Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 904
Filtrar
1.
Exp Physiol ; 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39456127

RESUMO

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by pulmonary and systemic inflammation. Inflammatory mediators show relationships with shortness of breath, exercise intolerance and health related quality of life. Pulmonary rehabilitation (PR), a comprehensive education and exercise training programme, is the most effective therapy for COPD and is associated with reduced exacerbation and hospitalization rates and increased survival. Exercise training, the primary physiological intervention within PR, is known to exert a beneficial anti-inflammatory effect in health and chronic diseases. The question of this review article is whether exercise training can also make such a beneficial anti-inflammatory effect in COPD. Experimental studies using smoke exposure mice models suggest that the response of the immune system to exercise training is favourably anti-inflammatory. However, the evidence about the response of most known inflammatory mediators (C-reactive protein, tumour necrosis factor α, interleukin 6, interleukin 10) to exercise training in COPD patients is inconsistent, making it difficult to conclude whether regular exercise training has an anti-inflammatory effect in COPD. It is also unclear whether COPD patients with more persistent inflammation are a subgroup that would benefit more from hypothesized immunomodulatory effects of exercise training (i.e., personalized treatment). Nevertheless, it seems that PR combined with maintenance exercise training (i.e., lifestyle change) might be more beneficial in controlling inflammation and slowing disease progress in COPD patients, specifically in those with early stages of disease.

2.
Medicine (Baltimore) ; 103(41): e40083, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39465819

RESUMO

Traditional heart failure research often uses daytime population parameter estimates to assess hypoxia and arrhythmias. This approach might not accurately represent heart failure patients as nighttime cardiac behaviors offer crucial insights into their health, especially regarding oxygen levels and heart rhythms. We conducted a prospective study on nocturnal oxygen saturation and heart rate in home-dwelling heart failure patients over 6 nights. Patients were recruited from the Walter Reed National Military Medical Center heart failure clinic. Criteria included a clinical diagnosis of heart failure, a New York Heart Association (NYHA) classification of I to III, ages between 21 to 90, cognitive intactness, capability to use the wearable device, and willingness to use the device for 6 consecutive nights. Average oxygen saturation was 92% with individual readings ranging from 40% to 100%. The mean heart rate was 72 beats per minute (bpm), but individual rates ranged from 18 bpm to a high of 296 bpm. A significant drop in oxygen levels and sleep arrhythmias were consistently observed among participants. Heart failure patients demonstrate notable and variable desaturations and arrhythmias across multiple nights. A single-night sleep study or a 24-hour heart rate monitor may not comprehensively depict patients' oxygenation and heart rate irregularities. Our research highlights wearable devices' potency in medical research for capturing essential nocturnal data. In only 6 nights, we gleaned invaluable clinical insights for optimizing patient care. This study is pioneering, being the first to intensively examine nighttime oxygen levels and heart rates in home-based heart failure patients.


Assuntos
Arritmias Cardíacas , Insuficiência Cardíaca , Frequência Cardíaca , Hipóxia , Humanos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/complicações , Arritmias Cardíacas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Hipóxia/fisiopatologia , Feminino , Idoso , Frequência Cardíaca/fisiologia , Adulto , Idoso de 80 Anos ou mais , Saturação de Oxigênio/fisiologia , Adulto Jovem , Dispositivos Eletrônicos Vestíveis
3.
Cell Rep Med ; 5(10): 101777, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39413736

RESUMO

Approximately 50% of patients with surgically resected early-stage lung cancer develop distant metastasis. At present, there is no in vivo metastasis model to investigate the biology of human lung cancer metastases. Using well-characterized lung adenocarcinoma (LUAD) patient-derived organoids (PDOs), we establish an in vivo metastasis model that preserves the biologic features of human metastases. Results of whole-genome and RNA sequencing establish that our in vivo PDO metastasis model can be used to study clonality and tumor evolution and to identify biomarkers related to organotropism. Investigation of the response of KRASG12C PDOs to sotorasib demonstrates that the model can examine the efficacy of treatments to suppress metastasis and identify mechanisms of drug resistance. Finally, our PDO model cocultured with autologous peripheral blood mononuclear cells can potentially be used to determine the optimal immune-priming strategy for individual patients with LUAD.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Organoides , Humanos , Organoides/patologia , Adenocarcinoma de Pulmão/patologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Animais , Camundongos , Metástase Neoplásica , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Modelos Biológicos , Leucócitos Mononucleares/metabolismo
4.
J Virol ; 98(10): e0074424, 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39240111

