Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 162
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 120(12): e2203352120, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36927151

RESUMEN

Lineage-tracing technologies based on Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein 9 (CRISPR-Cas9) genome editing have emerged as a powerful tool for investigating development in single-cell contexts, but exact reconstruction of the underlying clonal relationships in experiment is complicated by features of the data. These complications are functions of the experimental parameters in these systems, such as the Cas9 cutting rate, the diversity of indel outcomes, and the rate of missing data. In this paper, we develop two theoretically grounded algorithms for the reconstruction of the underlying single-cell phylogenetic tree as well as asymptotic bounds for the number of recording sites necessary for exact recapitulation of the ground truth phylogeny at high probability. In doing so, we explore the relationship between the problem difficulty and the experimental parameters, with implications for experimental design. Lastly, we provide simulations showing the empirical performance of these algorithms and showing that the trends in the asymptotic bounds hold empirically. Overall, this work provides a theoretical analysis of phylogenetic reconstruction in single-cell CRISPR-Cas9 lineage-tracing technologies.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Sistemas CRISPR-Cas/genética , Filogenia , Linaje de la Célula/genética , Proteína 9 Asociada a CRISPR/genética
2.
Proc Natl Acad Sci U S A ; 120(21): e2221116120, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37192158

RESUMEN

Alternative splicing (AS) is prevalent in cancer, generating an extensive but largely unexplored repertoire of novel immunotherapy targets. We describe Isoform peptides from RNA splicing for Immunotherapy target Screening (IRIS), a computational platform capable of discovering AS-derived tumor antigens (TAs) for T cell receptor (TCR) and chimeric antigen receptor T cell (CAR-T) therapies. IRIS leverages large-scale tumor and normal transcriptome data and incorporates multiple screening approaches to discover AS-derived TAs with tumor-associated or tumor-specific expression. In a proof-of-concept analysis integrating transcriptomics and immunopeptidomics data, we showed that hundreds of IRIS-predicted TCR targets are presented by human leukocyte antigen (HLA) molecules. We applied IRIS to RNA-seq data of neuroendocrine prostate cancer (NEPC). From 2,939 NEPC-associated AS events, IRIS predicted 1,651 epitopes from 808 events as potential TCR targets for two common HLA types (A*02:01 and A*03:01). A more stringent screening test prioritized 48 epitopes from 20 events with "neoantigen-like" NEPC-specific expression. Predicted epitopes are often encoded by microexons of ≤30 nucleotides. To validate the immunogenicity and T cell recognition of IRIS-predicted TCR epitopes, we performed in vitro T cell priming in combination with single-cell TCR sequencing. Seven TCRs transduced into human peripheral blood mononuclear cells (PBMCs) showed high activity against individual IRIS-predicted epitopes, providing strong evidence of isolated TCRs reactive to AS-derived peptides. One selected TCR showed efficient cytotoxicity against target cells expressing the target peptide. Our study illustrates the contribution of AS to the TA repertoire of cancer cells and demonstrates the utility of IRIS for discovering AS-derived TAs and expanding cancer immunotherapies.


Asunto(s)
Neoplasias , Precursores del ARN , Masculino , Humanos , Precursores del ARN/metabolismo , Empalme Alternativo , Leucocitos Mononucleares/metabolismo , Receptores de Antígenos de Linfocitos T , Epítopos de Linfocito T , Inmunoterapia , Antígenos de Neoplasias , Péptidos/metabolismo , Neoplasias/genética , Neoplasias/terapia
3.
Brief Bioinform ; 24(5)2023 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-37580177

RESUMEN

Genomic variants affecting pre-messenger RNA splicing and its regulation are known to underlie many rare genetic diseases. However, common workflows for genetic diagnosis and clinical variant interpretation frequently overlook splice-altering variants. To better serve patient populations and advance biomedical knowledge, it has become increasingly important to develop and refine approaches for detecting and interpreting pathogenic splicing variants. In this review, we will summarize a few recent developments and challenges in using RNA sequencing technologies for rare disease investigation. Moreover, we will discuss how recent computational splicing prediction tools have emerged as complementary approaches for revealing disease-causing variants underlying splicing defects. We speculate that continuous improvements to sequencing technologies and predictive modeling will not only expand our understanding of splicing regulation but also bring us closer to filling the diagnostic gap for rare disease patients.


