RESUMO
Classically, chemokines coordinate leukocyte trafficking during immune responses; however, many chemokines have also been reported to possess direct antibacterial activity in vitro. Yet, the bacterial killing mechanism of chemokines and the biochemical properties that define which members of the chemokine superfamily are antimicrobial remain poorly understood. Here we report that the antimicrobial activity of chemokines is defined by their ability to bind phosphatidylglycerol and cardiolipin, two anionic phospholipids commonly found in the bacterial plasma membrane. We show that only chemokines able to bind these two phospholipids kill Escherichia coli and Staphylococcus aureus and that they exert rapid bacteriostatic and bactericidal effects against E. coli with a higher potency than the antimicrobial peptide beta-defensin 3. Furthermore, our data support that bacterial membrane cardiolipin facilitates the antimicrobial action of chemokines. Both biochemical and genetic interference with the chemokine-cardiolipin interaction impaired microbial growth arrest, bacterial killing, and membrane disruption by chemokines. Moreover, unlike conventional antibiotics, E. coli failed to develop resistance when placed under increasing antimicrobial chemokine pressure in vitro. Thus, we have identified cardiolipin and phosphatidylglycerol as novel binding partners for chemokines responsible for chemokine antimicrobial action. Our results provide proof of principle for developing chemokines as novel antibiotics resistant to bacterial antimicrobial resistance mechanisms.
RESUMO
Background and purpose: Integrating simultaneous interstitial hyperthermia in high-dose-rate brachytherapy treatments (HDR-BT) is expected to lead to enhanced therapeutic effect. However, there is currently no device available for such an integration. In this study, we presented and validated the thermobrachytherapy (TBT) preclinical prototype system that is able to seamlessly integrate into the HDR-BT workflow. Materials and methods: The TBT system consisted of an advanced radiofrequency power delivery and control system, dual-function interstitial applicators, and integrated connection and impedance matching system. The efficiency and minimum heating ability of the system was calculated performing calorimetric experiments. The effective-heating-length and heating pattern was evaluated using single-applicator split phantom experiments. The heating independence between applicators, the ability of the system to adaptable and predictable temperature steering was evaluated using multi-applicator split phantom experiments. Results: The system satisfied interstitial hyperthermia requirements. It demonstrated 50 % efficiency and ability to reach 6 °C temperature increase in 6 min. Effective-heating-length of the applicator was 43.7 mm, following the initial design. Heating pattern interference between applicators was lower than recommended. The system showed its ability to generate diverse heating patterns by adjusting the phase and amplitude settings of each electrode, aligning well with simulations (minimum agreement of 88 %). Conclusions: The TBT preclinical prototype system complied with IHT requirements, and agreed well with design criteria and simulations, hence performing as expected. The preclinical prototype TBT system can now be scaled to an in-vivo validation prototype, including an adaptable impedance matching solution, appropriate number of channels, and ensuring biocompatibility and regulatory compliance.
RESUMO
Magnetic resonance thermometry (MRT) can measure in-vivo 3D-temperature changes in real-time and noninvasively. However, for the oropharynx region and the entire head and neck, motion potentially introduces large artifacts. Considering long treatment times of 60-90 min, this study aims to evaluate whether MRT around the oropharynx is clinically feasible for hyperthermia treatments and quantify the effects of breathing and swallowing on MRT performance. A 3D-ME-FGRE sequence was used in a phantom cooling down and around the oropharynx of five volunteers over â¼75 min. The imaging protocol consisted of imaging with acceleration (ARC = 2), number of image averages (NEX = 1,2 and 3). For volunteers, the acquisitions included a breath-hold scan and scans with deliberate swallowing. MRT performance was quantified in neck muscle, spinal cord and masseter muscle, using mean average error (MAE), mean error (ME) and spatial standard deviation (SD). In phantom, an increase in NEX leads to a significant decrease in SD, but MAE and ME were unchanged. No significant difference was found in volunteers between the different scans. There was a significant difference between the regions evaluated: neck muscle had the best MAE (=1.96 °C) and SD (=0.82 °C), followed by spinal cord (MAE = 3.17 °C, SD = 0.92 °C) and masseter muscle (MAE = 4.53 °C, SD = 1.16 °C). Concerning the ME, spinal cord did best, then neck muscle and masseter muscle, with values of -0.64 °C, 1.15 °C and -3.05 °C respectively. Breathing, swallowing, and different ways of imaging (acceleration and NEX) do not significantly influence the MRT performance in the oropharynx region. The ROI selected however, leads to significant differences.
Assuntos
Imageamento por Ressonância Magnética , Orofaringe , Termometria , Humanos , Imageamento por Ressonância Magnética/métodos , Termometria/métodos , Orofaringe/diagnóstico por imagem , Masculino , Adulto , Hipertermia Induzida/métodos , Feminino , Imagens de FantasmasRESUMO
BACKGROUND: Retinoblastoma is the most common intra-ocular malignancy in children and frequently presents in very young patients who commonly require intravenous carboplatin. Delivering this is challenging due to a lack of uniform dosing recommendations, rapid changes in physiological function and the risk of side-effects. METHODS: We conducted a retrospective review of neonates and infants in the UK with retinoblastoma, who have undergone carboplatin therapeutic drug monitoring (TDM). We report on the pharmacokinetic, treatment efficacy and toxicity data. RESULTS: In total, 29 patients (median age 5 weeks at treatment onset) underwent a total of 74 TDM guided cycles of chemotherapy, involving real time sampling and dose adjustment. An additional 13 patients underwent TDM sampling to modify doses between cycles. Without the adoption of TDM guided dosing, carboplatin exposures would have been ≥20% outside the target AUC in 38/78 (49%) of treatment cycles. Excellent responses and a reassuringly low incidence of toxicities were observed following dose adjustment, despite the young patient age and the implementation of dose increases in the majority of cases. CONCLUSIONS: Real time TDM is safe, effective and deliverable for neonates and infants receiving carboplatin for retinoblastoma and should be considered standard of care up to the age of 6 months.
Assuntos
Carboplatina , Monitoramento de Medicamentos , Neoplasias da Retina , Retinoblastoma , Humanos , Retinoblastoma/tratamento farmacológico , Carboplatina/administração & dosagem , Lactente , Recém-Nascido , Monitoramento de Medicamentos/métodos , Reino Unido , Feminino , Estudos Retrospectivos , Masculino , Neoplasias da Retina/tratamento farmacológico , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos , Resultado do TratamentoRESUMO
Deterministic formation of membrane scission necks by protein machinery with multiplexed functions is critical in biology. A microbial example is M2 viroporin, a proton pump from the influenza A virus that is multiplexed with membrane remodeling activity to induce budding and scission in the host membrane during viral maturation. In comparison, the dynamin family constitutes a class of eukaryotic proteins implicated in mitochondrial fission, as well as various budding and endocytosis pathways. In the case of Dnm1, the mitochondrial fission protein in yeast, the membrane remodeling activity is multiplexed with mechanoenzyme activity to create fission necks. It is not clear why these functions are combined in these scission processes, which occur in drastically different compositions and solution conditions. In general, direct experimental access to changing neck sizes induced by individual proteins or peptide fragments is challenging due to the nanoscale dimensions and influence of thermal fluctuations. Here, we use a mechanical model to estimate the size of scission necks by leveraging small-angle X-ray scattering structural data of protein-lipid systems under different conditions. The influence of interfacial tension, lipid composition, and membrane budding morphology on the size of the induced scission necks is systematically investigated using our data and molecular dynamic simulations. We find that the M2 budding protein from the influenza A virus has robust pH-dependent membrane activity that induces nanoscopic necks within the range of spontaneous hemifission for a broad range of lipid compositions. In contrast, the sizes of scission necks generated by mitochondrial fission proteins strongly depend on lipid composition, which suggests a role for mechanical constriction.
