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Nature Communications Jun 2024Factor-dependent termination uses molecular motors to remodel transcription machineries, but the associated mechanisms, especially in eukaryotes, are poorly understood....
Factor-dependent termination uses molecular motors to remodel transcription machineries, but the associated mechanisms, especially in eukaryotes, are poorly understood. Here we use single-molecule fluorescence assays to characterize in real time the composition and the catalytic states of Saccharomyces cerevisiae transcription termination complexes remodeled by Sen1 helicase. We confirm that Sen1 takes the RNA transcript as its substrate and translocates along it by hydrolyzing multiple ATPs to form an intermediate with a stalled RNA polymerase II (Pol II) transcription elongation complex (TEC). We show that this intermediate dissociates upon hydrolysis of a single ATP leading to dissociation of Sen1 and RNA, after which Sen1 remains bound to the RNA. We find that Pol II ends up in a variety of states: dissociating from the DNA substrate, which is facilitated by transcription bubble rewinding, being retained to the DNA substrate, or diffusing along the DNA substrate. Our results provide a complete quantitative framework for understanding the mechanism of Sen1-dependent transcription termination in eukaryotes.
Topics: Saccharomyces cerevisiae Proteins; Saccharomyces cerevisiae; RNA Polymerase II; Transcription Termination, Genetic; Adenosine Triphosphate; DNA Helicases; Single Molecule Imaging; RNA Helicases; Transcription, Genetic; RNA, Fungal; DNA, Fungal; Hydrolysis
PubMed: 38879529
DOI: 10.1038/s41467-024-49527-z -
Cell Death & Disease Jun 2024Tamoxifen has been the mainstay therapy to treat early, locally advanced, and metastatic estrogen receptor-positive (ER + ) breast cancer, constituting around 75% of...
Tamoxifen has been the mainstay therapy to treat early, locally advanced, and metastatic estrogen receptor-positive (ER + ) breast cancer, constituting around 75% of all cases. However, the emergence of resistance is common, necessitating the identification of novel therapeutic targets. Here, we demonstrated that long-noncoding RNA LINC00152 confers tamoxifen resistance by blocking tamoxifen-induced ferroptosis, an iron-mediated cell death. Mechanistically, inhibiting LINC00152 reduces the mRNA stability of phosphodiesterase 4D (PDE4D), leading to activation of the cAMP/PKA/CREB axis and increased expression of the TRPC1 Ca channel. This causes cytosolic Ca overload and generation of reactive oxygen species (ROS) that is, on the one hand, accompanied by downregulation of FTH1, a member of the iron sequestration unit, thus increasing intracellular Fe levels; and on the other hand, inhibition of the peroxidase activity upon reduced GPX4 and xCT levels, in part by cAMP/CREB. These ultimately restore tamoxifen-dependent lipid peroxidation and ferroptotic cell death which are reversed upon chelating Ca or overexpressing GPX4 or xCT. Overexpressing PDE4D reverses LINC00152 inhibition-mediated tamoxifen sensitization by de-activating the cAMP/Ca/ferroptosis axis. Importantly, high LINC00152 expression is significantly correlated with high PDE4D/low ferroptosis and worse survival in multiple cohorts of tamoxifen- or tamoxifen-containing endocrine therapy-treated ER+ breast cancer patients. Overall, we identified LINC00152 inhibition as a novel mechanism of tamoxifen sensitization via restoring tamoxifen-dependent ferroptosis upon destabilizing PDE4D, increasing cAMP and Ca levels, thus leading to ROS generation and lipid peroxidation. Our findings reveal LINC00152 and its effectors as actionable therapeutic targets to improve clinical outcome in refractory ER+ breast cancer.
Topics: Humans; Tamoxifen; Breast Neoplasms; Ferroptosis; Female; RNA, Long Noncoding; Cyclic AMP; Calcium; Drug Resistance, Neoplasm; Cell Line, Tumor; Animals; Receptors, Estrogen; Mice; Reactive Oxygen Species; MCF-7 Cells
PubMed: 38879508
DOI: 10.1038/s41419-024-06814-3 -
Biomedicine & Pharmacotherapy =... Jul 2024Idiopathic pulmonary fibrosis (IPF) is a severe disability due to progressive lung dysfunction. IPF has long been viewed as a non-immune form of pulmonary fibrosis, but...