Asunto(s)
Enfermedades Raras , Transcriptoma , Humanos , Enfermedades Raras/diagnóstico , Enfermedades Raras/genética , Empalme del ARN , Proteínas , Aprendizaje Automático , Mutación
4.
Small ; : e2307210, 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38279606

RESUMEN

Sepsis is a life-threatening condition that can progress to septic shock as the body's extreme response to pathogenesis damages its own vital organs. Staphylococcus aureus (S. aureus) accounts for 50% of nosocomial infections, which are clinically treated with antibiotics. However, methicillin-resistant strains (MRSA) have emerged and can withstand harsh antibiotic treatment. To address this problem, curcumin (CCM) is employed to prepare carbonized polymer dots (CPDs) through mild pyrolysis. Contrary to curcumin, the as-formed CCM-CPDs are highly biocompatible and soluble in aqueous solution. Most importantly, the CCM-CPDs induce the release of neutrophil extracellular traps (NETs) from the neutrophils, which entrap and eliminate microbes. In an MRSA-induced septic mouse model, it is observed that CCM-CPDs efficiently suppress bacterial colonization. Moreover, the intrinsic antioxidative, anti-inflammatory, and anticoagulation activities resulting from the preserved functional groups of the precursor molecule on the CCM-CPDs prevent progression to severe sepsis. As a result, infected mice treated with CCM-CPDs show a significant decrease in mortality even through oral administration. Histological staining indicates negligible organ damage in the MRSA-infected mice treated with CCM-CPDs. It is believed that the in vivo studies presented herein demonstrate that multifunctional therapeutic CPDs hold great potential against life-threatening infectious diseases.

5.
RNA ; 28(12): 1643-1658, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36198425

RESUMEN

The E. coli 6S RNA is an RNA polymerase (RNAP) inhibitor that competes with σ70-dependent DNA promoters for binding to RNAP holoenzyme (RNAP:σ70). The 6S RNA when bound is then used as a template to synthesize a short product RNA (pRNA; usually 13-nt-long). This pRNA changes the 6S RNA structure, triggering the 6S RNA:pRNA complex to release and allowing DNA-dependent housekeeping gene expression to resume. In high nutrient conditions, 6S RNA turnover is extremely rapid but becomes very slow in low nutrient environments. This leads to a large accumulation of inhibited RNAP:σ70 in stationary phase. As pRNA initiates synthesis with ATP, we and others have proposed that the 6S RNA release rate strongly depends on ATP levels as a proxy for sensing the cellular metabolic state. By purifying endogenous 6S RNA:pRNA complexes using RNA Mango and using reverse transcriptase to generate pRNA-cDNA chimeras, we demonstrate that 6S RNA:pRNA formation can be simultaneous with 6S RNA 5' maturation. More importantly, we find a dramatic accumulation of capped pRNAs during stationary phase. This indicates that ATP levels in stationary phase are low enough for noncanonical initiator nucleotides (NCINs) such as NAD+ and NADH to initiate pRNA synthesis. In vitro, mutation of the conserved 6S RNA template sequence immediately upstream of the pRNA transcriptional start site can increase or decrease the pRNA capping efficiency, suggesting that evolution has tuned the biological 6S RNA sequence for an optimal capping rate. NCIN-initiated pRNA synthesis may therefore be essential for cell viability in low nutrient conditions.


Asunto(s)
Escherichia coli , Nucleótidos , Escherichia coli/genética , Escherichia coli/metabolismo , Nucleótidos/metabolismo , Transcripción Genética , Conformación de Ácido Nucleico , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , ARN Polimerasas Dirigidas por ADN/metabolismo , Adenosina Trifosfato/metabolismo , Regulación Bacteriana de la Expresión Génica , Factor sigma/genética , Factor sigma/metabolismo
6.
Nano Lett ; 23(11): 4916-4922, 2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37257060

RESUMEN

Understanding and characterizing the mechanical behavior of colloidal nanocrystal (NC) assemblies are important for developing nanocrystalline materials with exceptional mechanical properties for robust electronic, thermoelectric, photovoltaic, and optoelectronic devices. However, the limited ranges of Young's modulus, hardness, and fracture toughness (≲1-10 GPa, ≲50-500 MPa, and ≲10-50 kPa m1/2, respectively) in as-synthesized NC assemblies present challenges for their mechanical stability and therefore their practical applications. In this work, we demonstrate using a combination of nanoindentation measurements and coarse-grained modeling that the mechanical response of assemblies of as-synthesized NCs is governed by the van der Waals interactions of the organic surface ligands. More importantly, we report tremendous ∼60× enhancements in Young's modulus and hardness and an ∼80× enhancement in fracture toughness of CdSe NC assemblies through a simple inorganic Sn2S64- ligand exchange process. Moreover, our observation of softening in nanocrystalline materials with decreasing CdSe NC diameter is consistent with atomistic simulations.

