Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 469
Filtrar
Más filtros

Intervalo de año de publicación
1.
Cell ; 160(4): 607-618, 2015 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-25662012

RESUMEN

EBER2 is an abundant nuclear noncoding RNA expressed by the Epstein-Barr virus (EBV). Probing its possible chromatin localization by CHART revealed EBER2's presence at the terminal repeats (TRs) of the latent EBV genome, overlapping previously identified binding sites for the B cell transcription factor PAX5. EBER2 interacts with PAX5 and is required for the localization of PAX5 to the TRs. EBER2 knockdown phenocopies PAX5 depletion in upregulating the expression of LMP2A/B and LMP1, genes nearest the TRs. Knockdown of EBER2 also decreases EBV lytic replication, underscoring the essential role of the TRs in viral replication. Recruitment of the EBER2-PAX5 complex is mediated by base-pairing between EBER2 and nascent transcripts from the TR locus. The interaction is evolutionarily conserved in the related primate herpesvirus CeHV15 despite great sequence divergence. Using base-pairing with nascent RNA to guide an interacting transcription factor to its DNA target site is a previously undescribed function for a trans-acting noncoding RNA.


Asunto(s)
Herpesvirus Humano 4/metabolismo , Factor de Transcripción PAX5/metabolismo , ARN Viral/metabolismo , Secuencia de Bases , Ensayo de Cambio de Movilidad Electroforética , Técnicas de Silenciamiento del Gen , Herpesvirus Humano 4/genética , Humanos , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN Viral/química , ARN Viral/genética , Secuencias Repetidas en Tándem , Proteínas de la Matriz Viral/genética , Replicación Viral
2.
Nucleic Acids Res ; 52(11): 6596-6613, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38554103

RESUMEN

The androgen receptor (AR) is a ligand-dependent nuclear transcription factor belonging to the steroid hormone nuclear receptor family. Due to its roles in regulating cell proliferation and differentiation, AR is tightly regulated to maintain proper levels of itself and the many genes it controls. AR dysregulation is a driver of many human diseases including prostate cancer. Though this dysregulation often occurs at the RNA level, there are many unknowns surrounding post-transcriptional regulation of AR mRNA, particularly the role that RNA secondary structure plays. Thus, a comprehensive analysis of AR transcript secondary structure is needed. We address this through the computational and experimental analyses of two key isoforms, full length (AR-FL) and truncated (AR-V7). Here, a combination of in-cell RNA secondary structure probing experiments (targeted DMS-MaPseq) and computational predictions were used to characterize the static structural landscape and conformational dynamics of both isoforms. Additionally, in-cell assays were used to identify functionally relevant structures in the 5' and 3' UTRs of AR-FL. A notable example is a conserved stem loop structure in the 5'UTR of AR-FL that can bind to Poly(RC) Binding Protein 2 (PCBP2). Taken together, our results reveal novel features that regulate AR expression.


Asunto(s)
Conformación de Ácido Nucleico , Receptores Androgénicos , Receptores Androgénicos/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/química , Humanos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/química , ARN Mensajero/metabolismo , ARN Mensajero/genética , ARN Mensajero/química , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Masculino
3.
Proc Natl Acad Sci U S A ; 120(2): e2211055120, 2023 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-36595676

RESUMEN

Endemic Burkitt lymphoma (eBL) is a pediatric cancer coendemic with malaria in sub-Saharan Africa, suggesting an etiological link between them. However, previous cross-sectional studies of limited geographic areas have not found a convincing association. We used spatially detailed data from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) study to assess this relationship. EMBLEM is a case-control study of eBL from 2010 through 2016 in six regions of Kenya, Uganda, and Tanzania. To measure the intensity of exposure to the malaria parasite, Plasmodium falciparum, among children in these regions, we used high-resolution spatial data from the Malaria Atlas Project to estimate the annual number of P. falciparum infections from 2000 through 2016 for each of 49 districts within the study region. Cumulative P. falciparum exposure, calculated as the sum of annual infections by birth cohort, varied widely, with a median of 47 estimated infections per child by age 10, ranging from 4 to 315 infections. eBL incidence increased 39% for each 100 additional lifetime P. falciparum infections (95% CI: 6.10 to 81.04%) with the risk peaking among children aged 5 to 11 and declining thereafter. Alternative models using estimated annual P. falciparum infections 0 to 10 y before eBL onset were inconclusive, suggesting that eBL risk is a function of cumulative rather than recent cross-sectional exposure. Our findings provide population-level evidence that eBL is a phenotype related to heavy lifetime exposure to P. falciparum malaria and support emphasizing the link between malaria and eBL.


