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1.
Biochem J ; 480(9): 665-684, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37115711

RESUMEN

Necroptosis is a mode of programmed, lytic cell death that is executed by the mixed lineage kinase domain-like (MLKL) pseudokinase following activation by the upstream kinases, receptor-interacting serine/threonine protein kinase (RIPK)-1 and RIPK3. Dysregulated necroptosis has been implicated in the pathophysiology of many human diseases, including inflammatory and degenerative conditions, infectious diseases and cancers, provoking interest in pharmacological targeting of the pathway. To identify small molecules impacting on the necroptotic machinery, we performed a phenotypic screen using a mouse cell line expressing an MLKL mutant that kills cells in the absence of upstream death or pathogen detector receptor activation. This screen identified the vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) tyrosine kinase inhibitor, ABT-869 (Linifanib), as a small molecule inhibitor of necroptosis. We applied a suite of cellular, biochemical and biophysical analyses to pinpoint the apical necroptotic kinase, RIPK1, as the target of ABT-869 inhibition. Our study adds to the repertoire of established protein kinase inhibitors that additionally target RIPK1 and raises the prospect that serendipitous targeting of necroptosis signalling may contribute to their clinical efficacy in some settings.


Asunto(s)
Proteínas Quinasas , Humanos , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Necroptosis , Factor A de Crecimiento Endotelial Vascular/metabolismo , Apoptosis , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo
2.
J Infect Dis ; 228(Suppl 7): S536-S547, 2023 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-37145895

RESUMEN

Ebola virus (EBOV) causes lethal disease in humans but not in mice. Here, we generated recombinant mouse-adapted (MA) EBOVs, including 1 based on the previously reported serially adapted strain (rMA-EBOV), along with single-reporter rMA-EBOVs expressing either fluorescent (ZsGreen1 [ZsG]) or bioluminescent (nano-luciferase [nLuc]) reporters, and dual-reporter rMA-EBOVs expressing both ZsG and nLuc. No detriment to viral growth in vitro was seen with inclusion of MA-associated mutations or reporter proteins. In CD-1 mice, infection with MA-EBOV, rMA-EBOV, and single-reporter rMA-EBOVs conferred 100% lethality; infection with dual-reporter rMA-EBOV resulted in 73% lethality. Bioluminescent signal from rMA-EBOV expressing nLuc was detected in vivo and ex vivo using the IVIS Spectrum CT. Fluorescent signal from rMA-EBOV expressing ZsG was detected in situ using handheld blue-light transillumination and ex vivo through epi-illumination with the IVIS Spectrum CT. These data support the use of reporter MA-EBOV for studies of Ebola virus in animal disease models.


Asunto(s)
Vacunas contra el Virus del Ébola , Ebolavirus , Fiebre Hemorrágica Ebola , Humanos , Animales , Ratones , Ebolavirus/genética , Virulencia , Mutación
3.
J Infect Dis ; 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38064677

RESUMEN

Nipah virus (NiV) is a highly pathogenic paramyxovirus. The Syrian hamster model recapitulates key features of human NiV disease and is a critical tool for evaluating antivirals and vaccines. Here we describe longitudinal humoral immune responses in NiV-infected Syrian hamsters. Samples were obtained 1-28 days after infection and analyzed by ELISA, neutralization, and Fc-mediated effector function assays. NiV infection elicited robust antibody responses against the nucleoprotein and attachment glycoprotein. Levels of neutralizing antibodies were modest and only detectable in surviving animals. Fc-mediated effector functions were mostly observed in nucleoprotein-targeting antibodies. Antibody levels and activities positively correlated with challenge dose.

