ABSTRACT
Background: Acute coronary syndrome (ACS) hospital admissions decreased during the start of the COVID-19 outbreak. Information is limited on how Google searches were related to patients' behaviour during this time. Methods: We examined de-identified data from 2019 through 2020 regarding the following monthly items: (i) admissions for ACS from the Veterans Affairs Healthcare System; (ii) out-of-hospital cardiac arrest (OHCA) from the National Emergency Medical Services Information System (NEMSIS) public dataset; and (iii) Google searches for "chest pain," "coronavirus," "chest pressure," and "hospital safe" from Google Trends. We analyzed the trends for ACS admissions, OHCA, and Google searches. Results: During the early months of the first COVID-19 outbreak, the following occurred: (i) Veterans Affairs data showed a significant reduction in ACS admissions at a national and regional (Florida) level; (ii) the NEMSIS database showed a marked increase in OHCA at a national level; and (iii) Google Trends showed a significant increase in the before-mentioned Google searches at a national and regional level. Conclusions: ACS hospital admissions decreased during the beginning of the pandemic, likely owing to delayed healthcare utilization secondary to patients fear of acquiring a COVID-19 infection. Concordantly, the volume of Google searches for hospital safety and ACS symptoms increased, along with OHCA events, during the same time. Our results suggest that Google Trends may be a useful tool to predict patients' behaviour and increase preparedness for future events, but statistical strategies to establish association are needed.
Contexte: Les admissions à l'hôpital pour un syndrome coronarien aigu (SCA) ont diminué au début de la pandémie de COVID-19. Or, il existe peu de données sur les recherches effectuées par les patients dans Google pendant cette période. Méthodologie: Nous avons examiné des données mensuelles dépersonnalisées de 2019 à 2020 sur les éléments suivants : i) admissions pour un SCA dans le système de santé de Veterans Affairs aux États-Unis; ii) arrêts cardiaques extrahospitaliers (ACEH) de l'ensemble de données publiques du National Emergency Medical Services Information System (NEMSIS); et iii) les recherches dans Google selon Google Trends pour « chest pain ¼ (douleur thoracique), « coronavirus ¼, « chest pressure ¼ (oppression thoracique) et « hospital safe ¼ (sécurité dans les hôpitaux). Nous avons également analysé les tendances relatives aux admissions pour un SCA, aux ACEH et aux recherches dans Google. Résultats: Pour les premiers mois de la première vague de COVID-19, les observations sont les suivantes : i) les données de Veterans Affairs ont montré une réduction significative des admissions pour un SCA à l'échelle nationale et régionale (Floride); ii) la base de données du NEMSIS a montré une augmentation marquée des ACEH à l'échelle nationale; et iii) les tendances observées au moyen de Google Trends indiquent une augmentation significative à l'échelle nationale et régionale des recherches dans Google à l'aide des termes mentionnés précédemment. Conclusions: Les admissions à l'hôpital pour un SCA ont diminué au début de la pandémie, probablement en raison de la crainte des patients de contracter la COVID-19, qui les a amenés à repousser le recours à des soins de santé. Pendant la même période, le volume des recherches dans Google à propos de la sécurité dans les hôpitaux et les symptômes de SCA a augmenté, tout comme le nombre d'ACEH. Nos résultats semblent indiquer que Google Trends pourrait être un outil pratique pour prédire les comportements des patients et mieux se préparer aux événements futurs, mais il convient d'élaborer des stratégies statistiques permettant de mieux caractériser ces liens.
ABSTRACT
Cellular machines formed by the interaction and assembly of macromolecules are essential in many processes of the living cell. These assemblies involve homo- and hetero-associations, including protein-protein, protein-DNA, protein-RNA, and protein-polysaccharide associations, most of which are reversible. This chapter describes the use of analytical ultracentrifugation, light scattering, and fluorescence-based methods, well-established biophysical techniques, to characterize interactions leading to the formation of macromolecular complexes and their modulation in response to specific or unspecific factors. We also illustrate, with several examples taken from studies on bacterial processes, the advantages of the combined use of subsets of these techniques as orthogonal analytical methods to analyze protein oligomerization and polymerization, interactions with ligands, hetero-associations involving membrane proteins, and protein-nucleic acid complexes.