7.
Int J Mol Sci ; 25(2)2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38256117

RESUMEN

Atherosclerosis is an inflammatory disease of the arteries associated with alterations in lipid and other metabolism and is a major cause of cardiovascular disease (CVD). LDL consists of several subclasses with different sizes, densities, and physicochemical compositions. Small dense LDL (sd-LDL) is a subclass of LDL. There is growing evidence that sd-LDL-C is associated with CVD risk, metabolic dysregulation, and several pathophysiological processes. In this study, we present a straightforward membrane device filtration method that can be performed with simple laboratory methods to directly determine sd-LDL in serum without the need for specialized equipment. The method consists of three steps: first, the precipitation of lipoproteins with magnesium harpin; second, the collection of effluent from a 100 nm filter; and third, the quantification of sd-LDL-ApoB in the effluent with an SH-SAW biosensor. There was a good correlation between ApoB values obtained using the centrifugation (y = 1.0411x + 12.96, r = 0.82, n = 20) and filtration (y = 1.0633x + 15.13, r = 0.88, n = 20) methods and commercially available sd-LDL-C assay values. In addition to the filtrate method, there was also a close correlation between sd-LDL-C and ELISA assay values (y = 1.0483x - 4489, r = 0.88, n = 20). The filtration treatment method also showed a high correlation with LDL subfractions and NMR spectra ApoB measurements (y = 2.4846x + 4.637, r = 0.89, n = 20). The presence of sd-LDL-ApoB in the effluent was also confirmed by ELISA assay. These results suggest that this filtration method is a simple and promising pretreatment for use with the SH-SAW biosensor as a rapid in vitro diagnostic (IVD) method for predicting sd-LDL concentrations. Overall, we propose a very sensitive and specific SH-SAW biosensor with the ApoB antibody in its sensitive region to monitor sd-LDL levels by employing a simple delay-time phase shifted SH-SAW device. In conclusion, based on the demonstration of our study, the SH-SAW biosensor could be a strong candidate for the future measurement of sd-LDL.


Asunto(s)
Antígenos de Grupos Sanguíneos , Enfermedades Cardiovasculares , Humanos , LDL-Colesterol , Tecnología , Anticuerpos , Arterias
8.
J Biol Chem ; 298(6): 101957, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35452675

RESUMEN

Japanese encephalitis is a mosquito-borne disease caused by the Japanese encephalitis virus (JEV) that is prevalent in Asia and the Western Pacific. Currently, there is no effective treatment for Japanese encephalitis. Curcumin (Cur) is a compound extracted from the roots of Curcuma longa, and many studies have reported its antiviral and anti-inflammatory activities. However, the high cytotoxicity and very low solubility of Cur limit its biomedical applications. In this study, Cur carbon quantum dots (Cur-CQDs) were synthesized by mild pyrolysis-induced polymerization and carbonization, leading to higher water solubility and lower cytotoxicity, as well as superior antiviral activity against JEV infection. We found that Cur-CQDs effectively bound to the E protein of JEV, preventing viral entry into the host cells. In addition, after continued treatment of JEV with Cur-CQDs, a mutant strain of JEV was evolved that did not support binding of Cur-CQDs to the JEV envelope. Using transmission electron microscopy, biolayer interferometry, and molecular docking analysis, we revealed that the S123R and K312R mutations in the E protein play a key role in binding Cur-CQDs. The S123 and K312 residues are located in structural domains II and III of the E protein, respectively, and are responsible for binding to receptors on and fusing with the cell membrane. Taken together, our results suggest that the E protein of flaviviruses represents a potential target for the development of CQD-based inhibitors to prevent or treat viral infections.