4.
Proc Natl Acad Sci U S A ; 117(15): 8468-8475, 2020 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-32234780

RESUMEN

The necroptosis cell death pathway has been implicated in host defense and in the pathology of inflammatory diseases. While phosphorylation of the necroptotic effector pseudokinase Mixed Lineage Kinase Domain-Like (MLKL) by the upstream protein kinase RIPK3 is a hallmark of pathway activation, the precise checkpoints in necroptosis signaling are still unclear. Here we have developed monobodies, synthetic binding proteins, that bind the N-terminal four-helix bundle (4HB) "killer" domain and neighboring first brace helix of human MLKL with nanomolar affinity. When expressed as genetically encoded reagents in cells, these monobodies potently block necroptotic cell death. However, they did not prevent MLKL recruitment to the "necrosome" and phosphorylation by RIPK3, nor the assembly of MLKL into oligomers, but did block MLKL translocation to membranes where activated MLKL normally disrupts membranes to kill cells. An X-ray crystal structure revealed a monobody-binding site centered on the α4 helix of the MLKL 4HB domain, which mutational analyses showed was crucial for reconstitution of necroptosis signaling. These data implicate the α4 helix of its 4HB domain as a crucial site for recruitment of adaptor proteins that mediate membrane translocation, distinct from known phospholipid binding sites.


Asunto(s)
Materiales Biomiméticos/farmacología , Membrana Celular/metabolismo , Dominio de Fibronectina del Tipo III , Necrosis , Oligopéptidos/farmacología , Proteínas Quinasas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Cristalografía por Rayos X , Humanos , Fosforilación , Conformación Proteica , Proteínas Quinasas/química , Multimerización de Proteína , Transporte de Proteínas
5.
Environ Microbiol ; 24(10): 4561-4569, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35837859

RESUMEN

An imported case of monkeypox was diagnosed in December 2019 in a traveller returning from Nigeria to the UK. Subsequently, environmental sampling was performed at two adjoining single-room residences occupied by the patient and their sibling. Monkeypox virus DNA was identified in multiple locations throughout both properties, and monkeypox virus was isolated from several samples 3 days after the patient was last in these locations. Positive samples were identified following the use of both vacuum and surface sampling techniques; these methodologies allowed for environmental analysis of potentially contaminated porous and non-porous surfaces via real-time quantitative reverse transcriptase PCR analysis in addition to viral isolation to confirm the presence of infection-competent virus. This report confirms the potential for infection-competent monkeypox virus to be recovered in environmental settings associated with known positive cases and the necessity for rapid environmental assessment to reduce potential exposure to close contacts and the general public. The methods adopted in this investigation may be used for future confirmed cases of monkeypox in order to establish levels of contamination, confirm the presence of infection-competent material and to identify locations requiring additional cleaning.


Asunto(s)
Monkeypox virus , Mpox , ADN Viral , Brotes de Enfermedades , Humanos , Mpox/diagnóstico , Mpox/epidemiología , Monkeypox virus/genética , Reino Unido
6.
J Gen Virol ; 102(4)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33913803

RESUMEN

Infectious SARS-CoV-2 can be recovered from the oral cavities and saliva of COVID-19 patients with potential implications for disease transmission. Reducing viral load in patient saliva using antiviral mouthwashes may therefore have a role as a control measure in limiting virus spread, particularly in dental settings. Here, the efficacy of SARS-CoV-2 inactivation by seven commercially available mouthwashes with a range of active ingredients were evaluated in vitro. We demonstrate ≥4.1 to ≥5.5 log10 reduction in SARS-CoV-2 titre following a 1 min treatment with commercially available mouthwashes containing 0.01-0.02 % stabilised hypochlorous acid or 0.58 % povidone iodine, and non-specialist mouthwashes with both alcohol-based and alcohol-free formulations designed for home use. In contrast, products containing 1.5 % hydrogen peroxide or 0.2 % chlorhexidine gluconate were ineffective against SARS-CoV-2 in these tests. This study contributes to the growing body of evidence surrounding virucidal efficacy of mouthwashes/oral rinses against SARS-CoV-2, and has important applications in reducing risk associated with aerosol generating procedures in dentistry and potentially for infection control more widely.


