Cloning and expression of the 4D8 gene from Hyalomma asiaticum tick

Hyalomma asiaticum tick, an important ectozoic parasite causes tickle, pain, anemia, weight loss, and paralysis in its hosts, which include humans, cattle, sheep, horses, camels, and hares. The 4D8 gene can be a potential vaccine candidate antigen for H. asiaticum. In the present study, we cloned and expressed the 4D8 gene of H. asiaticum from Xinjiang Province. Primers were designed according to the H. asiaticum tick 4D8 gene sequence available in GenBank. The gene was amplified by reverse transcription-polymerase chain reaction and the fragments were subcloned into the prokaryotic expression vector pET30a and the recombinant vector pET30a-4D8 was constructed. The expressed recombinant protein was purified and its biological activity was investigated by western blot. Results revealed that the recombinant protein was a biologically active fusion protein with a molecular weight of 20 kDa. The purified 4D8 protein would provide a strong foundation for further studies on this protein.

First detection of Candidatus Rickettsia barbariae in the flea Vermipsylla alakurt from north-western China

Background

Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Vermipsylla alakurt is mainly distributed in alpine pastoral areas of Kazakhstan, Mongolia, China and Nepal, and infests sheep, yaks and horses, causing irritation, poor condition, anaemia and even death. However, to date, no rickettsial agents have been reported in V. alakurt.

Findings

A total of 133 fleas were collected directly from the tails of three sheep flocks (n = 335) in Minfeng County, Xinjiang Uygur Autonomous Region, north-western China. Of these, 55 fleas were identified by morphological examination and molecular analysis of four loci (the ribosomal 18S and 28S rDNA genes and the mitochondrial genes cytochrome  c oxidase subunit II and elongation factor 1-alpha). Eight Rickettsia-specific gene fragments originated from seven genes: the 17-kilodalton antigen gene (17-kDa), citrate synthase gene (gltA), 16S rRNA gene (rrs), outer membrane protein A gene (ompA), surface cell antigen 1 gene (sca1), PS120 protein gene (gene D), and outer membrane protein B gene (ompB, two fragments), were used to identify the species of Rickettsia in 53 fleas. The amplified products were sequenced and included in a phylogenetic analysis to verify the taxonomic identification of the rickettsial agents. Based on morphological and molecular evidence, the flea was identified as Vermipsylla alakurt. Nine samples were positive (16.98 %, 9/53) for Rickettsia spp. The phylogenetic tree revealed that the rickettsial agents found in V. alakurt cluster with Candidatus Rickettsia barbariae.

Conclusions

Our study suggests that: (i) V. alakurt may serve as a carrier for Candidatus R. barbariae; and (ii) Candidatus R. barbariae, previously reported in Israel, is the eighth newly discovered validated Rickettsia species in China. This finding extends our knowledge of the distribution of Candidatus R. barbariae and the profile of carriers, which not only comprise ticks but also fleas.

The flavonoid baicalein rescues synaptic plasticity and memory deficits in a mouse model of Alzheimer's disease

Increasing evidence suggests that disruptions of synaptic functions correlate with the severity of cognitive deficit in Alzheimer's disease (AD). Our previous study demonstrated that baicalein enhances long-term potentiation (LTP) in acute rat hippocampal slices and improves hippocampus-dependent contextual fear conditioning in rats. Given that baicalein possess various biological activities, especially its effects on synaptic plasticity and cognitive function, we examined the effect of baicalein on synaptic function both in vitro and in vivo in AD model. The effect of baicalein on Aβ42 oligomer impaired LTP was investigated by electrophysiological methods. Baicalein was administered orally via drinking water to the APP/PS1 mice and sex- and age-matched wild-type mice. Treatment started at 5 months of age and mice were assessed for cognition and AD-like pathology at 7-month-old. Cognition was analyzed by Morris water maze test, fear conditioning test, and novel object recognition test. Changes in hippocampal 12/15 Lipoxygenase (12/15LO) and glycogen synthase kinase 3β (GSK3β) activity, Aβ production, tau phosphorylation, synaptic plasticity, and dendritic spine density were evaluated. Baicalein prevented Aβ-induced impairments in hippocampal LTP through activation of serine threonine Kinase (Akt) phosphorylation. Long-term oral administration of baicalein inhibited 12/15LO and GSK3β activity, reduced β-secretase enzyme (BACE1), decreased the concentration of total Aβ, and prevented phosphorylation of tau in APP/PS1 mice. Meanwhile, baicalein restored spine number, synaptic plasticity, and memory deficits. Our results strengthen the potential of the flavonoid baicalein as a novel and promising oral bioactive therapeutic agent that prevents memory deficits in AD.