Assuntos
Membrana Celular , Membrana Celular/metabolismo , Membrana Celular/química , Proteínas da Matriz Viral/metabolismo , Proteínas da Matriz Viral/química , Dinaminas/metabolismo , Dinaminas/química , Vírus da Influenza A/metabolismo , Espalhamento a Baixo Ângulo , Proteínas ViroporinasRESUMO
AIMS: Heart failure (HF), a global pandemic affecting millions of individuals, calls for adequate predictive guidance for improved therapy. Congestion, a key factor in HF-related hospitalizations, further underscores the need for timely interventions. Proactive monitoring of intracardiac pressures, guided by pulmonary artery (PA) pressure, offers opportunities for efficient early-stage intervention, since haemodynamic congestion precedes clinical symptoms. METHODS: The BioMEMS study, a substudy of the MONITOR-HF trial, proposes a multifaceted approach integrating blood biobank data with traditional and novel HF parameters. Two additional blood samples from 340 active participants in the MONITOR-HF trial were collected at baseline, 3-, 6-, and 12-month visits and stored for the BioMEMS biobank. The main aims are to identify the relationship between temporal biomarker patterns and PA pressures derived from the CardioMEMS-HF system, and to identify the biomarker profile(s) associated with the risk of HF events and cardiovascular death. CONCLUSION: Since the prognostic value of single baseline measurements of biomarkers like N-terminal pro-B-type natriuretic peptide is limited, with the BioMEMS study we advocate a dynamic, serial approach to better capture HF progression. We will substantiate this by relating repeated biomarker measurements to PA pressures. This design rationale presents a comprehensive review on cardiac biomarkers in HF, and aims to contribute valuable insights into personalized HF therapy and patient risk assessment, advancing our ability to address the evolving nature of HF effectively.
Assuntos
Biomarcadores , Insuficiência Cardíaca , Artéria Pulmonar , Humanos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/sangue , Biomarcadores/sangue , Prognóstico , Artéria Pulmonar/fisiopatologia , Feminino , Masculino , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Idoso , Pressão Propulsora Pulmonar/fisiologia , Doença Crônica , Pessoa de Meia-IdadeRESUMO
AIMS: Despite clear guideline recommendations for initiating four drug classes in all patients with heart failure (HF) with reduced ejection fraction (HFrEF) and the availability of rapid titration schemes, information on real-world implementation lags behind. Closely following the 2021 ESC HF guidelines and 2023 focused update, the TITRATE-HF study started to prospectively investigate the use, sequencing, and titration of guideline-directed medical therapy (GDMT) in HF patients, including the identification of implementation barriers. METHODS AND RESULTS: TITRATE-HF is an ongoing long-term HF registry conducted in the Netherlands. Overall, 4288 patients from 48 hospitals were included. Among these patients, 1732 presented with de novo, 2240 with chronic, and 316 with worsening HF. The median age was 71 years (interquartile range [IQR] 63-78), 29% were female, and median ejection fraction was 35% (IQR 25-40). In total, 44% of chronic and worsening HFrEF patients were prescribed quadruple therapy. However, only 1% of HFrEF patients achieved target dose for all drug classes. In addition, quadruple therapy was more often prescribed to patients treated in a dedicated HF outpatient clinic as compared to a general cardiology outpatient clinic. In each GDMT drug class, 19% to 36% of non-use in HFrEF patients was related to side-effects, intolerances, or contraindications. In the de novo HF cohort, 49% of patients already used one or more GDMT drug classes for other indications than HF. CONCLUSION: This first analysis of the TITRATE-HF study reports relatively high use of GDMT in a contemporary HF cohort, while still showing room for improvement regarding quadruple therapy. Importantly, the use and dose of GDMT were suboptimal, with the reasons often remaining unclear. This underscores the urgency for further optimization of GDMT and implementation strategies within HF management.
Assuntos
Progressão da Doença , Insuficiência Cardíaca , Sistema de Registros , Volume Sistólico , Humanos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Feminino , Masculino , Idoso , Volume Sistólico/fisiologia , Pessoa de Meia-Idade , Países Baixos , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Doença Crônica , Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Quimioterapia CombinadaRESUMO
We explore the potential of nanocrystals (a term used equivalently to nanoparticles) as building blocks for nanomaterials, and the current advances and open challenges for fundamental science developments and applications. Nanocrystal assemblies are inherently multiscale, and the generation of revolutionary material properties requires a precise understanding of the relationship between structure and function, the former being determined by classical effects and the latter often by quantum effects. With an emphasis on theory and computation, we discuss challenges that hamper current assembly strategies and to what extent nanocrystal assemblies represent thermodynamic equilibrium or kinetically trapped metastable states. We also examine dynamic effects and optimization of assembly protocols. Finally, we discuss promising material functions and examples of their realization with nanocrystal assemblies.
