Secretory delivery of heterologous proteins in attenuated <Emphasis Type="Italic">Vibrio anguillarum</Emphasis> for potential use in vaccine design

To synthesize and secrete heterologous proteins in an attenuated Vibrio anguillarum strain for potential multivalent live vaccine development, different antigen-delivery systems based on bacterial-originated secretion signal peptides (SPs) were designed and identified in this work. Four SPs were derived from hemolysin of Escherichia coli, RTX protein of V. cholerae, hemolysin of V. anguillarum, zinc-metalloprotease of V. anguillarum, respectively, and their abilities to support secretion of green fluorescent protein (GFP) in an attenuated V. anguillarum strain MVAV6203 were assayed. Immunodetection of GFP showed that the capability of the tested signal leaders to direct secretion of GFP varied greatly. Although all the four signal peptide-fused GFPs could be expressed correctly and trapped intracellularly in recombinant strains, only the EmpA signal peptide could confer efficient secretion to GFP. For the investigation of its potential application in live bacteria carrier vaccines, a heterologous protein EseB of Edwardsiella tarda was fused to the SP(empA) antigen-delivery system and introduced into the strain MVAV6203. Further analysis of EseB demonstrated that the constructed SP(empA) antigen-delivery system could be used to secrete foreign protein in attenuated V. anguillarum and be available for carrier vaccines development.     

Acidic microenvironment enhances MT1-MMP-mediated cancer cell motility through integrin β1/cofilin/F-actin axis

Tumor acidic microenvironment is the main feature of many solid tumors.As a part of the tumor microenvironment,it has a profound impact on the occurrence and de...     

Nitrate increases cisplatin chemosensitivity of oral squamous cell carcinoma via REDD1/AKT signaling pathway

Although cisplatin is one of the chemotherapeutics most frequently used in oral squamous cell carcinoma (OSCC) treatment,it exerts multiple side effects and poo...     

Lanthanum relieves salinity-induced oxidative stress in <Emphasis Type="Italic">Saussurea involucrata</Emphasis>

Changes in growth, physiological and biochemical characteristics under salt stress with or without La³⁺ treatment in Saussurea involucrata Kar. et Kir. were investigated. The results showed that La³⁺ relieved the plant growth inhibition, improved the leaf water potential and water content, increased the soluble protein and the proline contents and decreased malondialdehyde content under salt stress. Further, addition of La³⁺ significantly increased the activities of superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase, decreased the photosynthetic pigment decomposition and increased the ratio of total chlorophyll to carotenoids under salt stress.     

Body mass and behavior in Swiss mice subjected to continuous or discontinuous food restriction and refeeding

Food restriction (FR) is hypothesized to decrease body fat content of an animal and thus prevent obesity. However, the response of energy budget to a continuous (CFR) or discontinuous FR (DFR) remains inconsistent. In the present study, effects of CFR or DFR and refeeding on energy budget and behavior were examined in male Swiss mice. CFR significantly decreased the energy expenditure associated with basal metabolic rate (BMR) and activity behavior, but not sufficiently to compensate for energy deficit and thus resulted in lower body mass and fat content. DFR mice had a significantly higher food intake on ad libitum days and showed increases in BMR and activity after 4 weeks’ DFR, which might resulted in lower body mass and less body fat than controls. After being refed ad libitum, both CFR and DFR mice had similar body mass, BMR, and behavioral patterns to controls but had 95% and 75% higher fat content. This suggested that not only CFR but also DFR would be a significant factor in the process of obesity for animals that were refed ad libitum. It also indicated that food restriction interrupted many times by periods of ad libitum feeding had the same long-term effects like continuous underfeeding.     

Derivation and characterization of human embryonic stem cell lines from the Chinese population

Human embryonic stem cells(hESCs) can self-renew indefinitely and differentiate into all cell types in the human body.Therefore,they are valuable in regenerative medicine,human developmental biology and drug discovery.A number of hESC lines have been derived from the Chinese population, but limited of them are available for research purposes.Here we report the derivation and characterization of two hESC lines derived from human blastocysts of Chinese origin.These hESCs express alkaline phosphatase and hE...     

A Durable Alternative for Proton‐Exchange Membranes: Sulfonated Poly(Benzoxazole Thioether Sulfone)s

To develop a durable proton‐exchange membrane (PEM) for fuel‐cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s ( SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid–base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier‐transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy (¹H NMR and ¹⁹F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three‐electrode cell configuration. The physicochemical properties of the membranes vital to fuel‐cell performance are also carefully evaluated under conditions relevant to fuel‐cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25°C to 90°C and excellent thermal stability up to 250°C. Upon elimination of unstable end groups, the co‐polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO‐HFB‐60 (HFB‐60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel‐cell performance to that of an NRE 212 membrane at 80°C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel‐cell applications.     

Antifibrotic effect of the Chinese herbs, Astragalus mongholicus and Angelica sinensis, in a rat model of chronic puromycin aminonucleoside nephrosis

Nephrotic syndrome has long been treated in China with two herbs, Astragalus mongholicus and Angelica sinensis, which may have antifibrotic effects. METHODS: Rats with chronic puromycin-induced nephrosis were treated with Astragalus and Angelica 3 mL/d (n = 7) or enalapril 10 mg/kg/d (n = 7). Normal control rats (n = 7) received saline rather than puromycin, and an untreated control group (n = 7) received puromycin but no treatment. After 12 weeks, stained sections of the glomerulus and tubulointerstitium were evaluated for injury. Immunohistochemistry staining measured extracellular matrix components, transforming growth factor-beta1 (TGFbeta1), osteopontin, ED-1-positive cells, and alpha-actin. TGFbeta1 mRNA was assessed by in situ hybridization. Renin, ACE activity, angiotensin, and aldosterone were measured by radioimmunoassay or colorimetry. In the untreated rats, chronic renal injury progressed to marked fibrosis at 12 weeks. Astragalus and Angelica significantly reduced deterioration of renal function and histologic damage. Expressions of type III and IV collagen, fibronectin, and laminin also decreased significantly. This anti-fibrotic effect was similar to that of enalapril. The herbs had no effect on the renin-angiotensin system but did reduce the number of ED-1-positive, and alpha-actin positive cells and expression of osteopontin compared to untreated controls. The combination of Astragalus and Angelica retarded the progression of renal fibrosis and deterioration of renal function with comparable effects of enalapril. These effects were not caused by blocking the intrarenal renin-angiotensin system, but associated with suppression of the overexpression of TGFbeta1 and osteopontin, reduction of infiltrating macrophages, and less activation of renal intrinsic cells [corrected].     

Molecular cloning, characterization and expression of a C-type lectin cDNA in Chinese mitten crab, Eriocheir sinensis

C-type lectins are pattern-recognition proteins which are functionally important for pathogen recognition and immune regulation in vertebrates and invertebrates. In this study, a lectin cDNA named as Es-Lectin was cloned and characterized from the Chinese mitten crab, Eriocheir sinensis. The full-length sequence of this Es-Lectin cDNA was 651 bp, including an open reading frame of 483 bp encoding 160 amino acids. The predicted molecular weight of the Es-Lectin was 11.8 kDa. A typical signal peptide of 21 amino acids was deduced at the N-terminus of the predicted protein. This Es-Lectin belongs to a C-type lectin and contains six cysteines, a conserved EPN motif (Glu-Pro-Asn) and an imperfect WND (Trp-Asn-Asp) motif (FND, Phe-Asn-Asp). This Es-Lectin had 55% and 32% identity with other two C-type lectins in E. sinensis, and 29-36% homology with decapods. Although the Es-Lectin was also expressed in gill, hepatopancreas, intestine, muscle and stomach, its expression in haemocytes was the greatest. The expression of Es-Lectins in haemocytes increased at 1.5 h after the Aeromonas hydrophila challenge. After a slight decrease, the Es-Lectin expression in haemocytes significantly increased at 48 h post-challenge. The diverse distribution of Es-Lectin and its enhancement by bacterial challenge indicate that C-type lectins are important in the innate immune response to bacterial infection, and can be activated for innate immune response in crab at the initial stage after pathogen infection.