259 research outputs found

    The Arabidopsis mutant, fy-1, has an ABA-insensitive germination phenotype

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    Arabidopsis FY, a homologue of the yeast RNA 3' processing factor Pfs2p, regulates the autonomous floral transition pathway through its interaction with FCA, an RNA binding protein. It is demonstrated here that FY also influences seed dormancy. Freshly-harvested seed of the Arabidopsis fy-1 mutant germinated readily in the absence of stratification or after-ripening. Furthermore, the fy-1 mutant showed less ABA sensitivity compared with the wild type, Ler, under identical conditions. Freshly-harvested seed of fy-1 had significantly higher ABA levels than Ler, even though Ler was dormant and fy-1 germinated readily. The PPLPP domains of FY, which are required for flowering control, were not essential for the ABA-influenced repression of germination. FLC expression analysis in seeds of different genotypes suggested that the effect of FY on dormancy may not be elicited through FLC. No significant differences in CYP707A1, CYP707A2, NCED9, ABI3, and ABI4 were observed between freshly-harvested Ler and fy-1 imbibed for 48 h. GA3ox1 and GA3ox2 rapidly increased over the 48 h imbibition period for fy-1, with no significant increases in these transcripts for Ler. ABI5 levels were significantly lower in fy-1 over the 48 h imbibition period. The results suggest that FY is involved in the development of dormancy and ABA sensitivity in Arabidopsis seed

    Contribution of common and rare variants to bipolar disorder susceptibility in extended pedigrees from population isolates.

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    Current evidence from case/control studies indicates that genetic risk for psychiatric disorders derives primarily from numerous common variants, each with a small phenotypic impact. The literature describing apparent segregation of bipolar disorder (BP) in numerous multigenerational pedigrees suggests that, in such families, large-effect inherited variants might play a greater role. To identify roles of rare and common variants on BP, we conducted genetic analyses in 26 Colombia and Costa Rica pedigrees ascertained for bipolar disorder 1 (BP1), the most severe and heritable form of BP. In these pedigrees, we performed microarray SNP genotyping of 838 individuals and high-coverage whole-genome sequencing of 449 individuals. We compared polygenic risk scores (PRS), estimated using the latest BP1 genome-wide association study (GWAS) summary statistics, between BP1 individuals and related controls. We also evaluated whether BP1 individuals had a higher burden of rare deleterious single-nucleotide variants (SNVs) and rare copy number variants (CNVs) in a set of genes related to BP1. We found that compared with unaffected relatives, BP1 individuals had higher PRS estimated from BP1 GWAS statistics (P = 0.001 ~ 0.007) and displayed modest increase in burdens of rare deleterious SNVs (P = 0.047) and rare CNVs (P = 0.002 ~ 0.033) in genes related to BP1. We did not observe rare variants segregating in the pedigrees. These results suggest that small-to-moderate effect rare and common variants are more likely to contribute to BP1 risk in these extended pedigrees than a few large-effect rare variants

    A metabolite-derived protein modification integrates glycolysis with KEAP1-NRF2 signalling.

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    Mechanisms that integrate the metabolic state of a cell with regulatory pathways are necessary to maintain cellular homeostasis. Endogenous, intrinsically reactive metabolites can form functional, covalent modifications on proteins without the aid of enzymes1,2, and regulate cellular functions such as metabolism3-5 and transcription6. An important 'sensor' protein that captures specific metabolic information and transforms it into an appropriate response is KEAP1, which contains reactive cysteine residues that collectively act as an electrophile sensor tuned to respond to reactive species resulting from endogenous and xenobiotic molecules. Covalent modification of KEAP1 results in reduced ubiquitination and the accumulation of NRF27,8, which then initiates the transcription of cytoprotective genes at antioxidant-response element loci. Here we identify a small-molecule inhibitor of the glycolytic enzyme PGK1, and reveal a direct link between glycolysis and NRF2 signalling. Inhibition of PGK1 results in accumulation of the reactive metabolite methylglyoxal, which selectively modifies KEAP1 to form a methylimidazole crosslink between proximal cysteine and arginine residues (MICA). This posttranslational modification results in the dimerization of KEAP1, the accumulation of NRF2 and activation of the NRF2 transcriptional program. These results demonstrate the existence of direct inter-pathway communication between glycolysis and the KEAP1-NRF2 transcriptional axis, provide insight into the metabolic regulation of the cellular stress response, and suggest a therapeutic strategy for controlling the cytoprotective antioxidant response in several human diseases

    Distinct GSDMB protein isoforms and protease cleavage processes differentially control pyroptotic cell death and mitochondrial damage in cancer cells

