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Open Heart Aug 2022To estimate the incidence and HRs for bleeding for different dual antiplatelet therapies (DAPT) in a real-world population with acute coronary syndrome (ACS) undergoing... (Randomized Controlled Trial)
Randomized Controlled Trial
Real-world bleeding in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) and prescribed different combinations of dual antiplatelet therapy (DAPT) in England: a population-based cohort study emulating a 'target trial'.
OBJECTIVE
To estimate the incidence and HRs for bleeding for different dual antiplatelet therapies (DAPT) in a real-world population with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) in England.
DESIGN
A retrospective, population-based cohort study emulating a target randomised controlled trial (tRCT).
DATA SOURCES
Linked Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES).
SETTING
Primary and secondary care.
PARTICIPANTS
Patients ≥18 years old with ACS undergoing emergency PCI.
INTERVENTIONS
Aspirin and clopidogrel (AC, reference) versus aspirin and prasugrel (AP) or aspirin and ticagrelor (AT); AP evaluated only in patients with ST-elevation myocardial infarction (STEMI).
MAIN OUTCOME MEASURES
Primary: any bleeding up to 12 months after the index event (HES- or CPRD- recorded). Secondary: HES-recorded bleeding, CPRD-recorded bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular and cerebrovascular events (MACCE).
RESULTS
In ACS, the rates of any bleeding for AC and AT were 89 per 1000 person years and 134 per 1000 person years, respectively. In STEMI, rates for AC, AP and AT were 93 per 1000 person years, 138 per 1000 person years and 143 per 100 person years, respectively. In ACS, compared with AC, AT increased the hazard of any bleeding (HR: 1.47, 95% CI 1.19 to 1.82) but did not reduce MACCE (HR: 1.06, 95% CI 0.89 to 1.27). In STEMI, compared with AC, AP and AT increased the hazard of any bleeding (HR: 1.77, 95% CI 1.21 to 2.59 and HR: 1.50, 95% CI 1.10 to 2.05, respectively) but did not reduce MACCE (HR: 1.10, 95% CI 0.80 to 1.51 and HR: 1.21, 95% CI 0.94 to 1.51, respectively). Non-adherence to the prescribed DAPT regimen was 28% in AC (29% in STEMI only), 31% in AP (STEMI only) and 33% in AT (32% in STEMI only).
CONCLUSIONS
In a real-world population with ACS, DAPT with ticagrelor or prasugrel are associated with increased bleeding compared with DAPT with clopidogrel.
TRIAL REGISTRATION NUMBER
ISRCTN76607611.
Topics: Acute Coronary Syndrome; Adolescent; Aspirin; Clopidogrel; Cohort Studies; Dinucleoside Phosphates; Hemorrhage; Humans; Percutaneous Coronary Intervention; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Retrospective Studies; ST Elevation Myocardial Infarction; Ticagrelor
PubMed: 35961692
DOI: 10.1136/openhrt-2022-001999 -
Scientific Reports Feb 2023Epithelial ovarian cancer is the most lethal gynecological malignancy, owing notably to its high rate of therapy-resistant recurrence in spite of good initial response...
Inhibition of nicotinamide dinucleotide salvage pathway counters acquired and intrinsic poly(ADP-ribose) polymerase inhibitor resistance in high-grade serous ovarian cancer.
Epithelial ovarian cancer is the most lethal gynecological malignancy, owing notably to its high rate of therapy-resistant recurrence in spite of good initial response to chemotherapy. Although poly(ADP-ribose) polymerase inhibitors (PARPi) have shown promise for ovarian cancer treatment, extended therapy usually leads to acquired PARPi resistance. Here we explored a novel therapeutic option to counter this phenomenon, combining PARPi and inhibitors of nicotinamide phosphoribosyltransferase (NAMPT). Cell-based models of acquired PARPi resistance were created through an in vitro selection procedure. Using resistant cells, xenograft tumors were grown in immunodeficient mice, while organoid models were generated from primary patient tumor samples. Intrinsically PARPi-resistant cell lines were also selected for analysis. Our results show that treatment with NAMPT inhibitors effectively sensitized all in vitro models to PARPi. Adding nicotinamide mononucleotide, the resulting NAMPT metabolite, abrogated the therapy-induced cell growth inhibition, demonstrating the specificity of the synergy. Treatment with olaparib (PARPi) and daporinad (NAMPT inhibitor) depleted intracellular NAD+ , induced double-strand DNA breaks, and promoted apoptosis as monitored by caspase-3 cleavage. The two drugs were also synergistic in mouse xenograft models and clinically relevant patient-derived organoids. Therefore, in the context of PARPi resistance, NAMPT inhibition could offer a promising new option for ovarian cancer patients.