Asunto(s)
Linfoma de Burkitt , Malaria Falciparum , Malaria , Humanos , Linfoma de Burkitt/epidemiología , Linfoma de Burkitt/genética , Plasmodium falciparum , Estudios de Casos y Controles , Uganda/epidemiología , Kenia/epidemiología , Tanzanía/epidemiología , Estudios Transversales , Malaria Falciparum/complicaciones , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Malaria/epidemiología
4.
Biochemistry ; 63(10): 1287-1296, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38727003

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) frameshift stimulatory element (FSE) is necessary for programmed -1 ribosomal frameshifting (-1 PRF) and optimized viral efficacy. The FSE has an abundance of context-dependent alternate conformations, but two of the structures most crucial to -1 PRF are an attenuator hairpin and a three-stem H-type pseudoknot structure. A crystal structure of the pseudoknot alone features three RNA stems in a helically stacked linear structure, whereas a 6.9 Å cryo-EM structure including the upstream heptameric slippery site resulted in a bend between two stems. Our previous research alluded to an extended upstream multibranch loop that includes both the attenuator hairpin and the slippery site-a conformation not previously modeled. We aim to provide further context to the SARS-CoV-2 FSE via computational and medium resolution cryo-EM approaches, by presenting a 6.1 Å cryo-EM structure featuring a linear pseudoknot structure and a dynamic upstream multibranch loop.


Asunto(s)
Microscopía por Crioelectrón , Sistema de Lectura Ribosómico , Conformación de Ácido Nucleico , ARN Viral , SARS-CoV-2 , SARS-CoV-2/química , SARS-CoV-2/genética , ARN Viral/química , ARN Viral/genética , ARN Viral/metabolismo , Humanos , Modelos Moleculares , COVID-19/virología
5.
Circulation ; 148(20): 1636-1664, 2023 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-37807920

RESUMEN

A growing appreciation of the pathophysiological interrelatedness of metabolic risk factors such as obesity and diabetes, chronic kidney disease, and cardiovascular disease has led to the conceptualization of cardiovascular-kidney-metabolic syndrome. The confluence of metabolic risk factors and chronic kidney disease within cardiovascular-kidney-metabolic syndrome is strongly linked to risk for adverse cardiovascular and kidney outcomes. In addition, there are unique management considerations for individuals with established cardiovascular disease and coexisting metabolic risk factors, chronic kidney disease, or both. An extensive body of literature supports our scientific understanding of, and approach to, prevention and management for individuals with cardiovascular-kidney-metabolic syndrome. However, there are critical gaps in knowledge related to cardiovascular-kidney-metabolic syndrome in terms of mechanisms of disease development, heterogeneity within clinical phenotypes, interplay between social determinants of health and biological risk factors, and accurate assessments of disease incidence in the context of competing risks. There are also key limitations in the data supporting the clinical care for cardiovascular-kidney-metabolic syndrome, particularly in terms of early-life prevention, screening for risk factors, interdisciplinary care models, optimal strategies for supporting lifestyle modification and weight loss, targeting of emerging cardioprotective and kidney-protective therapies, management of patients with both cardiovascular disease and chronic kidney disease, and the impact of systematically assessing and addressing social determinants of health. This scientific statement uses a crosswalk of major guidelines, in addition to a review of the scientific literature, to summarize the evidence and fundamental gaps related to the science, screening, prevention, and management of cardiovascular-kidney-metabolic syndrome.