Asunto(s)
Virus de la Encefalitis Japonesa (Especie) , Encefalitis Japonesa , Puntos Cuánticos , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , Carbono , Virus de la Encefalitis Japonesa (Especie)/química , Virus de la Encefalitis Japonesa (Especie)/genética , Encefalitis Japonesa/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Proteínas del Envoltorio Viral/metabolismo
9.
J Urol ; 210(3): 438-445, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37378576

RESUMEN

PURPOSE: Technetium-99m-sestamibi single-photon emission CT/x-ray CT is an emerging clinical tool to differentiate oncocytic tumors from renal cell carcinomas. We report data from a large institutional cohort of patients who underwent technetium-99m-sestamibi scans during evaluation of renal masses. MATERIALS AND METHODS: Patients who underwent technetium-99m-sestamibi single-photon emission CT/x-ray CT between February 2020 and December 2021 were included in the analysis. Scans were defined as "hot" for oncocytic tumor when technetium-99m-sestamibi uptake was qualitatively equivalent or higher between the mass of interest and normal renal parenchyma, suggesting oncocytoma, hybrid oncocytic/chromophobe tumor, or chromophobe renal cell carcinoma. Demographic, pathological, and management strategy data were compared between "hot" and "cold" scans. For individuals who underwent diagnostic biopsy or extirpative procedures, the concordance between radiological findings and pathology was indexed. RESULTS: A total of 71 patients (with 88 masses) underwent technetium-99m-sestamibi imaging with 60 (84.5%) patients having at least 1 "cold" mass on imaging and 11 (15.5%) patients exhibiting only "hot" masses. Pathology was available for 7 "hot" masses, with 1 biopsy specimen (14.3%) being discordant (clear cell renal cell carcinoma). Five patients with "cold" masses underwent biopsy. Out of 5 biopsied masses, 4 (80%) were discordant oncocytomas. Of the extirpated specimens, 35/40 (87.5%) harbored renal cell carcinoma and 5/40 (12.5%) yielded discordant oncocytomas. In sum, 20% of pathologically sampled masses that were "cold" on technetium-99m-sestamibi imaging still harbored oncocytoma/hybrid oncocytic/chromophobe tumor/chromophobe renal cell carcinoma. CONCLUSIONS: Further work is needed to define utility of technetium-99m-sestamibi in real-world clinical practice. Our data suggest this imaging strategy is not yet ready to replace biopsy.


Asunto(s)
Adenoma Oxifílico , Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Tecnecio Tc 99m Sestamibi , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Adenoma Oxifílico/diagnóstico por imagen , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada de Emisión de Fotón Único/métodos , Radiofármacos
10.
J Med Virol ; 95(11): e29243, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-38009231

RESUMEN

The fight against hand, foot, and mouth disease (HFMD) remains an arduous challenge without existing point-of-care (POC) diagnostic platforms for accurate diagnosis and prompt case quarantine. Hence, the purpose of this salivary biomarker discovery study is to set the fundamentals for the realization of POC diagnostics for HFMD. Whole salivary proteome profiling was performed on the saliva obtained from children with HFMD and healthy children, using a reductive dimethylation chemical labeling method coupled with high-resolution mass spectrometry-based quantitative proteomics technology. We identified 19 upregulated (fold change = 1.5-5.8) and 51 downregulated proteins (fold change = 0.1-0.6) in the saliva samples of HFMD patients in comparison to that of healthy volunteers. Four upregulated protein candidates were selected for dot blot-based validation assay, based on novelty as biomarkers and exclusions in oral diseases and cancers. Salivary legumain was validated in the Singapore (n = 43 healthy, 28 HFMD cases) and Taiwan (n = 60 healthy, 47 HFMD cases) cohorts with an area under the receiver operating characteristic curve of 0.7583 and 0.8028, respectively. This study demonstrates the feasibility of a broad-spectrum HFMD POC diagnostic test based on legumain, a virus-specific host systemic signature, in saliva.