Topics: Humans; Animals; Mice; Female; Poly(ADP-ribose) Polymerase Inhibitors; Niacinamide; Antineoplastic Agents; Ovarian Neoplasms; Dinucleoside Phosphates
PubMed: 36849518
DOI: 10.1038/s41598-023-30081-5 -
Current Eye Research 2015To compare signs and symptoms of dry eye in keratoconus (KC) patients versus healthy subjects.
PURPOSE
To compare signs and symptoms of dry eye in keratoconus (KC) patients versus healthy subjects.
METHODS
A total of 15 KC patients (KC group, n = 15 eyes) and 16 healthy subjects (control group, 16 eyes) were enrolled in this study. The Schirmer I test with no anesthetic, tear break-up time (TBUT), corneal staining characteristics, and ocular surface disease index (OSDI) scores were evaluated for both groups. Impression cytology, combined with/scanning laser confocal microscopy (LCM), was performed to evaluate goblet cell density, mucin cloud height (MCH), and goblet cell layer thickness (CLT). Finally, tear concentrations of di-adenosine tetraphosphate (Ap4A) were assessed. Results were statistically analyzed using Shapiro-Wilk and non-parametric Wilcoxon rank sum tests. Statistical significance was set at p < 0.05.
RESULTS
KC patients had lower tear volumes and greater corneal staining than did healthy subjects (p < 0.05). OSDI scores were 44.96 ± 8.65 and 17.78 ± 6.50 for the KC and control groups, respectively (p < 0.05). We found no statistically significant differences in TBUT between groups. Impression cytology revealed lower goblet cell densities in KC group patients versus control group subjects (84.88 ± 32.98 and 128.88 ± 50.60 cells/mm,(2) respectively, p < 0.05). There was a statistically significant reduction in MCH and CLT in KC group patients compared with control group subjects. Ap4A tear concentrations were higher in KC group patients than in control group subjects (2.56 ± 1.10 and 0.15 ± 0.12 µM, respectively, p < 0.05).
CONCLUSIONS
The parameters evaluated in this study indicate that KC patients suffer greater symptoms of dry eye and greater tear instability, primarily due to the decreased mucin production in their tears, than do healthy patients with no KC.
Topics: Adolescent; Adult; Biomarkers; Cell Count; Dinucleoside Phosphates; Dry Eye Syndromes; Eye Proteins; Female; Goblet Cells; Healthy Volunteers; Humans; Keratoconus; Male; Microscopy, Confocal; Mucins; Pilot Projects; Surveys and Questionnaires; Tears; Young Adult
PubMed: 25495191
DOI: 10.3109/02713683.2014.987871 -
Cell Reports Apr 2023Programmed cell suicide of infected bacteria, known as abortive infection (Abi), serves as an immune defense strategy to prevent the propagation of bacteriophage...
Programmed cell suicide of infected bacteria, known as abortive infection (Abi), serves as an immune defense strategy to prevent the propagation of bacteriophage viruses. Many Abi systems utilize bespoke cyclic nucleotide immune messengers generated upon infection to mobilize cognate death effectors. Here, we identify a family of bacteriophage nucleotidyltransferases (NTases) that synthesize competitor cyclic dinucleotide (CDN) ligands and inhibit TIR NADase effectors activated via a linked STING CDN sensor domain (TIR-STING). Through a functional screen of NTase-adjacent phage genes, we uncover candidate inhibitors of cell suicide induced by heterologous expression of tonically active TIR-STING. Among these, we demonstrate that a virus MazG-like nucleotide pyrophosphohydrolase, Atd1, depletes the starvation alarmone (p)ppGpp, revealing a potential role for the alarmone-activated host toxin MazF as an executioner of TIR-driven Abi. Phage NTases and counterdefenses like Atd1 preserve host viability to ensure virus propagation and represent tools to modulate TIR and STING immune responses.
Topics: Bacteria; Bacteriophages; Dinucleoside Phosphates; Guanosine Pentaphosphate; Immunity; Nucleotides; Nucleotidyltransferases
PubMed: 36952342
DOI: 10.1016/j.celrep.2023.112305 -
Biophysical Journal Jun 2022Heme has been shown to have a crucial role in the signal transduction mechanism of the facultative photoheterotrophic bacterium Rhodobacter sphaeroides. It interacts...