Subject(s)
Proteins , RNA , Spectrometry, Fluorescence , Proteins/chemistry , Macromolecular Substances , Ultracentrifugation/methodsABSTRACT
Septal Myectomy (SM) and Alcohol Septal Ablation (ASA) improve symptoms in patients with Hypertrophic Cardiomyopathy with outflow tract obstruction (oHCM). However, outcomes data in this population is predominantly from specialized centers. The National Inpatient Database was queried from 2011 to 2019 for relevant international classification of diseases (ICD)-9 and -10 diagnostic and procedural codes. We compared baseline characteristics and in-hospital outcomes of patients with oHCM who underwent SM vs ASA. A p-value < 0.001 was considered statistically significant. We identified 15,119 patients with oHCM who underwent septal reduction therapies, of whom 57.4% underwent SM, and 42.6% underwent ASA. Patients who underwent SM had higher all-cause mortality (OR: 1.8 (1.3-2.5)), post-procedure ischemic stroke (OR: 2.3 (1.7-3.2)), acute kidney injury (OR: 1.4 (1.2-1.7)), vascular complications (OR: 3.6 (2.3-5.3)), ventricular septal defect (OR: 4.4 (3.2-6.1)), cardiogenic shock (OR: 1.7 (1.3-2.3)), sepsis (OR: 3.2 (1.9-5.4)), and left bundle branch block (OR: 3.5 (3-4)), compared to ASA. Patients who underwent ASA had higher post-procedure complete heart block (OR: 1.3 (1.1-1.4)), right bundle branch block (OR: 6.3 (5-7.7)), ventricular tachycardia (OR: 2.2 (1.9-2.6)), supraventricular tachycardia (OR: 1.6 (1.4-2)), and more commonly required pacemaker insertion (OR: 1.4 (1.3-1.7)) (p < 0.001 for all) compared to SM. This nationwide analysis evidenced that patients undergoing SM had higher in-hospital mortality and periprocedural complications than ASA; however, those undergoing ASA had more post-procedure conduction abnormalities and pacemaker implantation. The implications of these findings warrant further investigation regarding patient selection strategies for these therapies.
Subject(s)
Cardiomyopathy, Hypertrophic , Inpatients , Humans , Treatment Outcome , Heart Septum/surgery , Ethanol , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/surgeryABSTRACT
PaaX is a transcriptional repressor of the phenylacetic acid (PAA) catabolic pathway, a central route for bacterial aerobic degradation of aromatic compounds. Induction of the route is achieved through the release of PaaX from its promoter sequences by the first compound of the pathway, phenylacetyl-coenzyme A (PA-CoA). We report the crystal structure of PaaX from Escherichia coli W. PaaX displays a novel type of fold for transcription regulators, showing a dimeric conformation where the monomers present a three-domain structure: an N-terminal winged helix-turn-helix domain, a dimerization domain similar to the Cas2 protein and a C-terminal domain without structural homologs. The domains are separated by a crevice amenable to harbour a PA-CoA molecule. The biophysical characterization of the protein in solution confirmed several hints predicted from the structure, i.e. its dimeric conformation, a modest importance of cysteines and a high dependence of solubility and thermostability on ionic strength. At a moderately acidic pH, the protein formed a stable folding intermediate with remaining α-helical structure, a disrupted tertiary structure and exposed hydrophobic patches. Our results provide valuable information to understand the stability and mechanism of PaaX and pave the way for further analysis of other regulators with similar structural configurations.
Subject(s)
Escherichia coli Proteins , Escherichia coli , Escherichia coli/metabolism , Repressor Proteins/metabolism , Promoter Regions, Genetic , Phenylacetates , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolismABSTRACT
Administration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS-CoV-2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific cytotoxic T cell responses, such as dendritic cell (DC) cross-priming, represent a promising field but have not yet been explored. Here, a broadly nAb, TNT , are first generated by grafting an anti-RBD biparatopic tandem nanobody onto a trimerbody scaffold. Cryo-EM data show that the TNT structure allows simultaneous binding to all six RBD epitopes, demonstrating a high-avidity neutralizing interaction. Then, by C-terminal fusion of an anti-DNGR-1 scFv to TNT , the bispecific trimerbody TNT DNGR-1 is generated to target neutralized virions to type 1 conventional DCs (cDC1s) and promote T cell cross-priming. Therapeutic administration of TNT DNGR-1, but not TNT , protects K18-hACE2 mice from a lethal SARS-CoV-2 infection, boosting virus-specific humoral responses and CD8+ T cell responses. These results further strengthen the central role of interactions with immune cells in the virus-neutralizing antibody activity and demonstrate the therapeutic potential of the Fc-free strategy that can be used advantageously to provide both immediate and long-term protection against SARS-CoV-2 and other viral infections.