RESUMO
AIMS: To describe the baseline characteristics of participants in the FINEARTS-HF trial, contextualized with prior trials including patients with heart failure (HF) with mildly reduced and preserved ejection fraction (HFmrEF/HFpEF). The FINEARTS-HF trial is comparing the effects of the non-steroidal mineralocorticoid receptor antagonist finerenone with placebo in reducing cardiovascular death and total worsening HF events in patients with HFmrEF/HFpEF. METHODS AND RESULTS: Patients with symptomatic HF, left ventricular ejection fraction (LVEF) ≥40%, estimated glomerular filtration rate ≥ 25 ml/min/1.73 m2, elevated natriuretic peptide levels and evidence of structural heart disease were enrolled and randomized to finerenone titrated to a maximum of 40 mg once daily or matching placebo. We validly randomized 6001 patients to finerenone or placebo (mean age 72 ± 10 years, 46% women). The majority were New York Heart Association functional class II (69%). The baseline mean LVEF was 53 ± 8% (range 34-84%); 36% of participants had a LVEF <50% and 64% had a LVEF ≥50%. The median N-terminal pro-B-type natriuretic peptide (NT-proBNP) was 1041 (interquartile range 449-1946) pg/ml. A total of 1219 (20%) patients were enrolled during or within 7 days of a worsening HF event, and 3247 (54%) patients were enrolled within 3 months of a worsening HF event. Compared with prior large-scale HFmrEF/HFpEF trials, FINEARTS-HF participants were more likely to have recent (within 6 months) HF hospitalization and greater symptoms and functional limitations. Further, concomitant medications included a larger percentage of sodium-glucose cotransporter 2 inhibitors and angiotensin receptor-neprilysin inhibitors than previous trials. CONCLUSIONS: FINEARTS-HF has enrolled a broad range of high-risk patients with HFmrEF and HFpEF. The trial will determine the safety and efficacy of finerenone in this population.
Assuntos
Insuficiência Cardíaca , Antagonistas de Receptores de Mineralocorticoides , Naftiridinas , Volume Sistólico , Humanos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/tratamento farmacológico , Volume Sistólico/fisiologia , Feminino , Masculino , Idoso , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Naftiridinas/uso terapêutico , Método Duplo-Cego , Função Ventricular Esquerda/fisiologia , Função Ventricular Esquerda/efeitos dos fármacos , Pessoa de Meia-Idade , Resultado do Tratamento , Taxa de Filtração Glomerular/fisiologia , Peptídeo Natriurético Encefálico/sangueRESUMO
BACKGROUND AND AIMS: In patients with chronic heart failure (HF), the MONITOR-HF trial demonstrated the efficacy of pulmonary artery (PA)-guided HF therapy over standard of care in improving quality of life and reducing HF hospitalizations and mean PA pressure. This study aimed to evaluate the consistency of these benefits in relation to clinically relevant subgroups. METHODS: The effect of PA-guided HF therapy was evaluated in the MONITOR-HF trial among predefined subgroups based on age, sex, atrial fibrillation, diabetes mellitus, left ventricular ejection fraction, HF aetiology, cardiac resynchronization therapy, and implantable cardioverter defibrillator. Outcome measures were based upon significance in the main trial and included quality of life-, clinical-, and PA pressure endpoints, and were assessed for each subgroup. Differential effects in relation to the subgroups were assessed with interaction terms. Both unadjusted and multiple testing adjusted interaction terms were presented. RESULTS: The effects of PA monitoring on quality of life, clinical events, and PA pressure were consistent in the predefined subgroups, without any clinically relevant heterogeneity within or across all endpoint categories (all adjusted interaction P-values were non-significant). In the unadjusted analysis of the primary endpoint quality-of-life change, weak trends towards a less pronounced effect in older patients (Pinteraction = .03; adjusted Pinteraction = .33) and diabetics (Pinteraction = .01; adjusted Pinteraction = .06) were observed. However, these interaction effects did not persist after adjusting for multiple testing. CONCLUSIONS: This subgroup analysis confirmed the consistent benefits of PA-guided HF therapy observed in the MONITOR-HF trial across clinically relevant subgroups, highlighting its efficacy in improving quality of life, clinical, and PA pressure endpoints in chronic HF patients.
