There is no highly effective chemotherapy for malignant gliomas to date. We found that dimethylaminomicheliolide (DMAMCL), a selective inhibitor of acute myeloid leukemia (AML) stem/progenitor cells, inhibited the growth of glioma cells.
The distribution of DMAMCL in brain was analyzed by an ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS) system. The anti-tumor evaluations of DMAMCL in vitro were performed by MTT, FACS and RT-PCR. In vivo, the mixture of C6 cells and matrigel was injected into caudatum, and the anti-tumor activity of DMAMCL was evaluated by tumor growth and rat survival. The toxicity of DMAMCL was evaluated by body weight, daily food intake, hematological or serum biochemical analyses, and histological appearance of tissues.
The IC50 values of DMAMCL against the C6 and U-87MG cell lines in vitro were 27.18 ± 1.89 μM and 20.58 ± 1.61 μM, respectively. DAMMCL down-regulated the anti-apoptosis gene Bcl-2 and increased apoptosis in C6 and U-87MG cells in a dose-dependent manner. In a C6 rat tumor model, daily administration of DMAMCL for 21 days reduced the burden of C6 tumors by 60% to 88% compared to controls, and more than doubled the mean lifespan of tumor-bearing rats. Distribution analysis showed that the DMAMCL concentration was higher in the brain than in plasma. Evaluations for toxicity revealed that oral administration of DMAMCL at 200 or 300 mg/kg once a day for 21 days did not result in toxicity.
These results suggest that DMAMCL is highly promising for the treatment of glioma.
Influenza B virus is an enveloped negative-strand RNA virus that contributes considerably to annual influenza illnesses in human. The matrix protein of influenza B virus (BM1) acts as a cytoplasmic-nuclear shuttling protein during the early and late stages of infection. The mechanism of this intracellular transport of BM1 was revealed through the identification of two leucine-rich CRM1-dependent nuclear export signals (NESs) (3 to 14 amino acids [aa] and 124 to 133 aa), one bipartite nuclear localization signal (NLS) (76 to 94 aa), and two phosphorylation sites (80T and 84S) in BM1. The biological function of the NLS and NES regions were determined through the observation of the intracellular distribution of enhanced green fluorescent protein (EGFP)-tagged signal peptides, and wild-type, NES-mutant, and NLS-mutant EGFP-BM1. Furthermore, the NLS phosphorylation sites 80T and 84S, were found to be required for the nuclear accumulation of EGFP-NLS and for the efficient binding of EGFP-BM1 to human importin-α1. Moreover, all of these regions/sites were required for the generation of viable influenza B virus in a 12-plasmid virus rescue system.
IMPORTANCE This study expands our understanding of the life cycle of influenza B virus by defining the dynamic mechanism of the nucleocytoplasmic shuttle of BM1 and could provide a scientific basis for the development of antiviral medication.
The influenza A virus nuclear export protein (NEP) plays crucial roles in the nuclear export of the viral ribonucleoprotein complex through the chromosome region maintenance 1 (CRM1)-mediated cellular protein transport system. However, the detailed mechanism of NEP nucleocytoplasmic trafficking remains incompletely understood. Here, we investigated the subcellular localization of NEP from two strains of H1N1 influenza A virus and found that 2009 swine-origin H1N1 influenza A virus A/California/04/2009 (CA04) NEP displayed a distinct cellular distribution pattern, forming unique nuclear aggregates, compared to A/WSN/33 (H1N1) (WSN) NEP. Characterization of the nucleocytoplasmic transport pathways of these two NEPs showed that they both enter the nucleus by passive diffusion but are exported through the nuclear export receptor CRM1-mediated pathway with different efficiencies. The two identified nuclear export signals (NESs) on the two NEPs functioned similarly despite differences in their amino acid sequences. Using a two-hybrid assay, we confirmed that the CA04 NEP interacts less efficiently with CRM1 and that a threonine residue at position 48 is responsible for the nuclear aggregation. The present study revealed the dissimilarity in subcellular NEP transport processes between the 2009 pandemic (H1N1) influenza A virus CA04 and the laboratory-adapted H1N1 virus WSN and uncovered the mechanism responsible for this difference.
IMPORTANCE Because the efficiency of the nucleocytoplasmic transport of viral components is often correlated with the viral RNA polymerase activity, propagation, and host range of influenza viruses, the present study investigated the subcellular localization of NEP from two strains of H1N1 influenza virus. We found that the NEPs of both A/California/04/2009 (H1N1) (CA04) and A/WSN/33 (H1N1) (WSN) enter the nucleus by passive diffusion but are exported with different efficiencies, which were caused by weaker binding activity between the CA04 NEP and CRM1. The results of the present study revealed characteristics of the nuclear import and export pathways of NEP and the mechanism responsible for the differences in the cellular distribution of NEP between two H1N1 strains.
Cholesterol 25-hydroxylase (CH25H) as an interferon-stimulated gene (ISG) has recently been shown to exert broad antiviral activity through the production of 25-hydroxycholesterol (25HC), which is believed to inhibit the virus-cell membrane fusion during viral entry. However, little is known about the function of CH25H on HCV infection and replication and whether antiviral function of CH25H is exclusively mediated by 25HC. In the present study, we have found that although 25HC produced by CH25H can inhibit HCV replication, CH25H mutants lacking the hydroxylase activity still carry the antiviral activity against HCV but not other viruses such as MHV-68. Further studies have revealed that CH25H can interact with the NS5A protein of HCV and inhibit its dimer formation, which is essential for HCV replication. Thus, our work has uncovered a novel mechanism by which CH25H restricts HCV replication, suggesting that CH25H inhibits viral infection through both 25HC-dependent and independent events.
Sugarcane smut can cause losses in cane yield and sugar content that range from 30% to total crop failure. Losses tend to increase with the passage of years. Sporisorium scitamineum is the fungus that causes sugarcane smut. This fungus has the potential to infect all sugarcane species unless a species is resistant to biotrophic fungal pathogens. However, it remains unclear how the fungus breaks through the cell walls of sugarcane and causes the formation of black or gray whip-like structures on the sugarcane plants.
Here, we report the first high-quality genome sequence of S. scitamineum assembled de novo with a contig N50 of 41 kb, a scaffold N50 of 884 kb and genome size 19.8 Mb, containing an estimated 6,636 genes. This phytopathogen can utilize a wide range of carbon and nitrogen sources. A reduced set of genes encoding plant cell wall hydrolytic enzymes leads to its biotrophic lifestyle, in which damage to the host should be minimized. As a bipolar mating fungus, a and b loci are linked and the mating-type locus segregates as a single locus. The S. scitamineum genome has only 6 G protein-coupled receptors (GPCRs) grouped into five classes, which are responsible for transducing extracellular signals into intracellular responses, however, the genome is without any PTH11-like GPCR. There are 192 virulence associated genes in the genome of S. scitamineum, among which 31 expressed in all the stages, which mainly encode for energy metabolism and redox of short-chain compound related enzymes. Sixty-eight candidates for secreted effector proteins (CSEPs) were found in the genome of S. scitamineum, and 32 of them expressed in the different stages of sugarcane infection, which are probably involved in infection and/or triggering defense responses. There are two non-ribosomal peptide synthetase (NRPS) gene clusters that are involved in the generation of ferrichrome and ferrichrome A, while the terpenes gene cluster is composed of three unknown function genes and seven biosynthesis related genes.
As a destructive pathogen to sugar industry, the S. scitamineum genome will facilitate future research on the genomic basis and the pathogenic mechanisms of sugarcane smut.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-996) contains supplementary material, which is available to authorized users.
Sporisorium scitamineum, Sugarcane smut; Pathogenic mechanisms, G-protein coupled receptors, Carbohydrate degrading enzymes, Biotrophic properties, Candidates for secreted effector proteins, Secondary metabolic pathways
To investigate the vehicle induced air pollution situations both inside and outside the tunnel, the field measurement of the pollutants concentrations and its diurnal variations was performed inside and outside the Xiangyin tunnel in Shanghai from 13:00 on April 24th to 13:00 on April 25th, 2013. The highest hourly average concentrations of pollutants were quantified that CO, NO, NO2 and NOX inside the tunnel were 13.223 mg/m3, 1.829 mg/m3, 0.291 mg/m3 and 3.029 mg/m3, respectively, while the lowest ones were 3.086 mg/m3, 0.344 mg/m3, 0.080 mg/m3 and 0.619 mg/m3. Moreover, the concentrations of pollutants were higher during the daytime, and lower at night, which is relevant to the traffic conditions inside the tunnel. Pollutants concentrations inside the tunnel were much higher than those outside the tunnel. Then in a case of slow wind, the effect of wind is much smaller than the impact of pollution sources. Additionally, the PM2.5 concentrations climbed to the peak sharply (468.45 µg/m3) during the morning rush hours. The concentrations of organic carbon (OC) and elemental carbon (EC) in PM2.5 inside the tunnel were 37.09–99.06 µg/m3 and 22.69–137.99 µg/m3, respectively. Besides, the OC/EC ratio ranged from 0.72 to 2.19 with an average value of 1.34. Compared with the results of other tunnel experiments in Guangzhou and Shenzhen, China, it could be inferred that the proportion of HDVs through the Xiangyin tunnel is relatively lower.
The effects of natural variability, especially El Niño-Southern Oscillation (ENSO) effects, have been the focus of several recent studies on the change of drought patterns with climate change. The interannual relationship between ENSO and the global climate is not stationary and can be modulated by the Pacific Decadal Oscillation (PDO). However, the global land distribution of the dry–wet changes associated with the combination of ENSO and the PDO remains unclear. In the present study, this is investigated using a revised Palmer Drought Severity Index dataset (sc_PDSI_pm). We find that the effect of ENSO on dry–wet changes varies with the PDO phase. When in phase with the PDO, ENSO-induced dry–wet changes are magnified with respect to the canonical pattern. When out of phase, these dry–wet variations weaken or even disappear. This remarkable contrast in ENSO's influence between the two phases of the PDO highlights exciting new avenues for obtaining improved global climate predictions. In recent decades, the PDO has turned negative with more La Niña events, implying more rain and flooding over land. La Niña-induced wet areas become wetter and the dry areas become drier and smaller due to the effects of the cold PDO phase.
Ocean internal-wave phenomena occur with the variation in seawater vertical temperature, and most internal-wave detections are dependent on the measurement of seawater vertical temperature. A seawater temperature sensor based on a microfiber knot resonator (MKR) is designed theoretically and demonstrated experimentally in this paper. Especially, the dependences of sensing sensitivity on fiber diameter and probing wavelength are studied. Calculated results show that sensing sensitivity increases with the increasing microfiber diameter with the range of 2.30–3.91 μm and increases with the increasing probing wavelength, which reach good agreement with results obtained by experiments. By choosing the appropriate parameters, the maximum sensitivity measured can reach to be 22.81 pm/°C. The seawater temperature sensor demonstrated here shows advantages of small size, high sensitivity, easy fabrication, and easy integration with fiber systems, which may offer a new optical method to detect temperature of seawater or ocean internal-wave phenomenon and offer valuable reference for assembling micro sensors used for other parameters related to seawater, such as salinity, refractive index, concentration of NO3− and so on.
microfiber; knot resonator; seawater temperature; sensing; ocean internal-wave
Fibroblast growth factor receptor (FGFR) gene amplification has been reported in different types of cancer. We performed an up-to-date meta-analysis to further characterize the prognostic value of FGFR gene amplification in patients with cancer.
A search of several databases, including MEDLINE (PubMed), EMBASE, Web of Science, and China National Knowledge Infrastructure, was conducted to identify studies examining the association between FGFR gene amplification and cancer. A total of 24 studies met the inclusion criteria, and overall incidence rates, hazard risk (HR), overall survival, disease-free survival, and 95% confidence intervals (CIs) were calculated employing fixed- or random-effects models depending on the heterogeneity of the included studies.
In the meta-analysis of 24 studies, the prevalence of FGFR gene amplification was FGFR1: 0.11 (95% CI: 0.08–0.13) and FGFR2: 0.04 (95% CI: 0.02–0.06). Overall survival was significantly worse among patients with FGFR gene amplification: FGFR1 [HR 1.57 (95% CI: 1.23–1.99); p = 0.0002] and FGFR2 [HR 2.27 (95% CI: 1.73–3.00); p<0.00001].
Current evidence supports the conclusion that the outcomes of patients with FGFR gene amplified cancers is worse than for those with non-FGFR gene amplified cancers.
We present a simple quality assessment index for stereoscopic images based on 3D gradient magnitude. To be more specific, we construct 3D volume from the stereoscopic images across different disparity spaces and calculate pointwise 3D gradient magnitude similarity (3D-GMS) along three horizontal, vertical, and viewpoint directions. Then, the quality score is obtained by averaging the 3D-GMS scores of all points in the 3D volume. Experimental results on four publicly available 3D image quality assessment databases demonstrate that, in comparison with the most related existing methods, the devised algorithm achieves high consistency alignment with subjective assessment.
Rabex-5 and Rabaptin-5 function together to activate Rab5 and further promote early endosomal fusion in endocytosis. The Rabex-5 GEF activity is autoinhibited by the Rabex-5 CC domain (Rabex-5CC) and activated by the Rabaptin-5 C2-1 domain (Rabaptin-5C21) with yet unknown mechanism. We report here the crystal structures of Rabex-5 in complex with the dimeric Rabaptin-5C21 (Rabaptin-5C212) and in complex with Rabaptin-5C212 and Rab5, along with biophysical and biochemical analyses. We show that Rabex-5CC assumes an amphipathic α-helix which binds weakly to the substrate-binding site of the GEF domain, leading to weak autoinhibition of the GEF activity. Binding of Rabaptin-5C21 to Rabex-5 displaces Rabex-5CC to yield a largely exposed substrate-binding site, leading to release of the GEF activity. In the ternary complex the substrate-binding site of Rabex-5 is completely exposed to bind and activate Rab5. Our results reveal the molecular mechanism for the regulation of the Rabex-5 GEF activity.
Cells need to allow various molecules to pass through the plasma membrane on their surface. Some molecules have to enter the cell, whereas others have to leave. Cells rely on a process called endocytosis to move large molecules into the cell. This involves part of the membrane engulfing the molecule to form a ‘bubble’ around it. This bubble, which is called an endosome, then moves the molecule to final destination inside the cell.
A protein called Rab5 controls how a new endosome is produced. However, before this can happen, various other molecules—including two proteins called Rabex-5 and Rabaptin-5—must activate the Rab5 protein. Exactly how these three proteins interact with each other was unknown.
Zhang et al. used X-ray crystallography to examine the structures of the complexes formed when Rabex-5 and Rabaptin-5 bind to each other, both when Rab5 is present, and also when it is absent. Biochemical and biophysical experiments confirmed that the Rabex-5/Rabaptin-5 complex is able to activate Rab5.
Zhang et al. also found that Rabex-5, on its own, folds so that the site that normally binds to Rab5 instead binds to a different part of Rabex-5, thus preventing endocytosis. However, when Rabaptin-5 forms a complex with Rabex-5, the Rab5 binding site is freed up.
The Rabex-5/Rabaptin-5 complex can switch between a V shape and a linear structure. Binding to Rab5 stabilizes the linear form of the complex, which then helps activate Rab5, and subsequently the activated Rab5 can interact with other downstream molecules, triggering endocytosis.
crystal structure; Rab5; rabex-5; Rabaptin-5; GEF activity; molecular mechanism; E. coli; human
Chitinases (EC 22.214.171.124), expressed during the plant-pathogen interaction, are associated with plant defense against pathogens. In the present study, a positive correlation between chitinase activity and sugarcane smut resistance was found. ScChi (GenBank accession no. KF664180), a Class III chitinase gene, encoded a 31.37 kDa polypeptide, was cloned and identified. Subcellular localization revealed ScChi targeting to the nucleus, cytoplasm and the plasma membrane. Real-time quantitative PCR (RT-qPCR) results showed that ScChi was highly expressed in leaf and stem epidermal tissues. The ScChi transcript was both higher and maintained longer in the resistance cultivar during challenge with Sporisorium scitamineum. The ScChi also showed an obvious induction of transcription after treatment with SA (salicylic acid), H2O2, MeJA (methyl jasmonate), ABA (abscisic acid), NaCl, CuCl2, PEG (polyethylene glycol) and low temperature (4 °C). The expression levels of ScChi and six immunity associated marker genes were upregulated by the transient overexpression of ScChi. Besides, histochemical assay of Nicotiana benthamiana leaves overexpressing pCAMBIA 1301-ScChi exhibited deep DAB (3,3′-diaminobenzidinesolution) staining color and high conductivity, indicating the high level of H2O2 accumulation. These results suggest a close relationship between the expression of ScChi and plant immunity. In conclusion, the positive responses of ScChi to the biotic and abiotic stimuli reveal that this gene is a stress-related gene of sugarcane.
chitinase; Saccharum officinarum; Sporisorium scitamineum; subcellular localization; gene expression; abiotic stress
Angelica sinensis has antioxidative and neuroprotective effects. In the present study, we aimed to determine the neuroprotective effect of polysaccharides isolated from Angelica sinensis. In a preliminary experiment, Angelica sinensis polysaccharides not only protected PC12 neuronal cells from H2O2-induced cytotoxicity, but also reduced apoptosis and intracellular reactive oxygen species levels, and increased the mitochondrial membrane potential induced by H2O2 treatment. In a rat model of local cerebral ischemia, we further demonstrated that Angelica sinensis polysaccharides enhanced the antioxidant activity in cerebral cortical neurons, increased the number of microvessels, and improved blood flow after ischemia. Our findings highlight the protective role of polysaccharides isolated from Angelica sinensis against nerve cell injury and impairment caused by oxidative stress.
nerve regeneration; cerebral ischemia; Angelica sinensis; polysaccharides; antioxidation; reactive oxygen species; mitochondrial membrane potential; apoptosis; microvessels; NSFC grant; neural regeneration
This study was conducted to evaluate the application value of optimized treatment with radiofrequency (RF) thermotherapy and immunotherapy combined with CyberKnife for advanced high-risk tumors. The database of 1,013 patients with 2,136 tumor lesions and 1,237 target areas who underwent treatment with CyberKnife between November, 2010 and November, 2012, was retrospectively reviewed. We randomly assigned 505 eligible patients (observation group) to RF thermotherapy and adoptive immunotherapy with cytokine-induced killer cells and the remaining 508 patients (control group) to no adjuvant treatment. The patients in the two groups were recorded on efficacy assessment according to imageological examination, World Health Organization criteria, Karnofsky performance status, or radioimmunoassay (RIA) detection. The effective rate of the observation group was 75.05%, whereas that of the control group was 58.06% (P<0.05). The results revealed that CyberKnife combined with hyperthermia and biological therapy are highly effective in improving the local tumor control rate. Further analysis of the Karnofsky score and RIA detection confirmed that this type of combination therapy significantly improved the quality of life. The optimized treatment of RF thermotherapy and immunotherapy combined with CyberKnife may act synergistically in eliminating tumor cells, confirming the efficacy of this type of treatment for patients with advanced malignant tumors.
optimized treatment; CyberKnife; hyperthermia; immunotherapy; advanced high-risk tumor
In the current study, we showed that the combination of mammalian target of rapamycin (mTOR) inhibitor RAD001 (everolimus) and Akt inhibitor MK-2206 exerted synergistic cytotoxic effects against low-phosphatase and tensin homolog (PTEN) gastric cancer cells (HGC-27 and SNU-601 lines). In HGC-27 cells, RAD001 and MK-2206 synergistically induced G1/S cell cycle arrest, growth inhibition, cell death but not apoptosis. RAD001 and MK-2206 synergistically induced light chain 3B (LC3B) and beclin-1 expression, two important autophagy indicators. Meanwhile, the autophagy inhibitor 3-methyladenine (3-MA) and chloroquine inhibited the cytotoxic effects by RAD001 and MK-2206, suggesting that autophagic, but not apoptotic cell death was important for the cytotoxic effects by the co-administration. We observed that the combination of RAD001 and MK-2206 exerted enhanced effects on Akt/mTOR inhibition, cyclin D1 down-regulation and ERK/MAPK(extracellular signal-regulated kinase/mitogen-activated protein kinases) activation. Intriguingly, MEK/ERK inhibitors PD98059 and U0126 suppressed RAD001 plus MK-2206-induced beclin-1 expression, autophagy induction and cytotoxicity in HGC-27 cells. In conclusion, these results suggested that the synergistic anti-gastric cancer cells ability by RAD001 and MK-2206 involves ERK-dependent autophagic cell death pathway.
Catalase is an iron porphyrin enzyme, which serves as an efficient scavenger of reactive oxygen species (ROS) to avoid oxidative damage. In sugarcane, the enzymatic activity of catalase in a variety (Yacheng05–179) resistant to the smut pathogen Sporisorium scitamineum was always higher than that of the susceptible variety (Liucheng03–182), suggesting that catalase activity may have a positive correlation with smut resistance in sugarcane. To understand the function of catalase at the molecular level, a cDNA sequence of ScCAT1 (GenBank Accession No. KF664183), was isolated from sugarcane infected by S. scitamineum. ScCAT1 was predicted to encode 492 amino acid residues, and its deduced amino acid sequence shared a high degree of homology with other plant catalases. Enhanced growth of ScCAT1 in recombinant Escherichia coli Rosetta cells under the stresses of CuCl2, CdCl2 and NaCl indicated its high tolerance. Q-PCR results showed that ScCAT1 was expressed at relatively high levels in the bud, whereas expression was moderate in stem epidermis and stem pith. Different kinds of stresses, including S. scitamineum challenge, plant hormones (SA, MeJA and ABA) treatments, oxidative (H2O2) stress, heavy metal (CuCl2) and hyper-osmotic (PEG and NaCl) stresses, triggered a significant induction of ScCAT1. The ScCAT1 protein appeared to localize in plasma membrane and cytoplasm. Furthermore, histochemical assays using DAB and trypan blue staining, as well as conductivity measurement, indicated that ScCAT1 may confer the sugarcane immunity. In conclusion, the positive response of ScCAT1 to biotic and abiotic stresses suggests that ScCAT1 is involved in protection of sugarcane against reactive oxidant-related environmental stimuli.
Yuanhu Zhitong Tablet (YZT) is an example of a typical and relatively simple clinical herb formula that is widely used in clinics. It is generally believed that YZT play a therapeutical effect in vivo by the synergism of multiple constituents. Thus, it is necessary to build the relationship between the absorbed fingerprints and bioactivity so as to ensure the quality, safety and efficacy. In this study, a new combinative method, an intestinal absorption test coupled with a vasorelaxation bioactivity experiment in vitro, was a simple, sensitive, and feasible technique to study on the absorbed fingerprint-efficacy of YZT based on chemical analysis, vasorelaxation evaluation and data mining. As part of this method, an everted intestinal sac method was performed to determine the intestinal absorption of YZT solutions. YZT were dissolved in solution (n = 12), and the portion of the solution that was absorbed into intestinal sacs was analyzed using rapid-resolution liquid chromatography coupled with quadruple time-of-flight mass spectrometry (RRLC-Q-TOF/MS). Semi-quantitative analysis indicated the presence of 34 compounds. The effect of the intestinally absorbed solution on vasorelaxation of rat aortic rings with endothelium attached was then evaluated in vitro. The results showed that samples grouped by HCA from chemical profiles have similar bioactivity while samples in different groups displayed very different. Moreover, it established a relationship between the absorbed fingerprints and their bioactivity to identify important components by grey relational analysis, which could predict bioactive values based on chemical profiles and provide an evidence for the quantification of multi-constituents.
