ABSTRACT
OBJECTIVE: Streptococcus pneumoniae (Spn) is a common pathogen for pediatric pneumonia and leads to severe lung injury. This study is conducted to analyze the role of F-box and leucine rich repeat protein 19 (FBXL19) in Spn-induced lung injury in immature mice. METHODS: Immature mice were infected with Spn to record the survival rates and bacterial loads in bronchoalveolar lavage fluid. Levels of FBXL19 and FOXM1 in lung tissues were determined via real-time quantitative polymerase chain reaction or Western blotting. After the interference of FBXL19, its impacts on lung inflammatory injury were appraised by the lung wet/dry weight ratio, myeloperoxidase activity, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay. The binding of FBXL19 to forkhead box M1 (FOXM1) in mouse lung epithelial cells was determined. After MG132 treatment, the protein and ubiquitination levels of FOXM1 were measured. The functional rescue experiments were performed to analyze the role of FOXM1 in FBXL19-regulated lung injury. RESULTS: FBXL19 was downregulated while FOXM1 was upregulated in lung tissues of Spn-infected immature mice. Overexpression of FBXL19 reduced the degree of lung injury and inflammation. FBXL19 can bind to FOXM1 to reduce its protein level via ubiquitination degradation. MG132 reduced the ubiquitination and increased the protein level of FOXM1. Overexpression of FOXM1 reversed the protective role of FBXL19 overexpression in lung injury of Spn immature mice. CONCLUSION: FBXL19 was downregulated by Spn and FBXL19 overexpression alleviated lung injury by inducing ubiquitination and degradation of FOXM1 in Spn immature mice.
Subject(s)
F-Box Proteins , Lung Injury , Pneumonia , Animals , Mice , Streptococcus pneumoniae/metabolism , Lung Injury/genetics , Lung , Ubiquitination , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , F-Box Proteins/genetics , F-Box Proteins/metabolismABSTRACT
Reduced Graphene Oxide Wrapped Pd/TiO2 (r-GO@Pd/TiO2) which exhibited high photocatalytic activity under visible light was synthesized from commercial chemicals. The classic sol-gel method and the Ar gas bubbling composition was used in the preparation of the catalyst. Furthermore, the best Pd-doping concentration in crystals, the wrapping concentration of r-GO over nanoparticles, and the optimal calcination temperature were investigated to enhance the photocatalytic activity of the hybrid catalyst. The experimental results showed that the catalytic efficiency of r-GO@Pd/TiO2 reached maximum value at the optimum synthesis conditions: 0.7 wt% Pd-doped TiO2 by sol-gel process, calcination temperature of 550 °C, 1 mg of GO for 100 .gram wrapped Pd/TiO2. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) techniques were conducted to determine the nanostructure of the catalysts. The average crystallite size of nanoparticles was 14 nm with perfect dispersion of Pd dots and wraps of r-GO membrane. Methyl Blue was used as an organic dye model to test the ability in wastewater treatment of the catalysts. A comparison between different catalysts' characteristics was also studied. The r-GO@Pd/TiO2 showed a higher photocatalytic activity compared to Pd/TiO2 and commercial P25. Additionally, the complete dye reduction under visible light excitation indicated that wrapping r-GO round Pd/TiO2 improved the photocatalytic activity of catalysts. The determination of the stability of r-GO@Pd/TiO2 showed that its photocatalysis was persistent over several times of recycling examination. Therefore, r-GO@ Pd/TiO2 in wastewater treatment.
Subject(s)
Crystallization/methods , Graphite/chemistry , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Catalysis , Graphite/radiation effects , Light , Materials Testing , Metal Nanoparticles/radiation effects , Nanocomposites/radiation effects , Oxides/chemistry , Palladium/chemistry , Palladium/radiation effects , Titanium/chemistry , Titanium/radiation effects , Wastewater/chemistryABSTRACT
Pd-modified N-doped TiO2 nanoparticles were prepared by the sol-gel method. The X-ray diffraction (XRD) pattern indicated that the pure anatase TiO2 has been obtained. Transmission electron microscope (TEM) was used to observe the micro-morphology of the nanoparticles. The average size of the particles was 8.04 nm. The N2 adsorption isotherm of the resulted nanoparticles was the type IV with a H1 type hysteresis loop. The specific surface area was 145.2 m2 g(-1) and the average diameter of adsorption was 4.178 nm. These Pd-modified N-doped TiO2 nanoparticles were applied onto the surface of glass carbon electrode (GCE), and its electro-catalytic activity was tested by cyclic voltammetry (CV). The reduction peak currents showed a linear response to the dissolved oxygen (DO) concentrations ranging from 0.6 mg L(-1) to 7.2 mg L(-1) on the Pd-N-TiO2/ GCE. The linear regression equation was y = 3E - 6x + 1E-5 (R = 0.9909). The detection limit was 0.22 mg L(-1.) The result indicated that the Pd-N-TiO2 possessed a good electro-catalytic activity.