Asunto(s)
Enfermedad de Boca, Mano y Pie , Niño , Humanos , Enfermedad de Boca, Mano y Pie/diagnóstico , Biomarcadores/metabolismo , Cisteína Endopeptidasas/genética , Curva ROC
11.
Curr Oncol Rep ; 25(7): 699-708, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37010786

RESUMEN

PURPOSE OF REVIEW: Disparities in prostate cancer care and outcomes have been well recognized for decades. The purpose of this review is to methodically highlight known racial disparities in the care of prostate cancer patients, and in doing so, recognize potential strategies for overcoming these disparities moving forward. RECENT FINDINGS: Over the past few years, there has been a growing recognition and push towards addressing disparities in cancer care. This has led to improvements in care delivery trends and a narrowing of racial outcome disparities, but as we highlight in the following review, there is more to be addressed before we can fully close the gap in prostate cancer care delivery. While disparities in prostate cancer care are well recognized in the literature, they are not insurmountable, and progress has been made in identifying areas for improvement and potential strategies for closing the care gap.


Asunto(s)
Diversidad, Equidad e Inclusión , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/terapia , Atención a la Salud
12.
Nano Lett ; 22(12): 4669-4676, 2022 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-35639612

RESUMEN

Colloidal nanocrystal (NC) assemblies are promising for optoelectronic, photovoltaic, and thermoelectric applications. However, using these materials can be challenging in actual devices because they have a limited range of thermal conductivity and elastic modulus, which results in heat dissipation and mechanical robustness challenges. Here, we report thermal transport and mechanical measurements on single-domain colloidal PbS nanocrystal superlattices (NCSLs) that have long-range order as well as measurements on nanocrystal films (NCFs) that are comparatively disordered. Over an NC diameter range of 3.0-6.1 nm, we observe that NCSLs have thermal conductivities and Young's moduli that are up to ∼3 times higher than those of the corresponding NCFs. We also find that these properties are more sensitive to NC diameter in NCSLs relative to NCFs. Our measurements and computational modeling indicate that stronger ligand-ligand interactions due to enhanced ligand interdigitation and alignment in NCSLs account for the improved thermal transport and mechanical properties.


Asunto(s)
Nanopartículas , Ligandos , Nanopartículas/química
13.
Langmuir ; 38(43): 13279-13287, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36256617

RESUMEN

Gallium-based liquid metals (LMs) combine metallic properties with the deformability of a liquid, which makes them promising candidates for a variety of applications. To broaden the range of physical and chemical properties, a variety of solid additives have been incorporated into the LMs in the literature. In contrast, only a handful of secondary fluids have been incorporated into LMs to create foams (gas-in-LM) or emulsions (liquid-in-LM). LM foams readily form through mixing of LM in air, facilitated by the formation of a native oxide on the LM. In contrast, LM breaks up into microdroplets when mixed with a secondary liquid such as silicone oil. Stable silicone oil-in-LM emulsions form only during mixing of the oil with LM foam. In this work, we investigate the fundamental mechanism underlying this process. We describe two possible microscale mechanisms for emulsion formation: (1) oil replacing air in the foam or (2) oil creating additional features in the foam. The associated foam-to-emulsion density difference demonstrates that emulsions predominantly form through the addition of oxide-covered silicone oil capsules to the LM foam. We demonstrate this through density and surface wettability measurements and multiscale imaging of LM foam mixed with varied silicone oil contents in air or nitrogen environments. We also demonstrate the presence of a continuous silicone oil film on the emulsion surface and that this oil film prevents the embrittlement of contacting aluminum.

14.
J Urol ; 206(4): 1009-1019, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34032501

RESUMEN

PURPOSE: The Society for Improving Medical Professional Learning (SIMPL) app is an innovative, convenient and validated smartphone-based tool to evaluate residents' operative performance. In this study, we describe the initial implementation of SIMPL in our program's pediatric urology rotation-the first among urology residencies-and provide preliminary data on its adoption by residents and faculty. MATERIALS AND METHODS: Residents and faculty in our pediatric urology division submitted SIMPL evaluations following surgical cases from August 2019 to July 2020. Evaluations consisted of ratings in 3 domains: resident autonomy, resident operative performance and patient-related case complexity. An online survey was also used to gauge attitudes towards SIMPL, describe patterns of use and solicit feedback on areas for improvement. RESULTS: Eight residents and 6 faculty submitted 141 evaluations, with 76.6% of evaluated cases having both faculty and resident ratings. Verbal feedback was included in 94.2%. Faculty-resident agreement ranged from 68.6% to 75.2% (kappa=0.47 to 0.61). Faculty rated postgraduate year (PGY)-4 residents as more autonomous (p=0.040) and higher performing (p=0.028) than PGY-3 residents. All participants agreed that SIMPL was easy to use and compared favorably to existing avenues of feedback. Barriers to implementation included lack of reminders for evaluations and evaluation fatigue. CONCLUSIONS: The SIMPL application improved both frequency and quality of resident operative feedback. Among participants, SIMPL was preferred over the existing feedback system at our institution.