Phosphorylation of viral proteins plays important roles in the influenza A virus (IAV) life cycle. By using mass spectrometry, we identified tyrosine 132 (Y132) as a phosphorylation site of the matrix protein (M1) of the influenza virus A/WSN/1933(H1N1). Phosphorylation at this site is essential to the process of virus replication by controlling the nuclear import of M1. We further demonstrated that the phosphorylated tyrosine is crucial for the binding of M1 to the nuclear import factor importin-α1, since any substitutions at this site severely reduce this protein-protein interaction and damage the importin-α1-mediated nuclear import of M1. Additionally, the tyrosine phosphorylation which leads to the nuclear import of M1 is blocked by a Janus kinase inhibitor. The present study reveals a pivotal role of this tyrosine phosphorylation in the intracellular transportation of M1, which controls the process of viral replication.
In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.
Sporisorium scitamineum is a fungal smut pathogen epidemic in sugarcane producing areas. Early detection and proper identification of the smut are an essential requirement in its management practice. In this study, we developed a TaqMan real-time PCR assay using specific primers (bEQ-F/bEQ-R) and a TaqMan probe (bEQ-P) which were designed based on the bE (b East mating type) gene (Genbank Accession no. U61290.1). This method was more sensitive (a detection limit of 10 ag pbE DNA and 0.8 ng sugarcane genomic DNA) than that of conventional PCR (10 fg and 100 ng, resp.). Reliability was demonstrated through the positive detection of samples collected from artificially inoculated sugarcane plantlets (FN40). This assay was capable of detecting the smut pathogen at the initial stage (12 h) of infection and suitable for inspection of sugarcane pathogen-free seed cane and seedlings. Furthermore, quantification of pathogen was verified in pathogen-challenged buds in different sugarcane genotypes, which suggested its feasibility for evaluation of smut resistance in different sugarcane genotypes. Taken together, this novel assay can be used as a diagnostic tool for sensitive, accurate, fast, and quantitative detection of the smut pathogen especially for asymptomatic seed cane or plants and evaluation of smut resistance of sugarcane genotypes.
The molecular pathogenesis of renal cell carcinoma (RCC) is poorly
understood. Whole-genome and exome sequencing followed by innovative tumorgraft
analyses (to accurately determine mutant allele ratios) identified several
putative two-hit tumor suppressor genes including BAP1. BAP1, a
nuclear deubiquitinase, is inactivated in 15% of clear-cell RCCs. BAP1
cofractionates with and binds to HCF-1 in tumorgrafts. Mutations disrupting the
HCF-1 binding motif impair BAP1-mediated suppression of cell proliferation, but
not H2AK119ub1 deubiquitination. BAP1 loss sensitizes RCC cells in
vitro to genotoxic stress. Interestingly, BAP1 and
PBRM1 mutations anticorrelate in tumors
(P=3×10−5), and combined loss of
BAP1 and PBRM1 in a few RCCs was associated with rhabdoid features
(q=0.0007). BAP1 and PBRM1 regulate seemingly different
gene expression programs, and BAP1 loss was associated with high tumor grade
(q=0.0005). Our results establish the foundation for an
integrated pathological and molecular genetic classification of RCC, paving the
way for subtype-specific treatments exploiting genetic vulnerabilities.
Ions and water transported across the endothelium lining the blood–brain barrier contribute to the fluid secreted into the brain and are important in maintaining appropriate volume and ionic composition of brain interstitial fluid. Changes in this secretion process may occur after stroke. The present study identifies at transcript and protein level ion transporters involved in the movement of key ions and examines how levels of certain of these alter following oxidative stress. Immunohistochemistry provides evidence for Cl−/HCO3− exchanger, AE2, and Na+, HCO3− cotransporters, NBCe1 and NBCn1, on brain microvessels. mRNA analysis by RT-PCR reveals expression of these transporters in cultured rat brain microvascular endothelial cells (both primary and immortalized GPNT cells) and also Na+/H+ exchangers, NHE1 (primary and immortalized) and NHE2 (primary cells only). Knock-down using siRNA in immortalized GPNT cells identifies AE2 as responsible for much of the Cl−/HCO3− exchange following extracellular chloride removal and NHE1 as the transporter that accounts for most of the Na+/H+ exchange following intracellular acidification. Transcript levels of both AE2 and NHE1 are increased following hypoxia/reoxygenation. Further work is now required to determine the localization of the bicarbonate transporters to luminal or abluminal membranes of the endothelial cells as well as to identify and localize additional transport mechanisms that must exist for K+ and Cl−.
Rat brain endothelial cells; Blood–brain barrier; Brain interstitial fluid; Cl−/HCO3− exchanger AE2; Na+, HCO3− cotransporters, NBCe1 and NBCn1; Na+/H+ exchangers NHE1 and NHE2
Endoplasmic reticulum stress (ERS) is one of the mechanisms of apoptotic cell death. Inhibiting the apoptosis induced by ERS may be a novel therapeutic target in cardiovascular diseases. Icariin, a flavonoid isolated from Epimedium brevicornum Maxim, has been demonstrated to have cardiovascular protective effects, but its effects on ERS are unknown. In the present study, we focused on icariin and investigated whether it might protect the cardiac cell from apoptosis via inhibition of ERS. In H9c2 rat cardiomyoblast cells, pretreatment of icariin significantly inhibited cell apoptosis by tunicamycin, an ERS inducer. Icariin also decreased generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential and activation of caspase-3. Moreover, icariin inhibited upregulation of endoplasmic reticulum markers, GRP78, GRP94 and CHOP, elicited by tunicamycin. These results indicated that icariin could protect H9c2 cardiomyoblast cells from ERS-mitochondrial apoptosis in vitro, the mechanisms may be associated with its inhibiting of GRP78, GRP94 and CHOP and decreasing ROS generation directly. It may be a potential agent for treating cardiovascular disease.
icariin; endoplasmic reticulum stress; apoptosis; cardioprotection
Transient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction. Studies have showed that patients with TIA can have lasting cognitive functional impairment. Inherent brain activity in the resting state is spatially organized in a set of specific coherent patterns named resting state networks (RSNs), which epitomize the functional architecture of memory, language, attention, visual, auditory and somato-motor networks. Here, we aimed to detect differences in RSNs between TIA patients and healthy controls (HCs).
Twenty one TIA patients suffered an ischemic event and 21 matched HCs were enrolled in the study. All subjects were investigated using cognitive tests, psychiatric tests and functional magnetic resonance imaging (fMRI). Independent component analysis (ICA) was adopted to acquire the eight brain RSNs. Then one-sample t-tests were calculated in each group to gather the spatial maps of each RSNs, followed by second level analysis to investigate statistical differences on RSNs between twenty one TIA patients and 21 controls. Furthermore, a correlation analysis was performed to explore the relationship between functional connectivity (FC) and cognitive and psychiatric scales in TIA group.
Compared with the controls, TIA patients exhibited both decreased and increased functional connectivity in default mode network (DMN) and self-referential network (SRN), and decreased functional connectivity in dorsal attention network (DAN), central-executive network (CEN), core network (CN), somato-motor network (SMN), visual network (VN) and auditory network (AN). There was no correlation between neuropsychological scores and functional connectivity in regions of RSNs.
We observed selective impairments of RSN intrinsic FC in TIA patients, whose all eight RSNs had aberrant functional connectivity. These changes indicate that TIA is a disease with widely abnormal brain networks. Our results might put forward a novel way to look into neuro-pathophysiological mechanisms in TIA patients.