RESUMO

VRC01-class broadly neutralizing antibodies (bnAbs) have been isolated from people with HIV-1, but they have not yet been elicited by vaccination. They are extensively somatically mutated and sometimes accumulate CDRL1 deletions. Such indels may allow VRC01-class antibodies to accommodate the glycans expressed on a conserved N276 N-linked glycosylation site in loop D of the gp120 subunit. These glycans constitute a major obstacle in the development of VRC01-class antibodies, as unmutated antibody forms are unable to accommodate them. Although immunizations of knock-in mice expressing human VRC01-class B-cell receptors (BCRs) with specifically designed Env-derived immunogens lead to the accumulation of somatic mutations in VRC01-class BCRs, CDRL1 deletions are rarely observed, and the elicited antibodies display narrow neutralizing activities. The lack of broad neutralizing potential could be due to the absence of deletions, the lack of appropriate somatic mutations, or both. To address this point, we modified our previously determined prime-boost immunization with a germline-targeting immunogen nanoparticle (426c.Mod.Core), followed by a heterologous core nanoparticle (HxB2.WT.Core), by adding a final boost with a cocktail of various stabilized soluble Env trimers. We isolated VRC01-like antibodies with extensive somatic mutations and, in one case, a seven-amino acid CDRL1 deletion. We generated chimeric antibodies that combine the vaccine-elicited somatic mutations with CDRL1 deletions present in human mature VRC01 bnAbs. We observed that CDRL1 indels did not improve the neutralizing antibody activities. Our study indicates that CDRL1 length by itself is not sufficient for the broadly neutralizing phenotype of this class of antibodies. IMPORTANCE: HIV-1 broadly neutralizing antibodies will be a key component of an effective HIV-1 vaccine, as they prevent viral acquisition. Over the past decade, numerous broadly neutralizing antibodies (bnAbs) have been isolated from people with HIV. Despite an in-depth knowledge of their structures, epitopes, ontogenies, and, in a few rare cases, their maturation pathways during infection, bnAbs have, so far, not been elicited by vaccination. This necessitates the identification of key obstacles that prevent their elicitation by immunization and overcoming them. Here we examined whether CDRL1 shortening is a prerequisite for the broadly neutralizing potential of VRC01-class bnAbs, which bind within the CD4 receptor binding site of Env. Our findings indicate that CDRL1 shortening by itself is important but not sufficient for the acquisition of neutralization breadth, and suggest that particular combinations of amino acid mutations, not elicited so far by vaccination, are most likely required for the development of such a feature.


Assuntos
Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Amplamente Neutralizantes , Anticorpos Anti-HIV , HIV-1 , Polissacarídeos , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Humanos , Animais , Anticorpos Neutralizantes/imunologia , Camundongos , Polissacarídeos/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Anticorpos Monoclonais/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/genética , Glicosilação , Vacinas contra a AIDS/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Infecções por HIV/prevenção & controle , Receptores de Antígenos de Linfócitos B/imunologia , Epitopos/imunologia
5.
PLoS Pathog ; 20(9): e1012609, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39348381