Asunto(s)
Retroalimentación Formativa , Internado y Residencia/métodos , Aplicaciones Móviles , Procedimientos Quirúrgicos Urológicos/educación , Urología/educación , Competencia Clínica/estadística & datos numéricos , Docentes/estadística & datos numéricos , Estudios de Factibilidad , Humanos , Internado y Residencia/estadística & datos numéricos , Pediatría/educación , Proyectos Piloto , Reproducibilidad de los Resultados , Teléfono Inteligente , Urólogos/educación , Urólogos/estadística & datos numéricos
15.
Soft Matter ; 17(36): 8269-8275, 2021 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-34397076

RESUMEN

Gallium based liquid metals (LM) have prospective biomedical, stretchable electronics, soft robotics, and energy storage applications, and are being widely adopted as thermal interface materials. The danger of gallium corroding most metals used in microelectronics requires the cumbersome addition of "barrier" layers or LM break-up into droplets within an inert matrix such as silicone oil. Such LM-in-oil emulsions are stabilized by native oxide on the droplets but have decreased thermal performance. Here we show that mixing of the silicone oil into an LM-air foam yields emulsions with inverted phases. We investigate the stability of these oil-in-LM emulsions through a range of processing times and oil viscosities, and characterize the impact of these parameters on the materials' structure and thermal property relationships. We demonstrate that the emulsion with 40 vol% of 10 cSt silicone oil provides a unique thermal management material with a 10 W m-1 K-1 thermal conductivity and an exterior lubricant thin film that completely prevents corrosion of contacting aluminum.

16.
J Virol ; 93(10)2019 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-30814289

RESUMEN

Infection by enteroviruses can cause severe neurological complications in humans. The interactions between the enteroviral and host proteins may facilitate the virus replication and be involved in the pathogenicity of infected individuals. It has been shown that human enteroviruses possess various mechanisms to suppress host innate immune responses in infected cells. Previous studies showed that infection by enterovirus 71 (EV71) causes the degradation of MDA5, which is a critical cytoplasmic pathogen sensor in the recognition of picornaviruses for initiating transcription of type I interferons. In the present study, we demonstrated that the RNA-dependent RNA polymerase (RdRP; also denoted 3Dpol) encoded by EV71 interacts with the caspase activation and recruitment domains (CARDs) of MDA5 and plays a role in the inhibition of MDA5-mediated beta interferon (IFN-ß) promoter activation and mRNA expression. In addition, we found that the 3Dpol protein encoded by coxsackievirus B3 also interacted with MDA5 and downregulated the antiviral signaling initiated by MDA5. These findings indicate that enteroviral RdRP may function as an antagonist against the host antiviral innate immune response.IMPORTANCE Infection by enteroviruses causes severe neurological complications in humans. Human enteroviruses possess various mechanisms to suppress the host type I interferon (IFN) response in infected cells to establish viral replication. In the present study, we found that the enteroviral 3Dpol protein (or RdRP), which is a viral RNA-dependent RNA polymerase for replicating viral RNA, plays a role in the inhibition of MDA5-mediated beta interferon (IFN-ß) promoter activation. We further demonstrated that enteroviral 3Dpol protein interacts with the caspase activation and recruitment domains (CARDs) of MDA5. These findings indicate that enteroviral RdRP functions as an antagonist against the host antiviral response.


Asunto(s)
Enterovirus Humano A/metabolismo , Helicasa Inducida por Interferón IFIH1/metabolismo , ARN Polimerasa Dependiente del ARN/metabolismo , Dominio de Reclutamiento y Activación de Caspasas/genética , Dominio de Reclutamiento y Activación de Caspasas/fisiología , Enterovirus/genética , Enterovirus/metabolismo , Enterovirus Humano A/genética , Enterovirus Humano B/metabolismo , Infecciones por Enterovirus/virología , Células HEK293 , Interacciones Huésped-Patógeno , Humanos , Inmunidad Innata , Interferón Tipo I/metabolismo , Helicasa Inducida por Interferón IFIH1/genética , Interferón beta/metabolismo , Interferones/metabolismo , Interferones/fisiología , ARN Viral/genética , ARN Polimerasa Dependiente del ARN/genética , Transducción de Señal , Replicación Viral
17.
PLoS Pathog ; 14(5): e1007086, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29782554

