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Platelets Dec 2024Percutaneous coronary intervention (PCI) patients combined with thrombocytopenia (TP) are usually considered to be at low ischemic risk, receiving less proper...
Percutaneous coronary intervention (PCI) patients combined with thrombocytopenia (TP) are usually considered to be at low ischemic risk, receiving less proper antiplatelet therapy. However, recent studies reported a paradoxical phenomenon that PCI patients with TP were prone to experience thrombotic events, while the mechanisms and future treatment remain unclear. We aim to investigate whether inflammation modifies platelet reactivity among these patients. Consecutive 10 724 patients undergoing PCI in Fuwai Hospital were enrolled throughout 2013. High-sensitivity C-reactive protein (hsCRP) ≥2 mg/L was considered inflammatory status. TP was defined as platelet count <150×10/L. High on-treatment platelet reactivity (HTPR) was defined as adenosine diphosphate-induced platelet maximum amplitude of thromboelastogram >47mm. Among 6617 patients finally included, 879 (13.3%) presented with TP. Multivariate logistic regression demonstrated that patients with TP were associated with a lower risk of HTPR (odds ratio [OR] 0.64, 95% confidence interval [CI] 0.53-0.76) than those without TP in the overall cohort. In further analysis, among hsCRP <2 mg/L group, patients with TP exhibited a decreased risk of HTPR (OR 0.53, 95% CI 0.41-0.68); however, in hsCRP ≥2mg/L group, TP patients had a similar risk of HTPR as those without TP (OR 0.83, 95% CI 0.63-1.08). Additionally, these results remain consistent across subgroups, including patients presenting with acute coronary syndrome and chronic coronary syndrome. Inflammation modified the platelet reactivity of PCI patients with TP, providing new insights into the mechanisms of the increased thrombotic risk. Future management for this special population should pay more attention to inflammation status and timely adjustment of antiplatelet therapy in TP patients with inflammation.
Topics: Blood Platelets; Inflammation; Thrombocytopenia; Percutaneous Coronary Intervention; Prospective Studies; Cohort Studies; C-Reactive Protein; China; Male; Female; Middle Aged; Aged
PubMed: 38655673
DOI: 10.1080/09537104.2024.2327835 -
Iranian Journal of Pharmaceutical... 2023A novel series of thiadiazole compounds was synthesized through the reaction of thiosemicarbazone intermediates with 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)....
A novel series of thiadiazole compounds was synthesized through the reaction of thiosemicarbazone intermediates with 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The antiplatelet activity of the synthesized compounds was evaluated using an aggregation test with adenosine diphosphate (ADP) and arachidonic acid (AA) as platelet aggregation inducers. Among the synthesized analogs, compound 3b exhibited the most potent inhibition of platelet aggregation induced by ADP (half maximal inhibitory concentration [IC] = 39 ± 11 µM). Molecular docking studies of 3b revealed hydrogen bonds between the nitrogen of the thiadiazole ring and Lys280. The tolyl ring exhibited hydrophobic interactions with Tyr105, similar to the antagonist co-crystallized with PY (PDB ID: 4NTJ). These compounds have the potential to serve as lead molecules for designing PY inhibitors.
PubMed: 38655234
DOI: 10.5812/ijpr-141846 -
JAMA Network Open Apr 2024RAD51C and RAD51D are involved in DNA repair by homologous recombination. Germline pathogenic variants (PVs) in these genes are associated with an increased risk of...
IMPORTANCE
RAD51C and RAD51D are involved in DNA repair by homologous recombination. Germline pathogenic variants (PVs) in these genes are associated with an increased risk of ovarian and breast cancer. Understanding the homologous recombination deficiency (HRD) status of tumors from patients with germline PVs in RAD51C/D could guide therapeutic decision-making and improve survival.
OBJECTIVE
To characterize the clinical and tumor characteristics of germline RAD51C/D PV carriers, including the evaluation of HRD status.
DESIGN, SETTING, AND PARTICIPANTS
This retrospective cohort study included 91 index patients plus 90 relatives carrying germline RAD51C/D PV (n = 181) in Spanish hospitals from January 1, 2014, to December 31, 2021. Genomic and functional HRD biomarkers were assessed in untreated breast and ovarian tumor samples (n = 45) from June 2022 to February 2023.
MAIN OUTCOMES AND MEASURES
Clinical and pathologic characteristics were assessed using descriptive statistics. Genomic HRD by genomic instability scores, functional HRD by RAD51, and gene-specific loss of heterozygosity were analyzed. Associations between HRD status and tumor subtype, age at diagnosis, and gene-specific loss of heterozygosity in RAD51C/D were investigated using logistic regression or the t test.