Micro RNA-17-92 cluster mediates interleukin-4-suppressed IL-10 expression in B cells

The pathogenesis of allergen-related inflammation in the intestine is to be further understood. Micro RNA (miR) can regulate immune responses. This study aims to investigate the role of miR-17-92 cluster in the induction of food allergen-related inflammation in the intestine. In this study, a mouse model of food allergen-related intestinal inflammation was developed. Expression of miR-17-92 cluster in B cells of the intestinal mucosa was analyzed by real time quantitative RT-PCR. The results showed that the levels of miR-19a, one of the members of the miR-17-92 cluster, were detected in the B cells of the intestine of mice sensitized to ovalbumin, which was significantly higher than that in naïve control mice. The expression of IL-10 by B cells was significantly lower in the sensitized mice as compared with naive control mice. Exposure to IL-4 in the culture increased the expression of miR-19a as well as suppression the expression of IL-10 in B cells via remolding DNA structure at the IL-10 promoter locus. We conclude that B cells from sensitized mice show higher levels of miR-19a, which plays an important role in the suppression of IL-10 in the B cells.

Immobilization of nitrilase on bioinspired silica for efficient synthesis of 2-hydroxy-4-(methylthio) butanoic acid from 2-hydroxy-4-(methylthio) butanenitrile

In this paper, a simple and effective method using sodium metasilicate as precursor and amine as additive was first reported to immobilize recombinant nitrilase, for efficient production of 2-hydroxy-4-(methylthio) butanoic acid from 2-hydroxy-4-(methylthio) butanenitrile. High immobilization recovery of enzyme activity (above 90 %) was achieved. The immobilized enzyme displayed better thermal stability, pH stability and shelf life compared to free nitrilase. Moreover, it showed excellent reusability and could be recycled up to 16 batches without significant loss in activity. 200 mM 2-hydroxy-4-(methylthio) butanenitrile was completely converted by the immobilized enzyme within 30 min, and the accumulation amount of 2-hydroxy-4-(methylthio) butanoic acid reached 130 mmol/g of immobilized beads after 16 batches. These encouraging results demonstrated the efficiency of the new technology for nitrilase immobilization, which has great potential in preparation of 2-hydroxy-4-(methylthio) butanoic acid.

CD4+ T cell responses in Balb/c mice with food allergy induced by trinitrobenzene sulfonic acid and ovalbumin

The rapid increase in atopic diseases is potentially linked to increased hapten exposure, however, the role of haptens in the pathogenesis of food allergy remains unknown. Further studies are required to elucidate the cluster of differentiation 4 positive (CD4+) T cell response to food allergy induced by haptens. Dendritic cells were primed by trinitrobenzene sulfonic acid (TNBS) as a hapten or ovalbumin (OVA) as a model antigen, in a cell culture model. BALB/c mice were sensitized using TNBS and/or OVA. Intestinal Th1/Th2 cell and ovalbumin specific CD4+ T cells proliferation, intestinal cytokines (interleukin‑4 and interferon‑γ) in CD4+ T cells were evaluated. TNBS increased the expression of T cell immunoglobulin and mucin domain‑4 and tumor necrosis factor ligand superfamily member 4 in dendritic cells. Skewed Th2 cell polarization, extensive expression of interleukin‑4, reduced expression of interferon‑γ and forkhead box protein P3 were elicited following concomitant exposure to TNBS and OVA, with reduced regulatory T cells in the mouse intestinal mucosa, whereas a Th1 response was detected when challenged by TNBS or OVA alone. This data suggests that TNBS, as a hapten, combined with food antigens may lead to a Th2 cell response in the intestinal mucosa.