Subject(s)
Antibodies, Neutralizing , COVID-19 , Mice , Animals , Antibodies, Neutralizing/therapeutic use , T-Lymphocytes, Cytotoxic , SARS-CoV-2 , Cross-Priming , Dendritic CellsABSTRACT
The conserved process of cell division in bacteria has been a long-standing target for antimicrobials, although there are few examples of potent broad-spectrum compounds that inhibit this process. Most currently available compounds acting on division are directed towards the FtsZ protein, a self-assembling GTPase that is a central element of the division machinery in most bacteria. Benzodioxane-benzamides are promising candidates, but poorly explored in Gram-negatives. We have tested a number of these compounds on E. coli FtsZ and found that many of them significantly stabilized the polymers against disassembly and reduced the GTPase activity. Reconstitution in crowded cell-like conditions showed that FtsZ bundles were also susceptible to these compounds, including some compounds that were inactive on protofilaments in dilute conditions. They efficiently killed E. coli cells defective in the AcrAB efflux pump. The activity of the compounds on cell growth and division generally showed a good correlation with their effect in vitro, and our experiments are consistent with FtsZ being the target in vivo. Our results uncover the detrimental effects of benzodioxane-benzamides on permeable E. coli cells via its central division protein, implying that lead compounds may be found within this class for the development of antibiotics against Gram-negative bacteria.
Subject(s)
Bacterial Proteins , Escherichia coli , Bacterial Proteins/metabolism , Benzamides/pharmacology , Cytoskeletal Proteins/metabolism , Bacteria/metabolism , GTP Phosphohydrolases/metabolism , GTP Phosphohydrolases/pharmacologyABSTRACT
Chia (Salvia hispanica) is an emerging crop considered a functional food containing important substances with multiple potential applications. However, the molecular basis of some relevant chia traits, such as seed mucilage and polyphenol content, remains to be discovered. This study generates an improved chromosome-level reference of the chia genome, resolving some highly repetitive regions, describing methylation patterns, and refining genome annotation. Transcriptomic analysis shows that seeds exhibit a unique expression pattern compared to other organs and tissues. Thus, a metabolic and proteomic approach is implemented to study seed composition and seed-produced mucilage. The chia genome exhibits a significant expansion in mucilage synthesis genes (compared to Arabidopsis), and gene network analysis reveals potential regulators controlling seed mucilage production. Rosmarinic acid, a compound with enormous therapeutic potential, was classified as the most abundant polyphenol in seeds, and candidate genes for its complex pathway are described. Overall, this study provides important insights into the molecular basis for the unique characteristics of chia seeds.
Subject(s)
Salvia hispanica , Salvia , Salvia/genetics , Multiomics , Proteomics , Seeds/genetics , PolysaccharidesABSTRACT
A 67-year-old male presenting with an anterior ST-segment elevation myocardial infarction (STEMI) underwent stent placement in the left anterior descending coronary. The patient was discharged on an appropriate medical regimen containing dual antiplatelet therapy (DAPT). Four days later, the patient presented with repeat acute coronary syndrome symptomatology. Electrocardiogram demonstrated ongoing STEMI in the previously treated artery distribution. Emergency angiography revealed restenosis and total thrombotic occlusion. Post-intervention stenosis was 0% after aspiration thrombectomy and balloon angioplasty. Stent thrombosis is a high-mortality and therapeutically challenging condition requiring prepared clinicians who recognize predisposing risk factors and initiate early management.
ABSTRACT
There has been less emphasis on the prognostic impact of amyloidosis in patients with valvular heart disease (VHD). We aimed to determine the prevalence of amyloidosis in VHD and its clinical implications in terms of mortality. Patients hospitalized for VHD were identified using National Inpatient Sample 2016-2020 which were divided into 2 cohorts: with and without amyloidosis. Among 5,728,873 patients hospitalized with VHD, 11,715 patients had amyloidosis in which mitral valve disease has the highest prevalence (7.6%) followed by aortic (3.6%), and tricuspid valve disease (1%). Underlying amyloidosis is associated with higher mortality in VHD (OR 1.45, CI 1.2-1.7, P<0.001), mainly mitral valve disease (OR 1.44, CI 1.1-1.9, P<0.01). Patients with amyloidosis have higher adjusted mortality rates (5-6% vs 2.6%, P<0.01), longer mean length of stay (7.1 vs 5.7 days, P<0.001), but they have lower valvular intervention rates. In hospitalized VHD patients, underlying amyloidosis is associated with higher in-hospital mortality.