Asunto(s)
Antivirales/farmacología , Antisépticos Bucales/farmacología , SARS-CoV-2/efectos de los fármacos , Inactivación de Virus/efectos de los fármacos , COVID-19/prevención & control , COVID-19/transmisión , Supervivencia Celular/efectos de los fármacos , Humanos , Boca/virología , Carga Viral/efectos de los fármacos
7.
Anal Chem ; 93(32): 11108-11115, 2021 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-34348022

RESUMEN

Studies of the metal content of metalloproteins in tissues from the human central nervous system (CNS) can be compromised by preparative techniques which alter levels of, or interactions between, metals and the protein of interest within a complex mixture. We developed a methodological workflow combining size exclusion chromatography, native isoelectric focusing, and either proton or synchrotron X-ray fluorescence within electrophoresis gels to analyze the endogenous metal content of copper-zinc superoxide dismutase (SOD1) purified from minimal amounts (<20 mg) of post-mortem human brain and spinal cord tissue. Abnormal metallation and aggregation of SOD1 are suspected to play a role in amyotrophic lateral sclerosis and Parkinson's disease, but data describing SOD1 metal occupancy in human tissues have not previously been reported. Validating our novel approach, we demonstrated step-by-step metal preservation, preserved SOD1 activity, and substantial enrichment of SOD1 protein versus confounding metalloproteins. We analyzed tissues from nine healthy individuals and five CNS regions (occipital cortex, substantia nigra, locus coeruleus, dorsal spinal cord, and ventral spinal cord). We found that Cu and Zn were bound to SOD1 in a ratio of 1.12 ± 0.28, a ratio very close to the expected value of 1. Our methodological workflow can be applied to the study of endogenous native SOD1 in a pathological context and adapted to a range of metalloproteins from human tissues and other sources.


Asunto(s)
Esclerosis Amiotrófica Lateral , Zinc , Sistema Nervioso Central , Cobre , Humanos , Mutación , Superóxido Dismutasa/genética , Superóxido Dismutasa-1 , Flujo de Trabajo
8.
J Orthod ; 48(2): 110-117, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33573439

RESUMEN

OBJECTIVE: To explore and understand young people's perspectives of fixed orthodontic treatment. In particular, understanding how young people perceived and experienced having a fixed appliance and how their experiences can change during their treatment. DESIGN: Qualitative study carried out longitudinally. SETTING: In-depth qualitative interviews carried out in participants' homes, video diaries recorded by participants when and where they wish. PARTICIPANTS: Fifteen patients aged 10-15 years undergoing NHS fixed appliance treatment. METHODS: Data were collected by in-depth interviews and video diaries throughout the participants' course of orthodontic treatment. Data were analysed using thematic analysis. RESULTS: Young people's friends, family and social media influenced how young people felt about the appearance of their teeth. Young people can perceive negative social judgements are made about them based on the appearance of their teeth; however, the appearance of the brace was not a concern. For some of the young people, the presence of the brace formed a rite of passage throughout adolescence. Pain and discomfort caused by fixed appliances was expected and tolerated and felt normal with time. CONCLUSION: Young people's perceptions about appearance are influenced by people around them and social media. The physical feeling of the brace was normalised, although it did affect young people's lives.


Asunto(s)
Emociones , Adolescente , Niño , Humanos , Investigación Cualitativa
9.
J Clin Microbiol ; 58(11)2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-32839250

RESUMEN

The COVID-19 pandemic has necessitated a multifaceted rapid response by the scientific community, bringing researchers, health officials, and industry together to address the ongoing public health emergency. To meet this challenge, participants need an informed approach for working safely with the etiological agent, the novel human coronavirus SARS-CoV-2. Work with infectious SARS-CoV-2 is currently restricted to high-containment laboratories, but material can be handled at a lower containment level after inactivation. Given the wide array of inactivation reagents that are being used in laboratories during this pandemic, it is vital that their effectiveness is thoroughly investigated. Here, we evaluated a total of 23 commercial reagents designed for clinical sample transportation, nucleic acid extraction, and virus inactivation for their ability to inactivate SARS-CoV-2, as well as seven other common chemicals, including detergents and fixatives. As part of this study, we have also tested five filtration matrices for their effectiveness at removing the cytotoxic elements of each reagent, permitting accurate determination of levels of infectious virus remaining following treatment. In addition to providing critical data informing inactivation methods and risk assessments for diagnostic and research laboratories working with SARS-CoV-2, these data provide a framework for other laboratories to validate their inactivation processes and to guide similar studies for other pathogens.