RESUMEN

RNA viruses induce specialized membranous structures for use in genome replication. These structures are often referred to as replication organelles (ROs). ROs exhibit distinct lipid composition relative to other cellular membranes. In many picornaviruses, phosphatidylinositol-4-phosphate (PI4P) is a marker of the RO. Studies to date indicate that the viral 3A protein hijacks a PI4 kinase to induce PI4P by a mechanism unrelated to the cellular pathway, which requires Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1, GBF1, and ADP ribosylation factor 1, Arf1. Here we show that a picornaviral 3CD protein is sufficient to induce synthesis of not only PI4P but also phosphatidylinositol-4,5-bisphosphate (PIP2) and phosphatidylcholine (PC). Synthesis of PI4P requires GBF1 and Arf1. We identified 3CD derivatives: 3CDm and 3CmD, that we used to show that distinct domains of 3CD function upstream of GBF1 and downstream of Arf1 activation. These same 3CD derivatives still supported induction of PIP2 and PC, suggesting that pathways and corresponding mechanisms used to induce these phospholipids are distinct. Phospholipid induction by 3CD is localized to the perinuclear region of the cell, the outcome of which is the proliferation of membranes in this area of the cell. We conclude that a single viral protein can serve as a master regulator of cellular phospholipid and membrane biogenesis, likely by commandeering normal cellular pathways.


Asunto(s)
Péptido Hidrolasas/metabolismo , Fosfolípidos/biosíntesis , Picornaviridae/enzimología , Proteínas Virales/metabolismo , Factor 1 de Ribosilacion-ADP/metabolismo , Brefeldino A/farmacología , Membrana Celular/ultraestructura , Dactinomicina/farmacología , Aparato de Golgi/efectos de los fármacos , Aparato de Golgi/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HeLa , Humanos , Microscopía Electrónica de Transmisión , Biogénesis de Organelos , Fosfatos de Fosfatidilinositol/metabolismo , Poliovirus/enzimología , Inhibidores de la Síntesis de la Proteína/farmacología , Piridinas/farmacología , Quinolinas/farmacología
18.
Ophthalmology ; 127(7): 948-955, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32173113

RESUMEN

PURPOSE: Injection of pharmacotherapy into the suprachoroidal space, between the sclera and choroid, is an alternative delivery technique developed with the rationale of providing higher drug concentrations to posterior ocular structures compared with other intraocular and periocular injection procedures. This study was conducted to evaluate the safety and efficacy of suprachoroidally injected triamcinolone acetonide formulation (CLS-TA), a suspension of triamcinolone acetonide, in improving vision among patients with noninfectious uveitis complicated by macular edema (ME). DESIGN: Phase 3 masked, randomized trial. PARTICIPANTS: One hundred sixty patients with ME secondary to noninfectious uveitis. Patients were required to have a best-corrected visual acuity (BCVA) of 5 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters (Snellen equivalent, 20/800) and 70 or fewer ETDRS letters read (Snellen equivalent, 20/40) in the study eye. METHODS: Patients were randomized 3:2 to suprachoroidally injected CLS-TA or sham treatment, with administrations at day 0 and week 12. MAIN OUTCOME MEASURES: The primary end point was improvement from baseline of 15 or more ETDRS letters in BCVA at week 24. The secondary end point was reduction from baseline in central subfield thickness (CST) at week 24. RESULTS: In the CLS-TA arm, 47% of patients gained 15 or more ETDRS letters in BCVA versus 16% in the control arm (P < 0.001), meeting the primary end point. Mean reductions in CST from baseline were 153 µm versus 18 µm (P < 0.001). No serious adverse events (AEs) related to treatment were reported. Corticosteroid-associated AEs of elevated intraocular pressure occurred in 11.5% and 15.6% of the CLS-TA and control groups, respectively. Cataract AE rates were comparable (7.3% and 6.3%, respectively). CONCLUSIONS: Patients in the CLS-TA study arm experienced clinically significant improvement in vision relative to the sham procedure, demonstrating the efficacy of suprachoroidal injection of CLS-TA for the treatment of ME in a vision-threatening disorder.