Idiopathic pulmonary fibrosis (IPF) is a severe disability due to progressive lung dysfunction. IPF has long been viewed as a non-immune form of pulmonary fibrosis, but nowadays it is accepted that a chronic inflammatory response can exacerbate fibrotic patterns. IL-1-like cytokines and ATP are highly detected in the lung and broncho-alveolar lavage fluid of IPF patients. Because ATP binds the purinergic receptor P2RX7 involved in the release of IL-1-like cytokines, we aimed to understand the role of P2RX7 in IPF. PBMCs from IPF patients were treated with nintedanib or pirfenidone in the presence of ATP. Under these conditions, PBMCs still released IL-1-like cytokines and the pro-fibrotic TGFβ. Bulk and scRNAseq demonstrated that lung tissues of IPF patients had higher levels of P2RX7, especially on macrophages, which were correlated to T cell activity and inflammatory response with a TGFBI and IL-10 signature. A subcluster of macrophages in IPF lung tissues had 2055 genes that were not in common with the other subclusters, and that were involved in metabolic and PDGF, FGF and VEGF associated pathways. These data confirmed what observed on circulating cells that, although treated with anti-fibrotic agents, nintedanib or pirfenidone, they were still able to release IL-1 cytokines and the fibrogenic TGFβ. In conclusion, these data imply that because nintedanib and pirfenidone do not block ATP-induced IL-1-like cytokines and TGFβ induced during P2RX7 activation, it is plausible to consider P2RX7 on circulating cells and/or tissue biopsies as potential pharmacological tool for IPF patients.
Topics: Humans; Idiopathic Pulmonary Fibrosis; Pyridones; Indoles; Adenosine Triphosphate; Receptors, Purinergic P2X7; Male; Lung; Female; Cytokines; Aged; Leukocytes, Mononuclear; Middle Aged; Transforming Growth Factor beta; Macrophages; Signal Transduction
PubMed: 38876049
DOI: 10.1016/j.biopha.2024.116896 -
PloS One 2024Renal dysfunction is associated with poor outcomes in patients with coronavirus disease 2019 (COVID-19). In an effort to improve outcomes, intravenous remdesivir has... (Observational Study)
Observational Study
BACKGROUND AND AIM
Renal dysfunction is associated with poor outcomes in patients with coronavirus disease 2019 (COVID-19). In an effort to improve outcomes, intravenous remdesivir has been broadly used for the treatment of COVID-19 even in patients with low estimated glomerular filtration rate (eGFR). Our study assessed the residual risk of outcomes of patients with low eGFR despite treatment with remdesivir for COVID-19, during a timeframe prior to the expanded label across all levels of renal function.
METHODS
We conducted an observational, retrospective, multi-site cohort study of adults hospitalized with COVID-19 treated with at least one dose of remdesivir between November 6, 2020, and November 5, 2021. Electronic medical records were reviewed to obtain patient characteristics, related laboratory data, and outcomes. The primary endpoint was all-cause mortality by day 28. Multivariable logistic regression was used to evaluate association between groups.
RESULTS
The study population consisted of 3024 patients hospitalized with COVID-19 and treated with remdesivir. The median age was 67 [IQR 55, 77] years; 42.7% were women, and 88.6% were white. The median eGFR was 76.6 mL/min/1.73 m2 [IQR 52.5, 95.2]; the majority (67.2%) of patients had an eGFR ≥ 60, while 9% had an eGFR <30. All-cause mortality by day 28 was 8.7%. All-cause mortality rates were significantly higher among patients with impaired renal function (Odds Ratio [OR] 1.63 for patients with eGFR 30-59; OR 1.46 for eGFR 15-29; OR 2.42 for eGFR <15 and OR 5.44 for patients on dialysis) compared to patients with eGFR ≥60 mL/min/1.73m2.
CONCLUSIONS
Lower eGFR remains an independent risk factor for mortality in COVID-19 even in patients treated with remdesivir.
Topics: Humans; Alanine; Adenosine Monophosphate; Female; Male; Middle Aged; Aged; COVID-19 Drug Treatment; Glomerular Filtration Rate; Retrospective Studies; COVID-19; Antiviral Agents; Hospitalization; SARS-CoV-2; Kidney
PubMed: 38875257
DOI: 10.1371/journal.pone.0303896 -
European Journal of Sport Science Jun 2024It has been assumed that exercise intensity variation throughout a cycling time trial (TT) occurs in alignment of various metabolic changes to prevent premature task... (Randomized Controlled Trial)
Randomized Controlled Trial
It has been assumed that exercise intensity variation throughout a cycling time trial (TT) occurs in alignment of various metabolic changes to prevent premature task failure. However, this assumption is based on target metabolite responses, which limits our understanding of the complex interconnection of metabolic responses during exercise. The current study characterized the metabolomic profile, an untargeted metabolic analysis, after specific phases of a cycling 4-km TT. Eleven male cyclists performed three separated TTs in a crossover counterbalanced design, which were interrupted at the end of the fast-start (FS, 600 ± 205 m), even-pace (EP, 3600 ± 190 m), or end-spurt (ES, 4000 m) phases. Blood samples were taken before any exercise and 5 min after exercise cessation, and the metabolomic profile characterization was performed using Nuclear Magnetic Resonance metabolomics. Power output (PO) was also continually recorded. There were higher PO values during the FS and ES compared to the EP (all p < 0.05), which were accompanied by distinct metabolomic profiles. FS showed high metabolite expression in TCA cycle and its related pathways (e.g., glutamate, citric acid, and valine metabolism); whereas, the EP elicited changes associated with antioxidant effects and oxygen delivery adjustment. Finally, ES was related to pathways involved in NAD turnover and serotonin metabolism. These findings suggest that the specific phases of a cycling TT are accompanied by distinct metabolomic profiles, providing novel insights regarding the relevance of specific metabolic pathways on the process of exercise intensity regulation.
Topics: Humans; Male; Metabolome; Adult; Bicycling; Cross-Over Studies; Citric Acid Cycle; Serotonin; NAD; Young Adult; Glutamic Acid; Metabolomics; Valine; Citric Acid
PubMed: 38874966
DOI: 10.1002/ejsc.12108 -
Emerging Microbes & Infections Dec 2024The global outbreak of Mpox, caused by the monkeypox virus (MPXV), has attracted international attention and become another major infectious disease event after...
The global outbreak of Mpox, caused by the monkeypox virus (MPXV), has attracted international attention and become another major infectious disease event after COVID-19. The mRNA cap N7 methyltransferase (RNMT) of MPXV methylates the N7 position of the added guanosine to the 5'-cap structure of mRNAs and plays a vital role in evading host antiviral immunity. MPXV RNMT is composed of the large subunit E1 and the small subunit E12. How E1 and E12 of MPXV assembly remains unclear. Here, we report the crystal structures of E12, the MTase domain of E1 with E12 (E1-E12) complex, and the E1-E12-SAM ternary complex, revealing the detailed conformations of critical residues and the structural changes upon E12 binding to E1. Functional studies suggest that E1 N-terminal extension (Asp545-Arg562) and the small subunit E12 play an essential role in the binding process of SAM. Structural comparison of the AlphaFold2-predicted E1, E1-E12 complex, and the homologous D1-D12 complex of vaccinia virus (VACV) indicates an allosteric activating effect of E1 in MPXV. Our findings provide the structural basis for the MTase activity stimulation of the E1-E12 complex and suggest a potential interface for screening the anti-poxvirus inhibitors.
Topics: Methyltransferases; Monkeypox virus; Viral Proteins; Crystallography, X-Ray; RNA Caps; Models, Molecular; Humans; Protein Conformation; Protein Binding; RNA, Messenger
PubMed: 38873898
DOI: 10.1080/22221751.2024.2369193 -
Scientific Reports Jun 2024Currently, the increasing pollution of the environment by heavy metals is observed, caused both by natural factors and those related to human activity. They pose a...
Currently, the increasing pollution of the environment by heavy metals is observed, caused both by natural factors and those related to human activity. They pose a significant threat to human health and life. It is therefore important to find an effective way of protecting organisms from their adverse effects. One potential product showing a protective effect is green tea. It has been shown that EGCG, which is found in large amounts in green tea, has strong antioxidant properties and can therefore protect cells from the adverse effects of heavy metals. Therefore, the aim of the study was to investigate the effect of EGCG on cells exposed to Cd. In the study, CHO-K1 cells (Chinese hamster ovary cell line) were treated for 24 h with Cd (5 and 10 µM) and EGCG (0.5 and 1 µM) together or separately. Cell viability, ATP content, total ROS activity, mitochondrial membrane potential and apoptosis potential were determined. The results showed that, in tested concentrations, EGCG enhanced the negative effect of Cd. Further analyses are needed to determine the exact mechanism of action of EGCG due to the small number of publications on the subject and the differences in the results obtained in the research.
Topics: Catechin; Animals; CHO Cells; Apoptosis; Cricetulus; Oxidative Stress; Cadmium; Membrane Potential, Mitochondrial; Reactive Oxygen Species; Cell Survival; Antioxidants; Cricetinae; Adenosine Triphosphate
PubMed: 38871787
DOI: 10.1038/s41598-024-64478-7 -
Nature Communications Jun 2024Serpentinization, a geochemical process found on modern and ancient Earth, provides an ultra-reducing environment that can support microbial methanogenesis and...
Serpentinization, a geochemical process found on modern and ancient Earth, provides an ultra-reducing environment that can support microbial methanogenesis and acetogenesis. Several groups of archaea, such as the order Methanocellales, are characterized by their ability to produce methane. Here, we generate metagenomic sequences from serpentinized springs in The Cedars, California, and construct a circularized metagenome-assembled genome of a Methanocellales archaeon, termed Met12, that lacks essential methanogenesis genes. The genome includes genes for an acetyl-CoA pathway, but lacks genes encoding methanogenesis enzymes such as methyl-coenzyme M reductase, heterodisulfide reductases and hydrogenases. In situ transcriptomic analyses reveal high expression of a multi-heme c-type cytochrome, and heterologous expression of this protein in a model bacterium demonstrates that it is capable of accepting electrons. Our results suggest that Met12, within the order Methanocellales, is not a methanogen but a CO-reducing, electron-fueled acetogen without electron bifurcation.
Topics: Methane; Genome, Archaeal; Archaeal Proteins; Oxidoreductases; Metagenome; Phylogeny; Acetyl Coenzyme A; Carbon Dioxide; Metagenomics
PubMed: 38871712
DOI: 10.1038/s41467-024-48185-5 -
PloS One 2024ATP is actively maintained at high concentrations in cancerous tissues, where it promotes a malignant phenotype through P2 receptors. In this study, we first evaluated...
ATP is actively maintained at high concentrations in cancerous tissues, where it promotes a malignant phenotype through P2 receptors. In this study, we first evaluated the effect of extracellular ATP depletion with apyrase in SKOV-3, a cell line derived from metastatic ovarian carcinoma. We observed a decrease in cell migration and an increase in transepithelial electrical resistance and cell markers, suggesting a role in maintaining a mesenchymal phenotype. To identify the P2 receptor that mediated the effects of ATP, we compared the transcript levels of some P2 receptors and found that P2RX7 is three-fold higher in SKOV-3 cells than in a healthy cell line, namely HOSE6-3 (from human ovarian surface epithelium). Through bioinformatic analysis, we identified a higher expression of the P2RX7 transcript in metastatic tissues than in primary tumors; thus, P2X7 seems to be a promising effector for the malignant phenotype. Subsequently, we demonstrated the presence and functionality of the P2X7 receptor in SKOV-3 cells and showed through pharmacological approaches that its activity promotes cell migration and contributes to maintaining a mesenchymal phenotype. P2X7 activation using BzATP increased cell migration and abolished E-cadherin expression. On the other hand, a series of P2X7 receptor antagonists (A438079, BBG and OxATP) decreased cell migration. We used a CRISPR-based knock-out system directed to P2RX7. According to the results of our wound-healing assay, SKOV3-P2X7KO cells lacked receptor-mediated calcium mobilization and decreased migration. Altogether, these data let us propose that P2X7 receptor is a regulator for cancer cell migration and thus a potential drug target.
Topics: Humans; Receptors, Purinergic P2X7; Cell Movement; Ovarian Neoplasms; Female; Adenosine Triphosphate; Cell Line, Tumor; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic
PubMed: 38870128
DOI: 10.1371/journal.pone.0304062 -
Journal of Agricultural and Food... Jun 2024Several compounds with taste-modulating properties have been investigated, improving the taste impression without having a pronounced intrinsic taste. The best-known...
Several compounds with taste-modulating properties have been investigated, improving the taste impression without having a pronounced intrinsic taste. The best-known representatives of umami taste-modulating compounds are ribonucleotides and their derivatives. Especially the thio derivatives showed high taste-modulating potential in structure-activity relationship investigations. Therefore, this study focuses on the formation of guanosine 5'-monophosphate derivatives consisting of Maillard-type generated compounds like the aroma-active thiols (2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-furfurylthiol) and formaldehyde to gain insights into the potential of combinations of taste and aroma-active compounds. One literature-known (-(furfurylthiomethyl)-guanosine 5'-monophosphate) and three new derivatives (-(2-methyl-1-furylthiomethyl)-guanosine 5'-monophosphate, -((5-hydroxymethyl)-2-methyl-1-furylthiomethyl)-guanosine 5'-monophosphate, -((2-pentanon-1-yl)thiomethyl)-guanosine 5'-monophosphate) were successfully produced using green natural deep eutectic solvents and isolated, and their structures were completely elucidated. Besides the intrinsic taste properties, the kokumi and umami taste-modulating effects of the four derivatives were evaluated via psychophysical investigations, ranging from 19 to 22 μmol/L.
Topics: Maillard Reaction; Guanosine Monophosphate; Taste; Humans; Flavoring Agents; Male; Female; Molecular Structure; Adult; Young Adult
PubMed: 38869215
DOI: 10.1021/acs.jafc.4c03485