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Journal of Virology Jun 2024Chikungunya virus (CHIKV) is a mosquito-borne pathogen responsible for an acute musculoskeletal disease in humans. Replication of the viral RNA genome occurs in...
Chikungunya virus (CHIKV) is a mosquito-borne pathogen responsible for an acute musculoskeletal disease in humans. Replication of the viral RNA genome occurs in specialized membranous replication organelles (ROs) or spherules, which contain the viral replication complex. Initially generated by RNA synthesis-associated plasma membrane deformation, alphavirus ROs are generally rapidly endocytosed to produce type I cytopathic vacuoles (CPV-I), from which nascent RNAs are extruded for cytoplasmic translation. By contrast, CHIKV ROs are poorly internalized, raising the question of their fate and functionality at the late stage of infection. Here, using cryogenic-electron microscopy approaches, we investigate the outcome of CHIKV ROs and associated replication machinery in infected human cells. We evidence the late persistence of CHIKV ROs at the plasma membrane with a crowned protein complex at the spherule neck similar to the recently resolved replication complex. The unexpectedly heterogeneous and large diameter of these compartments suggests a continuous, dynamic growth of these organelles beyond the replication of a single RNA genome. Ultrastructural analysis of surrounding cytoplasmic regions supports that outgrown CHIKV ROs remain dynamically active in viral RNA synthesis and export to the cell cytosol for protein translation. Interestingly, rare ROs with a homogeneous diameter are also marginally internalized in CPV-I near honeycomb-like arrangements of unknown function, which are absent in uninfected controls, thereby suggesting a temporal regulation of this internalization. Altogether, this study sheds new light on the dynamic pattern of CHIKV ROs and associated viral replication at the interface with cell membranes in infected cells.IMPORTANCEThe Chikungunya virus (CHIKV) is a positive-stranded RNA virus that requires specialized membranous replication organelles (ROs) for its genome replication. Our knowledge of this viral cycle stage is still incomplete, notably regarding the fate and functional dynamics of CHIKV ROs in infected cells. Here, we show that CHIKV ROs are maintained at the plasma membrane beyond the first viral cycle, continuing to grow and be dynamically active both in viral RNA replication and in its export to the cell cytosol, where translation occurs in proximity to ROs. This contrasts with the homogeneous diameter of ROs during internalization in cytoplasmic vacuoles, which are often associated with honeycomb-like arrangements of unknown function, suggesting a regulated mechanism. This study sheds new light on the dynamics and fate of CHIKV ROs in human cells and, consequently, on our understanding of the Chikungunya viral cycle.
PubMed: 38940586
DOI: 10.1128/jvi.00368-24 -
Journal of Virology Jun 2024Coronavirus disease 2019 (COVID-19) has claimed millions of lives since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and lung disease...
UNLABELLED
Coronavirus disease 2019 (COVID-19) has claimed millions of lives since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and lung disease appears the primary cause of death in COVID-19 patients. However, the underlying mechanisms of COVID-19 pathogenesis remain elusive, and there is no existing model where human disease can be faithfully recapitulated and conditions for the infection process can be experimentally controlled. Herein we report the establishment of an human precision-cut lung slice (hPCLS) platform for studying SARS-CoV-2 pathogenicity and innate immune responses, and for evaluating the efficacy of antiviral drugs against SARS-CoV-2. We show that while SARS-CoV-2 continued to replicate during the course of infection of hPCLS, infectious virus production peaked within 2 days, and rapidly declined thereafter. Although most proinflammatory cytokines examined were induced by SARS-CoV-2 infection, the degree of induction and types of cytokines varied significantly among hPCLS from individual donors. Two cytokines in particular, IP-10 and IL-8, were highly and consistently induced, suggesting a role in the pathogenesis of COVID-19. Histopathological examination revealed focal cytopathic effects late in the infection. Transcriptomic and proteomic analyses identified molecular signatures and cellular pathways that are largely consistent with the progression of COVID-19 in patients. Furthermore, we show that homoharringtonine, a natural plant alkaloid derived from , not only inhibited virus replication but also production of pro-inflammatory cytokines, and thus ameliorated the histopathological changes caused by SARS-CoV-2 infection, demonstrating the usefulness of the hPCLS platform for evaluating antiviral drugs.