Asunto(s)
Edema Macular/tratamiento farmacológico , Triamcinolona Acetonida/administración & dosificación , Uveítis/complicaciones , Agudeza Visual , Coroides , Femenino , Glucocorticoides/administración & dosificación , Humanos , Inyecciones Intraoculares , Edema Macular/diagnóstico , Edema Macular/etiología , Masculino , Persona de Mediana Edad , Tomografía de Coherencia Óptica/métodos , Resultado del Tratamiento , Uveítis/diagnóstico , Uveítis/tratamiento farmacológico
19.
J Biomed Sci ; 27(1): 22, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31910851

RESUMEN

Upon EV-A71 infection of a host cell, EV-A71 RNA is translated into a viral polyprotein. Although EV-A71 can use the cellular translation machinery to produce viral proteins, unlike cellular translation, which is cap-dependent, the viral RNA genome of EV-A71 does not contain a 5' cap and the translation of EV-A71 protein is cap-independent, which is mediated by the internal ribosomal entry site (IRES) located in the 5' UTR of EV-A71 mRNA. Like many other eukaryotic viruses, EV-A71 manipulates the host cell translation devices, using an elegant RNA-centric strategy in infected cells. During viral translation, viral RNA plays an important role in controlling the stage of protein synthesis. In addition, due to the cellular defense mechanism, viral replication is limited by down-regulating translation. EV-A71 also utilizes protein factors in the host to overcome antiviral responses or even use them to promote viral translation rather than host cell translation. In this review, we provide an introduction to the known strategies for EV-A71 to exploit cellular translation mechanisms.


Asunto(s)
Enterovirus Humano A/fisiología , Infecciones por Enterovirus/metabolismo , Regulación Viral de la Expresión Génica/fisiología , Sitios Internos de Entrada al Ribosoma , Biosíntesis de Proteínas/fisiología , ARN Viral/metabolismo , Humanos
20.
Virol J ; 17(1): 21, 2020 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-32024541

RESUMEN

BACKGROUND: Human enterovirus 71 (EV-A71) is a non-enveloped virus that has a single stranded positive sense RNA genome. In a previous study, we showed that miR-876-5p upregulation was observed in the serum of patients with severe EV-A71 infection. Micro-876-5p (miR-876-5p) is a circulating miRNA that can be identified to modulate EV-A71 infections through both in vitro and in vivo studies. However, the regulatory mechanisms that involve miR-876-5p in the EV-A71 infection cycle remain unclear. METHODS: We demonstrated that miR-876-5p facilitated EV-A71 replication and expression by overexpression and knocking-down of miR-876-5p through the transfection of miR-876-5p plasmid and miR-876-5p inhibitor. Although miR-876-5p suppressed CREB5 expression, luciferase reporter assay confirmed this. We also evaluated the role of miR-876-5p in the EV-A71 infection cycle by CREB5 mediated by transfection with an anti-miR-876-5P inhibitor or in combination with an si-CREB5 plasmid. RESULTS: MicroR-876-5p was upregulated in EV-A71-infected neuroblastoma cells. Overexpression of miR-876-5p or knockdown of cyclic-AMP responsive element binding protein 5 (CREB5) promoted EV-A71 replication. The downregulation of miR-876-5p inhibited the accumulation of viral RNA and the production of viral proteins. Interestingly, CREB5 overexpression also suppressed EV-A71 replication. Our in vitro studies reveal that miR-876-5p directly targets CREB5. Finally, downregulation of CREB5 protein abated the inhibitory effect of anti-miR-876-5p and induced inhibitory effect of EV-A71 replication. CONCLUSIONS: Our results suggest that intracellular miR-876-5p promotes EV-A71 replication indirectly by targeting the host CREB5 protein.


Asunto(s)
Enterovirus Humano A/fisiología , Interacciones Microbiota-Huesped/genética , MicroARNs/genética , Replicación Viral , Animales , Antivirales , Línea Celular Tumoral , Proteína de Unión al Elemento de Respuesta al AMP Cíclico/genética , Regulación hacia Abajo , Enterovirus Humano A/genética , Humanos , Ratones , Ratones Endogámicos ICR , Neuroblastoma , Organismos Libres de Patógenos Específicos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA