Dybowskin-2CDYa (Dy2), with a broad antimicrobial spectrum and low hemolytic feature, is a newly discovered type of antimicrobial peptides from Rana dybowskii. In order to get a dual function peptide which inhibits bacterial growth and promotes cell proliferation, we cloned the gene of Dy2and hEGF (human epidermal growth factor) into the prokaryotic expression vector pET-30a(+). With isopropyl-?-D-thiogalactoside (IPTG) induction, a 13.7KDa peptide with a 6×His tag was highly expressed in the form of inclusion in E. coli BL2l (DE3). SDS-PAGE and western-blot confirmed the expression of the fusion peptide hEGF-Dy2. Under the optimized condition of 1.0mmol/L IPTG induction and incubation time 4h at 37o, the yield of hEGF-Dy2reached 30mg/L following purification on nickel-nitrilotriacetic acid (Ni-NTA) metal affinity chromatography matrices. The purified fusion peptide showed significant antibacterial activities against Staphylococcus aureus, Escherichia coli O157, Pseudomonas aeruginosa and proliferating activities on NIH3T3. These results indicated that the fusion peptide might have a good prospect in therapy of trauma and burns.
A single phase titanium oxycarbonitride TiC0.25O0.25N0.5 was prepared by sintering a homogenous mixture of TiO, TiC and TiN with a molar ratio of 1?:?1?:?2 by spark plasma sintering (SPS) at 1873 K. TiO0.25C0.25N0.5 was then used as the consumable anode for the USTB titanium process and the anode dissolution process was investigated by electrochemical methods. The results showed that TiO0.25C0.25N0.5 was electrochemically dissolved into Ti(2+) in the NaCl-KCl melts as determined by square-wave voltammetry analysis and simultaneously CO as well as N2 evolved in the anode as detected by mass spectroscopy. And TiO0.25C0.25N0.5 has exhibited a similar electron transfer resistance as TiC0.5O0.5 and TiN as measured by electrochemical impedance spectroscopy (EIS) analysis. By galvanostatic electrolysis, the cathode products were proved to be pure titanium powders. The results indicated that TiO0.25C0.25N0.5 is a suitable consumable anode for the USTB titanium process.
Epithelial ovarian cancer (EOC) is still a major gynecologic problem with poor 5 year survival rate due to distance metastases, despite routine surgery and chemotherapy. The precise underlying molecular mechanisms that trigger EOC migration and invasion are unclear. Recent studies suggest that the expression of microRNAs is widely dysregulated in ovarian cancer; and that they have evolved into tumorigenic processes, including cell proliferation, apoptosis and motility.
MicroRNAs (miRNAs) are a class of non-coding RNAs known to play important regulatory roles through targets, which can affect human cell proliferation, differentiation, and metabolism. Overlaps between different miRNA target prediction algorithms (MTPAs) are small, which limit the understanding of miRNAs biological functions. However, the overlaps increase on functional levels, such as Gene Ontology (GO), Protein-Protein Interaction Network (PPIN) and pathways. Here, we performed prioritization on existing predicted target sets for each miRNA by considering all the possible combinations of 7 functional levels. After analyzing the results of both single and multiple functional levels, we found that functional combination strategies including pathways and GO performed better in the prioritization of human miRNA target. The combination which performed best was "Pathway+GO BP+GO MF+GO CC+Target+PPIN". For the prioritized result of this combination, the valid target had top ranking, and our method performed better than the MTPAs after comparison adopting the validated ranking levels. Top genes in ranking lists generated by this strategy were either validated by experiments or share same functions with the corresponding miRNA/its validated genes in disease related biological processes.
Transcription factor PAX3/Pax3 contributes to diverse cell lineages during embryonic development and is important in tumourigenesis. We found that PAX3 is re-expressed in neuroblastoma and malignant neuroblastic (N-type) neuroblastoma cells had significantly higher PAX3 protein expression than their benign substrate-adherent (S-type) counterparts. Knock-down of PAX3 expression by siRNA transfection resulted in persistent cell growth inhibition in both types of neuroblastoma cell, owing to G1 cell cycle arrest and progressive apoptosis. Inhibition of PAX3 expression significantly decreased the attachment of S-type SH-EP1 cells to extra-cellular matrix proteins, fibronectin, laminin and collagen IV. Migration and invasion of both neuroblastoma cell types were markedly reduced after PAX3 down-regulation. PAX3 knock-down significantly augmented the cytotoxic effect of chemotherapeutic agents, etoposide, vincristine and cisplatin, commonly used to treat neuroblastoma. Microarray analyses revealed that particularly signalling pathways involving cell cycle, apoptosis, cell adhesion, cytoskeletal remodelling and development were altered by PAX3 down-regulation. Changes in PAX3 downstream genes identified by microarray analyses were validated in 47 genes by quantitative PCR. These novel findings lead us to propose that PAX3 might contribute to oncogenic characteristics of neuroblastoma cells by regulating a variety of crucial signalling pathways.
