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Virulence Dec 2024The global surge in multidrug-resistant bacteria owing to antibiotic misuse and overuse poses considerable risks to human and animal health. With existing antibiotics...
The global surge in multidrug-resistant bacteria owing to antibiotic misuse and overuse poses considerable risks to human and animal health. With existing antibiotics losing their effectiveness and the protracted process of developing new antibiotics, urgent alternatives are imperative to curb disease spread. Notably, improving the bactericidal effect of antibiotics by using non-antibiotic substances has emerged as a viable strategy. Although reduced nicotinamide adenine dinucleotide (NADH) may play a crucial role in regulating bacterial resistance, studies examining how the change of metabolic profile and bacterial resistance following by exogenous administration are scarce. Therefore, this study aimed to elucidate the metabolic changes that occur in (), which exhibits resistance to various antibiotics, following the exogenous addition of NADH using metabolomics. The effects of these alterations on the bactericidal activity of neomycin were investigated. NADH enhanced the effectiveness of aminoglycoside antibiotics against ATCC15947, achieving bacterial eradication at low doses. Metabolomic analysis revealed that NADH reprogrammed the ATCC15947 metabolic profile by promoting purine metabolism and energy metabolism, yielding increased adenosine triphosphate (ATP) levels. Increased ATP levels played a crucial role in enhancing the bactericidal effects of neomycin. Moreover, exogenous NADH promoted the bactericidal efficacy of tetracyclines and chloramphenicols. NADH in combination with neomycin was effective against other clinically resistant bacteria, including , methicillin-resistant , and . These results may facilitate the development of effective approaches for preventing and managing -induced infections and multidrug resistance in aquaculture and clinical settings.
Topics: Edwardsiella tarda; Anti-Bacterial Agents; NAD; Aminoglycosides; Animals; Fish Diseases; Microbial Sensitivity Tests; Enterobacteriaceae Infections; Adenosine Triphosphate; Neomycin; Drug Synergism; Metabolomics; Drug Resistance, Multiple, Bacterial
PubMed: 38884466
DOI: 10.1080/21505594.2024.2367647 -
Journal of Biomedical Optics Jun 2024To enable non-destructive longitudinal assessment of drug agents in intact tumor tissue without the use of disruptive probes, we have designed a label-free method to...
SIGNIFICANCE
To enable non-destructive longitudinal assessment of drug agents in intact tumor tissue without the use of disruptive probes, we have designed a label-free method to quantify the health of individual tumor cells in excised tumor tissue using multiphoton fluorescence lifetime imaging microscopy (MP-FLIM).
AIM
Using murine tumor fragments which preserve the native tumor microenvironment, we seek to demonstrate signals generated by the intrinsically fluorescent metabolic co-factors nicotinamide adenine dinucleotide phosphate [NAD(P)H] and flavin adenine dinucleotide (FAD) correlate with irreversible cascades leading to cell death.
APPROACH
We use MP-FLIM of NAD(P)H and FAD on tissues and confirm viability using standard apoptosis and live/dead (Caspase 3/7 and propidium iodide, respectively) assays.
RESULTS
Through a statistical approach, reproducible shifts in FLIM data, determined through phasor analysis, are shown to correlate with loss of cell viability. With this, we demonstrate that cell death achieved through either apoptosis/necrosis or necroptosis can be discriminated. In addition, specific responses to common chemotherapeutic treatment inducing cell death were detected.
CONCLUSIONS
These data demonstrate that MP-FLIM can detect and quantify cell viability without the use of potentially toxic dyes, thus enabling longitudinal multi-day studies assessing the effects of therapeutic agents on tumor fragments.
Topics: Animals; Mice; Cell Survival; Microscopy, Fluorescence, Multiphoton; Apoptosis; Flavin-Adenine Dinucleotide; NADP; Cell Line, Tumor; Optical Imaging
PubMed: 38881557
DOI: 10.1117/1.JBO.29.S2.S22709 -
Journal of Pharmacological Sciences Aug 2024The atrophic myocardium resulting from mechanical unloading and nutritional deprivation is considered crucial as maladaptive remodeling directly associated with heart...
The atrophic myocardium resulting from mechanical unloading and nutritional deprivation is considered crucial as maladaptive remodeling directly associated with heart failure, as well as interstitial fibrosis. Conversely, myocardial hypertrophy resulting from hemodynamic loading is perceived as compensatory stress adaptation. We previously reported the abundant presence of highly redox-active polysulfide molecules, termed supersulfide, with two or more sulfur atoms catenated in normal hearts, and the supersulfide catabolism in pathologic hearts after myocardial infarction correlated with worsened prognosis of heart failure. However, the impact of supersulfide on myocardial remodeling remains unclear. Here, we investigated the involvement of supersulfide metabolism in cardiomyocyte remodeling, using a model of adenosine 5'-triphosphate (ATP) receptor-stimulated atrophy and endothelin-1 receptor-stimulated hypertrophy in neonatal rat cardiomyocytes. Results revealed contrasting changes in intracellular supersulfide and its catabolite, hydrogen sulfide (HS), between cardiomyocyte atrophy and hypertrophy. Stimulation of cardiomyocytes with ATP decreased supersulfide activity, while HS accumulation itself did not affect cardiomyocyte atrophy. This supersulfide catabolism was also involved in myofibroblast formation of neonatal rat cardiac fibroblasts. Thus, unraveling supersulfide metabolism during myocardial remodeling may lead to the development of novel therapeutic strategies to improve heart failure.
Topics: Animals; Myocytes, Cardiac; Sulfides; Hydrogen Sulfide; Cells, Cultured; Ventricular Remodeling; Adenosine Triphosphate; Rats; Atrophy; Cardiomegaly; Heart Failure; Animals, Newborn; Rats, Sprague-Dawley
PubMed: 38880546
DOI: 10.1016/j.jphs.2024.05.002 -
Nature Communications Jun 2024Neurofibromatosis Type II (NFII) is a genetic condition caused by loss of the NF2 gene, resulting in activation of the YAP/TAZ pathway and recurrent Schwann cell tumors,...
Neurofibromatosis Type II (NFII) is a genetic condition caused by loss of the NF2 gene, resulting in activation of the YAP/TAZ pathway and recurrent Schwann cell tumors, as well as meningiomas and ependymomas. Unfortunately, few pharmacological options are available for NFII. Here, we undertake a genome-wide CRISPR/Cas9 screen to search for synthetic-lethal genes that, when inhibited, cause death of NF2 mutant Schwann cells but not NF2 wildtype cells. We identify ACSL3 and G6PD as two synthetic-lethal partners for NF2, both involved in lipid biogenesis and cellular redox. We find that NF2 mutant Schwann cells are more oxidized than control cells, in part due to reduced expression of genes involved in NADPH generation such as ME1. Since G6PD and ME1 redundantly generate cytosolic NADPH, lack of either one is compatible with cell viability, but not down-regulation of both. Since genetic deficiency for G6PD is tolerated in the human population, G6PD could be a good pharmacological target for NFII.
Topics: Schwann Cells; Humans; CRISPR-Cas Systems; Glucosephosphate Dehydrogenase; Neurofibromin 2; Coenzyme A Ligases; Synthetic Lethal Mutations; Animals; Neurofibromatosis 2; NADP; Mice; Oxidation-Reduction
PubMed: 38879607
DOI: 10.1038/s41467-024-49298-7 -
Nature Communications Jun 2024One open question in the biology of growth factor receptors is how a quantitative input (i.e., ligand concentration) is decoded by the cell to produce specific...
One open question in the biology of growth factor receptors is how a quantitative input (i.e., ligand concentration) is decoded by the cell to produce specific response(s). Here, we show that an EGFR endocytic mechanism, non-clathrin endocytosis (NCE), which is activated only at high ligand concentrations and targets receptor to degradation, requires a tripartite organelle platform involving the plasma membrane (PM), endoplasmic reticulum (ER) and mitochondria. At these contact sites, EGFR-dependent, ER-generated Ca oscillations are sensed by mitochondria, leading to increased metabolism and ATP production. Locally released ATP is required for cortical actin remodeling and EGFR-NCE vesicle fission. The same biochemical circuitry is also needed for an effector function of EGFR, i.e., collective motility. The multiorganelle signaling platform herein described mediates direct communication between EGFR signaling and mitochondrial metabolism, and is predicted to have a broad impact on cell physiology as it is activated by another growth factor receptor, HGFR/MET.
Topics: Mitochondria; ErbB Receptors; Endoplasmic Reticulum; Humans; Signal Transduction; Adenosine Triphosphate; Endocytosis; Animals; Cell Membrane; Calcium Signaling; Calcium
PubMed: 38879572
DOI: 10.1038/s41467-024-49543-z -
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