Caveolin-1 identified as a key mediator of acute lung injury using bioinformatics and functional research

Acute lung injury (ALI) is a potentially life-threatening, devastating disease with an extremely high rate of mortality. The underlying mechanism of ALI is currently unclear. In this study, we aimed to confirm the hub genes associated with ALI and explore their functions and molecular mechanisms using bioinformatics methods. Five microarray datasets available in GEO were used to perform Robust Rank Aggregation (RRA) to identify differentially expressed genes (DEGs) and the key genes were identified via the protein-protein interaction (PPI) network. Lipopolysaccharide intraperitoneal injection was administered to establish an ALI model. Overall, 40 robust DEGs, which are mainly involved in the inflammatory response, protein catabolic process, and NF-κB signaling pathway were identified. Among these DEGs, we identified two genes associated with ALI, of which the CAV-1/NF-κB axis was significantly upregulated in ALI, and was identified as one of the most effective targets for ALI prevention. Subsequently, the expression of CAV-1 was knocked down using AAV-shCAV-1 or CAV-1-siRNA to study its effect on the pathogenesis of ALI in vivo and in vitro. The results of this study indicated that CAV-1/NF-κB axis levels were elevated in vivo and in vitro, accompanied by an increase in lung inflammation and autophagy. The knockdown of CAV-1 may improve ALI. Mechanistically, inflammation was reduced mainly by decreasing the expression levels of CD3 and F4/80, and activating autophagy by inhibiting AKT/mTOR and promoting the AMPK signaling pathway. Taken together, this study provides crucial evidence that CAV-1 knockdown inhibits the occurrence of ALI, suggesting that the CAV-1/NF-κB axis may be a promising therapeutic target for ALI treatment.Subject terms: Cell signalling, Respiratory tract diseases     

磁性聚乙二醇载体固定化α淀粉酶的研究

α淀粉酶广泛应用于粮食加工、食品、酿造、发酵、纺织品和医药工业［1］．由于固定化酶的优点,国内外研究人员对固定化糖化酶［2,3］和固定化α淀粉酶[4]的制备及在淀粉酶法生产葡萄糖方面的应用作了大量的研究,显示了工业应用前景．然而,迄今为止,用磁性载体固定化α淀粉酶尚未见报道．我们用磁性聚乙二醇胶体粒子作载体,制备出具有磁响应性强、稳定性强、活力高的固定化α淀粉酶．由于具有磁响应性,可借助外部磁场方便简单地回收酶,为该酶工业化生产葡萄糖提供了一种新的途径．而且,由于磁性的优点,也为该酶在食品、医药、纺织…     

Eye drop delivery of nano-polymeric micelle formulated genes with cornea-specific promoters

BACKGROUND: This study evaluates the eye drop delivery of genes with cornea-specific promoters, i.e., keratin 12 (K12) and keratocan (Kera3.2) promoters, by non-ionic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) polymeric micelles (PM) to mouse and rabbit eyes, and investigates the underlying mechanisms. METHODS: Three PM-formulated plasmids (pCMV-Lac Z, pK12-Lac Z and pKera3.2-Lac Z) containing the Lac Z gene for beta-galactosidase (beta-Gal) whose expression was driven by the promoter of either the cytomegalovirus early gene, the keratin 12 gene or the keratocan gene, were characterized by critical micelle concentration (CMC), dynamic light scattering (DLS), and atomic force microscopy (AFM). Transgene expression in ocular tissue after gene delivery was analyzed by 5-bromo-4-chloro-3-indolyl-beta-D-galactoside (X-Gal) color staining, 1,2-dioxetane beta-Gal enzymatic activity measurement, and real-time polymerase chain reaction (PCR) analysis. The delivery mechanisms of plasmid-PM on mouse and rabbit corneas were evaluated by EDTA and RGD (arginine-glycine-aspartic acid) peptide. RESULTS: The sizes of the three plasmid-PM complexes were around 150-200 nm with unimodal distribution. Enhanced stability was found for three plasmid-PM formulations after DNase I treatment. After six doses of eye drop delivery of pK12-Lac Z-PM three times a day, beta-Gal activity was significantly increased in both mouse and rabbit corneas. Stroma-specific Lac Z expression was only found in pKera3.2-Lac Z-PM-treated animals with pretreatment by 5 mM EDTA, an opener of junctions. Lac Z gene expression in both pK12-Lac Z-PM and pKera3.2-Lac Z-PM delivery groups was decreased by RGD peptide pretreatment. CONCLUSIONS: Cornea epithelium- and stroma-specific gene expression could be achieved using cornea-specific promoters of keratin 12 and keratocan genes, and the gene was delivered with PM formulation through non-invasive, eye drop in mice and rabbits. The transfection mechanism of plasmid-PM may involve endocytosis and particle size dependent paracellular transport.     

Phosphorylation on tyrosine-15 of p34(Cdc2) by ErbB2 inhibits p34(Cdc2) activation and is involved in resistance to taxol-induced apoptosis

ErbB2 overexpression confers resistance to taxol-induced apoptosis by inhibiting p34(Cdc2) activation. One mechanism is via ErbB2-mediated upregulation of p21(Cip1), which inhibits Cdc2. Here, we report that the inhibitory phosphorylation on Cdc2 tyrosine (Y)15 (Cdc2-Y15-p) is elevated in ErbB2-overexpressing breast cancer cells and primary tumors. ErbB2 binds to and colocalizes with cyclin B-Cdc2 complexes and phosphorylates Cdc2-Y15. The ErbB2 kinase domain is sufficient to directly phosphorylate Cdc2-Y15. Increased Cdc2-Y15-p in ErbB2-overexpressing cells corresponds with delayed M phase entry. Expressing a nonphosphorylatable mutant of Cdc2 renders cells more sensitive to taxol-induced apoptosis. Thus, ErbB2 membrane RTK can confer resistance to taxol-induced apoptosis by directly phosphorylating Cdc2.     

