Proteomics analysis of plasma membrane from liver sinusoidal endothelial cells after partial hepatectomy by an improved two-dimensional electrophoresis

Liver regeneration is an angiogenesis-associated phenomenon. To identify key plasma membrane (PM) proteins of endothelial cells involved in the initiation of angiogenesis during liver regeneration, the PM of liver sinusoidal endothelial cells (LSEC) at 72 h after partial hepatectomy was enriched by an established in vivo membrane density perturbation method. The differentially expressed membrane proteins compared to those from sham operation were quantified using an improved two-dimensional 16-BAC/SDS-PAGE and identified by LC-MS/MS. Several proteins were further confirmed by cICAT labeling quantitative strategy. A total of 47 proteins were identified including known and novel proteins involved in angiogenesis or liver regeneration, such as inducible nitric oxide synthase, type IV collagen, and integrin beta3. Our results indicated that the combination of the membrane density perturbation strategy and the improved two-dimensional electrophoresis (2-DE) method are useful for investigating the endothelial dysfunctions in vivo.     

Simple and rapid detection of Salmonella serovar Enteritidis under field conditions by loop‐mediated isothermal amplification

Aim: The objective of this study is to develop a serovar‐specific loop‐mediated isothermal amplification (LAMP) method for sensitive, rapid, and inexpensive detection of Salmonella serovar Enteritidis under field conditions. Methods: A set of six specific primers was designed with Salmonella Enteritidis DNA as the target. LAMP conditions were optimized by incubating the target DNA with the Bst DNA polymerase large fragment in a simple water bath. The sensitivity and specificity of LAMP was then compared with those of fluorescent quantitative real‐time polymerase chain reaction (FQ‐PCR). Results: The results were as follows. (1) Serovar‐specific Salmonella Enteritidis DNA was amplified at 65°C in as early as 20 min in a water bath. (2) A colour change visible to the naked eye indicated a positive amplification reaction. (3) The detection limit of the LAMP assay was 4 copies μl^?1; thus, the sensitivity and specificity of this assay is similar to those of the FQ‐PCR. Conclusions: LAMP is a high‐throughput detection technique with high sensitivity, specificity, and simplicity; these factors make it suitable for specifically detecting Salmonella Enteritidis under field conditions and in laboratory settings. Thus, LAMP eliminates the need for complicated equipment and technical training in the detection of this specific serovar. Significance and impact of the study: This is the first study involving the use of LAMP to detect Salmonella serovar‐specific DNA sequences. It is also the first to report an ideal method of distinguishing between Salmonella Enteritidis and other Salmonella under field conditions.     

Periplasmic proteins of Escherichia coli are highly resistant to aggregation: reappraisal for roles of molecular chaperones in periplasm

Periplasmic proteins of Gram-negative bacteria like Escherichia coli are subjected to immediate affect of environmental fluctuation that may unfold proteins, due to the permeability of the outer membrane to small molecules. They are thus supposedly protected by certain molecular chaperones. Nevertheless, no homologues of typical molecular chaperones have so far been found in periplasm, and the recently reported chaperone activities of periplasmic protein disulfide isomerase (PDI) and peptidyl prolyl isomerase (PPI) seem to be too weak to satisfy such assumed needs. In an attempt to reveal whether periplasmic proteins exhibit certain unusual properties, we discovered that such proteins as a whole are highly resistant to aggregation under a wide variety of denaturing conditions. Furthermore, in an effort to unveil the nature behind this phenomenon we purified and examined four prominent periplasmic proteins. Our results demonstrate that these proteins unfold at rather mild denaturing conditions and expose hydrophobic surfaces during such unfolding process, but hardly form complexes with a typical molecular chaperone. Based on these observations, we propose that the periplasmic proteins have been evolved to resist the formation of aggregates when subjected to various denaturing conditions and molecular chaperones may thus not be needed in periplasm.     

Analysis of B-Class Genes NAP3L3 and NAP3L4 in Narcissus tazetta var. chinensis

Very few flower organ identity genes have been characterized in Chinese narcissus (Narcissus tazetta var. chinensis), which has petaloid sepals. Here, we report the cloning of two full-length B-class genes, namely NAP3L3 and NAP3L4, that are orthologs of the DEFICIENS lineage. Both genes are highly expressed in the second whorl of the perianth and in the stamens. NAP3L4 is also expressed strongly in the ovule. The functions of these two genes were further analyzed using transgenic plants. Ectopic expression of either gene in Arabidopsis gave no obvious floral organ transformation phenotypes. In yeast two-hybrid assays, NAP3L3 and NAP3L4 failed to homodimerize and interacted weakly with each other. The data suggest that these two genes might not be involved in the formation of petaloid sepals. Isolation and functional analysis of other B-class paralogs should be conducted to fully understand petaloid tepal development in Chinese narcissus.     

An oncolytic adenovirus delivering TSLC1 inhibits Wnt signaling pathway and tumor growth in SMMC-7721 xenograft mice model

Tumor suppressor in lung cancer-1(TSLC1)was first identified as a tumor suppressor for lung cancer,and frequently downregulated in various types of cancers incl...     

Beneficial Effects of Schisandrin B on the Cardiac Function in Mice Model of Myocardial Infarction

The fruit of Schisandra chinensis has been used in the traditional Chinese medicine for thousands of years. Accumulating evidence suggests that Schisandrin B (Sch B) has cardioprotection effect on myocardial ischemia in vitro. However, it is unclear whether Sch B has beneficial effects on continuous myocardial ischemia in vivo. The aim of the present study was to investigate whether Sch B could improve cardiac function and attenuate myocardial remodeling after myocardial infarction (MI) in mice. Mice model of MI was established by permanent ligation of the left anterior descending (LAD) coronary artery. Then the MI mice were randomly treated with Sch B or vehicle alone. After treatment for 3 weeks, Sch B could increase survival rate, improve heart function and decrease infarct size compared with vehicle. Moreover, Sch B could down-regulate some inflammatory cytokines, activate eNOS pathway, inhibit cell apoptosis, and enhance cell proliferation. Further in vitro study on H9c2 cells showed similar effects of Sch B on prevention of hypoxia-induced inflammation and cell apoptosis. Taken together, our results demonstrate that Sch B can reduce inflammation, inhibit apoptosis, and improve cardiac function after ischemic injury. It represents a potential novel therapeutic approach for treatment of ischemic heart disease.     

Ssp1 promotes actin depolymerization and is involved in stress response and new end take-off control in fission yeast

The ssp1 gene encodes a protein kinase involved in alteration of cell polarity in Schizosaccharomyces pombe. ssp1 deletion causes stress sensitivity, reminiscent of defects in the stress-activated MAP kinase, Spc1; however, the two protein kinases do not act through the same pathway. Ssp1 is localized mainly in the cytoplasm, but after a rise in external osmolarity it is rapidly recruited to the plasma membrane, preferentially to active growth zones and septa. Loss of Ssp1 function inhibits actin relocalization during osmotic stress, in cdc3 and cdc8 mutant backgrounds, and in the presence of latrunculin A, implicating Ssp1 in promotion of actin depolymerization. We propose a model in which Ssp1 can be activated independently of Spc1 and can partially compensate for its loss. The ssp1 deletion mutant exhibited monopolar actin distribution, but new end take-off (NETO) could be induced in these cells by exposure to KCl or to latrunculin A pulse treatment. This treatment induced NETO in cdc10 cells arrested in G1 but not in tea1 cells. This suggests that cells that contain intact cell end markers are competent to undergo NETO throughout interphase, and Ssp1 is involved in generating the NETO stimulus by enlarging the actin monomer pool.