RESUMO

We previously demonstrated that in Ifnar1-/-Ifngr1-/- or Stat1-/- suckling mice lacking intact type I and type II interferon (IFN) signaling, rhesus rotavirus (RRV) infection causes a lethal disease with clinical manifestations similar to biliary atresia, including acholic stools, oily fur, growth retardation, and excess mortality. Elevated levels of viral RNA are detected in the bile ducts and liver of diseased pups together with severe inflammatory responses in these tissues. However, the viral determinants and the molecular mechanisms driving this process remain incompletely understood. Using an optimized rotavirus (RV) reverse genetics system, we generated a panel of recombinant RVs that encode non-structural protein 1 (NSP1) derived from different RV strains. We found that compared to the parental simian SA11 strain that is less biliary pathogenic, SA11 containing an RRV-derived NSP1 resulted in severe biliary obstructive disease comparable to that associated with RRV infection, reflected by high levels of viral RNA and inflammation in the biliary tract, liver, and pancreas. In contrast, RRV containing an SA11-originated NSP1 showed only mild biliary obstruction comparable to what was observed during SA11 infection. Infection with a monoreassortant RRV virus carrying NSP1 from the bovine RV UK strain also showed substantially reduced viral replication in extra-intestinal organs and did not develop clinical biliary diseases. Mechanistically, RRV NSP1 seemed to promote active viral replication in hepatocytes and this expanded tropism led to enhanced infiltration of CD4 and CD8 T cells, causing immunopathology and damage in the hepatobiliary system. These results highlight an unexpectedly important role of RV NSP1 in viral replication and disease progression in extra-intestinal tissues.


Assuntos
Infecções por Rotavirus , Rotavirus , Proteínas não Estruturais Virais , Animais , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Infecções por Rotavirus/virologia , Rotavirus/patogenicidade , Camundongos , Atresia Biliar/virologia , Atresia Biliar/genética , Macaca mulatta , Replicação Viral , Humanos
6.
J Clin Med ; 13(18)2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39337079

RESUMO

Objectives: Fatigue is a prominent feature of long COVID (LC) and may be related to several pathophysiologic mechanisms, including immune hyperstimulation. Aerobic endurance exercise training may be a useful therapy, with appropriate attention to preventing post-exertional malaise. Methods: Fourteen participants completed a pilot study of aerobic exercise training (twenty 1.5 h sessions of over 10 weeks). Cardiorespiratory fitness, 6 min walk distance, quality of life, symptoms, 7-day physical activity, immunophenotype, and inflammatory biomarkers were measured before and after exercise training. Results: The participant characteristics at baseline were as follows: 53.5 ± 11.6 yrs, 53% f, BMI 32.5 ± 8.4, 42% ex-smokers, 15.1 ± 8.8 months since initial COVID-19 infection, low normal pulmonary function testing, V.O2peak 19.3 ± 5.1 mL/kg/min, 87 ± 17% predicted. After exercise training, participants significantly increased their peak work rate (+16 ± 20 W, p = 0.010) and V.O2peak (+1.55 ± 2.4 mL/kg/min, p = 0.030). Patients reported improvements in fatigue severity (-11%), depression (-42%), anxiety (-29%), and dyspnea level (-46%). There were no changes in 6MW distance or physical activity. The circulating number of CD3+, CD4+, CD19+, CD14++CD16, and CD16++CD14+ monocytes and CD56+ cells (assessed with flow cytometry) increased with acute exercise (rest to peak) and was not diminished or augmented by exercise training. Plasma concentrations of TNF-α, IL-6, IL-8, IL-10, INF-γ, and INF-λ were normal at study entry and not affected by training. Conclusions: Aerobic endurance exercise training in individuals with LC delivered beneficial effects on cardiorespiratory fitness, quality of life, anxiety, depression, and fatigue without detrimental effects on immunologic function.