Generalized energy failure criterion

Discovering a generalized criterion that can predict the mechanical failure of various different structural materials is one of ultimate goals for scientists in both material and mechanics communities. Since the first study on the failure criterion of materials by Galileo, about three centuries have passed. Now we eventually find the “generalized energy criterion”, as presented here, which appears to be one universal law for various different kinds of materials. The validity of the energy criterion for quantitatively predicting the failure is experimentally confirmed using a metallic glass. The generalized energy criterion reveals the competition and interaction between shear and cleavage, the two fundamental inherent failure mechanisms, and thus provides new physical insights into the failure prediction of materials and structural components.

Long-range magnetic coupling across a polar insulating layer

Magnetic interactions in solids are normally mediated by short-range exchange or weak dipole fields. Here we report a magnetic interaction that can propagate over long distances (∼10 nm) across a polar insulating oxide spacer. Evidence includes oscillations of magnetization, coercivity and field-cooled loop shift with the thickness of LaAlO₃ in La_0.67Sr_0.33MnO₃/LaAlO₃/SrTiO₃ heterostructures. Similar modifications of the hysteresis loop appear when two coupled films of La_0.67Sr_0.33MnO₃ are separated by LaAlO₃, or another polar insulator, but they are absent when the oxide spacer layer is nonpolar. The loop shift is attributed to strong spin–orbit coupling and Dzyaloshinskii–Moriya interaction at the interfaces. There is evidence from inelastic light scattering that the polar spacer mediates long-range transmission of orbital magnetization. This coupling mechanism is expected to apply for any conducting ferromagnetic oxide with mixed valence; in view of electron hopping frequency involved, it raises the prospect of terahertz tunability of magnetic coupling.

Magnetic interactions in solids are usually short-range or else they involve itinerant electrons. Here, the authors evidence a long-range magnetic coupling mediated by orbital moments in a polar spacer layer of nonmagnetic insulating oxide, with a sign which oscillates with spacer thickness.

Full Electroresistance Modulation in a Mixed-Phase Metallic Alloy

We report a giant, ∼22%, electroresistance modulation for a metallic alloy above room temperature. It is achieved by a small electric field of 2  kV/cm via piezoelectric strain-mediated magnetoelectric coupling and the resulting magnetic phase transition in epitaxial FeRh/BaTiO_{3} heterostructures. This work presents detailed experimental evidence for an isothermal magnetic phase transition driven by tetragonality modulation in FeRh thin films, which is in contrast to the large volume expansion in the conventional temperature-driven magnetic phase transition in FeRh. Moreover, all the experimental results in this work illustrate FeRh as a mixed-phase model system well similar to phase-separated colossal magnetoresistance systems with phase instability therein.

Biosynthetic Pathway Analysis for Improving the Cordycepin and Cordycepic Acid Production in Hirsutella sinensis