RESULTS
A total of 9507 index patients were reviewed, and 91 patients (1.0%) were found to carry a PV in RAD51C/D; 90 family members with a germline PV in RAD51C/D were also included. A total of 157 of carriers (86.7%) were women and 181 (55.8%) had received a diagnosis of cancer, mainly breast cancer or ovarian cancer. The most prevalent PVs were c.1026+5_1026+7del (11 of 56 [19.6%]) and c.709C>T (9 of 56 [16.1%]) in RAD51C and c.694C>T (20 of 35 [57.1%]) in RAD51D. In untreated breast cancer and ovarian cancer, the prevalence of functional and genomic HRD was 55.2% (16 of 29) and 61.1% (11 of 18) for RAD51C, respectively, and 66.7% (6 of 9) and 90.0% (9 of 10) for RAD51D. The concordance between HRD biomarkers was 91%. Tumors with the same PV displayed contrasting HRD status, and age at diagnosis did not correlate with the occurrence of HRD. All breast cancers retaining the wild-type allele were estrogen receptor positive and lacked HRD.
CONCLUSIONS AND RELEVANCE
In this cohort study of germline RAD51C/D breast cancer and ovarian cancer, less than 70% of tumors displayed functional HRD, and half of those that did not display HRD were explained by retention of the wild-type allele, which was more frequent among estrogen receptor-positive breast cancers. Understanding which tumors are associated with RAD51C/D and HRD is key to identify patients who can benefit from targeted therapies, such as PARP (poly [adenosine diphosphate-ribose] polymerase) inhibitors.
Topics: Adult; Female; Humans; Breast Neoplasms; DNA-Binding Proteins; Genetic Predisposition to Disease; Germ-Line Mutation; Homologous Recombination; Ovarian Neoplasms; Prevalence; Retrospective Studies; Spain; Rad51 Recombinase
PubMed: 38648056
DOI: 10.1001/jamanetworkopen.2024.7811 -
ACS Chemical Biology May 2024Viral macrodomains that can bind to or hydrolyze protein adenosine diphosphate ribosylation (ADP-ribosylation) have emerged as promising targets for antiviral drug...
Viral macrodomains that can bind to or hydrolyze protein adenosine diphosphate ribosylation (ADP-ribosylation) have emerged as promising targets for antiviral drug development. Many inhibitor development efforts have been directed against the severe acute respiratory syndrome coronavirus 2 macrodomain 1 (SARS-CoV-2 Mac1). However, potent inhibitors for viral macrodomains are still lacking, with the best inhibitors still in the micromolar range. Based on , a remdesivir precursor, and our previous studies, we have designed and synthesized potent binders of SARS-CoV-2 Mac1 and other viral macrodomains including those of Middle East respiratory syndrome coronavirus (MERS-CoV), Venezuelan equine encephalitis virus (VEEV), and Chikungunya virus (CHIKV). We show that the 1'-CN group of promotes binding to all four viral macrodomains tested while capping the 1″-OH of -diphosphate-ribose with a simple phenyl ring further contributes to binding. Incorporating these two structural features, the best binders show 20- to 6000-fold increases in binding affinity over ADP-ribose for SARS-CoV-2, MERS-CoV, VEEV, and CHIKV macrodomains. Moreover, building on these potent binders, we have developed two highly sensitive fluorescence polarization tracers that only require nanomolar proteins and can effectively resolve the binding affinities of nanomolar inhibitors. Our findings and probes described here will facilitate future development of more potent viral macrodomain inhibitors.
Topics: Humans; Adenosine Diphosphate Ribose; Adenosine Monophosphate; Antiviral Agents; Chikungunya virus; COVID-19; COVID-19 Drug Treatment; Encephalitis Virus, Venezuelan Equine; Fluorescence Polarization; Middle East Respiratory Syndrome Coronavirus; Protein Binding; Protein Domains; SARS-CoV-2
PubMed: 38646883
DOI: 10.1021/acschembio.4c00027 -
PloS One 2024Sterile alpha and TIR motif-containing 1 (SARM1) is a protein involved in programmed death of injured axons. Following axon injury or a drug-induced insult, the TIR...