Assuntos
Insuficiência Cardíaca , Artéria Pulmonar , Qualidade de Vida , Humanos , Insuficiência Cardíaca/terapia , Insuficiência Cardíaca/fisiopatologia , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Artéria Pulmonar/fisiopatologia , Doença Crônica , Volume Sistólico/fisiologia , Terapia de Ressincronização Cardíaca/métodos , Desfibriladores ImplantáveisRESUMO
BACKGROUND: Several ethnic minorities have an increased risk of cardiovascular events, but previous European trials that investigated clinical outcome after coronary stenting did not assess the patients' ethnic background. AIMS: To compare ethnic minority and Western European trial participants in terms of both cardiovascular risk profile and 1year clinical outcome after percutaneous coronary intervention. METHODS: In the BIO-RESORT and BIONYX randomised trials, which assessed new-generation drug-eluting stents, information on patients' self-reported ethnic background was prospectively collected. Pooled patient-level data of 5803 patients, enrolled in the Netherlands and Belgium, were analysed in this prespecified analysis. The main endpoint was target vessel failure after 1 year. RESULTS: Patients were classified as belonging to an ethnic minority (nâ¯= 293, 5%) or of Western European origin (nâ¯= 5510, 95%). Follow-up data were available in 5772 of 5803 (99.5%) patients. Ethnic minority patients were younger, less often female, more often current smokers, more often medically treated for diabetes, and more often had a positive family history of coronary artery disease. The main endpoint target vessel failure did not differ between ethnic minority and Western European patients (3.5% vs 4.9%, hazard ratio 0.71, 95% confidence interval 0.38-1.33; pâ¯= 0.28). There was also no difference in mortality, myocardial infarction, and repeat revascularisation rates. CONCLUSIONS: Despite the unfavourable cardiovascular risk profile of ethnic minority patients, short-term clinical outcome after treatment with contemporary drug-eluting stents was highly similar to that in Western European patients. Further efforts should be made to ensure the enrolment of more ethnic minority patients in future coronary stent trials.
RESUMO
Volumetric functional imaging of transient cellular signaling and motion dynamics poses a significant challenge to current microscopy techniques, primarily due to limitations in hardware bandwidth and the restricted photon budget within short exposure times. In response to this challenge, we present squeezed light field microscopy (SLIM), a computational imaging method that enables rapid detection of high-resolution three-dimensional (3D) light signals using only a single, low-format camera sensor area. SLIM pushes the boundaries of 3D optical microscopy, achieving over one thousand volumes per second across a large field of view of 550 µm in diameter and 300 µm in depth. Using SLIM, we demonstrated blood cell velocimetry across the embryonic zebrafish brain and in a free-moving tail exhibiting high-frequency swinging motion. The millisecond temporal resolution also enables accurate voltage imaging of neural membrane potentials in the leech ganglion. These results collectively establish SLIM as a versatile and robust imaging tool for high-speed microscopy applications.
RESUMO
Background: Despite its global significance, challenges associated with understanding the epidemiology and accurately detecting, measuring, and characterizing the true burden of seasonal influenza remain in many resource-poor settings. Methods: A prospective observational study was conducted in Cambodia at 28 health facilities between 2007 and 2020 utilizing passive surveillance data of patients presenting with acute undifferentiated febrile illness (AUFI) to describe the prevalence of influenza A and B and characterize associated risk factors and symptoms using a questionnaire. A comparison of rapid influenza diagnostic tests (RIDTs) and real-time reverse transcription polymerase chain reaction (rRT-PCR) results was also conducted. Results: Of 30 586 total participants, 5634 (18.4%) tested positive for either influenza A or B, with 3557 (11.6%) positive for influenza A and 2288 (7.5%) positive for influenza B during the study. Influenza A and B were strongly associated with the rainy season (odds ratio [OR], 2.30; P < .001) and being from an urban area (OR, 1.45; P < .001). Analysis of individual symptoms identified cough (OR, 2.8; P < .001), chills (OR, 1.4; P < .001), and sore throat (OR, 1.4; P < .001) as having the strongest positive associations with influenza among patients with AUFI. Analysis comparing RIDTs and rRT-PCR calculated the overall sensitivity of rapid tests to be 0.492 (95% CI, 0.479-0.505) and specificity to be 0.993 (95% CI, 0.992-0.994) for both influenza type A and B. Conclusions: Findings from this 14-year study include describing the epidemiology of seasonal influenza over a prolonged time period and identifying key risk factors and clinical symptoms associated with infection; we also demonstrate the poor sensitivity of RIDTs in Cambodia.