Asunto(s)
Betacoronavirus/efectos de los fármacos , Indicadores y Reactivos/farmacología , Inactivación de Virus/efectos de los fármacos , Animales , Betacoronavirus/aislamiento & purificación , COVID-19 , Prueba de COVID-19 , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/virología , Filtración/instrumentación , Humanos , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/virología , SARS-CoV-2 , Células Vero
10.
J Gen Virol ; 100(8): 1208-1221, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31268416

RESUMEN

The family Hantaviridae mostly comprises rodent-borne segmented negative-sense RNA viruses, many of which are capable of causing devastating disease in humans. In contrast, hantavirus infection of rodent hosts results in a persistent and inapparent infection through their ability to evade immune detection and inhibit apoptosis. In this study, we used Tula hantavirus (TULV) to investigate the interplay between viral and host apoptotic responses during early, peak and persistent phases of virus infection in cell culture. Examination of early-phase TULV infection revealed that infected cells were refractory to apoptosis, as evidenced by the complete lack of cleaved caspase-3 (casp-3C) staining, whereas in non-infected bystander cells casp-3C was highly abundant. Interestingly, at later time points, casp-3C was abundant in infected cells, but the cells remained viable and able to continue shedding infectious virus, and together these observations were suggestive of a TULV-associated apoptotic block. To investigate this block, we viewed TULV-infected cells using laser scanning confocal and wide-field deconvolution microscopy, which revealed that TULV nucleocapsid protein (NP) colocalized with, and sequestered, casp-3C within cytoplasmic ultrastructures. Consistent with casp-3C colocalization, we showed for the first time that TULV NP was cleaved in cells and that TULV NP and casp-3C could be co-immunoprecipitated, suggesting that this interaction was stable and thus unlikely to be solely confined to NP binding as a substrate to the casp-3C active site. To account for these findings, we propose a novel mechanism by which TULV NP inhibits apoptosis by spatially sequestering casp-3C from its downstream apoptotic targets within the cytosol.


Asunto(s)
Apoptosis , Caspasa 3/metabolismo , Infecciones por Hantavirus/enzimología , Proteínas de la Nucleocápside/metabolismo , Orthohantavirus/metabolismo , Animales , Caspasa 3/genética , Citosol/enzimología , Citosol/virología , Orthohantavirus/genética , Infecciones por Hantavirus/genética , Infecciones por Hantavirus/fisiopatología , Infecciones por Hantavirus/virología , Interacciones Huésped-Patógeno , Humanos , Proteínas de la Nucleocápside/genética , Unión Proteica
11.
J Virol ; 92(11)2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29563292