Hirsutella sinensis is considered as the only correct anamorph of Ophiocordyceps sinensis. To improve cordycepin and cordycepic acid production in H. sinensis, the biosynthetic pathways of cordycepin and cordycepic acid were predicted, and verified by cloning and expressing genes involved in these pathways, respectively. Then, 5'-nucleotidase participating in biosynthetic pathway of cordycepin, hexokinase, and glucose phosphate isomerase involved in biosynthetic pathway of cordycepic acid, were demonstrated playing important roles in the corresponding biosynthetic pathway by real-time PCR, accompanying with significantly up-regulated 15.03-, 5.27-, and 3.94-fold, respectively. Moreover, the metabolic regulation of H. sinensis was performed. As expected, cordycepin production reached 1.09 mg/g when additional substrate of 5'-nucleotidase was 4 mg/mL, resulting in an increase of 201.1 % compared with the control. In the same way, cordycepic acid production reached 26.6 and 23.4 % by adding substrate of hexokinase or glucose phosphate isomerase, leading to a rise of 77.3 and 55.1 %, respectively. To date, this is the first time to improve cordycepin and cordycepic acid production through metabolic regulation based on biosynthetic pathway analysis, and metabolic regulation is proved as a simple and effective way to enhance the output of cordycepin and cordycepic acid in submerged cultivation of H. sinensis.

D-Serine in the nucleus accumbens region modulates behavioral sensitization and extinction of conditioned place preference

BACKGROUND

D-serine, the endogenous co-agonist of N-methyl-D-aspartate receptors (NMDARs), is considered to be essential for learning and memory. The aim of the current investigation was to systematically evaluate the role of D-serine on addiction behaviors considered to be mediated by the nucleus accumbens (NAc).

METHODS

D-Serine concentration in the NAc was measured by high-performance liquid chromatography (HPLC). Cocaine-induced behavioral sensitization and conditioned place preference (CPP) models were used to evaluate the relation between changes in serine in the nucleus accumbens and cocaine-induced behavioral effects. The expression of serine racemase (SR), D-amino acid oxidase (DAAO), the cAMP response element-binding protein (CREB) and upstream kinases, and N-methyl-D-aspartate (NMDA) receptors subunits were analyzed by western blot. Long-term depression (LTD) in the NAc was investigated by electrophysiological methods.

RESULTS

The NAc slices obtained from the behavioral sensitization rats presented significantly reduced D-serine concentrations, increased expression of DAAO, and down-regulated expression of SR in a dose-dependent manner. Furthermore, D-serine injections into the nucleus accumbens blocked the development of behavioral sensitization and caused extinction of CPP. The ERK-CREB-Fos pathway and the NMDA receptor NR2B subunits in the NAc were involved in the cocaine-induced behavioral sensitization. We also found that D-serine was essential for NMDAR-dependent LTD and D-serine-regulated LTD in a bell-shaped concentration-dependent manner. The disrupted NMDAR-dependent LTD in the NAc of cocaine-treated rats was reversed by D-serine.

CONCLUSIONS

Our results provide evidence for a critical role of D-serine in synaptic plasticity relevant to cocaine addiction and indicate that D-serine may be an effective therapeutic agent for cocaine addiction.

Parallel charge sheets of electron liquid and gas in La0.5Sr0.5TiO3/SrTiO3 heterostructures

We show here a new phenomenon in La_0.5Sr_0.5TiO₃/SrTiO₃ (LSTO/STO) heterostructures; that is a coexistence of three-dimensional electron liquid (3DEL) and 2D electron gas (2DEG), separated by an intervening insulating LSTO layer. The two types of carriers were revealed through multi-channel analysis of the evolution of nonlinear Hall effect as a function of film thickness, temperature and back gate voltage. We demonstrate that the 3D electron originates from La doping in LSTO film and the 2D electron at the surface of STO is due to the polar field in the intervening insulating layer. As the film thickness is reduced below a critical thickness of 6 unit cells (uc), an abrupt metal-to-insulator transition (MIT) occurs without an intermediate semiconducting state. The properties of the LSTO layer grown on different substrates suggest that the insulating phase of the intervening layer is a result of interface strain induced by the lattice mismatch between the film and substrate. Further, by fitting the magnetoresistance (MR) curves, the 6 unit cell thick LSTO is shown to exhibit spin-orbital coupling. These observations point to new functionalities, in addition to magnetism and superconductivity in STO-based systems, which could be exploited in a multifunctional context.