Sterile alpha and TIR motif-containing 1 (SARM1) is a protein involved in programmed death of injured axons. Following axon injury or a drug-induced insult, the TIR domain of SARM1 degrades the essential molecule nicotinamide adenine dinucleotide (NAD+), leading to a form of axonal death called Wallerian degeneration. Degradation of NAD+ by SARM1 is essential for the Wallerian degeneration process, but accumulating evidence suggest that other activities of SARM1, beyond the mere degradation of NAD+, may be necessary for programmed axonal death. In this study we show that the TIR domains of both human and fruit fly SARM1 produce 1''-2' and 1''-3' glycocyclic ADP-ribose (gcADPR) molecules as minor products. As previously reported, we observed that SARM1 TIR domains mostly convert NAD+ to ADPR (for human SARM1) or cADPR (in the case of SARM1 from Drosophila melanogaster). However, we now show that human and Drosophila SARM1 additionally convert ~0.1-0.5% of NAD+ into gcADPR molecules. We find that SARM1 TIR domains produce gcADPR molecules both when purified in vitro and when expressed in bacterial cells. Given that gcADPR is a second messenger involved in programmed cell death in bacteria and likely in plants, we propose that gcADPR may play a role in SARM1-induced programmed axonal death in animals.
Topics: Animals; Humans; Wallerian Degeneration; NAD; Drosophila melanogaster; Axons; Bacteria; Adenosine Diphosphate Ribose; Armadillo Domain Proteins; Cytoskeletal Proteins
PubMed: 38635746
DOI: 10.1371/journal.pone.0302251 -
International Journal of Cardiology.... Apr 2024In this study, we investigated clinical prediction factors of nonchronic total occlusion lesion (NCTOL) progression in patients who underwent percutaneous coronary...
Clinical prediction factors of nonchronic total occlusion lesion progression in patients with unstable angina receiving percutaneous coronary intervention for chronic total occlusion lesions.
BACKGROUND
In this study, we investigated clinical prediction factors of nonchronic total occlusion lesion (NCTOL) progression in patients who underwent percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions.
METHODS
In total, 450 patients with unstable angina (mean age = 57.1 ± 9.2 years) who underwent PCI for CTO lesions between January 2016 and December 2018 at Beijing Anzhen Hospital were enrolled in this study. A clinical and angiographic follow-up examination was performed 12 months postoperatively. The patients were divided into NCTOL progression (145 cases) and control (305 cases) groups based on the outcome of the 12-month angiographic follow-up. The clinical and angiographic features of the participants were analyzed.
RESULTS
The adenosine diphosphate-induced platelet aggregation (ADP-IPA) rate and levels of lipoprotein (a) () in the NCTOL progression group were significantly higher than those in the control group (51.89 ± 14.81 39.63 ± 17.12, < 0.01; 0.22 ± 0.26 0.14 ± 0.18, < 0.05, respectively). Logistic regression showed that the ADP-IPA rate (odds ratio = 1.047, 95 % confidence interval: 1.014-1.082, = 0.005) and (odds ratio = 11.972, 95 % confidence interval: 1.230-116.570, = 0.033) were independent predictors of NCTOL progression. Partial correlation analysis demonstrated that the ADP-IPA rate was positively correlated with NCTOL progression ( = 0. 351, < 0.001). Receiver operating characteristic curve showed that the boundary point of the ADP-IPA rate to predict NCTOL progression was 30 % (sensitivity, 86.2 %; specificity, 68.9 %).
CONCLUSIONS
NCTOL progression is an important cause of recurrent PCI in patients with coronary artery disease after PCI for CTO lesions. The ADP-IPA rate is a useful predictor for NCTOL progression in patients with unstable angina who undergo PCI for CTO lesions.
PubMed: 38628294
DOI: 10.1016/j.ijcha.2024.101395 -
The Biochemical Journal Apr 2024The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. When activated by increases in ADP:ATP and/or AMP:ATP ratios (signalling energy deficit),...
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. When activated by increases in ADP:ATP and/or AMP:ATP ratios (signalling energy deficit), AMPK acts to restore energy balance. Binding of AMP to one or more of three CBS repeats (CBS1, CBS3, CBS4) on the AMPK-γ subunit activates the kinase complex by three complementary mechanisms: (i) promoting α-subunit Thr172 phosphorylation by the upstream kinase LKB1; (ii) protecting against Thr172 dephosphorylation; (iii) allosteric activation. Surprisingly, binding of ADP has been reported to mimic the first two effects, but not the third. We now show that at physiologically relevant concentrations of Mg.ATP2- (above those used in the standard assay) ADP binding does cause allosteric activation. However, ADP causes only a modest activation because (unlike AMP), at concentrations just above those where activation becomes evident, ADP starts to cause competitive inhibition at the catalytic site. Our results cast doubt on the physiological relevance of the effects of ADP and suggest that AMP is the primary activator in vivo. We have also made mutations to hydrophobic residues involved in binding adenine nucleotides at each of the three γ subunit CBS repeats of the human α2β2γ1 complex and examined their effects on regulation by AMP and ADP. Mutation of the CBS3 site has the largest effects on all three mechanisms of AMP activation, especially at lower ATP concentrations, while mutation of CBS4 reduces the sensitivity to AMP. All three sites appear to be required for allosteric activation by ADP.