8.
Mil Med ; 189(Suppl 3): 423-430, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39160867

RESUMO

INTRODUCTION: Simulation-based medical training has been shown to be effective and is widely used in civilian hospitals; however, it is unclear how widely and how effectively simulation is utilized in the U.S. Military Health System (MHS). The current operational state of medical simulation in the MHS is unknown, and there remains a need for a system-wide assessment of whether and how the advances in simulation-based medical training are employed to meet the evolving needs of the present-day warfighter. Understanding the types of skills and methods used within simulation programs across the enterprise is important data for leaders as they plan for the future in terms of curriculum development and the investment of resources. The aim of the present study is to survey MHS simulation programs in order to determine the prevalence of skills taught, the types of learners served, and the most common methodologies employed in this worldwide health care system. MATERIALS AND METHODS: A cross-sectional survey of simulation activities was distributed to the medical directors of all 93 simulation programs in the MHS. The survey was developed by the authors based on lists of critical wartime skills published by the medical departments of the US Army, Navy, and Air Force. Respondents were asked to indicate the types of learners trained at their program, which of the 82 unique skills included in the survey are trained at their site, and for each skill the modalities of simulation used, i.e., mannequin, standardized patients, part task trainers, augmented/virtual reality tools, or cadaver/live tissue. RESULTS: Complete survey responses were obtained from 75 of the 93 (80%) MHS medical simulation training programs. Across all skills included in the survey, those most commonly taught belonged predominantly to the categories of medic skills and nursing skills. Across all sites, the most common category of learner was the medic/corpsman (95% of sites), followed by nurses (87%), physicians (83%), non-medical combat lifesavers (59%), and others (28%) that included on-base first responders, law enforcement, fire fighters, and civilians. The skills training offered by programs included most commonly the tasks associated with medics/corpsmen (97%) followed by nursing (81%), advanced provider (77%), and General Medical Officer (GMO) skills (47%). CONCLUSION: The survey demonstrated that the most common skills taught were all related to point of injury combat casualty care and addressed the most common causes of death on the battlefield. The availability of training in medic skills, nursing skills, and advanced provider skills were similar in small, medium, and large programs. However, medium and small programs were less likely to deliver training for advanced providers and GMOs compared to larger programs. Overall, this study found that simulation-based medical training in the MHS is focused on medic and nursing skills, and that large programs are more likely to offer training for advanced providers and GMOs. Potential gaps in the availability of existing training are identified as over 50% of skills included in the nursing, advanced provider, and GMO skill categories are not covered by at least 80% of sites serving those learners.


Assuntos
Treinamento por Simulação , Humanos , Treinamento por Simulação/métodos , Treinamento por Simulação/estatística & dados numéricos , Treinamento por Simulação/normas , Inquéritos e Questionários , Estudos Transversais , Estados Unidos , Currículo/tendências , Currículo/normas , Currículo/estatística & dados numéricos , Competência Clínica/estatística & dados numéricos , Competência Clínica/normas , Medicina Militar/educação , Medicina Militar/métodos , Medicina Militar/estatística & dados numéricos , Serviços de Saúde Militar/estatística & dados numéricos , Serviços de Saúde Militar/normas
9.
J Appl Physiol (1985) ; 137(5): 1130-1144, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39205640

RESUMO

Quantitating exercise ventilatory and gas exchange dynamics affords insights into physiological control processes and cardiopulmonary dysfunction. We designed a novel waveform, the chirp waveform, to efficiently extract moderate-intensity exercise response dynamics. In the chirp waveform, work rate fluctuates sinusoidally with constant amplitude as sinusoidal period decreases progressively from ∼8.5 to 1.4 min over 30 min of cycle ergometry. We hypothesized that response dynamics of pulmonary ventilation (V̇e) and gas exchange [oxygen uptake (V̇o2) and carbon dioxide output (V̇co2)] extracted from chirp waveform are similar to those obtained from stepwise transitions. Thirty-one participants [14 young healthy, 7 older healthy, and 10 patients with chronic obstructive pulmonary disease (COPD)] exercised on three occasions. Participants first performed ramp-incremental exercise for gas exchange threshold (GET) determination. In randomized order, the next two visits involved either chirp or stepwise waveforms. Work rate amplitude (20 W to ∼95% GET work rate) and exercise duration (30 min) were the same for both waveforms. A first-order linear transfer function with a single system gain (G) and time constant (τ) characterized response dynamics. Agreement between model parameters extracted from chirp and stepwise waveforms was established using Bland-Altman analysis and Rothery's concordance coefficient (RCC). V̇e, V̇o2, and V̇co2 Gs showed no systematic bias (P > 0.178) and moderate-to-good agreement (RCC > 0.772, P < 0.01) between waveforms. Similarly, no systematic bias (P = 0.815) and good agreement (RCC = 0.837, P < 0.001) was found for τV̇o2. Despite moderate agreement for τV̇co2 (RCC = 0.794, P < 0.001) and τV̇e (RCC = 0.722, P = 0.083), chirp τ was less [-6.9(11.7) s and -12.2(22.5) s, respectively]. We conclude that the chirp waveform is a promising method for measuring exercise response dynamics and investigating physiological control mechanisms.NEW & NOTEWORTHY We investigated the ability of a novel waveform to extract exercise ventilatory and gas exchange dynamics. In the chirp waveform, work rate fluctuates sinusoidally with constant amplitude as sinusoidal period decreases progressively over 30 min of exercise. In a study of 31 healthy individuals and patients with COPD, comparison of exercise dynamics derived from chirp to those from stepwise waveforms suggests that the chirp waveform is a promising method for derivation of exercise response dynamics.


Assuntos
Exercício Físico , Consumo de Oxigênio , Troca Gasosa Pulmonar , Ventilação Pulmonar , Humanos , Troca Gasosa Pulmonar/fisiologia , Masculino , Exercício Físico/fisiologia , Adulto , Feminino , Consumo de Oxigênio/fisiologia , Ventilação Pulmonar/fisiologia , Pessoa de Meia-Idade , Adulto Jovem , Teste de Esforço/métodos , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Idoso , Dióxido de Carbono/metabolismo
10.
Science ; 385(6712): 954-961, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39208112

RESUMO

Recent respiratory outbreaks have garnered substantial attention, yet most respiratory monitoring remains confined to physical signals. Exhaled breath condensate (EBC) harbors rich molecular information that could unveil diverse insights into an individual's health. Unfortunately, challenges related to sample collection and the lack of on-site analytical tools impede the widespread adoption of EBC analysis. Here, we introduce EBCare, a mask-based device for real-time in situ monitoring of EBC biomarkers. Using a tandem cooling strategy, automated microfluidics, highly selective electrochemical biosensors, and a wireless reading circuit, EBCare enables continuous multimodal monitoring of EBC analytes across real-life indoor and outdoor activities. We validated EBCare's usability in assessing metabolic conditions and respiratory airway inflammation in healthy participants, patients with chronic obstructive pulmonary disease or asthma, and patients after COVID-19 infection.


Assuntos
Testes Respiratórios , Expiração , Máscaras , Humanos , Asma/diagnóstico , Biomarcadores/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Testes Respiratórios/métodos , Testes Respiratórios/instrumentação , COVID-19/diagnóstico , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Manejo de Espécimes/métodos , Manejo de Espécimes/instrumentação , Doenças Respiratórias
11.
JMIR Med Educ ; 10: e56342, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39118469

RESUMO

Background: Teaching medical students the skills required to acquire, interpret, apply, and communicate clinical information is an integral part of medical education. A crucial aspect of this process involves providing students with feedback regarding the quality of their free-text clinical notes. Objective: The goal of this study was to assess the ability of ChatGPT 3.5, a large language model, to score medical students' free-text history and physical notes. Methods: This is a single-institution, retrospective study. Standardized patients learned a prespecified clinical case and, acting as the patient, interacted with medical students. Each student wrote a free-text history and physical note of their interaction. The students' notes were scored independently by the standardized patients and ChatGPT using a prespecified scoring rubric that consisted of 85 case elements. The measure of accuracy was percent correct. Results: The study population consisted of 168 first-year medical students. There was a total of 14,280 scores. The ChatGPT incorrect scoring rate was 1.0%, and the standardized patient incorrect scoring rate was 7.2%. The ChatGPT error rate was 86%, lower than the standardized patient error rate. The ChatGPT mean incorrect scoring rate of 12 (SD 11) was significantly lower than the standardized patient mean incorrect scoring rate of 85 (SD 74; P=.002). Conclusions: ChatGPT demonstrated a significantly lower error rate compared to standardized patients. This is the first study to assess the ability of a generative pretrained transformer (GPT) program to score medical students' standardized patient-based free-text clinical notes. It is expected that, in the near future, large language models will provide real-time feedback to practicing physicians regarding their free-text notes. GPT artificial intelligence programs represent an important advance in medical education and medical practice.