Chemical constituents of Allophylus africanus

Four new compounds, alloeudesmenol (1), hanocokinoside (3), allotaraxerolide (4), and alloaminoacetaldehyde (5), together with two known compound, stigmastane-3β,4β-diol (2) and pinitol 6 (a and b) were isolated and identified from the whole plant of Allophylus africanus.

HMGB1 Promotes Mitochondrial Dysfunction-Triggered Striatal Neurodegeneration via Autophagy and Apoptosis Activation

Impairments in mitochondrial energy metabolism are thought to be involved in many neurodegenerative diseases. The mitochondrial inhibitor 3-nitropropionic acid (3-NP) induces striatal pathology mimicking neurodegeneration in vivo. Previous studies showed that 3-NP also triggered autophagy activation and apoptosis. In this study, we focused on the high-mobility group box 1 (HMGB1) protein, which is important in oxidative stress signaling as well as in autophagy and apoptosis, to explore whether the mechanisms of autophagy and apoptosis in neurodegenerative diseases are associated with metabolic impairment. To elucidate the role of HMGB1 in striatal degeneration, we investigated the impact of HMGB1 on autophagy activation and cell death induced by 3-NP. We intoxicated rat striata with 3-NP by stereotaxic injection and analyzed changes in expression HMGB1, proapoptotic proteins caspase-3 and phospho-c-Jun amino-terminal kinases (p-JNK). 3-NP–induced elevations in p-JNK, cleaved caspase-3, and autophagic marker LC3-II as well as reduction in SQSTM1 (p62), were significantly reduced by the HMGB1 inhibitor glycyrrhizin. Glycyrrhizin also significantly inhibited 3-NP–induced striatal damage. Neuronal death was replicated by exposing primary striatal neurons in culture to 3-NP. It was clear that HMGB1 was important for basal autophagy which was shown by rescue of cells through HMGB1 targeting shRNA approach.3-NP also induced the expression of HMGB1, p-JNK, and LC3-II in striatal neurons, and p-JNK expression was significantly reduced by shRNA knockdown of HMGB1, an effect that was reversed by exogenously increased expression of HMGB1. These results suggest that HMGB1 plays important roles in signaling for both autophagy and apoptosis in neurodegeneration induced by mitochondrial dysfunction.

Molecular characterization of a novel ovary-specific gene fem-1 homolog from the oriental river prawn, Macrobrachium nipponense

The feminization-1 (fem-1) gene is characterized by one of the most common protein-protein interaction motifs, ankyrin repeat motifs, displays many expression patterns in vertebrates and invertebrates, and plays an essential role in the sex-determination/differentiation pathway in Caenorhabditis elegans. In this study, a fem-1 homolog, designated as Mnfem-1, was first cloned from the oriental river prawn Macrobrachium nipponense. The prawn Mnfem-1 gene consists of six exons and five introns. The full-length cDNA (2603bp) of Mnfem-1 contains an open reading frame (ORF) encoding a protein of 622 amino acids. The Mnfem-1 RNA and protein are exclusively expressed in the ovary in adult prawns as revealed by RT-PCR and immunofluorescence analysis, respectively. In situ hybridization results showed that strong positive signals were concentrated at the edge of the previtellogenic and vitellogenic oocyte. During embryogenesis, Mnfem-1 is highly expressed in both unfertilized eggs and embryos at cleavage stage and thereafter dropped to a low level from blastula to zoea, indicating that the Mnfem-1 in early embryos is maternal. After hatching, the Mnfem-1 expression significantly increased in the larvae at length of 2cm, an important stage of sex differentiation. Yeast two hybridization results showed that the Mnfem-1 protein can be potentially interactive with cathepsin L and proteins containing the domains of insulinase, ankyrin or ubiquitin. Our results suggested that Mnfem-1 could have roles in prawn ovarian development and sex determination/differentiation.

