Search

Antler velvet polypeptide (VAP) is a prominent bioactive component of antler velvet. Whereas uncharacterized crude extracts have typically been used in pharmacological studies, in this study, the velvet polypeptide was isolated and purified by acid water extraction, ethanol precipitation, ammonium sulfate fractionation and precipitation, and chromatography, progressively. Human umbilical vein endothelial cells (HUVECs) were induced with [H.sub.2][O.sub.2] followed purified polypeptide treatment. Cell viability was evaluated by MTT assay. The apoptosis of cells was detected by fluorescence microscopy and flow cytometry. A cell analyzer was used to measure the mitochondrial membrane potential. The intracellular reactive oxygen species (ROS) levels were determined by flow cytometry. Oxidative stress related biochemical parameters were detected, and the expression of apoptosis-related proteins was examined by Western blot analysis. The results indicated that a 7.0 kDa polypeptide (VAP II) was isolated from antler velvet. VAP II enhanced cell viability, decreased cell apoptosis, reversed depolarization of mitochondrial membrane potential, decreased ROS levels, inhibited oxidative stress, and regulated the downstream signaling apoptotic cascade expression caused by [H.sub.2][O.sub.2]. The protective effects of VAP II on HUVECs suggests a potential strategy for the treatment of cardiovascular disease. Key words: antler velvet polypeptides, oxidative stress, antioxidant, apoptosis. Le polypeptide de bois de velours (VAP pour << antler velvet polypeptide >>) est un important compose bioactif des bois de velours. Alors que des extraits bruts non caracterises ont habituellement ete utilises dans le cadre d'etudes pharmacologiques, dans cette etude, nous avons isole et purifie le polypeptide de velours par une extraction acide-eau, la precipitation dans l'ethanol ainsi que le fractionnement et la precipitation a l'aide de sulfate d'ammonium, avec le passage progressif dans une colonne de chromatographie. Nous avons obtenu des cellules HUVEC (pour << human umbilical vein endothelial cells >>) par une induction l'aide de [H.sub.2][O.sub.2] suivie d'un traitement de purification des polypeptides. Nous avons evalue la viabilite des cellules l'aide du test MTT. Nous avons decele les cellules apoptotiques a l'aide de la microscopie par fluorescence et de la cytometrie en flux. Nous avons utilise un analyseur de cellules pour mesurer le potentiel des membranes mitochondriales. Nous avons mesure les derives reactifs de l'oxygene (ou ROS pour << reactive oxygen species >>) intracellulaires par cytometrie en flux. Nous avons detecte les parametres biochimiques lies au stress oxydatif et etudie l'expression des proteines liees a l'apoptose a l'aide de la technique d'immunobuvardage de Western. Les resultats ont revele l'isolation d'un polypeptide de 7,0 kDa (VAP II) partir de bois de velours. Le VAP II pourrait entrainer une augmentation de la viabilite des cellules, une attenuation de l'apoptose cellulaire, la depolarisation inverse du potentiel des membranes mitochondriales, diminuer les taux de ROS, inhiber le stress oxydatif et assurer la regulation de l'expression de la cascade de la signalisation apoptotique causee par le [H.sub.2][O.sub.2] en aval. Les effets protecteurs du VAP II contre les lesions des cellules HUVEC ont permis d'obtenir une strategie eventuelle dans le traitement de la maladie cardiovasculaire. [Traduit par la Redaction] Mots-cles : polypeptide de bois de velours, stress oxydatif, antioxydant, apoptose., Introduction There has recently been a surge of interest in the benefits from the natural products used in traditional and herbal medicines. To date, the majority of studies conducted worldwide [...]

Mitochondrial dysfunction and oxidative stress play essential roles in the pathogenesis of diabetic nephropathy (DN). The respiratory oxygen consumption and oxidative stress status of kidney mitochondria are closely associated with the development of DN. In this study, raspberry ketone (RK), the predominant bioactive component extracted from raspberry, was applied to treat the established DN mice model. This study investigated whether RK protects the kidneys of high-fat and high-sugar/streptozotocin (STZ)-induced diabetic rats by inhibiting oxidative stress and ameliorating mitochondrial dysfunction. Besides, the DN mice models were established by injecting high-fat and high-sugar/STZ (130 mg/kg, intraperitoneal injection). The animals were randomly divided into the control group (normal saline, ig), DN group (normal saline, ig), DN + RK group (200 mg/kg RK + normal saline, ig), DN + RK group (400 mg/kg RK + normal saline, ig), and DN + Metformin (Met) (200 mg/kg Met + normal saline, ig). Regular monitoring of fasting blood glucose (FBG) levels was observed in mice. After 10 weeks of drug treatment, the kidneys of mice in each group were analyzed using ultrasound, and the mice were euthanized humanely. Kidney weight (KW)/body weight (BW) and kidney injury, mitochondrial function, and oxidative stress indicators were determined. The histopathological changes in renal tissue were observed after hematoxylin and eosin (H&E) staining. The results recommended that RK has a renoprotective function on DN mice by improving mitochondrial dysfunction and inhibiting oxidative stress. [ABSTRACT FROM AUTHOR]

A study was conducted to analyze the benefits of applying the Cosserat Spectrum theory to boundary value problems in thermoelasticity. A solution technique for thermoelasticity was determined using heat flow examples. Results indicated that theory supports the fast convergence of discrete Cosserat eigen functions and optimizes the elastic energy based on a variational thermoelastic principle for such functions.

Increasing studies have concentrated on investigating circular RNAs (circRNAs) as pivotal regulators in the progression of numerous diseases and biological processes and abundant evidence shows that circRNAs are participated in the regulation of innate immune responses. Several studies showed that Ricin Toxin (RT) could induce inflammatory injury. There was no research on the particular functions and underlying mechanisms of circRNAs in RT-induced inflammation. In this study, RNA sequencing performed on RT-treated and normal RAW264.7 macrophage cells was used to investigated the differentially expressed circRNAs. Based on the dataset, the expression of circEpc1 (mmu_circ_0,000,842) was identified higher in RT-treated cells. Moreover, gain-and-loss function assays showed that circEpc1 function as a promoter in RT-induced inflammation in vivo and in vitro. Mechanistically, circEpc1 acted as a miR-5114 sponge to relieve the suppressive effect of miR-5114 on its target NOD2 and thereby activating NF-κB and MAPK signaling pathways. Our results illuminated a link between RT-induced inflammation and the circEpc1 regulatory loop and provided novel insight into the functions of circRNA in innate immune, which may emerge as a potential target in immunotherapy to control the RT-induced inflammatory injury. [ABSTRACT FROM AUTHOR]

Ricin toxin (RT), extracted from castor bean, is a type II ribosome-inactivating protein (RIP). As a biothreat agent, there is no effective antidote for RT to date, but recent advances in antibody research may have meet this need. This study aimed to produce human single-chain antibody variable fragments (HuscFvs) that bind to and interfere with RT activity for further clinical use. The purified RT component was used in phage biopanning to select ricin-bound HuscFv-displayed phage clones from synthetic (Tomlinson I + J) phage display libraries. The selected HuscFv, named JE11, showed an almost 100% protective effect to HeLa cells by mixing with RT at a 1:1000 ratio in vitro. The antibody showed an 83% protection against injection of 2 × LD50 RT dose mice within 72 h. This research has therapeutic potential for the diagnosis and treatment of RT poisoning. [ABSTRACT FROM AUTHOR]

We developed an electrochemical aptasensor based on cocoon-like DNA nanostructures as signal tags for highly sensitive and selective detection of Escherichia coli O157:H7. The stable cocoon-like DNA nanostructures synthesized by the rolling circle amplification reaction were loaded with hemin as electrochemical signal tags to amplify the signals. The single-stranded DNA capture probes were modified on the surface of a Au electrode via a Au–S bond. The E. coli O157:H7 specific aptamer and capture probe formed double-stranded DNA structures on the Au electrode. The aptamer preferentially bound to E. coli O157:H7, causing the dissociation of some aptamer-capture probes and releasing some capture probes. Subsequently, the free capture probes hybridized with the DNA nanostructures through the cDNA sequence. Under optimal conditions, the change in the electrochemical signal was proportional to the logarithm of E. coli O157:H7 concentration, from 10 to 106 CFU mL−1, and the detection limit was estimated to be 10 CFU mL−1. The electrochemical aptasensor could be readily used to detect various pathogenic bacteria and to provide a new method of early diagnosis of pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

Ricin toxin binding subunit B (RTB) is a galactose-binding lectin protein derived from the beans of the castor oil plant (Ricinus communis). Our previous studies have reported a direct immunomodulatory effect of recombinant RTB, which stimulates RAW264.7 cells to produce cytokines including TNF-α. However, the role of RTB in innate immune response and its specific mechanism have not been reported in detail. In this work, the results showed that RTB treatment of macrophages significantly increased TLR4 protein levels. RTB also activated TLR4 downstream events, including MyD88, IRAK, and TRAF6, resulting in macrophage activation and TNF-α production. This process is reflected in the increase of IκB phosphorylation. TLR4 knockdown macrophages treated with RTB exhibited greatly reduced IκB phosphorylation and TNF-α secretion. Moreover, treatment with MyD88 inhibitor also suppressed TNF-α production. The docking of RT and TLR4 was simulated by computer, and the contact residues were concentrated on RTB. Our results suggest that recombinant RTB can activate mouse macrophages to secrete TNF-α through activation of NF-κB via the TLR4 signaling pathways. [ABSTRACT FROM AUTHOR]

A sandwich-type electrochemical biosensor was successfully constructed for the sensitive detection of pathogenic bacteria. In this biosensor platform, methylene blue (MB) organic–inorganic nanocomposites (MB@MI) were synthesized from magainin I (MI, antimicrobial peptide specific to Escherichia coli O157:H7), Cu3(PO4)2 and MB via a one-pot method, and were explored as a novel electrochemical signal label of biosensors generating amplified electrochemical signals by differential pulse voltammetry (DPV). E. coli O157:H7 specifically sandwich bound to the aptamers on the electrode surface and MB@MI nanocomposites, and the changes in the current signal generated on the electrode surface were used for the quantitative determination of E. coli O157:H7. Under optimum conditions, the proposed biosensor showed excellent performance with a wide linear range of 102–107 CFU mL−1 and a low detection limit of 32 CFU mL−1, featuring favorable selectivity, repeatability and stability. According to the experiments conducted on real samples, the proposed approach is capable of detecting pathogenic bacteria in clinical diagnostics. [ABSTRACT FROM AUTHOR]

Type 2 diabetes constitutes a serious threat to the health of patients, but there is currently no ideal treatment in the clinic. Glucagon-like peptide-1 and human umbilical cord mesenchymal stem cells have been confirmed to have antidiabetic effects, but both of them have certain defects in the process of antidiabetes, which cannot meet the need of clinical treatment. We hypothesized that human umbilical cord mesenchymal stem cells can be used as a vector to construct a novel cell line that expresses GLP-1 in vivo for a long time. And this cell strain results in lowering blood glucose in type 2 diabetic mice. The results showed that after 3 weeks of intramuscular injection of the new cell line, the fasting blood glucose of type 2 diabetic mice returned to the normal range, and the hypoglycemic effect was maintained within 3 weeks after putting an end to the drug. At the same time, during the administration, the mice lost weight, the food intake decreased, the half-life of GLP-1 in the body prolonged, the IR reduced, and the pancreatic function recovered. The results of this study indicate that the novel cell line can prolong the half-life of GLP-1 in vivo and effectively lower blood sugar, which is a feasible method to improve type 2 diabetes. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this study is to establish a rapid and accurate method based on multiplex polymerase chain reaction (PCR) combined with suspension array xTAG (Flexible Sequence‐tagged, xTAG) technology to simultaneously detect Salmonella Typhimurium, Brucella spp., Bacillus cereus and Shigella spp. in raw milk. The primers were designed based on the specific target gene of the four pathogenic bacteria, and then the TAG sequence was used to modify the primers. First, the products of PCR were hybridised with microspheres labelled with anti‐TAG, and then they were conjugated to streptavidin phycoerythrin. Finally, the products were detected on a Luminex 200 analyser. The results showed that the detection of milk samples demonstrated 100% specificity. The hybridisation conditions were successfully optimised. We successfully constructed a rapid, simple and high‐throughput method to detect four foodborne pathogens. In conclusion, the established xTAG detection method provides a highly specific and reliable way to detect four kinds of foodborne pathogens in milk products. [ABSTRACT FROM AUTHOR]

Although Ricin toxin binding subunit B (RTB) can promote the activation of macrophages and modulate the cell-mediated immunity, its applications are severely limited due to the intrinsic properties of proteins, like poor stability and low efficacy of cellular uptake. In this work, the stable nanoparticles were prepared by supramolecular assembling of carbon dots (CDs) and RTB. The formed CDs-RTB possesses robust stability and can protect RTB against enzymatic hydrolysis. More importantly, CDs-RTB can promote macrophages proliferation, improve the generation of NO, IL-6 and TNF-α in RAW264.7 cells and increase the expression of mRNA, indicating the enhanced immunomodulatory activity of CDs-RTB. This work highlights the potential of using CDs as a simple and stable platform to assemble RTB and effectively promotes the application of RTB as the immunostimulant. [ABSTRACT FROM AUTHOR]

Background: Ebola virus emerged in West Africa in December 2013. The high population mobility and poor public health infrastructure in this region led to the development of the largest Ebola virus disease (EVD) outbreak to date. Methodology/Principal findings: On September 26, 2014, China dispatched a Mobile Biosafety Level-3 Laboratory (MBSL-3 Lab) and a well-trained diagnostic team to Sierra Leone to assist in EVD diagnosis using quantitative real-time PCR, which allowed the diagnosis of suspected EVD cases in less than 4 hours from the time of sample receiving. This laboratory was composed of three container vehicles equipped with advanced ventilation system, communication system, electricity and gas supply system. We strictly applied multiple safety precautions to reduce exposure risks. Personnel, materials, water and air flow management were the key elements of the biosafety measures in the MBSL-3 Lab. Air samples were regularly collected from the MBSL-3 Lab, but no evidence of Ebola virus infectious aerosols was detected. Potentially contaminated objects were also tested by collecting swabs. On one occasion, a pipette tested positive for EVD. A total of 1,635 suspected EVD cases (824 positive [50.4%]) were tested from September 28 to November 11, 2014, and no member of the diagnostic team was infected with Ebola virus or other pathogens, including Lassa fever. The specimens tested included blood (69.2%) and oral swabs (30.8%) with positivity rates of 54.2% and 41.9%, respectively. The China mobile laboratory was thus instrumental in the EVD outbreak response by providing timely and reliable diagnostics. Conclusions/Significance: The MBSL-3 Lab significantly contributed to establishing a suitable laboratory response capacity during the emergence of EVD in Sierra Leone. [ABSTRACT FROM AUTHOR]

Apoptosis triggered by ricin toxin (RT) has previously been associated with certain cellular organellar compartments, but the diversity in the composition of the organellar proteins remains unclear. Here, we applied a shotgun proteomics strategy to examine the differential expression of proteins in the mitochondria, nuclei, and cytoplasm of HeLa cells treated and not treated with RT. Data were combined with a global bioinformatics analysis and experimental confirmations. A total of 3107 proteins were identified. Bioinformatics predictors (Proteome Analyst, WoLF PSORT, TargetP, MitoPred, Nucleo, MultiLoc, and k-nearest neighbor) and a Bayesian model that integrated these predictors were used to predict the locations of 1349 distinct organellar proteins. Our data indicate that the Bayesian model was more efficient than the individual implementation of these predictors. Additionally, a Biomolecular Interaction Network (BIN) analysis was used to identify 149 BIN subnetworks. Our experimental confirmations indicate that certain apoptosis-related proteins (e.g. cytochrome c, enolase, lamin B, Bax, and Drp1) were found to be translocated and had variable expression levels. These results provide new insights for the systematic understanding of RT-induced apoptosis responses. [ABSTRACT FROM AUTHOR]