Subject(s)
Heart Valve Diseases , Humans , Prevalence , Prognosis , Heart Valve Diseases/complications , Heart Valve Diseases/epidemiologyABSTRACT
BACKGROUND: C3G is a guanine nucleotide exchange factor (GEF) that activates Rap1 to promote cell adhesion. Resting C3G is autoinhibited and the GEF activity is released by stimuli that signal through tyrosine kinases. C3G is activated by tyrosine phosphorylation and interaction with Crk adaptor proteins, whose expression is elevated in multiple human cancers. However, the molecular details of C3G activation and the interplay between phosphorylation and Crk interaction are poorly understood. METHODS: We combined biochemical, biophysical, and cell biology approaches to elucidate the mechanisms of C3G activation. Binding of Crk adaptor proteins to four proline-rich motifs (P1 to P4) in C3G was characterized in vitro using isothermal titration calorimetry and sedimentation velocity, and in Jurkat and HEK293T cells by affinity pull-down assays. The nucleotide exchange activity of C3G over Rap1 was measured using nucleotide-dissociation kinetic assays. Jurkat cells were also used to analyze C3G translocation to the plasma membrane and the C3G-dependent activation of Rap1 upon ligation of T cell receptors. RESULTS: CrkL interacts through its SH3N domain with sites P1 and P2 of inactive C3G in vitro and in Jurkat and HEK293T cells, and these sites are necessary to recruit C3G to the plasma membrane. However, direct stimulation of the GEF activity requires binding of Crk proteins to the P3 and P4 sites. P3 is occluded in resting C3G and is essential for activation, while P4 contributes secondarily towards complete stimulation. Tyrosine phosphorylation of C3G alone causes marginal activation. Instead, phosphorylation primes C3G lowering the concentration of Crk proteins required for activation and increasing the maximum activity. Unexpectedly, optimal activation also requires the interaction of CrkL-SH2 domain with phosphorylated C3G. CONCLUSION: Our study revealed that phosphorylation of C3G by Src and Crk-binding form a two-factor mechanism that ensures tight control of C3G activation. Additionally, the simultaneous SH2 and SH3N interaction of CrkL with C3G, required for the activation, reveals a novel adaptor-independent function of Crk proteins relevant to understanding their role in physiological signaling and their deregulation in diseases. Video abstract.
Subject(s)
Guanine Nucleotide-Releasing Factor 2 , Nuclear Proteins , Humans , Guanine Nucleotide Exchange Factors/metabolism , Guanine Nucleotide-Releasing Factor 2/metabolism , HEK293 Cells , Nuclear Proteins/metabolism , Nucleotides/metabolism , Proto-Oncogene Proteins c-crk/metabolism , src Homology Domains , Tyrosine/metabolismABSTRACT
Cytokinesis is a fundamental process for bacterial survival and proliferation, involving the formation of a ring by filaments of the GTPase FtsZ, spatio-temporally regulated through the coordinated action of several factors. The mechanisms of this regulation remain largely unsolved, but the inhibition of FtsZ polymerization by the nucleoid occlusion factor SlmA and filament stabilization by the widely conserved cross-linking protein ZapA are known to play key roles. It was recently described that FtsZ, SlmA and its target DNA sequences (SlmA-binding sequence (SBS)) form phase-separated biomolecular condensates, a type of structure associated with cellular compartmentalization and resistance to stress. Using biochemical reconstitution and orthogonal biophysical approaches, we show that FtsZ-SlmA-SBS condensates captured ZapA in crowding conditions and when encapsulated inside cell-like microfluidics microdroplets. We found that, through non-competitive binding, the nucleotide-dependent FtsZ condensate/polymer interconversion was regulated by the ZapA/SlmA ratio. This suggests a highly concentration-responsive tuning of the interconversion that favours FtsZ polymer stabilization by ZapA under conditions mimicking intracellular crowding. These results highlight the importance of biomolecular condensates as concentration hubs for bacterial division factors, which can provide clues to their role in cell function and bacterial survival of stress conditions, such as those generated by antibiotic treatment.