Assuntos
Estudantes de Medicina , Humanos , Estudos Retrospectivos , Educação de Graduação em Medicina/métodos , Avaliação Educacional/métodos , Idioma , Anamnese/métodos , Anamnese/normas , Competência Clínica/normas , Masculino
12.
Mol Metab ; 86: 101983, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38960128

RESUMO

Mitochondria facilitate thousands of biochemical reactions, covering a broad spectrum of anabolic and catabolic processes. Here we demonstrate that the adipocyte mitochondrial proteome is markedly altered across multiple models of insulin resistance and reveal a consistent decrease in the level of the mitochondrial processing peptidase miPEP. OBJECTIVE: To determine the role of miPEP in insulin resistance. METHODS: To experimentally test this observation, we generated adipocyte-specific miPEP knockout mice to interrogate its role in the aetiology of insulin resistance. RESULTS: We observed a strong phenotype characterised by enhanced insulin sensitivity and reduced adiposity, despite normal food intake and physical activity. Strikingly, these phenotypes vanished when mice were housed at thermoneutrality, suggesting that metabolic protection conferred by miPEP deletion hinges upon a thermoregulatory process. Tissue specific analysis of miPEP deficient mice revealed an increment in muscle metabolism, and upregulation of the protein FBP2 that is involved in ATP hydrolysis in the gluconeogenic pathway. CONCLUSION: These findings suggest that miPEP deletion initiates a compensatory increase in skeletal muscle metabolism acting as a protective mechanism against diet-induced obesity and insulin resistance.


Assuntos
Adipócitos , Resistência à Insulina , Camundongos Knockout , Músculo Esquelético , Obesidade , Animais , Camundongos , Obesidade/metabolismo , Obesidade/genética , Músculo Esquelético/metabolismo , Adipócitos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo
13.
bioRxiv ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38765992

RESUMO

Acute gastroenteritis remains the second leading cause of death among children under the age of 5 worldwide. While enteric viruses are the most common etiology, the drivers of their virulence remain incompletely understood. We recently found that cells infected with rotavirus, the most prevalent enteric virus in infants and young children, initiate hundreds of intercellular calcium waves that enhance both fluid secretion and viral spread. Understanding how rotavirus triggers intercellular calcium waves may allow us to design safer, more effective vaccines and therapeutics, but we still lack a mechanistic understanding of this process. In this study, we used existing virulent and attenuated rotavirus strains, as well as reverse engineered recombinants, to investigate the role of rotavirus nonstructural protein 4 (NSP4) in intercellular calcium wave induction using in vitro , organoid, and in vivo model systems. We found that the capacity to induce purinergic intercellular calcium waves (ICWs) segregated with NSP4 in both simian and murine-like rotavirus backgrounds, and NSP4 expression alone was sufficient to induce ICWs. NSP4's ability to function as a viroporin, which conducts calcium out of the endoplasmic reticulum, was necessary for ICW induction. Furthermore, viroporin activity and the resulting ICWs drove transcriptional changes indicative of innate immune activation, which were lost upon attenuation of viroporin function. Multiple aspects of RV disease severity in vivo correlated with the generation of ICWs, identifying a critical link between viroporin function, intercellular calcium waves, and enteric viral virulence.

14.
Proc Natl Acad Sci U S A ; 121(20): e2402653121, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38722808

RESUMO

The intrinsically disordered C-terminal peptide region of severe acute respiratory syndrome coronavirus 2 nonstructural protein-1 (Nsp1-CT) inhibits host protein synthesis by blocking messenger RNA (mRNA) access to the 40S ribosome entrance tunnel. Aqueous copper(II) ions bind to the disordered peptide with micromolar affinity, creating a possible strategy to restore protein synthesis during host infection. Electron paramagnetic resonance (EPR) and tryptophan fluorescence measurements on a 10-residue model of the disordered protein region (Nsp1-CT10), combined with advanced quantum mechanics calculations, suggest that the peptide binds to copper(II) as a multidentate ligand. Two optimized computational models of the copper(II)-peptide complexes were derived: One corresponding to pH 6.5 and the other describing the complex at pH 7.5 to 8.5. Simulated EPR spectra based on the calculated model structures are in good agreement with experimental spectra.