Asunto(s)
Enfermedades Cardiovasculares , Síndrome Metabólico , Insuficiencia Renal Crónica , Estados Unidos/epidemiología , Humanos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Síndrome Metabólico/diagnóstico , Síndrome Metabólico/epidemiología , Síndrome Metabólico/terapia , American Heart Association , Factores de Riesgo , Riñón , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/terapia
6.
Circulation ; 148(20): 1606-1635, 2023 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-37807924

RESUMEN

Cardiovascular-kidney-metabolic health reflects the interplay among metabolic risk factors, chronic kidney disease, and the cardiovascular system and has profound impacts on morbidity and mortality. There are multisystem consequences of poor cardiovascular-kidney-metabolic health, with the most significant clinical impact being the high associated incidence of cardiovascular disease events and cardiovascular mortality. There is a high prevalence of poor cardiovascular-kidney-metabolic health in the population, with a disproportionate burden seen among those with adverse social determinants of health. However, there is also a growing number of therapeutic options that favorably affect metabolic risk factors, kidney function, or both that also have cardioprotective effects. To improve cardiovascular-kidney-metabolic health and related outcomes in the population, there is a critical need for (1) more clarity on the definition of cardiovascular-kidney-metabolic syndrome; (2) an approach to cardiovascular-kidney-metabolic staging that promotes prevention across the life course; (3) prediction algorithms that include the exposures and outcomes most relevant to cardiovascular-kidney-metabolic health; and (4) strategies for the prevention and management of cardiovascular disease in relation to cardiovascular-kidney-metabolic health that reflect harmonization across major subspecialty guidelines and emerging scientific evidence. It is also critical to incorporate considerations of social determinants of health into care models for cardiovascular-kidney-metabolic syndrome and to reduce care fragmentation by facilitating approaches for patient-centered interdisciplinary care. This presidential advisory provides guidance on the definition, staging, prediction paradigms, and holistic approaches to care for patients with cardiovascular-kidney-metabolic syndrome and details a multicomponent vision for effectively and equitably enhancing cardiovascular-kidney-metabolic health in the population.


Asunto(s)
Enfermedades Cardiovasculares , Sistema Cardiovascular , Síndrome Metabólico , Estados Unidos/epidemiología , Humanos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Síndrome Metabólico/diagnóstico , Síndrome Metabólico/epidemiología , Síndrome Metabólico/terapia , American Heart Association , Factores de Riesgo , Riñón
7.
Antimicrob Agents Chemother ; 68(5): e0101023, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38501805

RESUMEN

A major challenge for tuberculosis (TB) drug development is to prioritize promising combination regimens from a large and growing number of possibilities. This includes demonstrating individual drug contributions to the activity of higher-order combinations. A BALB/c mouse TB infection model was used to evaluate the contributions of each drug and pairwise combination in the clinically relevant Nix-TB regimen [bedaquiline-pretomanid-linezolid (BPaL)] during the first 3 weeks of treatment at human equivalent doses. The rRNA synthesis (RS) ratio, an exploratory pharmacodynamic (PD) marker of ongoing Mycobacterium tuberculosis rRNA synthesis, together with solid culture CFU counts and liquid culture time to positivity (TTP) were used as PD markers of treatment response in lung tissue; and their time-course profiles were mathematically modeled using rate equations with pharmacologically interpretable parameters. Antimicrobial interactions were quantified using Bliss independence and Isserlis formulas. Subadditive (or antagonistic) and additive effects on bacillary load, assessed by CFU and TTP, were found for bedaquiline-pretomanid and linezolid-containing pairs, respectively. In contrast, subadditive and additive effects on rRNA synthesis were found for pretomanid-linezolid and bedaquiline-containing pairs, respectively. Additionally, accurate predictions of the response to BPaL for all three PD markers were made using only the single-drug and pairwise effects together with an assumption of negligible three-way drug interactions. The results represent an experimental and PD modeling approach aimed at reducing combinatorial complexity and improving the cost-effectiveness of in vivo systems for preclinical TB regimen development.


