, Sutterella, Shigella, and Xenorhabdus) were identified as the marked bacterial taxa that characterized the progression and outcome of colitis and are regulated by GPR35-mediated KA sensing. Our findings highlight that GPR35-mediated KA sensing is an essential defense mechanism against disorder of gut microbiota in UC. The results provide insights into the key role of specific metabolites and their monitor in maintaining gut homeostasis.

Nanocrystals with metastable high-pressure phases under ambient conditions.

The ambient metastability of the rock-salt phase in well-defined model systems comprising nanospheres or nanorods of cadmium selenide, cadmium sulfide, or both was investigated as a function of composition, initial crystal phase, particle structure, shape, surface functionalization, and ordering level of their assemblies. Our experiments show that these nanocrystal systems exhibit ligand-tailorable reversibility in the rock salt-to-zinc blende solid-phase transformation. Interparticle sintering was used to engineer kinetic barriers in the phase transformation to produce ambient-pressure metastable rock-salt structures in a controllable manner. Interconnected nanocrystal networks were identified as an essential structure that hosted metastable high-energy phases at ambient conditions. These findings suggest general rules for transformation-barrier engineering that are useful in the rational design of next-generation materials.

Thermoresponsive poly(N-isopropylacrylamide)/graphene/Au nanocomposite hydrogel for water treatment by a laser-assisted approach.

The thermoresponsive poly(N-isopropylacrylamide)/graphene/Au multicomponent hydrogel is prepared by the simultaneous in-situ formation of Au nanoparticles and the reduction of graphene oxide, assisted by NIR laser irradiation of a prefabricated PNIPAM/GO hydrogel with auric acid precursor, showing great potential for water treatment owing to the excellent photothermal effect.

Infliximab enhances the therapeutic effectiveness of octreotide on acute necrotizing pancreatitis in rat model.

OBJECTIVES: To investigate the synergistic activity of infliximab to the therapeutic effectiveness of octreotide in a rat model of acute necrotizing pancreatitis (ANP). METHODS: Forty Sprague-Dawley rats were randomly divided into sham-operated group (SO), ANP group (ANP), octreotide group (OG), infliximab group (IG), and combination group (CG) (n = 8 in each group). The ANP model was induced by biliopancreatic duct injection with 4.5% of sodium taurocholate solution. Rats of the OG, IG, and CG were given a tail vein injection of octreotide (10 µg/kg), infliximab (8 mg/kg), and infliximab (8 mg/kg), respectively, combined with octreotide (10 µg/kg) at 6 hours after modeling. All rats in each group were killed at 24 hours after modeling. Serum biochemical indicator and partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) of rats were determined. Pathological severity score of organs were evaluated. RESULTS: The serum biochemical indicator and organs' pathology score of OG , IG, and CG were obviously lower than those in the ANP group, and those in the CG were the lowest (P < 0.05). The PaO2/FiO2 levels in the OG, IG, and CG were significantly higher than that in the ANP group (P < 0.05). CONCLUSION: Infliximab could significantly lower the serum biochemical indicator, improve organs' function, and enhance the therapeutic effectiveness of octreotide on ANP.