A broad-range survey of ticks from livestock in Northern Xinjiang: changes in tick distribution and the isolation of Borrelia burgdorferi sensu stricto

Background

Borreliosis is highly prevalent in Xinjiang Uygur Autonomous Region, China. However, little is known about the presence of Borrelia pathogens in tick species in this region, in addition Borrelia pathogens have not been isolated from domestic animals.

Methods

We collected adult ticks from domestic animals at 19 sampling sites in 14 counties in northern Xinjiang from 2012 to 2014. Ticks were identified to species by morphology and were molecularly analysed by sequences of mitochondrial 16S rDNA gene; 4–8 ticks of each species at every sampling site were sequenced. 112 live adult ticks were selected for each species in every county, and were used to culture Borrelia pathogens; the genotypes were then determined by sequences of the 5S-23S rRNA intergenic spacer and the outer surface protein A (ospA) gene.

Results

A total of 5257 adult ticks, belonging to four genera and seven species, were collected. Compared with three decades ago, the abundance of the five common tick species during the peak ixodid tick season has changed. Certain tick species, such as Rhipicephalus turanicus (Rh. turanicus), was found at Jimusaer, Yining, Fukang, and Chabuchaer Counties for the first time. Additionally, the sequence analyses showed that the Hyalomma asiaticum (Hy. asiaticum), Haemaphysalis punctata (Ha. punctata), and Dermacentor marginatus (D. marginatus) that were collected from different sampling sites (≥3 sites) shared identical 16S rDNA sequences respectively. For the tick species that were collected from the same county, such as Hy. asiaticum from Shihezi County and Rh. turanicus from Yining County, their 16S rDNA sequences showed genetic diversity. In addition, sixteen Borrelia isolates were found in Hy. asiaticum, Ha. punctata, D. marginatus and Rh. turanicus, which infested cattle, sheep, horse and camel in Yining, Chabuchaer, Shihezi and Shawan Counties. All of the isolates were genetically identified as B. Burgdorferi sensu stricto.

Conclusions

Warmer and wetter climate may have contributed to the altered distribution and abundance of the five most common ticks in northern Xinjiang. The genetic analyses showed that certain tick species, such as Hy. asiaticum or Rh. turanicus, exhibit genetic commonness or diversity. Additionally, this study is the first to isolate B. burgdorferi sensu stricto in Hy. asiaticum asiaticum, H. punctata, D. nuttalli and D. marginatus ticks from domestic animals. These ticks may transmit borreliosis among livestock.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-1021-0) contains supplementary material, which is available to authorized users.

Molecular cloning and expression analysis of a novel BCCP subunit gene from Aleurites moluccana

Aleurites moluccana L. is grown as a roadside tree in southern China and the oil content of its seed is higher than other oil plants, such as Jatropha curcas and Camellia oleifera. A. moluccana is considered a promising energy plant because its seed oil could be used to produce biodiesel and bio-jet fuel. In addition, the bark, leaves, and kernels of A. moluccana have various medical and commercial uses. Here, a novel gene coding the biotin carboxyl carrier protein subunit (BCCP) was cloned from A. moluccana L. using the homology cloning method combined with rapid amplification of cDNA end (RACE) technology. The isolated full-length cDNA sequence (designated AM-accB) was 1188 bp, containing a 795-bp open reading frame coding for 265 amino acids. The deduced amino acid sequence of AM-accB contained a biotinylated domain located between amino acids 190 and 263. A. moluccana BCCP shows high identity at the amino acid level to its homologues in other higher plants, such as Vernicia fordii, J. curcas, and Ricinus communis (86, 77, and 70%, respectively), which all contain conserved domains for ACCase activity. The expression of the AM-accB gene during the middle stage of development and maturation in A. moluccana seeds was higher than that in early and later stages. The expression pattern of the AM-accB gene is very similar to that of the oil accumulation rate.