Asunto(s)
Antituberculosos , Diarilquinolinas , Modelos Animales de Enfermedad , Linezolid , Ratones Endogámicos BALB C , Mycobacterium tuberculosis , Animales , Antituberculosos/farmacología , Antituberculosos/farmacocinética , Antituberculosos/uso terapéutico , Linezolid/farmacología , Linezolid/farmacocinética , Diarilquinolinas/farmacología , Diarilquinolinas/farmacocinética , Ratones , Mycobacterium tuberculosis/efectos de los fármacos , Femenino , Nitroimidazoles/farmacología , Nitroimidazoles/farmacocinética , Nitroimidazoles/uso terapéutico , Quimioterapia Combinada , Pulmón/microbiología , Pulmón/efectos de los fármacos , Tuberculosis/tratamiento farmacológico , Tuberculosis/microbiología , Pruebas de Sensibilidad Microbiana , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/microbiología
8.
Microcirculation ; 31(5): e12859, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38818977

RESUMEN

OBJECTIVE: The endothelium regulates crucial aspects of vascular function, including hemostasis, vasomotor tone, proliferation, immune cell adhesion, and microvascular permeability. Endothelial cells (ECs), especially in arterioles, are pivotal for flow distribution and peripheral resistance regulation. Investigating vascular endothelium physiology, particularly in microvascular ECs, demands precise isolation and culturing techniques. METHODS: Freshly isolated ECs are vital for examining protein expression, ion channel behavior, and calcium dynamics. Establishing primary endothelial cell cultures is crucial for unraveling vascular functions and understanding intact microvessel endothelium roles. Despite the significance, detailed protocols and comparisons with intact vessels are scarce in microvascular research. We developed a reproducible method to isolate microvascular ECs, assessing substrate influence by cultivating cells on fibronectin and gelatin matrix gels. This comparative approach enhances our understanding of microvascular endothelial cell biology. RESULTS: Microvascular mesenteric ECs expressed key markers (VE-cadherin and eNOS) in both matrix gels, confirming cell culture purity. Under uncoated conditions, ECs were undetected, whereas proteins linked to smooth muscle cells and fibroblasts were evident. Examining endothelial cell (EC) physiological dynamics on distinct matrix substrates revealed comparable cell length, shape, and Ca2+ elevations in both male and female ECs on gelatin and fibronectin matrix gels. Gelatin-cultured ECs exhibited analogous membrane potential responses to acetylcholine (ACh) or adenosine triphosphate (ATP), contrasting with their fibronectin-cultured counterparts. In the absence of stimulation, fibronectin-cultured ECs displayed a more depolarized resting membrane potential than gelatin-cultured ECs. CONCLUSIONS: Gelatin-cultured ECs demonstrated electrical behaviors akin to intact endothelium from mouse mesenteric arteries, thus advancing our understanding of endothelial cell behavior within diverse microenvironments.


Asunto(s)
Células Endoteliales , Gelatina , Microvasos , Óxido Nítrico Sintasa de Tipo III , Animales , Células Endoteliales/metabolismo , Células Endoteliales/citología , Ratones , Femenino , Masculino , Microvasos/citología , Microvasos/metabolismo , Microvasos/fisiología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Células Cultivadas , Fibronectinas/metabolismo , Fibronectinas/farmacología , Geles , Antígenos CD/metabolismo , Cadherinas/metabolismo , Cultivo Primario de Células , Endotelio Vascular/metabolismo , Endotelio Vascular/citología
9.
RNA ; 28(4): 508-522, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34983822

RESUMEN

Influenza A kills hundreds of thousands of people globally every year and has the potential to generate more severe pandemics. Influenza A's RNA genome and transcriptome provide many potential therapeutic targets. Here, nuclear magnetic resonance (NMR) experiments suggest that one such target could be a hairpin loop of 8 nucleotides in a pseudoknot that sequesters a 3' splice site in canonical pairs until a conformational change releases it into a dynamic 2 × 2-nt internal loop. NMR experiments reveal that the hairpin loop is dynamic and able to bind oligonucleotides as short as pentamers. A 3D NMR structure of the complex contains 4 and likely 5 bp between pentamer and loop. Moreover, a hairpin sequence was discovered that mimics the equilibrium of the influenza hairpin between its structure in the pseudoknot and upon release of the splice site. Oligonucleotide binding shifts the equilibrium completely to the hairpin secondary structure required for pseudoknot folding. The results suggest this hairpin can be used to screen for compounds that stabilize the pseudoknot and potentially reduce splicing.