RESUMEN

There is increasing interest recently in developing intranasal vaccines against respiratory tract infections. The antibody response is critical for vaccine-induced protection, and T follicular helper cells (TFH) are considered important for mediating the antibody response. Most data supporting the role for TFH in the antibody response are from animal studies, and direct evidence from humans is limited, apart from the presence of TFH-like cells in blood. We studied the activation and induction of TFH and their role in the anti-influenza antibody response induced by a live-attenuated influenza vaccine (LAIV) in human nasopharynx-associated lymphoid tissue (NALT). TFH activation in adenotonsillar tissues was analyzed by flow cytometry, and anti-hemagglutinin (anti-HA) antibodies were examined following LAIV stimulation of tonsillar mononuclear cells (MNC). Induction of antigen-specific TFH by LAIV was studied by flow cytometry analysis of induced TFH and CD154 expression. LAIV induced TFH proliferation, which correlated with anti-HA antibody production, and TFH were shown to be critical for the antibody response. Induction of TFH from naive T cells by LAIV was shown in newly induced TFH expressing BCL6 and CD21, followed by the detection of anti-HA antibodies. Antigen specificity of LAIV-induced TFH was demonstrated by expression of the antigen-specific T cell activation marker CD154 upon challenge by H1N1 virus antigen or HA. LAIV-induced TFH differentiation was inhibited by BCL6, interleukin-21 (IL-21), ICOS, and CD40 signaling blocking, and that diminished anti-HA antibody production. In conclusion, we demonstrated the induction by LAIV of antigen-specific TFH in human NALT that provide critical support for the anti-influenza antibody response. Promoting antigen-specific TFH in NALT by use of intranasal vaccines may provide an effective vaccination strategy against respiratory infections in humans.IMPORTANCE Airway infections, such as influenza, are common in humans. Intranasal vaccination has been considered a biologically relevant and effective way of immunization against airway infection. The vaccine-induced antibody response is crucial for protection against infection. Recent data from animal studies suggest that one type of T cells, TFH, are important for the antibody response. However, data on whether TFH-mediated help for antibody production operates in humans are limited due to the lack of access to human immune tissue containing TFH In this study, we demonstrate the induction of TFH in human immune tissue, providing critical support for the anti-influenza antibody response, by use of an intranasal influenza vaccine. Our findings provide direct evidence that TFH play a critical role in vaccine-induced immunity in humans and suggest a novel strategy for promoting such cells by use of intranasal vaccines against respiratory infections.


Asunto(s)
Anticuerpos Antivirales/inmunología , Hemaglutininas Virales/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Activación de Linfocitos/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Vacunas Atenuadas/inmunología , Administración Intranasal , Adolescente , Adulto , Formación de Anticuerpos/inmunología , Linfocitos B/inmunología , Antígenos CD40/antagonistas & inhibidores , Ligando de CD40/biosíntesis , Células Cultivadas , Niño , Preescolar , Humanos , Inmunidad Mucosa/inmunología , Proteína Coestimuladora de Linfocitos T Inducibles/antagonistas & inhibidores , Gripe Humana/prevención & control , Gripe Humana/virología , Interleucinas/antagonistas & inhibidores , Membrana Mucosa/inmunología , Nasofaringe/inmunología , Proteínas Proto-Oncogénicas c-bcl-6/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-6/biosíntesis , Receptores de Complemento 3d/biosíntesis , Adulto Joven
12.
Acta Neuropathol ; 134(1): 113-127, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28527045

RESUMEN

Neuronal loss in numerous neurodegenerative disorders has been linked to protein aggregation and oxidative stress. Emerging data regarding overlapping proteinopathy in traditionally distinct neurodegenerative diseases suggest that disease-modifying treatments targeting these pathological features may exhibit efficacy across multiple disorders. Here, we describe proteinopathy distinct from classic synucleinopathy, predominantly comprised of the anti-oxidant enzyme superoxide dismutase-1 (SOD1), in the Parkinson's disease brain. Significant expression of this pathology closely reflected the regional pattern of neuronal loss. The protein composition and non-amyloid macrostructure of these novel aggregates closely resembles that of neurotoxic SOD1 deposits in SOD1-associated familial amyotrophic lateral sclerosis (fALS). Consistent with the hypothesis that deposition of protein aggregates in neurodegenerative disorders reflects upstream dysfunction, we demonstrated that SOD1 in the Parkinson's disease brain exhibits evidence of misfolding and metal deficiency, similar to that seen in mutant SOD1 in fALS. Our data suggest common mechanisms of toxic SOD1 aggregation in both disorders and a potential role for SOD1 dysfunction in neuronal loss in the Parkinson's disease brain. This shared restricted proteinopathy highlights the potential translation of therapeutic approaches targeting SOD1 toxicity, already in clinical trials for ALS, into disease-modifying treatments for Parkinson's disease.