Lipoxin A4 ameliorates ischemia/reperfusion induced spinal cord injury in rabbit model

Ischemia/reperfusion (I/R) induced spinal cord injury is an important pathologic mechanism leading to the paraplegia observed after surgery to repairaortic aneurysms. This study aims to investigate the neuroprotective effects of Lipoxin A4 and its potential mechanism in a rabbit model with I/R spinal cord injury. Forty-five rabbits were randomly divided into three groups: sham group, I/R group and Lipoxin A4 group. Rabbits were subject to 30 min aortic occlusion to induce transient spinal cord ischemia. All animals were sacrificed after neurological evaluation with modified Tarlov criteria at the 48th hour after reperfusion, and the spinal cord segments (L4-6) were harvested for histopathological examination, as well as local malondialdehyde (MDA) and total superoxide dismutase (SOD) activity analysis. All animals in the I/R group became paraplegic. While after 48-hour treatment, compared with I/R group, Lipoxin A4 significantly improved neurological function, reduced cell apoptosis and MDA levels as well as increased SOD activity (P < 0.05). These results suggest that Lipoxin A4 can ameliorate I/R induced spinal cord injury in Rabbit through its antiapoptosis and antioxidant activity.

BRAF activated non-coding RNA (BANCR) promoting gastric cancer cells proliferation via regulation of NF-κB1

BACKGROUND AND OBJECTIVE

Long non-coding RNA, BANCR, has been demonstrated to contribute to the proliferation and migration of tumors. However, its molecular mechanism underlying gastric cancer is still unknown. In present study, we investigated whether BANCR was involved in the development of gastric cancer cells via regulation of NF-κB1.

METHODS

Human gastric cancer tissues were isolated as well as human gastric cell lines MGC803 and BGC823 were cultured to investigate the role of BANCR in gastric cancer.

RESULTS

BANCR expression was significantly up-regulated in gastric tumor tissues and gastric cell lines. Down-regulation of BANCR inhibited gastric cancer cell growth and promoted cell apoptosis, and it also contributed to a significant decrease of NF-κB1 (P50/105) expression and 3'UTR of NF-κB1 activity. Overexpression of NF-κB1 reversed the effect of BANCR on cancer cell growth and apoptosis. MiroRNA-9 (miR-9) targeted NF-κB1, and miR-9 inhibitor also reversed the effects of BANCR on gastric cancer cell growth and apoptosis.

CONCLUSION

BANCR was highly expressed both in gastric tumor tissues and in cancer cells. NF-κB1 and miR-9 were involved in the role of BANCR in gastric cancer cell growth and apoptosis.

Improvement and characterization of a hyperthermophilic glucose isomerase from Thermoanaerobacter ethanolicus and its application in production of high fructose corn syrup

High fructose corn syrup (HFCS) is an alternative of liquid sweetener to sucrose that is isomerized by commercial glucose isomerase (GI). One-step production of 55 % HFCS by thermostable GI has been drawn more and more attentions. In this study, a new hyperthermophilic GI from Thermoanaerobacter ethanolicus CCSD1 (TEGI) was identified by genome mining, and then a 1317 bp fragment encoding the TEGI was synthesized and expressed in Escherichia coli BL21(DE3). To improve the activity of TEGI, two amino acid residues, Trp139 and Val186, around the active site and substrate-binding pocket based on the structural analysis and molecular docking were selected for site-directed mutagenesis. The specific activity of mutant TEGI-W139F/V186T was 2.3-fold and the value of k  cat/K  m was 1.86-fold as compared to the wild type TEGI, respectively. Thermostability of mutant TEGI-W139F/V186T at 90 °C for 24 h showed 1.21-fold extension than that of wild type TEGI. During the isomerization of glucose to fructose, the yield of fructose could maintain above 55.4 % by mutant TEGI-W139F/V186T as compared to 53.8 % by wild type TEGI at 90 °C. This study paved foundation for the production of 55 % HFCS using the thermostable TEGI.