Development of mechanistically based model for simulating soluble microbial products generation in an aerated/non-aerated SBR

Soluble microbial products (SMPs) are considered as the main organic components in wastewater treatment plant effluent from biological wastewater treatment systems. To investigate and explore SMP metabolism pathway for further treatment and control, two innovative mechanistically based activated sludge models were developed by extension of activated sludge model no.3 (ASM3). One was the model by combining SMP formation and degradation (ASM3-SMP model) processes with ASM3, and the other by combining both SMP and simultaneous substrate storage and growth (SSSG) mechanisms with ASM3 (SSSG-ASM3-SMP model). The detailed schematic modification and process supplements were introduced for comprehensively understanding all the mechanisms involved in the activated sludge process. The evaluations of these two models were demonstrated by a laboratory-scale sequencing batch reactor (SBR) operated under aerated/non-aerated conditions. The simulated and measured results indicated that SMP comprised about 83% of total soluble chemical oxygen demand (SCOD) in which biomass-associated products (BAPs) were predominant compared with utilization-associated products (UAPs). It also elucidated that there should be a minimum SMP value as the reactive time increases continuously and this conclusion could be used to optimize effluent SCOD in activated sludge processes. The comparative results among ASM3, ASM3-SMP and SSSG-ASM3-SMP models and the experimental measurements (SCOD, ammonia and nitrate nitrogen) showed clearly the best agreement with SSSG-ASM3-SMP simulation values (R = 0.993), strongly suggesting that both SMP formation and degradation and SSSG mechanisms are necessary in biologically activated sludge modeling for municipal wastewater treatment.     

Targeting inhibition of GluR1 Ser845 phosphorylation with an RNA aptamer that blocks AMPA receptor trafficking

Phosphorylation at glutamate receptor subunit 1(GluR1) Ser845 residue has been widely accepted to involve in GluR1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking, but the in vivo evidence has not yet been established. One of the main obstacles is the lack of effective methodologies to selectively target phosphorylation at single amino acid residue. In this study, the Escherichia  coli -expressed glutathione- S -transferase-tagged intracellular carboxyl-terminal domain of GluR1 (cGluR1) was phosphorylated by protein kinase A for in vitro selection. We have successfully selected aptamers which effectively bind to phospho-Ser845 cGluR1 protein, but without binding to phospho-Ser831 cGluR1 protein. Moreover, pre-binding of the unphospho-cGluR1 protein with these aptamers inhibits protein kinase A-mediated phosphorylation at Ser845 residue. In contrast, the pre-binding of aptamer A2 has no effect on protein kinase C-mediated phosphorylation at Ser831 residue. Importantly, the representative aptamer A2 can effectively bind the mammalian GluR1 that inhibited GluR1/GluR1-containing AMPA receptor trafficking to the cell surface and abrogated forskolin-stimulated phosphorylation at GluR1 Ser845 in both green fluorescent protein–GluR1-transfected human embryonic kidney cells and cultured rat cortical neurons. The strategy to use aptamer to modify single-residue phosphorylation is expected to facilitate evaluation of the potential role of AMPA receptors in various forms of synaptic plasticity including that underlying psychostimulant abuse.     

Evaluation of genotoxicity of combined soil pollution by cadmium and imidacloprid

Cadmium (Cd) is one of the important pollutants of soil and the genotoxicity of Cd-contaminated soil was studied in combination with imidacloprid. The single cell gel electrophoresis or comet assay was used to quantify DNA strand breaks as a measure of DNA damage induced by Cd and imidacloprid contamination in soil. The soil was artificially contaminated by Cd 2 h at 25℃ and were used in the comet assay. DNA damage was measured as the values of percentage of nuclei with tails, tail length, tail DNA, tail moment (TM), and Olive tail moment (OTM). DNA damages of root tips of Vicia faba increased after Cd treatment and there were dose-related increases in DNA damage measured as these parameters. However, the addition of imidacloprid further increased the DNA damage. These data confirmed the genotoxic effect of Cd to plants, and that the combined pollution with imidacloprid can enhance the genotoxicity of Cd.     

松果体昼夜节律生物钟分子机制的研究进展

在各种非哺乳类脊椎动物中 ,松果体起着中枢昼夜节律振荡器的作用。近来 ,在鸟类松果体中相继发现了几种钟基因 ,如Per、Cry、Clock和Bmal等 ,其表达的时间变化规律与哺乳类视交叉上核 (SCN)的非常相似。钟的振荡由其自身调控反馈环路的转录和翻译组成 ,鸟类松果体和哺乳类SCN似乎具有共同的钟振荡基本分子构架 ;若干钟基因产物作为正向或负向调节子影响钟的振荡 ;昼夜性的控时机制同时也需要翻译后事件的参与。这些过程对钟振荡器的稳定性和 /或钟导引的光输入通路有着重要的调控作用