Asunto(s)
Esclerosis Amiotrófica Lateral/patología , Encéfalo/patología , Enfermedad de Parkinson/patología , Superóxido Dismutasa-1/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Esclerosis Amiotrófica Lateral/enzimología , Encéfalo/enzimología , Recuento de Células , Femenino , Humanos , Immunoblotting , Inmunohistoquímica , Cuerpos de Lewy/enzimología , Cuerpos de Lewy/patología , Masculino , Microscopía Fluorescente , Persona de Mediana Edad , Neuronas/enzimología , Neuronas/patología , Enfermedad de Parkinson/enzimología , Agregación Patológica de Proteínas/enzimología , Agregación Patológica de Proteínas/patología , Pliegue de Proteína , Médula Espinal/enzimología , Médula Espinal/patología
13.
Clin Sci (Lond) ; 130(8): 565-74, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26957644

RESUMEN

Copper is a biometal essential for normal brain development and function, thus copper deficiency or excess results in central nervous system disease. Well-characterized disorders of disrupted copper homoeostasis with neuronal degeneration include Menkes disease and Wilson's disease but a large body of evidence also implicates disrupted copper pathways in other neurodegenerative disorders, including Parkinson's disease, Alzheimer's disease, Amyotrophic lateral sclerosis, Huntington's disease and prion diseases. In this short review we critically evaluate the data regarding changes in systemic and brain copper levels in Parkinson's disease, where alterations in brain copper are associated with regional neuronal cell death and disease pathology. We review copper regulating mechanisms in the human brain and the effects of dysfunction within these systems. We then examine the evidence for a role for copper in pathogenic processes in Parkinson's disease and consider reports of diverse copper-modulating strategies in in vitro and in vivo models of this disorder. Copper-modulating therapies are currently advancing through clinical trials for Alzheimer's and Huntington's disease and may also hold promise as disease modifying agents in Parkinson's disease.


Asunto(s)
Antiparkinsonianos/uso terapéutico , Encéfalo/efectos de los fármacos , Cobre/metabolismo , Enfermedad de Parkinson/tratamiento farmacológico , Animales , Encéfalo/metabolismo , Encéfalo/fisiopatología , Homeostasis , Humanos , Estrés Oxidativo/efectos de los fármacos , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/fisiopatología , alfa-Sinucleína/metabolismo
14.
Anal Chem ; 87(13): 6639-45, 2015 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-26020362

RESUMEN

Redox-active metals in the brain mediate numerous biochemical processes and are also implicated in a number of neurodegenerative diseases. A number of different approaches are available for quantitatively measuring the spatial distribution of biometals at an image resolution approaching the subcellular level. Measured biometal levels obtained using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS; spatial resolution 15 µm × 15 µm) were within the range of those obtained using X-ray fluorescence microscopy (XFM; spatial resolution 2 µm × 7 µm) and regional changes in metal concentration across discrete brain regions were replicated to the same degree. Both techniques are well suited to profiling changes in regional biometal distribution between healthy and diseased brain tissues, but absolute quantitation of metal levels varied significantly between methods, depending on the metal of interest. Where all possible variables affect metal levels, independent of a treatment/phenotype are controlled, either method is suitable for examining differences between experimental groups, though, as with any method for imaging post mortem brain tissue, care should be taken when interpreting the total metal levels with regard to physiological concentrations.


Asunto(s)
Espectrometría de Masas/métodos , Metales/análisis , Microscopía Fluorescente/métodos , Sistema Nervioso/química , Animales , Rayos Láser , Ratones , Ratones Endogámicos C57BL
15.
Curr Opin Struct Biol ; 88: 102891, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39059047

RESUMEN

Necroptosis is a lytic form of programmed cell death implicated in inflammatory pathologies, leading to intense interest in the underlying mechanisms and therapeutic prospects. Here, we review our current structural understanding of how the terminal executioner of the pathway, the dead kinase, mixed lineage kinase domain-like (MLKL), is converted from a dormant to killer form by the upstream regulatory kinase, RIPK3. RIPK3-mediated phosphorylation of MLKL's pseudokinase domain toggles a molecular switch that induces dissociation from a cytoplasmic platform, assembly of MLKL oligomers, and trafficking to the plasma membrane, where activated MLKL accumulates and permeabilises the lipid bilayer to induce cell death. We highlight gaps in mechanistic knowledge of MLKL's activation, how mechanisms diverge between species, and the power of modelling in advancing structural insights.

16.
ACS Sustain Chem Eng ; 12(8): 3044-3060, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38425834

RESUMEN

The heterostructure WO3/BiVO4-based photoanodes have garnered significant interest for photoelectrochemical (PEC) solar-driven water splitting to produce hydrogen. However, challenges such as inadequate charge separation and photocorrosion significantly hinder their performance, limiting overall solar-to-hydrogen conversion efficiency. The incorporation of cocatalysts has shown promise in improving charge separation at the photoanode, yet mitigating photocorrosion remains a formidable challenge. Amorphous metal oxide-based passivation layers offer a potential solution to safeguard semiconductor catalysts. We examine the structural, surface morphological, and optical properties of two-step-integrated sputter and spray-coated TiO2 thin films and their integration onto WO3/BiVO4, both with and without NiOOH cocatalyst deposition. The J-V experiments reveal that the NiOOH cocatalyst enhances the photocurrent density of the WO3/BiVO4 photoanode in water splitting reactions from 2.81 to 3.87 mA/cm2. However, during prolonged operation, the photocurrent density degrades by 52%. In contrast, integrated sputter and spray-coated TiO2 passivation layer-coated WO3/BiVO4/NiOOH samples demonstrate a ∼88% enhancement in photocurrent density (5.3 mA/cm2) with minimal degradation, emphasizing the importance of a strategic coating protocol to sustain photocurrent generation. We further explore the feasibility of using natural mine wastewater as an electrolyte feedstock in PEC generation. Two-compartment PEC cells, utilizing both fresh water and metal mine wastewater feedstocks exhibit 66.6 and 74.2 µmol/h cm2 hydrogen generation, respectively. Intriguingly, the recovery of zinc (Zn2+) heavy metals on the cathode surface in the mine wastewater electrolyte is confirmed through surface morphology and elemental analysis. This work underscores the significance of passivation layer and cocatalyst coating methodologies in a sequential order to enhance charge separation and protect the photoanode from photocorrosion, contributing to sustainable hydrogen generation. Additionally, it suggests the potential of utilizing wastewater in electrolyzers as an alternative to freshwater resources.

17.
Virus Res ; 345: 199398, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38754786

RESUMEN

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne nairovirus with a wide geographic spread that can cause severe and lethal disease. No specific medical countermeasures are approved to combat this illness. The CCHFV L protein contains an ovarian tumor (OTU) domain with a cysteine protease thought to modulate cellular immune responses by removing ubiquitin and ISG15 post-translational modifications from host and viral proteins. Viral deubiquitinases like CCHFV OTU are attractive drug targets, as blocking their activity may enhance cellular immune responses to infection, and potentially inhibit viral replication itself. We previously demonstrated that the engineered ubiquitin variant CC4 is a potent inhibitor of CCHFV replication in vitro. A major challenge of the therapeutic use of small protein inhibitors such as CC4 is their requirement for intracellular delivery, e.g., by viral vectors. In this study, we examined the feasibility of in vivo CC4 delivery by a replication-deficient recombinant adenovirus (Ad-CC4) in a lethal CCHFV mouse model. Since the liver is a primary target of CCHFV infection, we aimed to optimize delivery to this organ by comparing intravenous (tail vein) and intraperitoneal injection of Ad-CC4. While tail vein injection is a traditional route for adenovirus delivery, in our hands intraperitoneal injection resulted in higher and more widespread levels of adenovirus genome in tissues, including, as intended, the liver. However, despite promising in vitro results, neither route of in vivo CC4 treatment resulted in protection from a lethal CCHFV infection.


Asunto(s)
Adenoviridae , Modelos Animales de Enfermedad , Virus de la Fiebre Hemorrágica de Crimea-Congo , Fiebre Hemorrágica de Crimea , Replicación Viral , Animales , Virus de la Fiebre Hemorrágica de Crimea-Congo/genética , Fiebre Hemorrágica de Crimea/virología , Ratones , Adenoviridae/genética , Proteínas Virales/genética , Proteínas Virales/metabolismo , Vectores Genéticos/genética , Antivirales/farmacología , Femenino , Hígado/virología , Humanos
18.
J Med Chem ; 66(4): 2361-2385, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36781172

RESUMEN

Necroptosis is a regulated caspase-independent form of necrotic cell death that results in an inflammatory phenotype. This process contributes profoundly to the pathophysiology of numerous neurodegenerative, cardiovascular, infectious, malignant, and inflammatory diseases. Receptor-interacting protein kinase 1 (RIPK1), RIPK3, and the mixed lineage kinase domain-like protein (MLKL) pseudokinase have been identified as the key components of necroptosis signaling and are the most promising targets for therapeutic intervention. Here, we review recent developments in the field of small-molecule inhibitors of necroptosis signaling, provide guidelines for their use as chemical probes to study necroptosis, and assess the therapeutic challenges and opportunities of such inhibitors in the treatment of a range of clinical indications.


Asunto(s)
Necroptosis , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Humanos , Necrosis , Apoptosis
19.
Sci Rep ; 13(1): 19384, 2023 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-37938597

RESUMEN

Reverse-transcription quantitative polymerase chain reaction assays are frequently used to evaluate gene expression in animal model studies. Data analyses depend on normalization using a suitable reference gene (RG) to minimize effects of variation due to sample collection, sample processing, or experimental set-up. Here, we investigated the suitability of nine potential RGs in laboratory animals commonly used to study viral hemorrhagic fever infection. Using tissues (liver, spleen, gonad [ovary or testis], kidney, heart, lung, eye, brain, and blood) collected from naïve animals and those infected with Crimean-Congo hemorrhagic fever (mice), Nipah (hamsters), or Lassa (guinea pigs) viruses, optimal species-specific RGs were identified based on five web-based algorithms to assess RG stability. Notably, the Ppia RG demonstrated stability across all rodent tissues tested. Optimal RG pairs that include Ppia were determined for each rodent species (Ppia and Gusb for mice; Ppia and Hrpt for hamsters; and Ppia and Gapdh for guinea pigs). These RG pair assays were multiplexed with viral targets to improve assay turnaround time and economize sample usage. Finally, a pan-rodent Ppia assay capable of detecting Ppia across multiple rodent species was developed and successfully used in ecological investigations of field-caught rodents, further supporting its pan-species utility.


Asunto(s)
Arenavirus del Nuevo Mundo , Virus del Dengue , Virus de la Fiebre Hemorrágica de Crimea-Congo , Cricetinae , Femenino , Masculino , Cobayas , Animales , Ratones , Modelos Animales , Ciclofilina A , ARN
20.
Ind Eng Chem Res ; 62(45): 19084-19094, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38020790

RESUMEN

For the first time, we demonstrate a photoelectrocatalysis technique for simultaneous surfactant pollutant degradation and green hydrogen generation using mesoporous WO3/BiVO4 photoanode under simulated sunlight irradiation. The materials properties such as morphology, crystallite structure, chemical environment, optical absorbance, and bandgap energy of the WO3/BiVO4 films are examined and discussed. We have tested the anionic type (sodium 2-naphthalenesulfonate (S2NS)) and cationic type surfactants (benzyl alkyl dimethylammonium compounds (BAC-C12)) as model pollutants. A complete removal of S2NS and BAC-C12 surfactants at 60 and 90 min, respectively, by applying 1.75 V applied potential vs RHE to the circuit, under 1 sun was achieved. An interesting competitive phenomenon for photohole utilization was observed between surfactants and adsorbed water. This led to the formation of H2O2 from water alongside surfactant degradation (anode) and hydrogen evolution (cathode). No byproducts were observed after the direct photohole mediated degradation of surfactants, implying its advantage over other AOPs and biological processes. In the cathode compartment, 82.51 µmol/cm2 and 71.81 µmol/cm2 of hydrogen gas were generated during the BAC-C12 and S2NS surfactant degradation process, respectively, at 1.75 V RHE applied potential.

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