Residue 75 of Interleukin‐8 is Crucial for its Interactions with Glycosaminoglycans

The interactions between regulatory proteins such as interleukin‐8 (IL‐8) and glycosaminoglycans are of great interest both for the general understanding of regulatory processes in biology and for the development of implant coatings and innovative materials that suppress undesired immune responses and improve wound healing. In previous work, a number of residues of IL‐8 that interact strongly with several glycosaminoglycans (GAGs) have been identified. In particular, the negatively charged Glu75 was reported to be involved in interactions with charged GAGs. To improve understanding of the role of this residue, we generated a selectively ¹⁵N‐labeled E75K variant of IL‐8(1–77) by expressed protein ligation. NMR and fluorescence spectroscopy in combination with molecular modeling were applied to evaluate the particular role of residue 75 in interactions with GAGs. Remarkably, more residues in the variant responded to GAG binding than in the wild‐type. For the first time, we identified amino acids 34 to 36 as additional residues in the loop region of IL‐8(1–77) that participate in the interactions with GAGs. These findings indicate that the N terminus of the E75K variant is more important as a second binding site for GAGs than that of the wild‐type IL‐8(1–77).     

Reduced Colonic Mucosal Injury in 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Poly ADP-Ribose Polymerase (TIPARP/PARP7)-Deficient Mice

Poly-ADP-ribose polymerases (PARPs) are important regulators of the immune system, including TCDD-inducible poly-ADP-ribose polymerase (TIPARP), also known as poly-ADP-ribose polymerase 7 (PARP7). PARP7 negatively regulates aryl hydrocarbon receptor (AHR) and type I interferon (IFN-I) signaling, both of which have been implicated in intestinal homeostasis and immunity. Since the loss of PARP7 expression increases AHR and IFN-I signaling, we used a murine dextran sulfate sodium (DSS)-induced colitis model to investigate the effect of PARP7 loss on DSS-induced intestinal inflammation. DSS-exposed Parp7^−/− mice had less body weight loss, lower disease index scores, and reduced expression of several inflammation genes, including interleukin IL-6, C-x-c motif chemokine ligand 1 (Cxcl1), and lipocalin-2, when compared with wild-type mice. However, no significant difference was observed between genotypes in the colonic expression of the AHR target gene cytochrome P450 1A1 (Cyp1a1). Moreover, no significant differences in microbial composition were observed between the genotypes. Our findings demonstrate that the absence of PARP7 protein results in an impaired immune response to colonic inflammation and suggests that PARP7 may participate in the recruitment of immune cells to the inflammation site, which may be due to its role in IFN-I signaling rather than AHR signaling.     

纱罗织造——用新技术革新老工艺

纱罗组织由于织造复杂且产品收益率低,多年来一直未受重视,但近年来纺织工程的发展重振了纱罗组织的生产.报道了为揭示纱罗织物的潜力和织造设备对纱罗织物各参数的影响所做扎实的研究工作,这些工作是扩大纱罗织物生产的基础.     

Hydrophobic,pellicular, monolithic capillary columns based on cross-linked polynorbornene for biopolymer separations

Monolithic capillary columns were prepared by transition metal-catalyzed ring-opening metathesis copolymerization of norborn-2-ene and 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo,endo-dimethanonaphthalene inside a silanized 200-microm-i.d. fused-silica capillary using a mixture of toluene and 2-propanol as porogen and Cl2(PCy3)2Ru(=CHPh) as initiator. The synthesized columns allowed the rapid and highly efficient separation of single- and double-stranded nucleic acids by ion-pair reversed-phase high-performance liquid chromatography and of proteins by reversed-phase high-performance liquid chromatography. Compared to 3-mm-i.d. analytical columns synthesized from an identical polymerization mixture, a considerable improvement in the peak widths at half-height of oligonucleotides in the order of 60-80% was obtained. Significant differences in morphology between the capillary column, where the surface of the monolith was rather soft and rugulose, and the analytical column, where the surface was very sharp and smooth, were observed, most probably due to differences in polymerization kinetics. The synthesized monoliths were successfully applied to the separation of the diastereomers of phosphorothioate oligodeoxynucleotides. To confirm the identity of the eluting compounds on the basis of their intact molecular masses, the chromatographic separation system was on-line hyphenated to electrospray ionization mass spectrometry.     

Real-time measurements of PM2.5 and ozone to assess the effectiveness of residential indoor air filtration in Shanghai homes

Portable air cleaners are increasingly used in polluted areas in an attempt to reduce human exposure; however, there has been limited work characterizing their effectiveness at reducing exposure. With this in mind, we recruited forty-three children with asthma from suburban Shanghai and deployed air cleaners (with HEPA and activated carbon filters) in their bedrooms. During both 2-week filtration and non-filtration periods, low-cost PM_2.5 and O₃ air monitors were used to measure pollutants indoors, outdoors, and for personal exposure. Indoor PM_2.5 concentrations were reduced substantially with the use of air cleaners, from 34 ± 17 to 10 ± 8 µg/m³, with roughly 80% of indoor PM_2.5 estimated to come from outdoor sources. Personal exposure to PM_2.5 was reduced from 40 ± 17 to 25 ± 14 µg/m³. The more modest reductions in personal exposure and high contribution of outdoor PM_2.5 to indoor concentrations highlight the need to reduce outdoor PM_2.5 and/or to clean indoor air in multiple locations. Indoor O₃ concentrations were generally low (mean = 8±4 ppb), and no significant difference was seen by filtration status. The concentrations of pollutants and the air cleaner effectiveness were highly variable over time and across homes, highlighting the usefulness of real-time air monitors for understanding individual exposure reduction strategies.     

Microbiological Environmental Monitoring After the Use of Air Purifier Ozone Generator

The work aimed to evaluate the indoor microbiological air quality after using the purifier ozone generator (Brizzamar®), by counting the total viable microorganisms. The plates containing the culture media were exposed on pre-defined locations for 10 min at the times 0 h (without purifier), 1, 2 and 3 h (with purifier). The results showed significant decreases in the microorganisms after using the purifier, reaching a reduction up to 80% of the fungi and bacteria in the environment after two hours. The amount of ozone in the atmosphere was kept at 0,01 ppm, which is considered non-toxic to human exposure. The purifier significantly improved the air quality in indoors.