Heme has been shown to have a crucial role in the signal transduction mechanism of the facultative photoheterotrophic bacterium Rhodobacter sphaeroides. It interacts with the transcriptional regulatory complex AppA/PpsR, in which AppA and PpsR function as the antirepressor and repressor, respectively, of photosynthesis gene expression. The mechanism, however, of this interaction remains incompletely understood. In this study, we combined electron paramagnetic resonance (EPR) spectroscopy and Förster resonance energy transfer (FRET) to demonstrate the ligation of heme in PpsR with a proposed cysteine residue. We show that heme binding in AppA affects the fluorescent properties of the dark-adapted state of the protein, suggesting a less constrained flavin environment compared with the absence of heme and the light-adapted state. We performed ultrafast transient absorption measurements in order to reveal potential differences in the dynamic processes in the full-length AppA and its heme-binding domain alone. Comparison of the CO-binding dynamics demonstrates a more open heme pocket in the holo-protein, qualitatively similar to what has been observed in the CO sensor RcoM-2, and suggests a communication path between the blue-light-using flavin (BLUF) and sensing containing heme instead of cobalamin (SCHIC) domains of AppA. We have also examined quantitatively the affinity of PpsR to bind to individual DNA fragments of the puc promoter using fluorescence anisotropy assays. We conclude that oligomerization of PpsR is initially triggered by binding of one of the two DNA fragments and observe a ∼10-fold increase in the dissociation constant K for DNA binding upon heme binding to PpsR. Our study provides significant new insight at the molecular level on the regulatory role of heme that modulates the complex transcriptional regulation in R. sphaeroides and supports the two levels of heme signaling, via its binding to AppA and PpsR and via the sensing of gases like oxygen.
Topics: Bacterial Proteins; Dinucleoside Phosphates; Flavins; Flavoproteins; Gene Expression Regulation, Bacterial; Heme; Repressor Proteins; Rhodobacter sphaeroides
PubMed: 35488435
DOI: 10.1016/j.bpj.2022.04.031 -
Journal of the American Chemical Society Oct 2021Triazole linkages (TLs) are mimics of the phosphodiester bond in oligonucleotides with applications in synthetic biology and biotechnology. Here we report the...
Triazole linkages (TLs) are mimics of the phosphodiester bond in oligonucleotides with applications in synthetic biology and biotechnology. Here we report the RuAAC-catalyzed synthesis of a novel 1,5-disubstituted triazole (TL) dinucleoside phosphoramidite as well as its incorporation into oligonucleotides and compare its DNA polymerase replication competency with other TL analogues. We demonstrate that TL has superior replication kinetics to these analogues and is accurately replicated by polymerases. Derived structure-biocompatibility relationships show that linker length and the orientation of a hydrogen bond acceptor are critical and provide further guidance for the rational design of artificial biocompatible nucleic acid backbones.
Topics: Catalysis; DNA; DNA-Directed DNA Polymerase; Dinucleoside Phosphates; Molecular Mimicry; Triazoles
PubMed: 34546729
DOI: 10.1021/jacs.1c08057 -
Biofouling Apr 2017A biofilm is a complex assemblage of microbial communities adhered to a biotic or an abiotic surface which is embedded within a self-produced matrix of extracellular... (Review)
Review
A biofilm is a complex assemblage of microbial communities adhered to a biotic or an abiotic surface which is embedded within a self-produced matrix of extracellular polymeric substances. Many transcriptional regulators play a role in triggering a motile-sessile switch and in consequently producing the biofilm matrix. This review is aimed at highlighting the role of two nucleotide signaling molecules (c-di-GMP and c-di-AMP), toxin antitoxin modules and a novel transcriptional regulator BolA in biofilm formation in various bacteria. In addition, it highlights the common themes that have appeared in recent research regarding the key regulatory components and signal transduction pathways that help Bacillus subtilis and Pseudomonas aeruginosa to acquire the biofilm mode of life.
Topics: Bacillus subtilis; Biofilms; Cyclic GMP; Dinucleoside Phosphates; Extracellular Matrix; Gene Expression Regulation, Bacterial; Pseudomonas aeruginosa; Signal Transduction
PubMed: 28347177
DOI: 10.1080/08927014.2017.1304541 -
Journal of the National Cancer Institute Oct 2019Age is one of the strongest predictors of cancer, chronic disease, and mortality, but biological responses to aging differ among people. Epigenetic DNA modifications...
BACKGROUND
Age is one of the strongest predictors of cancer, chronic disease, and mortality, but biological responses to aging differ among people. Epigenetic DNA modifications have been used to estimate "biological age," which may be a useful predictor of disease risk. We tested this hypothesis for breast cancer.
METHODS
Using a case-cohort approach, we measured baseline blood DNA methylation of 2764 women enrolled in the Sister Study, 1566 of whom subsequently developed breast cancer after an average of 6 years. Using three previously established methylation-based "clocks" (Hannum, Horvath, and Levine), we defined biological age acceleration for each woman by comparing her estimated biological age with her chronological age. Hazard ratios and 95% confidence intervals for breast cancer risk were estimated using Cox regression models. All statistical tests were two-sided.