Subject(s)
Acrylates , Biomolecular Condensates , Cytokinesis , PolymersABSTRACT
Dynamic biomolecular condensates formed by liquid-liquid phase separation can regulate the spatial and temporal organization of proteins, thus modulating their functional activity in cells. Previous studies showed that the cell division protein FtsZ from Escherichia coli formed dynamic phase-separated condensates with nucleoprotein complexes containing the FtsZ spatial regulator SlmA under crowding conditions, with potential implications for condensate-mediated spatiotemporal control of FtsZ activity in cell division. In the present study, we assessed formation of these condensates in the presence of lipid surfaces and glutamate ions to better approximate the E. coli intracellular environment. We found that potassium glutamate substantially promoted the formation of FtsZ-containing condensates when compared to potassium chloride in crowded solutions. These condensates accumulated on supported lipid bilayers and eventually fused, resulting in a time-dependent increase in the droplet size. Moreover, the accumulated condensates were dynamic, capturing protein from the external phase. FtsZ partitioned into the condensates at the lipid surface only in its guanosine diphosphate (GDP) form, regardless of whether it came from FtsZ polymer disassembly upon guanosine triphosphate (GTP) exhaustion. These results provide insights into the behavior of these GTP-responsive condensates in minimal membrane systems, which suggest how these membraneless assemblies may tune critical bacterial division events during the cell cycle.
Subject(s)
Carrier Proteins , Cytoskeletal Proteins , Escherichia coli Proteins , Anions/metabolism , Biomolecular Condensates , Carrier Proteins/metabolism , Cell Division , Cytoskeletal Proteins/metabolism , DNA/metabolism , Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Glutamic Acid/metabolism , Guanosine Triphosphate/metabolism , Lipid Bilayers/metabolismABSTRACT
Allopolyploidization, resulting in divergent genomes in the same cell, is believed to trigger a "genome shock", leading to broad genetic and epigenetic changes. However, little is understood about chromatin and gene-expression dynamics as underlying driving forces during allopolyploidization. Here, we examined the genome-wide DNase I-hypersensitive site (DHS) and its variations in domesticated allotetraploid cotton (Gossypium hirsutum and Gossypium barbadense, AADD) and its extant AA (Gossypium arboreum) and DD (Gossypium raimondii) progenitors. We observed distinct DHS distributions between G. arboreum and G. raimondii. In contrast, the DHSs of the two subgenomes of G. hirsutum and G. barbadense showed a convergent distribution. This convergent distribution of DHS was also present in the wild allotetraploids Gossypium darwinii and G. hirsutum var. yucatanense, but absent from a resynthesized hybrid of G. arboreum and G. raimondii, suggesting that it may be a common feature in polyploids, and not a consequence of domestication after polyploidization. We revealed that putative cis-regulatory elements (CREs) derived from polyploidization-related DHSs were dominated by several families, including Dof, ERF48, and BPC1. Strikingly, 56.6% of polyploidization-related DHSs were derived from transposable elements (TEs). Moreover, we observed positive correlations between DHS accessibility and the histone marks H3K4me3, H3K27me3, H3K36me3, H3K27ac, and H3K9ac, indicating that coordinated interplay among histone modifications, TEs, and CREs drives the DHS landscape dynamics under polyploidization. Collectively, these findings advance our understanding of the regulatory architecture in plants and underscore the complexity of regulome evolution during polyploidization.
Subject(s)
Gossypium , Histones , Chromatin/genetics , Deoxyribonuclease I , DNA Transposable Elements , Gossypium/genetics , Histones/geneticsABSTRACT
Transcatheter aortic valve replacement (TAVR) is well-established for severe symptomatic aortic stenosis (AS), but its use in rheumatic heart disease (RHD) has been limited. We systematically review the use of TAVR for severe symptomatic AS in RHD. Pubmed, Embase, and Scopus were searched for TAVR for symptomatic severe AS and proven or suspected RHD. Procedure characteristics, efficacy, and safety endpoints were collected and all definitions were based on the Valve Academic Research Consortium-2 (VARC-2) criteria. We included 3 case series and 12 case reports, with a total of 43 patients. Mean age was 76 years, 75% were female, and 85% had NYHA class III-IV symptoms. Follow up ranged from 1 to 29 months. Patients were moderate to high risk, with Society of Thoracic Surgery score ranging from 6.1% to 17.6%. The approach was transfemoral in 30 (83%) cases. Procedural success occurred in 37 (86%) patients. Of the 7 patients with periprocedural complications, 4 had valve dislodgement, 1 deployment failure, 1 unplanned cardiopulmonary bypass, and 1 moderate aortic regurgitation. Paravalvular leak was reported in 5 (11.6%) patients. Only 1 patient had heart block requiring pacemaker. Among 13 studies (23 patients), 30-day mortality was 0%. One case series with 19 patients had a 30-day, 1-year, 2-year, and 5-year mortality of 5%, 11%, 31%, and 48%, respectively. TAVR appears feasible for selected patients with rheumatic severe AS, albeit our results indicate a 14% incidence of device failure. Future randomized clinical trials may clarify the role of TAVR in this group.
Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Rheumatic Heart Disease , Transcatheter Aortic Valve Replacement , Aged , Aortic Valve/surgery , Aortic Valve Stenosis/surgery , Female , Humans , Male , Rheumatic Heart Disease/complications , Rheumatic Heart Disease/surgery , Risk Factors , Severity of Illness Index , Time Factors , Transcatheter Aortic Valve Replacement/methods , Treatment OutcomeABSTRACT
Academic medicine as a practice model provides unique benefits to society. Clinical care remains an important part of the academic mission; however, equally important are the educational and research missions. More specifically, the sustainability of health care in the United States relies on an educated and expertly trained physician workforce directly provided by academic medicine models. Similarly, the research charge to deliver innovation and discovery to improve health care and to cure disease is key to academic missions. Therefore, to support and promote the growth and sustainability of academic medicine, attracting and engaging top talent from fellows in training and early career faculty is of vital importance. However, as the health care needs of the nation have risen, clinicians have experienced unprecedented demand, and individual wellness and burnout have been examined more closely. Here, we provide a close look at the unique drivers of burnout in academic cardiovascular medicine and propose system-level and personal interventions to support individual wellness in this model.
Subject(s)
Burnout, Professional , Medicine , Physicians , American Heart Association , Burnout, Professional/prevention & control , Delivery of Health Care , Humans , United StatesABSTRACT
The pathophysiological process of ischemia and reperfusion injury (IRI), an inevitable step in organ transplantation, causes important biochemical and structural changes that can result in serious organ damage. IRI is relevant for early graft dysfunction and graft survival. Today, in a global context of organ shortages, most organs come from extended criteria donors (ECDs), which are more sensitive to IRI. The main objective of organ preservation solutions is to protect against IRI through the application of specific, nonphysiological components, under conditions of no blood or oxygen, and then under conditions of metabolic reduction by hypothermia. The composition of hypothermic solutions includes osmotic and oncotic buffering components, and they are intracellular (rich in potassium) or extracellular (rich in sodium). However, above all, they all contain the same type of components intended to protect against IRI, such as glutathione, adenosine and allopurinol. These components have not changed for more than 30 years, even though our knowledge of IRI, and much of the relevant literature, questions their stability or efficacy. In addition, several pharmacological molecules have been the subjects of preclinical studies to optimize this protection. Among them, trimetazidine, tacrolimus and carvedilol have shown the most benefits. In fact, these drugs are already in clinical use, and it is a question of repositioning them for this novel use, without additional risk. This new strategy of including them would allow us to shift from cold storage solutions to cold preservation solutions including multitarget pharmacological components, offering protection against IRI and thus protecting today's more vulnerable organs.
Subject(s)
Organ Preservation Solutions , Reperfusion Injury , Humans , Ischemia , Kidney , Organ Preservation , Organ Preservation Solutions/pharmacology , Reperfusion Injury/prevention & controlABSTRACT
Costimulation of tumor-infiltrating T lymphocytes by anti-4-1BB monoclonal antibodies (mAbs) has shown anti-tumor activity in human trials, but can be associated with significant off-tumor toxicities involving FcγR interactions. Here, we introduce albumin-fused mouse and human bispecific antibodies with clinically favorable pharmacokinetics designed to confine 4-1BB costimulation to the tumor microenvironment. These Fc-free 4-1BB agonists consist of an EGFR-specific VHH antibody, a 4-1BB-specific scFv, and a human albumin sequence engineered for high FcRn binding connected in tandem (LiTCo-Albu). We demonstrate in vitro cognate target engagement, EGFR-specific costimulatory activity, and FcRn-driven cellular recycling similar to non-fused FcRn high-binding albumin. The mouse LiTCo-Albu exhibited a prolonged circulatory half-life and in vivo tumor inhibition, with no indication of 4-1BB mAb-associated toxicity. Furthermore, we show a greater therapeutic effect when used in combination with PD-1-blocking mAbs. These findings demonstrate the feasibility of tumor-specific LiTCo-Albu antibodies for safe and effective costimulatory strategies in cancer immunotherapy.
ABSTRACT
AIMS: The aims of the Critical Care Cardiology Trials Network (CCCTN) are to develop a registry to investigate the epidemiology of cardiac critical illness and to establish a multicentre research network to conduct randomised clinical trials (RCTs) in patients with cardiac critical illness. METHODS AND RESULTS: The CCCTN was founded in 2017 with 16 centres and has grown to a research network of over 40 academic and clinical centres in the United States and Canada. Each centre enters data for consecutive cardiac intensive care unit (CICU) admissions for at least 2 months of each calendar year. More than 20 000 unique CICU admissions are now included in the CCCTN Registry. To date, scientific observations from the CCCTN Registry include description of variations in care, the epidemiology and outcomes of all CICU patients, as well as subsets of patients with specific disease states, such as shock, heart failure, renal dysfunction, and respiratory failure. The CCCTN has also characterised utilization patterns, including use of mechanical circulatory support in response to changes in the heart transplantation allocation system, and the use and impact of multidisciplinary shock teams. Over years of multicentre collaboration, the CCCTN has established a robust research network to facilitate multicentre registry-based randomised trials in patients with cardiac critical illness. CONCLUSION: The CCCTN is a large, prospective registry dedicated to describing processes-of-care and expanding clinical knowledge in cardiac critical illness. The CCCTN will serve as an investigational platform from which to conduct randomised controlled trials in this important patient population.
Subject(s)
Cardiology , Critical Illness , Humans , United States/epidemiology , Critical Illness/epidemiology , Coronary Care Units , Critical Care/methods , RegistriesABSTRACT
BACKGROUND: Brain death (BD) and steatosis are key risk factors to predict adverse post-transplant outcomes. We investigated the role of Neuregulin-1 (NRG1) in rat steatotic and non-steatotic liver transplantation (LT) from brain death donors (DBD). METHODS: NRG1 pathways were characterized after surgery. RESULTS: NRG1 and p21-activated kinase 1 (PAK1) levels increased in steatotic and non-steatotic grafts from DBDs. The abolishment of NRG1 effects reduced PAK1. When the effect of either NRG1 nor PAK1 was inhibited, injury and regenerative failure were exacerbated. The benefits of the NRG-1-PAK1 axis in liver grafts from DBDs were associated with increased vascular endothelial growth factor-A (VEGFA) and insulin growth factor-1 (IGF1) levels, respectively. Indeed, VEGFA administration in non-steatotic livers and IGF1 treatment in steatotic grafts prevented damage and regenerative failure resulting from the inhibition of either NRG1 or PAK-1 activity in each type of liver. Exogenous NRG1 induced greater injury than BD induction. CONCLUSIONS: This study indicates the benefits of endogenous NRG1 in liver grafts from DBDs and underscores the specificity of the NRG1 signaling pathway depending on the type of liver: NRG1-PAK1-VEGFA in non-steatotic livers and NRG1-PAK1-IGF1 in steatotic livers. Exogenous NRG1 is not an appropriate strategy to apply to liver grafts from DBD.
ABSTRACT
Sticholysins are pore-forming toxins produced by the sea anemone Stichodactyla helianthus. When they encounter a sphingomyelin-containing membrane, these proteins bind to it and oligomerize, a process that ends in pore formation. Mounting evidence indicates that StnII can favour the activity of StnI. Previous results have shown that these two isotoxins can oligomerize together. Furthermore, StnII appeared to potentiate the activity of StnI through the membrane-binding step of the process. Hence, isotoxin interaction should occur prior to membrane encounter. Here, we have used analytical ultracentrifugation to investigate the oligomerization of Stns in solution, both separately and together. Our results indicate that while StnI seems to be more prone to oligomerize in water solution than StnII, a small percentage of StnII in StnI-StnII mixtures promotes oligomerization.