RESUMO
Hyperthermia treatment consists of elevating the temperature of the tumor to increase the effectiveness of radiotherapy and chemotherapy. Hyperthermia treatment planning (HTP) is an important tool to optimize treatment quality using pre-treatment temperature predictions. The accuracy of these predictions depends on modeling uncertainties such as tissue properties and positioning. In this study, we evaluated if HTP accuracy improves when the patient is imaged inside the applicator at the start of treatment. Because perfusion is a major uncertainty source, the importance of accurate treatment position and anatomy was evaluated using different perfusion values. Volunteers were scanned using MR imaging without ("planning setup") and with the MR-compatible hyperthermia device ("treatment setup"). Temperature-based quality indicators were used to assess the differences between the standard, apparent and the optimized hyperthermia dose. We conclude that pre-treatment imaging can improve HTP predictions accuracy but also, that tissue perfusion modelling is crucial if temperature-based optimization is applied.
RESUMO
Swarming is a macroscopic phenomenon in which surface bacteria organize into a motile population. The flagellar motor that drives swarming in Pseudomonas aeruginosa is powered by stators MotAB and MotCD. Deletion of the MotCD stator eliminates swarming, whereas deletion of the MotAB stator enhances swarming. Interestingly, we measured a strongly asymmetric stator availability in the wild-type (WT) strain, with MotAB stators produced at an approximately 40-fold higher level than MotCD stators. However, utilization of MotCD stators in free swimming cells requires higher liquid viscosities, while MotAB stators are readily utilized at low viscosities. Importantly, we find that cells with MotCD stators are ~10× more likely to have an active motor compared to cells uses the MotAB stators. The spectrum of motility intermittency can either cooperatively shut down or promote flagellum motility in WT populations. In P. aeruginosa, transition from a static solid-like biofilm to a dynamic liquid-like swarm is not achieved at a single critical value of flagellum torque or stator fraction but is collectively controlled by diverse combinations of flagellum activities and motor intermittencies via dynamic stator utilization. Experimental and computational results indicate that the initiation or arrest of flagellum-driven swarming motility does not occur from individual fitness or motility performance but rather related to concepts from the "jamming transition" in active granular matter.IMPORTANCEIt is now known that there exist multifactorial influences on swarming motility for P. aeruginosa, but it is not clear precisely why stator selection in the flagellum motor is so important. We show differential production and utilization of the stators. Moreover, we find the unanticipated result that the two motor configurations have significantly different motor intermittencies: the fraction of flagellum-active cells in a population on average with MotCD is active ~10× more often than with MotAB. What emerges from this complex landscape of stator utilization and resultant motor output is an intrinsically heterogeneous population of motile cells. We show how consequences of stator recruitment led to swarming motility and how the stators potentially relate to surface sensing circuitry.