Detecting and interpreting certain system-level characteristics associated with human population genetic differences is a challenge for human geneticists. In this study, we conducted a population genetic study using the HapMap genotype data to identify certain special Gene Ontology (GO) categories associated with high/low genetic difference among 11 Hapmap populations. Initially, the genetic differences in each gene region among these populations were measured using allele frequency, linkage disequilibrium (LD) pattern, and transferability of tagSNPs. The associations between each GO term and these genetic differences were then identified. The results showed that cellular process, catalytic activity, binding, and some of their sub-terms were associated with high levels of genetic difference, and genes involved in these functional categories displayed, on average, high genetic diversity among different populations. By contrast, multicellular organismal processes, molecular transducer activity, and some of their sub-terms were associated with low levels of genetic difference. In particular, the neurological system process under the multicellular organismal process category had low levels of genetic difference; the neurological function also showed high evolutionary conservation between species in some previous studies. These results may provide a new insight into the understanding of human evolutionary history at the system-level.
Diabetes-induced hyperglycemia increases formation of advanced glycation end products (AGEs) and metal-catalyzed production of free radicals. This study compared the antioxidant capacities of dark and light soy sauces of different brands and investigated their abilities to inhibit AGEs and whether their mechanism of action was pre- or post-Amadori or involved chelation of transition metals. The antioxidant capacities of soy sauces were compared using the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate) method and by measuring their total phenolic contents. Model proteins (lysozyme, albumin) were glycated using fructose with or without soy sauces with subsequent analysis of cross-linked AGEs by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The effect of soy sauces on pre- and post-Amadori inhibition of AGEs was investigated by measuring fructosamine and AGEs following reincubation of ribose-glycated (ribated) lysozyme, respectively. Dark soy sauces had higher antioxidant capacities and phenolic content and were more effective inhibitors of post-Amadori-derived cross-linked AGEs. However, light soy sauces were more effective at inhibiting fructosamine and had more potent metal chelation properties. This study reports the antiglycation properties of soy sauces, but further studies are required to determine the constituents responsible for this effect and whether soy sauce consumption can reduce oxidative stress and AGEs in diabetic subjects.
Dynamic changes in callose content, which is deposited as a plant defense response to physiological changes, were analyzed during somatic embryogenesis in Eleutherococcus senticosus zygotic embryos plasmolyzed in 1.0 M mannitol. During plasmolysis, callose deposition was clearly observed inside the plasma membrane of zygotic embryo epidermal cells using confocal laser scanning microscopy. The callose content of zygotic embryos gradually increased between 0 and 12 h plasmolysis and remained stable after 24 h plasmolysis. During eight weeks induction of somatic embryogenesis, the callose content of explants plasmolyzed for 12 h was slightly higher than explants plasmolyzed for 6 or 24 h, with the largest differences observed after 6 weeks culture, which coincided with the maximum callose content and highest number of globular somatic embryos. The highest frequency of somatic embryo formation was observed in explants plasmolyzed for 12 h. The somatic embryo induction rate and number of somatic embryos per explant were markedly different in zygotic embryos pretreated with plasmolysis alone (78.0%, 43 embryos per explant) and those pretreated with plasmolysis and the callose synthase inhibitor 2-deoxy-d-glucose (11.5%, 8 embryos per explant). This study indicates that callose production is required for somatic embryogenesis in plasmolyzed explants.
Cellulose synthase (CESA), which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, -4, -7 and -8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.
Natural health products (NHP) which include minerals, vitamins and herbal remedies are not generally considered by medical practitioners as conventional medicines and as such are not frequently prescribed by health centres as either main-line or supplemental treatments. In the field of cardiovascular medicine, studies have shown that typically, less than half of patients suffering from coronary syndromes chose to take any form of NHP supplement and these products are rarely recommended by their medical practitioner. Vascular/endothelial cell damage is a key instigator of coronary arterial plaque development which often culminates in thrombosis and myocardial infarction (MI). Current treatment for patients known to be at risk of primary or secondary (MI) includes lipid lowering statins, anti-clotting agents (e.g. tissue plasminogen activator; tPA) and drugs for stabilization of blood pressure such as beta-blockers. However, evidence has been building which suggests that components of at least several NHP (e.g. aged garlic extract (AGExt), resveratrol and green tea extracts (GTE)) may have significant vascular protective effects through reduction of oxidative stress, lowering of blood pressure, reduction in platelet aggregation, vasodilation and inhibition of abnormal angiogenesis. Therefore, in this review we will discuss in detail the potential of these substances (chosen on the basis of their potency and complimentarity) as anti-atherosclerotic agents and the justification for their consideration as main-line additional supplements or prescriptions.
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