Molecular characterization of a Trichinella spiralis enolase and its interaction with the host's plasminogen.

The binding and activation of host plasminogen (PLG) by worm surface enolases has been verified to participate in parasite invasion, but the role of this processes during Trichinella spiralis infection has not been clarified. Therefore, the expression and immunolocalization of a T. spiralis enolase (TsENO) and its binding activity with PLG were evaluated in this study. Based on the three-dimensional (3D) molecular model of TsENO, the protein interaction between TsENO and human PLG was analysed by the ZDOCK server. The interacting residues were identified after analysis of the protein-protein interface by bioinformatics techniques. The key interacting residues were confirmed by a series of experiments. The qPCR analysis results demonstrated that Ts-eno was transcribed throughout the whole life cycle of T. spiralis. The immunofluorescence assay (IFA) results confirmed that TsENO was distributed on the T. spiralis surface. The binding assays showed that recombinant TsENO (rTsENO) and native TsENO were able to bind PLG. Four lysine residues (90, 289, 291 and 300) of TsENO were considered to be active residues for PLG interaction. The quadruple mutant (Lys90Ala + Lys289Ala + Lys291Ala + Lys300Ala) TsENO, in which the key lysine residues were substituted with alanine (Ala) residues, exhibited a reduction in PLG binding of nearly 50% (45.37%). These results revealed that TsENO has strong binding activity with human PLG. The four lysine residues (90, 289, 291 and 300) of TsENO play an important role in PLG binding and could accelerate PLG activation and invasion of the host's intestinal wall by T. spiralis.

Alkoxy Tetrazine Substitution at a Boron Center: A Strategy for Synthesizing Highly Fluorogenic Hydrophilic Probes.

Strongly fluorogenic boron dipyrromethene (BODIPY)-tetrazine probes have been obtained by introducing an alkoxy tetrazine fragment at the boron center. The fluorescence signal from these probes strongly increases by up to 225-fold after reaction with bioorthogonal coupling partners, and the hydrophilicity of probes is improved, such that they are suitable for live-cell imaging.

Preparation of core-shell nanofibers with selectively localized CNTs from Shish Kebab-like hierarchical composite micelles.

A novel and facile bottom-up strategy for preparing core-shell nanofibers with selectively localized carbon nanotubes is developed using hierarchical composite micelles of crystalline-coil copolymer and carbon nanotubes as the building blocks. An amphiphilic di-block copolymer of poly (p-dioxanone) (PPDO) and PEG (polyethylene glycol) functionalized with pyrene moieties at the chain ends of PPDO blocks (Py-PPDO-b-PEG) is designed for constructing composite micelles with multiwalled carbon nanotubes (MWCNTs). The self-assembly of Py-PPDO-b-PEG and MWCNTs is co-induced by the crystallization of PPDO blocks and the π-π stacking interactions between pyrene moieties and MWCNTs, resulting in composite micelles with "shish kebab"-like nanostructure. A mixture of composite micelles and polyvinyl alcohol (PVA) water solution is then used as the spinning solution for preparing electrospun nanofibers. The morphologies of the nanofibers with different composition are investigated by SEM and TEM. The results suggest that the MWCNTs selectively localized in the core of the nanofibers of MWCNTs/Py-PPDO-b-PEG/PVA. The alignment and interfusion of composite micelles during the formation of nanofibers may confine the carbon nanotubes in the hydrophobic core region. In contrast, the copolymer without pyrene moieties cannot form composite micelles, thus these nanofibers show selective localization of MWCNTs in the PVA shell region.

Trichinella spiralis cathepsin B bound and degraded host's intestinal type I collagen.