IMPORTANCE
Here, established an human precision-cut lung slice platform for assessing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, viral replication kinetics, innate immune response, disease progression, and antiviral drugs. Using this platform, we identified early induction of specific cytokines, especially IP-10 and IL-8, as potential predictors for severe coronavirus disease 2019 (COVID-19), and uncovered a hitherto unrecognized phenomenon that while infectious virus disappears at late times of infection, viral RNA persists and lung histopathology commences. This finding may have important clinical implications for both acute and post-acute sequelae of COVID-19. This platform recapitulates some of the characteristics of lung disease observed in severe COVID-19 patients and is therefore a useful platform for understanding mechanisms of SARS-CoV-2 pathogenesis and for evaluating the efficacy of antiviral drugs.
PubMed: 38940558
DOI: 10.1128/jvi.00794-24 -
Liver International : Official Journal... Jun 2024The porphyrias are a group of rare inborn errors of metabolism associated with various clinical presentations and long-term complications, making them relevant... (Review)
Review
The porphyrias are a group of rare inborn errors of metabolism associated with various clinical presentations and long-term complications, making them relevant differential diagnoses to consider for many clinical specialities, especially hepatologists, gastroenterologists and dermatologists. To diagnose a patient with porphyria requires appropriate biochemical investigations, as clinical features alone are not specific enough. Furthermore, it is important to be aware that abnormalities of porphyrin accumulation and excretion occur in many other disorders that are collectively far more common than the porphyrias. In this review, we provide an overview of porphyria-related tests with their strengths and limitations, give recommendations on requesting and diagnostic approaches in non-expert and expert laboratories for different clinical scenarios and discuss the role of genetic testing in the porphyrias. To diagnose porphyria in a currently symptomatic patient requires analysis of biochemical markers to demonstrate typical patterns of haem precursors in urine, faeces and blood. The use of genomic sequencing in diagnostic pathways for porphyrias requires careful consideration, and the demonstration of increased porphyrin-related markers is necessary prior to genomic testing in symptomatic patients. In the acute porphyrias, genomic testing is presently a useful adjunct for genetic counselling of asymptomatic family members and the most common cutaneous porphyria, porphyria cutanea tarda, is usually a sporadic, non-hereditary disease. Getting a correct and timely porphyria diagnosis is essential for delivering appropriate care and ensuring best patient outcome.
PubMed: 38940544
DOI: 10.1111/liv.16012 -
Journal of Crohn's & Colitis Jun 2024Reliable and easily accessible objective markers of disease activity to predict long-term treatment outcomes in severe ulcerative colitis (UC) are missing. We aimed to...
BACKGROUND AND AIMS
Reliable and easily accessible objective markers of disease activity to predict long-term treatment outcomes in severe ulcerative colitis (UC) are missing. We aimed to investigate if intestinal ultrasound (IUS) might predict long-term outcomes in hospitalized patients with severe UC treated with intravenous corticosteroids.
METHODS
Hospitalized patients with severe UC and IUS inflammation (bowel wall thickness (BWT)>3.0mm) starting IV corticosteroids were recruited at three university hospitals in Denmark. IUS was performed before treatment, 48±24 hours (h), 6±1 days, and 3 months after treatment initiation. Time until colectomy or need for new interventions was registered together with Mayo score at 3 months and partial Mayo score (pMayo) at 12-months. Follow-up time was 12 months.
RESULTS
Fifty-six patients were included in the final analysis. Forty-five (80%) patients needed intervention, including 9 colectomies, during the 12-month follow-up. After 48±24h: No patient with a BWT<3mm needed a colectomy, p=0.04. BWT≥4mm showed an increased risk of colectomy (odds ratio 9.5 (95%CI 1.5-186), p=0.03), while a BWT≥3mm showed an increased risk of intervention (3.6 (1.1-12.5), p=0.03). A BWT≥4mm resulted in a significantly shorter time until both colectomy, p=0.03, and treatment intensification (mean days 75 (95%CI24-127) vs. 176 (119-233), p=0.005. However, neither IUS parameters nor pMayo score, CRP, hemoglobin, or p-albumin could predict remission at 3- and 12-months.
CONCLUSION
BWT assessed at 48h post intravenous corticosteroid initiation in patients hospitalized with severe UC may identify patients with an increased risk of short- and long-term colectomy and predict a more aggressive short-term disease course.