RESULTS
Each of the three clocks showed that biological age acceleration was statistically significantly associated with increased risk of developing breast cancer (5-year age acceleration, Hannum's clock: hazard ratio [HR] = 1.10, 95% confidence interval [CI] = 1.00 to 1.21, P = .04; Horvath's clock: HR = 1.08, 95% CI = 1.00 to 1.17, P = .04; Levine's clock: HR = 1.15, 95% CI = 1.07 to 1.23, P < .001). For Levine's clock, each 5-year acceleration in biological age corresponded with a 15% increase in breast cancer risk. Although biological age may accelerate with menopausal transition, age acceleration in premenopausal women independently predicted breast cancer. Case-only analysis suggested that, among women who develop breast cancer, increased age acceleration is associated with invasive cancer (odds ratio for invasive = 1.09, 95% CI = 0.98 to 1.22, P = .10).
CONCLUSIONS
DNA methylation-based measures of biological age may be important predictors of breast cancer risk.
Topics: Adult; Aged; Aging; Breast Neoplasms; DNA Methylation; Dinucleoside Phosphates; Disease Susceptibility; Epigenesis, Genetic; Female; Gene Expression Regulation; Genetic Predisposition to Disease; Humans; Middle Aged; Odds Ratio; Prognosis; Proportional Hazards Models; Risk Assessment; Risk Factors
PubMed: 30794318
DOI: 10.1093/jnci/djz020 -
Protein Science : a Publication of the... Mar 2023Cyclic-di-nucleotide-based secondary messengers regulate various physiological functions, including stress responses in bacteria. Cyclic diadenosine monophosphate...
Cyclic-di-nucleotide-based secondary messengers regulate various physiological functions, including stress responses in bacteria. Cyclic diadenosine monophosphate (c-di-AMP) has recently emerged as a crucial second messenger with implications in processes including osmoregulation, antibiotic resistance, biofilm formation, virulence, DNA repair, ion homeostasis, and sporulation, and has potential therapeutic applications. The contrasting activities of the enzymes diadenylate cyclase (DAC) and phosphodiesterase (PDE) determine the equilibrium levels of c-di-AMP. Although c-di-AMP is suspected of playing an essential role in the pathophysiology of bacterial infections and in regulating host-pathogen interactions, the mechanisms of its regulation remain relatively unexplored in mycobacteria. In this report, we biochemically and structurally characterize the c-di-AMP synthase (MsDisA) from Mycobacterium smegmatis. The enzyme activity is regulated by pH and substrate concentration; conditions of significance in the homoeostasis of c-di-AMP levels. Substrate binding stimulates conformational changes in the protein, and pApA and ppApA are synthetic intermediates detectable when enzyme efficiency is low. Unlike the orthologous Bacillus subtilis enzyme, MsDisA does not bind to, and its activity is not influenced in the presence of DNA. Furthermore, we have determined the cryo-EM structure of MsDisA, revealing asymmetry in its structure in contrast to the symmetric crystal structure of Thermotoga maritima DisA. We also demonstrate that the N-terminal minimal region alone is sufficient and essential for oligomerization and catalytic activity. Our data shed light on the regulation of mycobacterial DisA and possible future directions to pursue.
Topics: Mycobacterium smegmatis; Bacterial Proteins; Dinucleoside Phosphates; Bacillus subtilis
PubMed: 36660887
DOI: 10.1002/pro.4568 -
Current Protocols Nov 2022This article describes a simple, reliable, efficient, and improved solution-phase method for the gram-scale chemical synthesis of RNA dinucleotides such as pA pA, pA pG,...
This article describes a simple, reliable, efficient, and improved solution-phase method for the gram-scale chemical synthesis of RNA dinucleotides such as pA pA, pA pG, and pA pU that utilizes phosphoramidite chemistry. The overall synthetic strategy involves three steps. The first step involves the coupling reaction between 5'-O-MMT protected nucleoside-3'-O-phosphoramidite and a protected nucleoside containing a free 5'-OH group in the presence of tetrazole, followed by the oxidation of phosphite triester using tert-butyl hydroperoxide to give the corresponding protected N pN. Next, the 5'-O-MMT is cleaved under 3% trichloroacetic acid in dichloromethane conditions. Finally, the 5'-hydroxyl group is phosphorylated by the use of an activated bis(2-cyanoethyl)-N,N-diisopropyl phosphoramidite using tetrazole, followed by the oxidation of trivalent to pentavalent phosphorus using tert-butyl hydroperoxide and subsequent deprotection using ammonium hydroxide to afford the corresponding RNA dinucleotide, pN pN, in good yields with high purity (>99.5%). © 2022 Wiley Periodicals LLC.
Topics: Dinucleoside Phosphates; Nucleosides; RNA; tert-Butylhydroperoxide; Tetrazoles
PubMed: 36342272
DOI: 10.1002/cpz1.583