Trichinellosis is a zoonotic parasitic disease that poses threats to human health, the meat industry, food safety, and huge financial losses. The critical stage of Trichinella spiralis (T. spiralis) infection is the invasion of intestinal larvae into the host's intestinal epithelial cells (IECs). T. spiralis Cathepsin B (TsCB) specifically interacts with IECs to facilitate the invasion of larvae. This study aims to look at how TsCB affects mouse IECs. TsCB was successfully cloned, expressed, and characterized, demonstrating its natural cysteine protease hydrolysis activity. A total of 140 proteins that interact with rTsCB were identified by GST pull-down combined with LC-MS/MS, including type I collagen, an essential component of the host's intestinal epithelial barrier system and intimately related to intestinal epithelial damage. TsCB transcription and expression levels rise, whereas type I collagen in the host's intestinal mucosa declines when the T. spiralis larvae invaded. Besides, it was discovered that TsCB bound to and degraded type I collagen of the host's intestine. This research can serve as a foundation for clarifying how T. spiralis invades the host's intestinal barrier and might provide information on potential targets for the creation of novel treatments to treat parasite illnesses.

Elucidation of the binding mechanism of astragaloside IV derivative with human serum albumin and its cardiotoxicity in zebrafish embryos.

LS-102 is a new derivative of astragaloside IV (AGS IV) that has been shown to possess potentially significant cardioprotective effects. However, there are no reports concerning its interaction with human serum albumin (HSA) and toxicology in vertebrates. The present investigation was undertaken to characterize the interaction of AGS IV and LS-102 with HSA using equilibrium dialysis and UHPLC-MS/MS methods, along with computational methods. Notably, the effects of AGS IV and LS-102 were studied in vivo using the zebrafish embryo model. Markers related to embryonic cardiotoxicity and thrombosis were evaluated. We showed that the plasma protein binding rate of AGS IV (94.04%-97.42%) was significantly higher than that of LS-102 (66.90%-69.35%). Through site marker competitive experiments and molecular docking, we found that AGS IV and LS-102 were located at the interface of subdomains IIA and IIIA, but the site I might be the primary binding site. Molecular dynamics revealed that AGS IV showed a higher binding free energy mainly due to the stronger hydrophobic and hydrogen bonding interactions. Moreover, the secondary structure implied no obvious effect on the protein structure and conformation during the binding of LS-102. LS-102 significantly ameliorated the astramizole-induced heart rate slowing, increased SV-BA spacing, and prevented arachidonic acid-induced thrombosis in zebrafish. To our knowledge, we are the first to reveal that LS-102 binds to HSA with reversible and moderate affinity, indicating its easy diffusion from the circulatory system to the target tissue, thereby providing significant insights into its pharmacokinetic and pharmacodynamic properties when spread in the human body. Our results also provide a reference for the rational clinical application of LS-102 in the cardiovascular field.

Application of serum exosomal hypoxia-inducible factor-1 alpha (HIF-1α) as potential circulating biomarker for bacterial peritonitis.

Bacterial peritonitis is a severe disease that diagnosis remains challenging for clinicians. Measuring biomarkers might be a rapid diagnostic method. The objective of this study was to analyze and evaluate the dynamic changes in HIF-1α concentration in serum exosomes during bacterial peritonitis. The pre-clinical application value of serum exosomal HIF-1α was evaluated via imipenem and cilastatin sodium (ICS) intervention in the bacterial peritonitis model. The new colorimetric method to quantitate dynamic expression changes of HIF-1α in serum exosomes during bacterial peritonitis was established by our team via using the gold seed-coated with aptamer-functionalized Au @ Au core-shell peroxidase mimic. The typical inflammatory cytokines of bacterial peritonitis were also measured. Following intramuscular administration with ICS, In-Vivo Xtreme imaging system was used to visualize abdominal infection extent. Meanwhile, HIF-1α concentration in rat serum exosomes and pro-inflammatory factors levels in serum were detected. The serum typical inflammatory cytokines levels were elevated in GFP-labeled E.coli induced bacterial peritonitis. The serum exosomal HIF-1α levels clearly increased at 12 h, reached the peak during 24-48 h, and then gradually decreased at 72 h. Following intramuscular administration with ICS, the abdominal infection extent, HIF-1α concentration in serum exosomes, and the serum pro-inflammatory factors levels were reduced at 24 h in GFP-labeled E. coli induced bacterial peritonitis model. The serum exosomal HIF-1α can be used as a biomarker in the early stage of bacterial peritonitis, which might provide the basic research in the pre-clinical for further predicting and monitoring the pathological process of bacterial peritonitis.