Assuntos
Proteínas de Bactérias , Pseudomonas aeruginosa , Pseudomonas aeruginosa/genética , Biofilmes , Movimento , Flagelos/genéticaRESUMO
It is unclear how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to the strong but ineffective inflammatory response that characterizes severe Coronavirus disease 2019 (COVID-19), with amplified immune activation in diverse cell types, including cells without angiotensin-converting enzyme 2 receptors necessary for infection. Proteolytic degradation of SARS-CoV-2 virions is a milestone in host viral clearance, but the impact of remnant viral peptide fragments from high viral loads is not known. Here, we examine the inflammatory capacity of fragmented viral components from the perspective of supramolecular self-organization in the infected host environment. Interestingly, a machine learning analysis to SARS-CoV-2 proteome reveals sequence motifs that mimic host antimicrobial peptides (xenoAMPs), especially highly cationic human cathelicidin LL-37 capable of augmenting inflammation. Such xenoAMPs are strongly enriched in SARS-CoV-2 relative to low-pathogenicity coronaviruses. Moreover, xenoAMPs from SARS-CoV-2 but not low-pathogenicity homologs assemble double-stranded RNA (dsRNA) into nanocrystalline complexes with lattice constants commensurate with the steric size of Toll-like receptor (TLR)-3 and therefore capable of multivalent binding. Such complexes amplify cytokine secretion in diverse uninfected cell types in culture (epithelial cells, endothelial cells, keratinocytes, monocytes, and macrophages), similar to cathelicidin's role in rheumatoid arthritis and lupus. The induced transcriptome matches well with the global gene expression pattern in COVID-19, despite using <0.3% of the viral proteome. Delivery of these complexes to uninfected mice boosts plasma interleukin-6 and CXCL1 levels as observed in COVID-19 patients.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Animais , Camundongos , Células Endoteliais , Proteoma , PeptídeosRESUMO
Patients with peripheral arterial disease (PADs), undergoing percutaneous coronary intervention (PCI), have higher adverse event risks. The effect of invasiveness of PADs treatment on PCI outcome is unknown. This study assessed the impact of the invasiveness of previous PADs treatment (invasive or non-invasive) on event risks after PCI with contemporary drug-eluting stents. This post-hoc analysis pooled 3-year patient-level data of PCI all-comer patients living in the eastern Netherlands, previously treated for PADs. PADs included symptomatic atherosclerotic lesion in the lower or upper extremities; carotid or vertebral arteries; mesenteric arteries or aorta. Invasive PADs treatment comprised endarterectomy, bypass surgery, percutaneous transluminal angioplasty, stenting or amputation; non-invasive treatment consisted of medication and participation in exercise programs. Primary endpoint was (coronary) target vessel failure: composite of cardiac mortality, target vessel-related myocardial infarction, or clinically indicated target vessel revascularization. Of 461 PCI patients with PADs, information on PADs treatment was available in 357 (77.4%) patients; 249 (69.7%) were treated invasively and 108 (30.3%) non-invasively. Baseline and PCI procedural characteristics showed no between-group difference. Invasiveness of PADs treatment was not associated with adverse event risks, including target vessel failure (20.5% vs. 16.0%; HR: 1.30, 95%-CI 0.75-2.26, p = 0.35), major adverse cardiac events (23.3% vs. 20.4%; HR: 1.16, 95%-CI 0.71-1.90, p = 0.55), and all-cause mortality (12.1% vs. 8.3%; HR: 1.48, 95%-CI 0.70-3.13, p = 0.30). In PADs patients participating in PCI trials, we found no significant relation between the invasiveness of previous PADs treatment and 3-year outcome after PCI. Consequently, high-risk PCI patients can be identified by consulting medical records, searching for PADs, irrespective of the invasiveness of PADs treatment.
Assuntos
Doença da Artéria Coronariana , Infarto do Miocárdio , Intervenção Coronária Percutânea , Doença Arterial Periférica , Humanos , Doença da Artéria Coronariana/cirurgia , Intervenção Coronária Percutânea/efeitos adversos , Resultado do Tratamento , Infarto do Miocárdio/etiologia , Doença Arterial Periférica/cirurgia , Doença Arterial Periférica/complicações , Fatores de RiscoRESUMO
Deterministic formation of membrane scission necks by protein machinery with multiplexed functions is critical in biology. A microbial example is the M2 viroporin, a proton pump from the influenza A virus which is multiplexed with membrane remodeling activity to induce budding and scission in the host membrane during viral maturation. In comparison, the dynamin family constitutes a class of eukaryotic proteins implicated in mitochondrial fission, as well as various budding and endocytosis pathways. In the case of Dnm1, the mitochondrial fission protein in yeast, the membrane remodeling activity is multiplexed with mechanoenzyme activity to create fission necks. It is not clear why these functions are combined in these scission processes, which occur in drastically different compositions and solution conditions. In general, direct experimental access to changing neck sizes induced by individual proteins or peptide fragments is challenging due to the nanoscale dimensions and influence of thermal fluctuations. Here, we use a mechanical model to estimate the size of scission necks by leveraging Small-Angle X-ray Scattering (SAXS) structural data of protein-lipid systems under different conditions. The influence of interfacial tension, lipid composition, and membrane budding morphology on the size of the induced scission necks is systematically investigated using our data and molecular dynamic simulations. We find that the M2 budding protein from the influenza A virus has robust pH-dependent membrane activity that induces nanoscopic necks within the range of spontaneous hemi-fission for a broad range of lipid compositions. In contrast, the sizes of scission necks generated by mitochondrial fission proteins strongly depend on lipid composition, which suggests a role for mechanical constriction.