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    Gasdermin (GSDM)-mediated pyroptosis is functionally involved in multiple diseases, but Gasdermin-B (GSDMB) exhibit cell death-dependent and independent activities in several pathologies including cancer. When the GSDMB pore-forming N-terminal domain is released by Granzyme-A cleavage, it provokes cancer cell death, but uncleaved GSDMB promotes multiple pro-tumoral effects (invasion, metastasis, and drug resistance). To uncover the mechanisms of GSDMB pyroptosis, here we determined the GSDMB regions essential for cell death and described for the first time a differential role of the four translated GSDMB isoforms (GSDMB1-4, that differ in the alternative usage of exons 6-7) in this process. Accordingly, we here prove that exon 6 translation is essential for GSDMB mediated pyroptosis, and therefore, GSDMB isoforms lacking this exon (GSDMB1-2) cannot provoke cancer cell death. Consistently, in breast carcinomas the expression of GSDMB2, and not exon 6-containing variants (GSDMB3-4), associates with unfavourable clinical-pathological parameters. Mechanistically, we show that GSDMB N-terminal constructs containing exon-6 provoke cell membrane lysis and a concomitant mitochondrial damage. Moreover, we have identified specific residues within exon 6 and other regions of the N-terminal domain that are important for GSDMB-triggered cell death as well as for mitochondrial impairment. Additionally, we demonstrated that GSDMB cleavage by specific proteases (Granzyme-A, Neutrophil Elastase and caspases) have different effects on pyroptosis regulation. Thus, immunocyte-derived Granzyme-A can cleave all GSDMB isoforms, but in only those containing exon 6, this processing results in pyroptosis induction. By contrast, the cleavage of GSDMB isoforms by Neutrophil Elastase or caspases produces short N-terminal fragments with no cytotoxic activity, thus suggesting that these proteases act as inhibitory mechanisms of pyroptosis. Summarizing, our results have important implications for understanding the complex roles of GSDMB isoforms in cancer or other pathologies and for the future design of GSDMB-targeted therapies.This study has been supported by the Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (MICINN-AEI, PID2019-104644RB-I00, PDC2022-133252-I00) -GMB-, (PID2021-126625OB-I00-MCIN/AEI/10.13039/501100011033 FEDER, EU.2022- and DTS20-00024 -ISCIII-) -PGP-, the Instituto de Salud Carlos III (CIBERONC, CB16/12/00295 -GMB- and CB16/12/00241 -JA-, and AC21_2/00020 ERA PerMed ERA-NET, PMP22/00054 Immune4ALL Personalized Medicine -GMB-, cofunded by NextGenerationEU), I “Semilla” CIBERONC-GEICAM Grant -GMB- and the AECC Scientific Foundation (FCAECC PROYE19036MOR and GCTRA18014MATI -GMB-), the National Institutes of Health (NIH, USA) (R01-DK123475) -J-KK- and it has been also supported by a startup fund to -J-KK- from the Ohio State University, the College of Medicine, Department of Surgery. DS contract is funded by CIBERONC partly supported by FEDER funds. SO is funded by the FCAECC (POSTD20028OLTR), SC is funded by the MICINN-AEI PRE2020-095658

    The Democratic Biopolitics of PrEP

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    PrEP (Pre-Exposure Prophylaxis) is a relatively new drug-based HIV prevention technique and an important means to lower the HIV risk of gay men who are especially vulnerable to HIV. From the perspective of biopolitics, PrEP inscribes itself in a larger trend of medicalization and the rise of pharmapower. This article reconstructs and evaluates contemporary literature on biopolitical theory as it applies to PrEP, by bringing it in a dialogue with a mapping of the political debate on PrEP. As PrEP changes sexual norms and subjectification, for example condom use and its meaning for gay subjectivity, it is highly contested. The article shows that the debate on PrEP can be best described with the concepts ‘sexual-somatic ethics’ and ‘democratic biopolitics’, which I develop based on the biopolitical approach of Nikolas Rose and Paul Rabinow. In contrast, interpretations of PrEP which are following governmentality studies or Italian Theory amount to either farfetched or trivial positions on PrEP, when seen in light of the political debate. Furthermore, the article is a contribution to the scholarship on gay subjectivity, highlighting how homophobia and homonormativity haunts gay sex even in liberal environments, and how PrEP can serve as an entry point for the destigmatization of gay sexuality and transformation of gay subjectivity. ‘Biopolitical democratization’ entails making explicit how medical technology and health care relates to sexual subjectification and ethics, to strengthen the voice of (potential) PrEP users in health politics, and to renegotiate the profit and power of Big Pharma

    Catalytic conversion of methylated aromatics over wood-derived chars – the role of reforming agents and the effect of methyl groups

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    Toluene steam reforming was performed over three wood-derived chars and compared with a previously-reported pyrolytic conversion study. The heterogeneous mechanism of toluene decomposition was not directly affected by the introduction of steam, but it caused gasification of char and toluene-derived coke, which prolonged the initial high conversion efficiency. Conversely, when oxygen was used as a substitute for steam, a direct ring-opening reaction of toluene was observed, rather than solid carbon combustion. A comparison of benzene, toluene, and p-xylene conversion revealed that the presence of a methyl group on the aromatic ring enhanced its decomposition, regardless of the catalyst’s activity. However, a second methyl group did not further improve the conversion and only served to increase the intensity of secondary recombination reactions