Anxiolytic and sedative effects of dehydroeffusol from Juncus effusus in mice.

Dehydroeffusol, a phenanthrene isolated from Juncus effusus L., possesses characteristic anxiolytic and sedative properties, as determined by an array of behavioral tests in mice. In the elevated plus-maze test, dehydroeffusol significantly increased the number of entries into the open arms and the time the mice spent in these arms in a dose-dependent manner, with a minimum effective dose of 2.5 mg/kg. Dehydroeffusol also significantly increased the head-dips of mice in the hole-board test in a dose-dependent manner, with a minimum effective dose of 5 mg/kg. Dehydroeffusol reduced mouse locomotion in the open-field test with a minimum effective dose of 5 mg/kg. In the rota-rod test, 1-5 mg/kg dehydroeffusol did not decrease the fall-down time of mice. The above results confirm that dehydroeffusol possesses anxiolytic and sedative properties and does not affect the general movement coordination of mice. This suggests that dehydroeffusol is a novel anxiolytic chemical derived from herbal medicines.

Identification of Active Compounds From Yi Nationality Herbal Formula Wosi Influencing COX-2 and VCAM-1 Signaling.

The Yi nationality herbal formula Wosi is used in China as a folk medicine to treat arthritis and related diseases. Despite its widespread use, the active ingredients, and pharmacological mechanisms are not performed. This is the first time to identify the active compounds from Wosi with the aim at providing the potential effect of Wosi and exploring its underlying anti-inflammatory mechanism in monosodium urate crystals (MSU)-induced arthritis rats. In this study, anti-hyperuricemia effect was assessed by reducing the serum uric acid levels and increasing uric acid excretion in the urine for the hyperuricemia rat model. Wosi significantly suppressed the degree of joint swelling and improved the symptoms of inflammation induced by MSU crystals. The inhibition of IL-2, IL-1ß, IFN-γ, and IL-6 secretion and IL-10 increase in the serum were also observed. This study also focuses on the screening of the main compounds from Wosi against cyclooxygenase for anti-inflammatory properties using molecular docking. The result showed 3-O-[α-L-pyran rhamnose(1-3)-ß-D-pyran glucuronic acid]- oleanolic acid, 3-O-(ß-D-pyran glucuronic acid)-oleanolic acid-28-O-ß-D-pyran glucoside, and 3-O-[α-L-pyran rhamnose(1-3)-ß-D-pyran glucuronic acid]-oleanolic acid-28-O-ß-D-pyran glucoside with a higher binding affinity for COX-2 than COX-1 which indicated relatively higher interaction than COX-1. The preferential selectivity toward inhibiting COX-2 enzyme over COX-1 of three compounds from Wosi were evaluated using in-vitro cyclooxygenases 1 and 2 (COX-1/2) inhibition assays. Meanwhile, the down-regulated protein expression of COX-2 and VCAM-1 in synovial tissue sections from ankle joints of experiments rats were confirmed by immunohistochemistry analysis after the Wosi treatment. In conclusion, three oleanolic acid glycosides were implied as mainly efficient compounds in Yi nationality herbal formula Wosi for arthritis therapy via selectively influencing COX-2 and VCAM-1 signaling.

Hierarchical planning for a surface mounting machine placement.

For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.

Phenanthrenes from Juncus effusus with anxiolytic and sedative activities.

Eight phenanthrenes, 7-carboxy-2-hydroxy-1-methyl-5-vinyl-phenanthrene (1); 2,7-dihydroxy-1-methyl-5-aldehyde-9,10-dihydrophenanthrene (2); dehydroeffusol (3); dehydrojuncusol (4); 7-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (5); 8-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (6); effusol (7) and juncusol (8), were isolated from the aerial part of Juncus effusus. Compounds 1 and 2 were identified as new constituents. Compounds 7 and 8 showed anxiolytic and sedative activities.