Topics: Adenosine Diphosphate; Adenosine Monophosphate; Humans; Allosteric Regulation; AMP-Activated Protein Kinases; Ligands; Phosphorylation; Adenosine Triphosphate; Enzyme Activation; Protein Binding
PubMed: 38592738
DOI: 10.1042/BCJ20240082 -
Frontiers in Oncology 2024ADP-dependent glucokinase (ADPGK) produces glucose-6-phosphate with adenosine diphosphate (ADP) as the phosphate group donor, in contrast to ATP-dependent hexokinases... (Review)
Review
ADP-dependent glucokinase (ADPGK) produces glucose-6-phosphate with adenosine diphosphate (ADP) as the phosphate group donor, in contrast to ATP-dependent hexokinases (HKs). Originally found in archaea, ADPGK is involved in glycolysis. However, its biological function in most eukaryotic organisms is still unclear, and the molecular mechanism of action requires further investigation. This paper provides a concise overview of ADPGK's origin, biological function and clinical application. It aims to furnish scientific information for the diagnosis and treatment of human metabolic diseases, neurological disorders, and malignant tumours, and to suggest new strategies for the development of targeted drugs.
PubMed: 38590647
DOI: 10.3389/fonc.2024.1358904 -
Frontiers in Immunology 2024CD39 is the major enzyme controlling the levels of extracellular adenosine triphosphate (ATP) via the stepwise hydrolysis of ATP to adenosine diphosphate (ADP) and...
CD39 is the major enzyme controlling the levels of extracellular adenosine triphosphate (ATP) via the stepwise hydrolysis of ATP to adenosine diphosphate (ADP) and adenosine monophosphate (AMP). As extracellular ATP is a strong promoter of inflammation, monoclonal antibodies (mAbs) blocking CD39 are utilized therapeutically in the field of immune-oncology. Though anti-CD39 mAbs are highly specific for their target, they lack deep penetration into the dense tissue of solid tumors, due to their large size. To overcome this limitation, we generated and characterized nanobodies that targeted and blocked human CD39. From cDNA-immunized alpacas we selected 16 clones from seven nanobody families that bind to two distinct epitopes of human CD39. Among these, clone SB24 inhibited the enzymatic activity of CD39. Of note, SB24 blocked ATP degradation by both soluble and cell surface CD39 as a 15kD monomeric nanobody. Dimerization via fusion to an immunoglobulin Fc portion further increased the blocking potency of SB24 on CD39-transfected HEK cells. Finally, we confirmed the CD39 blocking properties of SB24 on human PBMCs. In summary, SB24 provides a new small biological antagonist of human CD39 with potential application in cancer therapy.
Topics: Humans; Single-Domain Antibodies; Adenosine Triphosphate; Adenosine Monophosphate; Adenosine Diphosphate
PubMed: 38590528
DOI: 10.3389/fimmu.2024.1328306 -
The Journal of Biological Chemistry May 2024Actin bundling proteins crosslink filaments into polarized structures that shape and support membrane protrusions including filopodia, microvilli, and stereocilia. In...
Actin bundling proteins crosslink filaments into polarized structures that shape and support membrane protrusions including filopodia, microvilli, and stereocilia. In the case of epithelial microvilli, mitotic spindle positioning protein (MISP) is an actin bundler that localizes specifically to the basal rootlets, where the pointed ends of core bundle filaments converge. Previous studies established that MISP is prevented from binding more distal segments of the core bundle by competition with other actin-binding proteins. Yet whether MISP holds a preference for binding directly to rootlet actin remains an open question. By immunostaining native intestinal tissue sections, we found that microvillar rootlets are decorated with the severing protein, cofilin, suggesting high levels of ADP-actin in these structures. Using total internal reflection fluorescence microscopy assays, we also found that purified MISP exhibits a binding preference for ADP- versus ADP-Pi-actin-containing filaments. Consistent with this, assays with actively growing actin filaments revealed that MISP binds at or near their pointed ends. Moreover, although substrate attached MISP assembles filament bundles in parallel and antiparallel configurations, in solution MISP assembles parallel bundles consisting of multiple filaments exhibiting uniform polarity. These discoveries highlight nucleotide state sensing as a mechanism for sorting actin bundlers along filaments and driving their accumulation near filament ends. Such localized binding might drive parallel bundle formation and/or locally modulate bundle mechanical properties in microvilli and related protrusions.
Topics: Animals; Actin Cytoskeleton; Actin Depolymerizing Factors; Actins; Adenosine Diphosphate; Cell Cycle Proteins; Microfilament Proteins; Microvilli; Protein Binding
PubMed: 38588808
DOI: 10.1016/j.jbc.2024.107279