Assuntos
Cobre , Proteínas Intrinsicamente Desordenadas , SARS-CoV-2 , Proteínas não Estruturais Virais , Cobre/química , Cobre/metabolismo , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/química , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Ligação Proteica , Modelos Moleculares , COVID-19/virologia
15.
Viruses ; 16(5)2024 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-38793648

RESUMO

Small-animal models and reverse genetics systems are powerful tools for investigating the molecular mechanisms underlying viral replication, virulence, and interaction with the host immune response in vivo. Rotavirus (RV) causes acute gastroenteritis in many young animals and infants worldwide. Murine RV replicates efficiently in the intestines of inoculated suckling pups, causing diarrhea, and spreads efficiently to uninoculated littermates. Because RVs derived from human and other non-mouse animal species do not replicate efficiently in mice, murine RVs are uniquely useful in probing the viral and host determinants of efficient replication and pathogenesis in a species-matched mouse model. Previously, we established an optimized reverse genetics protocol for RV and successfully generated a murine-like RV rD6/2-2g strain that replicates well in both cultured cell lines and in the intestines of inoculated pups. However, rD6/2-2g possesses three out of eleven gene segments derived from simian RV strains, and these three heterologous segments may attenuate viral pathogenicity in vivo. Here, we rescued the first recombinant RV with all 11 gene segments of murine RV origin. Using this virus as a genetic background, we generated a panel of recombinant murine RVs with either N-terminal VP8* or C-terminal VP5* regions chimerized between a cell-culture-adapted murine ETD strain and a non-tissue-culture-adapted murine EW strain and compared the diarrhea rate and fecal RV shedding in pups. The recombinant viruses with VP5* domains derived from the murine EW strain showed slightly more fecal shedding than those with VP5* domains from the ETD strain. The newly characterized full-genome murine RV will be a useful tool for dissecting virus-host interactions and for studying the mechanism of pathogenesis in neonatal mice.


Assuntos
Proteínas do Capsídeo , Genética Reversa , Infecções por Rotavirus , Rotavirus , Replicação Viral , Animais , Humanos , Camundongos , Animais Recém-Nascidos , Proteínas do Capsídeo/genética , Linhagem Celular , Modelos Animais de Doenças , Genética Reversa/métodos , Rotavirus/genética , Rotavirus/patogenicidade , Infecções por Rotavirus/virologia , Virulência
17.
Nat Commun ; 15(1): 3469, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658526

RESUMO

Human parechoviruses (PeV-A) are increasingly being recognized as a cause of infection in neonates and young infants, leading to a spectrum of clinical manifestations ranging from mild gastrointestinal and respiratory illnesses to severe sepsis and meningitis. However, the host factors required for parechovirus entry and infection remain poorly characterized. Here, using genome-wide CRISPR/Cas9 loss-of-function screens, we identify myeloid-associated differentiation marker (MYADM) as a host factor essential for the entry of several human parechovirus genotypes including PeV-A1, PeV-A2 and PeV-A3. Genetic knockout of MYADM confers resistance to PeV-A infection in cell lines and in human gastrointestinal epithelial organoids. Using immunoprecipitation, we show that MYADM binds to PeV-A1 particles via its fourth extracellular loop, and we identify critical amino acid residues within the loop that mediate binding and infection. The demonstrated interaction between MYADM and PeV-A1, and its importance specifically for viral entry, suggest that MYADM is a virus receptor. Knockout of MYADM does not reduce PeV-A1 attachment to cells pointing to a role at the post-attachment stage. Our study suggests that MYADM is a multi-genotype receptor for human parechoviruses with potential as an antiviral target to combat disease associated with emerging parechoviruses.