PubMed: 38940464
DOI: 10.1093/ecco-jcc/jjae101 -
Movement Disorders Clinical Practice Jun 2024
PubMed: 38940375
DOI: 10.1002/mdc3.14153 -
Molecular Medicine Reports Aug 2024The coronavirus disease 2019 pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) seriously affected global public health security. Studies... (Review)
Review
The coronavirus disease 2019 pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) seriously affected global public health security. Studies on vaccines, neutralizing antibodies (NAbs) and small molecule antiviral drugs are currently ongoing. In particular, NAbs have emerged as promising therapeutic agents due to their well‑defined mechanism, high specificity, superior safety profile, ease of large‑scale production and simultaneous application for both prevention and treatment of viral infection. Numerous NAb therapeutics have entered the clinical research stages, demonstrating promising therapeutic and preventive effects. These agents have been used for outbreak prevention and control under urgent authorization processes. The present review summarizes the molecular targets of SARS‑CoV‑2‑associated NAbs and screening and identification techniques for NAb development. Moreover, the current shortcomings and challenges that persist with the use of NAbs are discussed. The aim of the present review is to offer a reference for the development of NAbs for any future emergent infectious diseases, including SARS‑CoV‑2.
Topics: Humans; Antibodies, Neutralizing; SARS-CoV-2; COVID-19; Antibodies, Viral; Antiviral Agents; Animals
PubMed: 38940338
DOI: 10.3892/mmr.2024.13272 -
Molecular Medicine Reports Aug 2024Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia...
Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia promotes microglial pyroptosis by increasing the oxygen extraction rate in an acute ischemic stroke model. C57BL/6 mice that underwent middle cerebral artery occlusion were used for assessment of blood glucose level and neurological function. The cerebral oxygen extraction ratio (CERO), oxygen consumption rate (OCR) and partial pressure of brain tissue oxygen (PbtO) were measured. To investigate the significance of the NOD‑like receptor protein 3 (NLRP3) inflammasome, NLRP3 mice were used, and the expression levels of NLRP3, caspase‑1, full‑length gasdermin D (GSDMD‑FL), GSDMD‑N domain (GSDMD‑N), IL‑1β and IL‑18 were evaluated. In addition, Z‑YVAD‑FMK, a caspase‑1 inhibitor, was used to treat microglia to determine whether activation of the NLRP3 inflammasome was required for the enhancing effect of hyperglycemia on pyroptosis. It was revealed that hyperglycemia accelerated cerebral injury in the acute ischemic stroke model, as evidenced by decreased latency to fall and the percentage of foot fault. Hyperglycemia aggravated hypoxia by increasing the oxygen extraction rate, as evidenced by increased CERO and OCR, and decreased PbtO in response to high glucose treatment. Furthermore, hyperglycemia‑induced microglial pyroptosis was confirmed by detection of increased levels of caspase‑1, GSDMD‑N, IL‑1β and IL‑18 and a decreased level of GSDMD‑FL. However, the knockout of NLRP3 attenuated these effects. Pharmacological inhibition of caspase‑1 also reduced the expression levels of GSDMD‑N, IL‑1β and IL‑18 in microglial cells. These results suggested that hyperglycemia stimulated NLRP3 inflammasome activation by increasing the oxygen extraction rate, thus leading to the aggravation of pyroptosis following ischemic stroke.
Topics: Animals; Pyroptosis; Microglia; Ischemic Stroke; Mice; NLR Family, Pyrin Domain-Containing 3 Protein; Oxygen; Male; Hyperglycemia; Inflammasomes; Mice, Inbred C57BL; Caspase 1; Disease Models, Animal; Mice, Knockout; Interleukin-1beta; Phosphate-Binding Proteins; Oxygen Consumption; Gasdermins
PubMed: 38940333
DOI: 10.3892/mmr.2024.13270 -
Journal of Global Health Jun 2024Considering the large population of bronchiectasis and chronic obstructive pulmonary disease (COPD) patients in China, we aimed to conduct a thorough analysis that...
Analysis of clinical characteristics, prognosis and influencing factors in patients with bronchiectasis-chronic obstructive pulmonary disease overlap syndrome: A prospective study for more than five years.
BACKGROUND
Considering the large population of bronchiectasis and chronic obstructive pulmonary disease (COPD) patients in China, we aimed to conduct a thorough analysis that investigates the clinical characteristics and prognosis of bronchiectasis-COPD overlap syndrome (BCOS). Further, we aimed to explore factors associated with acute exacerbation and death in BCOS, which may be of value in its early diagnosis and intervention.
METHODS
We recruited inpatients with COPD from the second Xiangya Hospital of Central South University in China in August 2016, with follow-up until March 2022. Patients in the BCOS group had to meet the criteria for diagnosing bronchiectasis. We used self-completion questionnaires, clinical records, and self-reported data as primary data collection methods. We used Kaplan-Meier survival analyses and Cox proportional hazard models to assess the risk of severe acute exacerbation and death for BCOS during the follow-up period.