RESUMO
Endothelial cells express neuropilin 1 (NRP1), endoglin (ENG) and vascular endothelial growth factor receptor 2 (VEGFR2), which regulate VEGF-A-mediated vascular development and angiogenesis. However, the link between complex formation among these receptors with VEGF-A-induced signaling and biology is yet unclear. Here, we quantify surface receptor interactions by IgG-mediated immobilization of one receptor, and fluorescence recovery after photobleaching (FRAP) measurements of the mobility of another coexpressed receptor. We observe stable ENG/NRP1, ENG/VEGFR2, and NRP1/VEGFR2 complexes, which are enhanced by VEGF-A. ENG augments NRP1/VEGFR2 interactions, suggesting formation of tripartite complexes bridged by ENG. Effects on signaling are measured in murine embryonic endothelial cells expressing (MEEC+/+) or lacking (MEEC-/-) ENG, along with NRP1 and/or ENG overexpression or knockdown. We find that optimal VEGF-A-mediated phosphorylation of VEGFR2 and Erk1/2 requires ENG and NRP1. ENG or NRP1 increase VEGF-A-induced sprouting, becoming optimal in cells expressing all three receptors, and both processes are inhibited by a MEK1/2 inhibitor. We propose a model where the maximal potency of VEGF-A involves a tripartite complex where ENG bridges VEGFR2 and NRP1, providing an attractive therapeutic target for modulation of VEGF-A signaling and biological responses.
Assuntos
Endoglina , Neuropilina-1 , Fator A de Crescimento do Endotélio Vascular , Receptor 2 de Fatores de Crescimento do Endotélio Vascular , Animais , Camundongos , Endoglina/genética , Endoglina/metabolismo , Células Endoteliais/metabolismo , Neuropilina-1/genética , Neuropilina-1/metabolismo , Fosforilação , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Transdução de SinaisRESUMO
OBJECTIVE: To investigate the potential of hybrid Pd/Fe-oxide magnetic nanoparticles designed for thermo-brachytherapy of breast cancer, considering their specific loss power (SLP) and clinical constraints in the applied magnetic field. METHODS: Hybrid nanoparticles consisting of palladium-core and iron oxide shell of increasing thickness, were suspended in water and their SLPs were measured at varying magnetic fields (12-26 mT peak) and frequencies (50-730 kHz) with a commercial alternating magnetic field generator (magneTherm™ Digital, nanoTherics Ltd.). RESULTS: Validation of the heating device used in this study with commercial HyperMag-C nanoparticles showed a small deviation (±4%) over a period of 1 year, confirming the reliability of the method. The integration of dual thermometers, one in the center and one at the bottom of the sample vial, allowed monitoring of homogeneity of the sample suspensions. SLPs measurements on a series of nanoparticles of increasing sizes showed the highest heating for the diameter of 21 nm (SLP = 225 W/g) at the applied frequencies of 346 and 730 kHz. No heating was observed for the nanoparticles with the size <14 nm, confirming the importance of the size-parameter. The heating ability of the best performing Pd/Fe-oxide-21 was calculated to be sufficient to ablate tumors with a radius ±4 and 12 mm using 10 and 1 mg/mL nanoparticle concentration, respectively. CONCLUSIONS: Nanoparticles consisting of non-magnetic palladium-core and magnetic iron oxide shell are suitable for magnetic hyperthermia/thermal ablation under clinically safe conditions of 346 kHz and 19.1 mT, with minimal eddy current effects in combination with maximum SLP.