25 research outputs found

    Antagonism between abscisic acid and ethylene in Arabidopsis acts in parallel with the reciprocal regulation of their metabolism and signaling pathways

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    Although abscisic acid (ABA) and ethylene have antagonistic functions in the control of plant growth and development, including seed germination and early seedling development, it remains unknown whether a convergent point exists between these two signaling pathways or whether they operate in parallel in Arabidopsis thaliana. To elucidate this issue, four ethylene mutants, ctr1, ein2, ein3, and ein6, were crossed with aba2 (also known as gin1-3) to generate double mutants. Genetic epistasis analysis revealed that all of the resulting double mutants displayed aba2 mutant phenotypes with a small plant size and wiltiness when grown in soil or on agar plates. Further ethylene sensitivity or triple response analyses demonstrated that these double mutants also retained the ctr1 or ein mutant phenotypes, showing ethylene constitutive triple and insensitive responses, respectively. Our current data therefore demonstrate that ABA and ethylene act in parallel, at least in primary signal transduction pathways. Moreover, by microarray analysis we found that an ACC oxidase (ACO) was significantly upregulated in the aba2 mutant, whereas the 9-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3) gene in ein2 was upregulated, and both the ABSCISIC ACID INSENSITIVE1 (ABI1) and cytochromeP450, family 707, subfamily A, polypeptide 2 (CYP707A2) genes in etr1-1 were downregulated. These data further suggest that ABA and ethylene may control the hormonal biosynthesis, catabolism, or signaling of each other to enhance their antagonistic effects upon seed germination and early seedling growth

    Reversine suppresses oral squamous cell carcinoma via cell cycle arrest and concomitantly apoptosis and autophagy

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    <p>Abstract</p> <p>Background</p> <p>The effective therapies for oral cancer patients of stage III and IV are generally surgical excision and radiation combined with adjuvant chemotherapy using 5-Fu and Cisplatin. However, the five-year survival rate is still less than 30% in Taiwan. Therefore, evaluation of effective drugs for oral cancer treatment is an important issue. Many studies indicated that aurora kinases (A, B and C) were potential targets for cancer therapies. Reversine was proved to be a novel aurora kinases inhibitor with lower toxicity recently. In this study, the potentiality for reversine as an anticancer agent in oral squamous cell carcinoma (OSCC) was evaluated.</p> <p>Methods</p> <p>Effects of reversine on cell growth, cell cycle progress, apoptosis, and autophagy were evaluated mainly by cell counting, flow cytometry, immunoblot, and immunofluorescence.</p> <p>Results</p> <p>The results demonstrated that reversine significantly suppressed the proliferation of two OSCC cell lines (OC2 and OCSL) and markedly rendered cell cycle arrest at G2/M stage. Reversine also induced cell death via both caspase-dependent and -independent apoptosis. In addition, reversine could inhibit Akt/mTORC1 signaling pathway, accounting for its ability to induce autophagy.</p> <p>Conclusions</p> <p>Taken together, reversine suppresses growth of OSCC via multiple mechanisms, which may be a unique advantage for developing novel therapeutic regimens for treatment of oral cancer in the future.</p

    SEPTIN12 Genetic Variants Confer Susceptibility to Teratozoospermia

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    It is estimated that 10–15% of couples are infertile and male factors account for about half of these cases. With the advent of intracytoplasmic sperm injection (ICSI), many infertile men have been able to father offspring. However, teratozoospermia still remains a big challenge to tackle. Septins belong to a family of cytoskeletal proteins with GTPase activity and are involved in various biological processes e.g. morphogenesis, compartmentalization, apoptosis and cytokinesis. SEPTIN12, identified by c-DNA microarray analysis of infertile men, is exclusively expressed in the post meiotic male germ cells. Septin12+/+/Septin12+/− chimeric mice have multiple reproductive defects including the presence of immature sperm in the semen, and sperm with bent neck (defect of the annulus) and nuclear DNA damage. These facts make SEPTIN12 a potential sterile gene in humans. In this study, we sequenced the entire coding region of SEPTIN12 in infertile men (n = 160) and fertile controls (n = 200) and identified ten variants. Among them is the c.474 G>A variant within exon 5 that encodes part of the GTP binding domain. The variant creates a novel splice donor site that causes skipping of a portion of exon 5, resulting in a truncated protein lacking the C-terminal half of SEPTIN12. Most individuals homozygous for the c.474 A allele had teratozoospermia (abnormal sperm <14%) and their sperm showed bent tail and de-condensed nucleus with significant DNA damage. Ex vivo experiment showed truncated SEPT12 inhibits filament formation in a dose-dependent manner. This study provides the first causal link between SEPTIN12 genetic variant and male infertility with distinctive sperm pathology. Our finding also suggests vital roles of SEPT12 in sperm nuclear integrity and tail development

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Influence of chemical composition on phase transformation and optoelectronic properties of Cu-Cr-O thin films by reactive magnetron sputtering

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    Cu–Cr–O films were co-sputtered from Cu and Cr targets on fused silica substrates. Then, these films were annealed at 700 °C for 2 h under controlled Ar atmosphere. [Cu]/[Cr] ratio was increased from 0.59 to 2.02 by increasing the Cu-target power from 10 W to 52 W. When the film was prepared at Cu-target power of 10 W, a pure spinel CuCr2O4 phase was formed in the film. As the Cu-target power increased to 22 W, the phase transformed gradually from spinel CuCr2O4 to delafossite CuCrO2. Further increase of Cu-target power resulted in the appearance of an additional monoclinic CuO phase. The [Cu]/[Cr] ratio was approximately 1 at Cu-target power of 22 W, which caused the film to exhibit pure delafossite CuCrO2 phase and high crystallinity. Accordingly, optimum electrical conductivity and visible transparency were achieved for the pure CuCrO2 film prepared at Cu-target power of 22 W with a figure of merit of 1.51 × 10−8 Ω−1. The formation of the CuO and CuCr2O4 phase was confirmed to deteriorated optoelectronic properties of films

    Designing a biochip following multiplex polymerase chain reaction for the detection of Salmonella serovars Typhimurium, Enteritidis, Infantis, Hadar, and Virchow in poultry products

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    Salmonella-contaminated foods, especially poultry-derived foods (eggs, chicken meat), are the major source of salmonellosis. Not only in the European Union (EU), but also in the United States, Japan, and other countries, has salmonellosis been an issue of concern for food safety control agencies. In 2005, EU regulation 1003/2005 set a target for the control and reduction of five target Salmonella enterica serovars—S. Typhimurium, S. Enteritidis, S. Infantis, S. Hadar, and S. Virchow—in breeding flocks. Thus, a simple biochip for the rapid detection of any of these five Salmonella serovars in poultry products may be required. The objectives of this study were to design S. Virchow-specific primers and to develop a biochip for the simultaneous identification of all or any of these five Salmonella serovars in poultry and poultry products. Experimentally, we designed novel polymerase chain reaction (PCR) primers for the specific detection of S. Virchow, S. Infantis, and S. Hadar. The specificity of all these primers and two known primer sets for S. Typhimurium and S. Enteritidis was then confirmed under the same PCR conditions using 57 target strains and 112 nontarget Salmonella strains as well as 103 non-Salmonella strains. Following multiplex PCR, strains of any of these five Salmonella serovars could be detected by a chromogenic biochip deployed with DNA probes specific to these five Salmonella serovars. In comparison with the multiplex PCR methods, the biochip assay could improve the detection limit of each of the Salmonella serovars from N×103 cfu/mL to N×102 cfu/mL sample in either the pure culture or the chicken meat samples. With an 8-hour enrichment step, the detection limit could reach up to N×100 cfu/mL

    Downregulation of Methionine Cycle Genes MAT1A and GNMT Enriches Protein-Associated Translation Process and Worsens Hepatocellular Carcinoma Prognosis.

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    The major biological methyl donor, S-adenosylmethionine (adoMet) synthesis occurs mainly in the liver. Methionine adenosyltransferase 1A (MAT1A) and glycine N-methyltransferase (GNMT) are two key enzymes involved in the functional implications of that variation. We collected 42 RNA-seq data from paired hepatocellular carcinoma (HCC) and its adjacent normal liver tissue from the Cancer Genome Atlas (TCGA). There was no mutation found in MAT1A or GNMT RNA in the 42 HCC patients. The 11,799 genes were annotated in the RNA-Seq data, and their expression levels were used to investigate the phenotypes of low MAT1A and low GNMT by Gene Set Enrichment Analysis (GSEA). The REACTOME_TRANSLATION gene set was enriched and visualized in a heatmap along with corresponding differences in gene expression between low MAT1A versus high MAT1A and low GNMT versus high GNMT. We identified 43 genes of the REACTOME_TRANSLATION gene set that are powerful prognosis factors in HCC. The significantly predicted genes were referred into eukaryotic translation initiation (EIF3B, EIF3K), eukaryotic translation elongation (EEF1D), and ribosomal proteins (RPs). Cell models expressing various MAT1A and GNMT proved that simultaneous restoring the expression of MAT1A and GNMT decreased cell proliferation, invasion, as well as the REACTOME_TRANSLATION gene EEF1D, consistent with a better prognosis in human HCC. We demonstrated new findings that downregulation or defect in MAT1A and GNMT genes can enrich the protein-associated translation process that may account for poor HCC prognosis. This is the first study demonstrated that MAT1A and GNMT, the 2 key enzymes involved in methionine cycle, could attenuate the function of ribosome translation. We propose a potential novel mechanism by which the diminished GNMT and MAT1A expression may confer poor prognosis for HCC

    PRKAG3 polymorphisms associated with sporadic Wolff–Parkinson–White syndrome among a Taiwanese population

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    Background: The aim of this study was to investigate whether mutation in AMP-activated protein kinase (AMPK) subunit genes (PRKAG3-230) is associated with sporadic, isolated Wolff–Parkinson–White (WPW) syndrome. Methods: This study consisted of 87 patients with symptomatic WPW syndrome and 93 healthy controls. PRKAG3-230 genotypes were determined using real-time polymerase chain reaction assay. Genotype and allele frequencies of PRKAG3-230 between patients with WPW syndrome and healthy controls were ascertained using chi-square test or Fisher exact test when appropriate. Results: PRKAG3-230 were genotyped in 87 patients (53 men and 34 women; age=24.4±18.0 years) with WPW syndrome and 93 healthy controls (57 men and 36 women; age=16.8±4.2 years). There were no significant differences between the two groups in terms of age and sex. The patients with CG and CG+CC genotypes had a significantly increased risk of WPW syndrome compared with those with GG genotype [odds ratio (OR)=1.99, 95% confidence interval (CI)=1.01–3.89, p=0.045; OR=1.99, 95% CI=1.04–3.78, p=0.037, respectively]. The allelic types were not associated with the risk of WPW syndrome. The patients with manifest type with CG and CG+CC genotypes had a significantly increased risk of WPW syndrome compared with those with GG genotype (OR=2.86, 95% CI=1.16–7.05, p=0.022; OR=2.84, 95% CI=1.19–6.80, p=0.019, respectively). The patients with right-side accessory pathways with CG and CG+CC genotypes had a significantly increased risk of WPW syndrome compared with those with GG genotype (OR=3.07, 95% CI=1.25–7.51, p=0.014; OR=2.84, 95% CI=1.19–6.80, p=0.019, respectively). The allelic types were not associated with the risk of WPW types and locations. Conclusion: This study shows that PRKAG3-230 may be associated with sporadic WPW syndrome among a Taiwanese population. Further studies are warranted to elucidate the role of mutations in AMPK subunit genes other than PRKAG3-230 in sporadic WPW syndrome

    Identification of novel variants in the SEPTIN12 gene.

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    <p>Genomic structure of the <i>SEPTIN12</i> gene and positions of the ten SNPs. Open bars indicate exons. The ATG start site is located at exon 2. Exon 3 to exon 8 encodes the GTP -Binding Domain of SETIN12. (B.–C.) Electropherograms showing DNA sequences. Lower panels show the variant (c.474C→A, Left; c.494T→A, Right) sequences, whereas the upper panels show the wild-type (normal) sequences. Red stars indicate locations of the variants.</p
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