RESULTS
A total of 875 patients were included and followed up. Patients in the BCOS group had more females, fewer smokers, lower discharge COPD assessment test (CAT) scores, lower forced vital capacity (FVC), a higher likelihood of co-occurring active tuberculosis, higher levels of eosinophils and inflammatory markers, and a higher rate of positive sputum cultures for Pseudomonas aeruginosa than patients in the COPD-only group. Patients in the acute exacerbation group (AE+) were found to have lower body mass index (BMI), more frequent acute exacerbations, higher modified Medical Research Council (mMRC) dyspnoea grade on admission, higher inflammatory markers, lower FVC, higher rates of using inhaled bronchodilators, and higher rates of both positive and Pseudomonas aeruginosa positive sputum cultures. Patients in the 'death' group were older, had a lower BMI, had spent longer time in the hospital, had higher mMRC dyspnoea grade and CAT scores upon admission and discharge, had higher levels of inflammatory markers, lower rates of using inhaled bronchodilators, were more likely to have a combination of pulmonary heart disease and obsolete pulmonary tuberculosis, as well as a higher rate of fungus-positive sputum cultures. Both erythrocyte sedimentation rate at baseline and Pseudomonas aeruginosa culture positivity were confirmed as independent predictors of severe acute exacerbation in multivariate analysis during the years of follow-up. Fungus culture positivity baseline blood urea nitrogen, baseline lymphocyte count, comorbidities with obsolete pulmonary tuberculosis and comorbidities with pulmonary heart disease were verified as independent predictors of death in multivariate analysis during the years of follow-up. Kaplan-Meier curves under survival analysis demonstrated no statistically significant difference in mortality between the COPD and the BCOS groups at the full one, two, and three years of follow-up.
CONCLUSIONS
Patients with BCOS present with reduced lung function, increased susceptibility to different complications, elevated blood eosinophils and inflammatory markers, and elevated rates of positive Pseudomonas aeruginosa cultures. These distinctive markers are linked to a greater risk of severe acute exacerbations and mortality.
Topics: Humans; Female; Pulmonary Disease, Chronic Obstructive; Male; Bronchiectasis; Middle Aged; Prospective Studies; Aged; Prognosis; China; Risk Factors; Syndrome; Disease Progression
PubMed: 38940273
DOI: 10.7189/jogh.14.04129 -
Clinical Otolaryngology : Official... Jun 2024As patients nowadays tend to have multiple diseases and complex medical histories, our aim was to identify high-quality, non-instrumental dysphagia screening tools used... (Review)
Review
INTRODUCTION
As patients nowadays tend to have multiple diseases and complex medical histories, our aim was to identify high-quality, non-instrumental dysphagia screening tools used for the detection of adult dysphagia cases in all disease categories in acute-care settings.
METHOD
A literature search was conducted in five databases from each database's earliest inception to 31 July 2021 and guided by five keywords: 'dysphagia', 'deglutition', 'screening', 'test' and 'measure'. Without limiting the search in any specific disease category, reviewers assessed original studies and identified tools if they had been validated against instrumental evaluations and if they had been designed as a pass-fail procedure to screen whether dysphagia is absent or present. We further excluded any tool if it was (1) for pediatric focus, or (2) a patient self-report questionnaire. All final tool candidates underwent a methodological quality appraisal using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).
RESULT
Out of 195 studies with 165 tools identified, 20 tool candidates underwent QUADAS-2 review. We found six high-quality, non-instrumental screening tools for detecting adult dysphagia cases in acute-care settings, including the Yale Swallow Protocol, Gugging Swallowing Screen, Toronto Bedside Swallowing Screening Test (both English and Portuguese versions), Sapienza Global Bedside Evaluation of Swallowing and Two-Step Thickened Water Test. These high-quality tools were developed primarily for patients with stroke. Only Yale Swallow Protocol was originally tested for heterogeneous populations with stroke, multiple sclerosis, traumatic brain injury, oesophageal surgery, neurosurgery and head-and-neck cancer.
CONCLUSIONS
The results highlight the gap in the unavailability of high-quality dysphagia screening tool in several emerged high-risk populations including elderly inpatients, or patients following endotracheal extubation. Further research is needed to determine whether these six tools can be effectively applied across different high-risk populations in acute-care settings to screen for cases finding.
PubMed: 38940226
DOI: 10.1111/coa.14194 -
Journal of Paediatrics and Child Health Jun 2024
PubMed: 38940194
DOI: 10.1111/jpc.16604