    FUS/TLS Is a Co-Activator of Androgen Receptor in Prostate Cancer Cells

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    Androgen receptor (AR) is a member of the nuclear receptor family of transcription factors. Upon binding to androgens, AR becomes transcriptionally active to regulate the expression of target genes that harbor androgen response elements (AREs) in their promoters and/or enhancers. AR is essential for the growth and survival of prostate cancer cells and is therefore a target for current and next-generation therapeutic modalities against prostate cancer. Pathophysiologically relevant protein-protein interaction networks involving AR are, however, poorly understood. In this study, we identified the protein FUsed/Translocated in LipoSarcoma (FUS/TLS) as an AR-interacting protein by co-immunoprecipitation of endogenous proteins in LNCaP human prostate cancer cells. The hormonal response of FUS expression in LNCaP cells was shown to resemble that of other AR co-activators. FUS displayed a strong intrinsic transactivation capacity in prostate cancer cells when tethered to basal promoters using the GAL4 system. Chromatin immunoprecipitation experiments showed that FUS was recruited to ARE III of the enhancer region of the PSA gene. Data from ectopic overexpression and “knock-down” approaches demonstrated that AR transcriptional activity was enhanced by FUS. Depletion of FUS reduced androgen-dependent proliferation of LNCaP cells. Thus, FUS is a novel co-activator of AR in prostate cancer cells

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Efficacy and Safety of Ixekizumab in the Treatment of Radiographic Axial Spondyloarthritis:Sixteen-Week Results From a Phase III Randomized, Double-Blind, Placebo-Controlled Trial in Patients With Prior Inadequate Response to or Intolerance of Tumor Necrosis Factor Inhibitors

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    Objective: To investigate the efficacy and safety of ixekizumab in patients with active radiographic axial spondyloarthritis (SpA) and prior inadequate response to or intolerance of 1 or 2 tumor necrosis factor inhibitors (TNFi). Methods: In this phase III randomized, double-blind, placebo-controlled trial, adult patients with an inadequate response to or intolerance of 1 or 2 TNFi and an established diagnosis of axial SpA (according to the Assessment of SpondyloArthritis international Society [ASAS] criteria for radiographic axial SpA, with radiographic sacroiliitis defined according to the modified New York criteria and ≥1 feature of SpA) were recruited and randomized 1:1:1 to receive placebo or 80-mg subcutaneous ixekizumab every 2 weeks (IXEQ2W) or 4 weeks (IXEQ4W), with an 80-mg or 160-mg starting dose. The primary end point was 40% improvement in disease activity according to the ASAS criteria (ASAS40) at week 16. Secondary outcomes and safety were also assessed. Results: A total of 316 patients were randomized to receive placebo (n = 104), IXEQ2W (n = 98), or IXEQ4W (n = 114). At week 16, significantly higher proportions of IXEQ2W patients (n = 30 [30.6%]; P = 0.003) or IXEQ4W patients (n = 29 [25.4%]; P = 0.017) had achieved an ASAS40 response versus the placebo group (n = 13 [12.5%]), with statistically significant differences reported as early as week 1 with ixekizumab treatment. Statistically significant improvements in disease activity, function, quality of life, and spinal magnetic resonance imaging–evident inflammation were observed after 16 weeks of ixekizumab treatment versus placebo. Treatment-emergent adverse events (AEs) with ixekizumab treatment were more frequent than with placebo. Serious AEs were similar across treatment arms. One death was reported (IXEQ2W group). Conclusion: Ixekizumab treatment for 16 weeks in patients with active radiographic axial SpA and previous inadequate response to or intolerance of 1 or 2 TNFi yields rapid and significant improvements in the signs and symptoms of radiographic axial SpA versus placebo

    The importance of inherent inorganics and the surface area of wood char for its gasification reactivity and catalytic activity towards toluene conversion

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    Gasification char is an effective catalyst for tar reforming because of the abundance of surface active sites, which are available for heterogeneous conversion of hydrocarbons and interactions with the reforming agents. This paper focuses on the importance of certain char properties for the gasification and catalytic reforming. Specifically, the gasification reactivity of spruce char is examined, along with its performance as a catalyst for toluene conversion. The material used for this work was produced via gasification of spruce wood chips in the pilot TwoStage Viking plant (Technical University of Denmark, Risø). To obtain a set of samples with varied surface area characteristics and inorganic content, three pre-treatments were applied to samples of this char: acid washing, steam activation, and high-temperature treatment. The gasification and catalytic experiments performed with the untreated and modified materials revealed that the reactivity of the char during gasification in CO2 depends mostly on the metal content in the sample, whereas the conversion of toluene was insensitive to the char inorganic content, but strongly correlated with the surface area available for heterogeneous reactions with toluene
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