Assuntos
Parechovirus , Infecções por Picornaviridae , Internalização do Vírus , Humanos , Linhagem Celular , Sistemas CRISPR-Cas , Células HEK293 , Organoides/virologia , Organoides/metabolismo , Parechovirus/genética , Parechovirus/metabolismo , Infecções por Picornaviridae/virologia , Infecções por Picornaviridae/metabolismo , Ligação Proteica , Receptores Virais/metabolismo , Receptores Virais/genética
18.
J Cachexia Sarcopenia Muscle ; 15(3): 1016-1029, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38649783

RESUMO

BACKGROUND: Skeletal muscle dysfunction is a common extrapulmonary manifestation of chronic obstructive pulmonary disease (COPD). Alterations in skeletal muscle myosin heavy chain expression, with reduced type I and increased type II myosin heavy chain expression, are associated with COPD severity when studied in largely male cohorts. The objectives of this study were (1) to define an abnormal myofibre proportion phenotype in both males and females with COPD and (2) to identify transcripts and transcriptional networks associated with abnormal myofibre proportion in COPD. METHODS: Forty-six participants with COPD were assessed for body composition, strength, endurance and pulmonary function. Skeletal muscle biopsies from the vastus lateralis were assayed for fibre-type distribution and cross-sectional area via immunofluorescence microscopy and RNA-sequenced to generate transcriptome-wide gene expression data. Sex-stratified k-means clustering of type I and IIx/IIax fibre proportions was used to define abnormal myofibre proportion in participants with COPD and contrasted with previously defined criteria. Single transcripts and weighted co-expression network analysis modules were tested for correlation with the abnormal myofibre proportion phenotype. RESULTS: Abnormal myofibre proportion was defined in males with COPD (n = 29) as <18% type I and/or >22% type IIx/IIax fibres and in females with COPD (n = 17) as <36% type I and/or >12% type IIx/IIax fibres. Half of the participants with COPD were classified as having an abnormal myofibre proportion. Participants with COPD and an abnormal myofibre proportion had lower median handgrip strength (26.1 vs. 34.0 kg, P = 0.022), 6-min walk distance (300 vs. 353 m, P = 0.039) and forced expiratory volume in 1 s-to-forced vital capacity ratio (0.42 vs. 0.48, P = 0.041) compared with participants with COPD and normal myofibre proportions. Twenty-nine transcripts were associated with abnormal myofibre proportions in participants with COPD, with the upregulated NEB, TPM1 and TPM2 genes having the largest fold differences. Co-expression network analysis revealed that two transcript modules were significantly positively associated with the presence of abnormal myofibre proportions. One of these co-expression modules contained genes classically associated with muscle atrophy, as well as transcripts associated with both type I and type II myofibres, and was enriched for genetic loci associated with bone mineral density. CONCLUSIONS: Our findings indicate that there are significant transcriptional alterations associated with abnormal myofibre proportions in participants with COPD. Transcripts canonically associated with both type I and type IIa fibres were enriched in a co-expression network associated with abnormal myofibre proportion, suggesting altered transcriptional regulation across multiple fibre types.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/patologia , Músculo Esquelético/metabolismo , Transcriptoma , Perfilação da Expressão Gênica
19.
Heliyon ; 10(5): e26191, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38463860

RESUMO

Smart learning environments (SLEs) have been developed to create an effective learning environment gradually and sustainably by applying technology. Given the growing dependence on technology daily, SLE will inevitably be incorporated into the teaching and learning process. Without transforming technology-enhanced learning environments into SLE, they are restricted to adding sophistication and lack pedagogical benefits, leading to wasteful educational investments. SLE research has grown over time, particularly during the COVID-19 pandemic in 2020-2021, which fundamentally altered the "landscape" of technology use in education. This study aims to discover how the stages of SLE transform from time to time by applying two bibliometric analysis approaches: publication performance analysis and science mapping. The dataset was created by extracting bibliometric data from Scopus, including 427 articles, 162 publication sources (journals and proceeding), and 1080 authors from 2002 to 2022. Three kinds of SLE research subjects were identified by keyword synthesis: SLE features, technological innovation, and adaptive learning systems. Adaptive learning and personalized learning are consistently used interchangeably to demonstrate the significance of supporting the diversity of student and teacher conditions. Learning analytics, essential to employing big data technology for educational data mining, is a new theme being considered increasingly in the future to achieve adaptive and personalized learning. The 20-year SLE research milestone, broken down into five stages with various focuses on goals and served as the foundation for creating a maturity model of SLE.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA