Identification of a UDP-glucose pyrophosphorylase from cotton (Gossypium hirsutum L.) involved in cellulose biosynthesis in Arabidopsis thaliana.

UDP-glucose pyrophosphorylase is an important regulatory enzyme for the development of plants and a critical enzyme in synthesis of glycogen. Here, we reported the cloning of a full-length UGP cDNA from cotton, named GhUGP. Real-time PCR analysis indicated the GhUGP expression in root, stem, leaf and flower of cotton, with a higher level in flower and root. The transcription level of GhUGP depended on sucrose and light in short time and increased under low temperature, but decreased in O(2) deficiency. Interestingly, the expression of GhUGP was significantly up-regulated after ethylene induction in cotton ovules. The over-expression of the GhUGP in Arabidopsis showed discrepant phenotype: increase in height and growth rate when compared with control lines. What is more, the transgenic Arabidopsis had increased contents of soluble sugars, starch and cellulose, but not in lignin content. Collectively, these results indicate that cotton UGPase participates in sucrose/polysaccharides metabolism and cell wall biosynthesis and provide theoretical deduction supporting GhUGP as a good candidate gene for improving the development of cotton fibers cell.

Topical cationic hairy particles targeting cell free DNA in dermis enhance treatment of psoriasis.

Abnormal high level of cell free DNA (cfDNA) triggers chronic inflammation to exacerbate psoriasis symptoms. Scavenging cfDNA by topical cationic polymeric nanoparticles has been certified as an effective therapeutic strategy for treating psoriasis. However, cationic cfDNA scavengers have a great potential risk to organs after entering systemic circulation through skin barrier. For better transformation to clinical application, herein a series of poly(2-(dimethylamino)ethyl methacrylate) (PDMA) grafted hairy silica particles (cSPs) with tunable PDMA length and particle size are applied to scavenge cfDNA in dermis. We reveal that the structure of cSPs correlates with the permeation ability across stratum corneum, retention time in dermis, binding affinity to cfDNA, and toxicity tolerance, which in turn affect the therapeutic effect. Especially, the cSPs of 700 nm show more accumulation and longer retention in psoriatic lesions, leading to excellent treatment results. They also outperform the cSPs of 200 nm at a lower administration frequency. Thus, we address the issues of size, cationic content of cSPs to open a potential new avenue to topically treatment of psoriasis by targeting cfDNA in dermis.

Phenothiazine-based oligomers as novel fluorescence probes for detecting vapor-phase nitro compounds.

To meet the need for rapid and low-cost chemical sensing of explosive, new fluorescence chemosensors based on oligophenothiazines for probing vapor-phase nitro compounds have been developed. The phenothiazine-based trimer P3 and pentamer P5 have been synthesized via Heck and Wittig reactions by convergent approach. It was found that they can detect the vapors of nitro compounds, including p-nitrotoluene (p-NT), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT) with good sensitivity and reversibility. And the sensor of P3 film gave a linear fluorescence quenching response to 7-800 ppb TNT with the detection limit of 4 ppb. For DNT vapor, a linear working range of the sensor was 2-24 ppm with the detection limit of 40 ppb. Meanwhile, the interferents, including common organic solvents, p-nitrophenol and 2,4-dinitrophenylhydrazine cannot lead to obvious fluorescence quenching, meaning that the film based on oligophenothiazines exhibited good specificity of fluorescence response to explosive. Based on the fluorescence lifetime and UV-vis absorption measurements, we suggested that the fluorescence quenching of oligophenothiazine-based films exposed to the vapors of nitro compounds was due to the formation of non-fluorescent charge-transfer complex between oligophenothiazine and nitro compounds.