Asunto(s)
Gripe Humana , Sitios de Empalme de ARN , Secuencia de Bases , Humanos , Gripe Humana/genética , Espectroscopía de Resonancia Magnética , Conformación de Ácido Nucleico , Oligonucleótidos , Sitios de Empalme de ARN/genética , ARN Mensajero/metabolismo
10.
Am J Hematol ; 99(1): 113-123, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38009642

RESUMEN

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk.


Asunto(s)
Linfoma de Burkitt , Malaria Falciparum , Malaria , Rasgo Drepanocítico , Humanos , África Oriental , Alelos , Linfoma de Burkitt/epidemiología , Linfoma de Burkitt/genética , Malaria Falciparum/epidemiología , Malaria Falciparum/genética , Malaria Falciparum/complicaciones , Rasgo Drepanocítico/epidemiología , Rasgo Drepanocítico/genética , Rasgo Drepanocítico/complicaciones , Nectinas/metabolismo
11.
Cerebrovasc Dis ; 53(1): 54-61, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37231793

RESUMEN

INTRODUCTION: Over half of patients with acute ischemic stroke are overweight or obese as defined by a body mass index (BMI) ≥25 kg/m2. Professional and government agencies recommend weight management for these persons to improve risk factors for cardiovascular disease, including hypertension, dyslipidemia, vascular inflammation, and diabetes. However, approaches to weight loss have not been adequately tested specifically in patients with stroke. In anticipation of a larger trial with vascular or functional outcomes, we tested the feasibility and safety of a 12-week partial meal replacement (PMR) intervention for weight loss in overweight or obese patients with a recent ischemic stroke. METHODS: This randomized open-label trial enrolled participants from December 2019 to February 2021 (with hiatus from March to August 2020 due to COVID-19 pandemic restrictions on research). Eligible patients had a recent ischemic stroke and BMI 27-49.9 kg/m2. Patients were randomized to a PMR diet (OPTAVIA® Optimal Weight 4 & 2 & 1 Plan®) plus standard care (SC) or SC alone. The PMR diet consisted of four meal replacements supplied to participants, two meals with lean protein and vegetables (self-prepared or supplied), and a healthy snack (also self-prepared or supplied). The PMR diet provided 1,100-1,300 calories per day. SC consisted of one instructional session on a healthy diet. Co-primary outcomes were ≥5% weight loss at 12 weeks and to identify barriers to successful weight loss among participants assigned to PMR. Safety outcomes included hospitalization, falls, pneumonia, or hypoglycemia requiring treatment by self or others. Due to the COVID-19 pandemic, study visits after August 2020 were by remote communication. RESULTS: We enrolled 38 patients from two institutions. Two patients in each arm were lost and could not be included in outcome analyses. At 12 weeks, 9/17 patients in the PMR group and 2/17 patients in the SC group achieved ≥5% weight loss (52.9% vs. 11.9%; Fisher's exact p = 0.03). Mean percent weight change in the PMR group was -3.0% (SD 13.7) and -2.6% (SD 3.4) in the SC group (Wilcoxon rank-sum p = 0.17). No adverse events were attributed to study participation. Some participants had difficulty completing home monitoring of weight. In the PMR group, participants reported that food cravings and dislike for some food products were barriers to weight loss. CONCLUSION: A PMR diet after ischemic stroke is feasible, safe, and effective for weight loss. In future trials, in-person or improved remote outcome monitoring may reduce anthropometric data variation.


Asunto(s)
COVID-19 , Accidente Cerebrovascular Isquémico , Humanos , Sobrepeso , Dieta Reductora/efectos adversos , Dieta Reductora/métodos , Pandemias , Obesidad/complicaciones , Obesidad/diagnóstico , Obesidad/terapia , Pérdida de Peso , Comidas
12.
J Phys Chem A ; 128(14): 2752-2762, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38551124

RESUMEN

Aluminum monofluoride (AlF) is a suitable molecule for laser cooling and trapping. Such experiments require extensive spectroscopic characterization of the electronic structure. Two of the theoretically predicted higher-lying triplet states of AlF, the counterparts of the well-characterized D1Δ and E1Π states, had not been experimentally identified yet. We here report on the characterization of the d3Π (v = 0-6) and e3Δ (v = 0-2) states, confirming the predicted energetic ordering of these states (J. Chem. Phys. 1988, 88, 5715-5725), as well as of the f3Σ+ (v = 0-2) state. The transition intensity of the d3Π, v = 3 - a3Π, v = 3 band is negligibly small. This band gets its weak, unexpected rotational structure via intensity borrowing from the nearby e3Δ, v = 2 - a3Π, v = 3 band, made possible via spin-orbit and spin-rotation interaction between the d3Π and e3Δ states. This interaction affects the equilibrium rotational constants in both states; their deperturbed values yield equilibrium internuclear distances that are consistent with the observations. We determined the ionization potential of AlF to be 78,492(1) cm-1 by ionization from the d3Π state.

13.
J Chem Phys ; 160(12)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38533884

RESUMEN

We formulate and implement the Variational Quantum Eigensolver Self Consistent Field (VQE-SCF) algorithm in combination with polarizable embedding (PE), thereby extending PE to the regime of quantum computing. We test the resulting algorithm, PE-VQE-SCF, on quantum simulators and demonstrate that the computational stress on the quantum device is only slightly increased in terms of gate counts compared to regular VQE-SCF. On the other hand, no increase in shot noise was observed. We illustrate how PE-VQE-SCF may lead to the modeling of real chemical systems using a simulation of the reaction barrier of the Diels-Alder reaction between furan and ethene as an example.

14.
Cell Mol Life Sci ; 80(5): 136, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37131079

RESUMEN

Influenza A virus (IAV) is a respiratory virus that causes epidemics and pandemics. Knowledge of IAV RNA secondary structure in vivo is crucial for a better understanding of virus biology. Moreover, it is a fundament for the development of new RNA-targeting antivirals. Chemical RNA mapping using selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) coupled with Mutational Profiling (MaP) allows for the thorough examination of secondary structures in low-abundance RNAs in their biological context. So far, the method has been used for analyzing the RNA secondary structures of several viruses including SARS-CoV-2 in virio and in cellulo. Here, we used SHAPE-MaP and dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) for genome-wide secondary structure analysis of viral RNA (vRNA) of the pandemic influenza A/California/04/2009 (H1N1) strain in both in virio and in cellulo environments. Experimental data allowed the prediction of the secondary structures of all eight vRNA segments in virio and, for the first time, the structures of vRNA5, 7, and 8 in cellulo. We conducted a comprehensive structural analysis of the proposed vRNA structures to reveal the motifs predicted with the highest accuracy. We also performed a base-pairs conservation analysis of the predicted vRNA structures and revealed many highly conserved vRNA motifs among the IAVs. The structural motifs presented herein are potential candidates for new IAV antiviral strategies.


Asunto(s)
COVID-19 , Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , SARS-CoV-2/genética , Virus de la Influenza A/genética , ARN Viral/genética , Genómica
15.
Proc Natl Acad Sci U S A ; 118(52)2021 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-34903581

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), continues to be a pressing health concern. In this study, we investigated the impact of SARS-CoV-2 infection on host microRNA (miRNA) populations in three human lung-derived cell lines, as well as in nasopharyngeal swabs from SARS-CoV-2-infected individuals. We did not detect any major and consistent differences in host miRNA levels after SARS-CoV-2 infection. However, we unexpectedly discovered a viral miRNA-like small RNA, named CoV2-miR-O7a (for SARS-CoV-2 miRNA-like ORF7a-derived small RNA). Its abundance ranges from low to moderate as compared to host miRNAs and it associates with Argonaute proteins-core components of the RNA interference pathway. We identify putative targets for CoV2-miR-O7a, including Basic Leucine Zipper ATF-Like Transcription Factor 2 (BATF2), which participates in interferon signaling. We demonstrate that CoV2-miR-O7a production relies on cellular machinery, yet is independent of Drosha protein, and is enhanced by the presence of a strong and evolutionarily conserved hairpin formed within the ORF7a sequence.


Asunto(s)
Regulación Viral de la Expresión Génica , ARN Pequeño no Traducido/metabolismo , ARN Viral/metabolismo , SARS-CoV-2/metabolismo , Proteínas Virales/genética , COVID-19/metabolismo , COVID-19/virología , Interacciones Huésped-Patógeno , Humanos , ARN Pequeño no Traducido/genética , ARN Viral/genética , SARS-CoV-2/genética
16.
Stroke ; 54(3): 894-904, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36541212

RESUMEN

Diabetes is a heterogeneous disease that affects 9% of the world's population (11% in the United States). The consequences of diabetes for the brain are severe; it nearly doubles a person's risk of stroke and is a major contributor to risk for cerebral small vessel disease and dementia. These effects on the brain are in addition to peripheral neuropathy, retinopathy, nephropathy, and coronary heart disease. In this article, we explain the treatments that can prevent or mitigate its harmful effects and propose a role for neurologists and other neurology clinicians in managing patients during routine care.


Asunto(s)
Diabetes Mellitus , Neurología , Accidente Cerebrovascular , Humanos , Estados Unidos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/terapia , Neurólogos , Diabetes Mellitus/epidemiología , Diabetes Mellitus/terapia , Atención al Paciente
17.
Stroke ; 54(8): 2013-2021, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37449424

RESUMEN

BACKGROUND: Patients with type 2 diabetes (T2D) and cardiovascular disease are at increased risk for recurrent ischemic events. Cardiovascular risk factor control is vital for secondary prevention, but how this compares among individuals with different T2D macrovascular complications is unknown. We aimed to determine if there might be differences in risk factor control in patients with T2D with previous stroke versus coronary artery disease (CAD). METHODS: Cross-sectional analyses were performed on 12 856 patients with T2D with prior history of stroke with or without CAD from 3 diabetes cardiovascular outcome trials: CARMELINA (The Cardiovascular and Renal Microvascular Outcome Study With Linagliptin), EMPA-REG OUTCOME (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients), and CAROLINA (The Cardiovascular Outcome Study of Linagliptin vs Glimepiride in Type 2 Diabetes). Risk factors at baseline assessed included dyslipidemia, hypertension, smoking, and current antiplatelet/anticoagulant therapy. Control, respectively, was defined as LDL (low-density lipoprotein)-C <100 mg/dL or statin use, systolic blood pressure <140 and diastolic blood pressure <90 mm Hg, not currently smoking, and use of an antiplatelet/anticoagulant medication. The odds ratio of 3 to 4 (or good) versus 0 to 2 (or suboptimal) risk factors controlled was analyzed by logistic regression models. RESULTS: The odds for good versus suboptimal risk factor control in patients with CAD alone was higher than in those with stroke alone across all 3 trials odds ratios (95% CI): CARMELINA, 2.05 (1.67-2.51), EMPA-REG OUTCOME, 2.50 (2.10-2.99), and CAROLINA, 1.63 (1.21-2.20). The respective odds ratios were lower (and rendered nonsignificant in CAROLINA) when cardiovascular risk factor control in patients with both CAD and stroke were compared with those with stroke alone: CARMELINA, 1.45 (1.13-1.87); EMPA-REG OUTCOME, 1.62 (1.25-2.08); and CAROLINA, 1.16 (0.74-1.83). CONCLUSIONS: In contemporary populations of patients with T2D, there was significant discordance in control of cardiovascular risk factors between patients with stroke versus CAD, with the former having less optimal control. The intermediate results in patients with both CAD and stroke suggest that these differences could be related at least in part to clinician factors. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT01243424, NCT01131676, NCT01897532.


Asunto(s)
Enfermedades Cardiovasculares , Enfermedad de la Arteria Coronaria , Diabetes Mellitus Tipo 2 , Accidente Cerebrovascular , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Linagliptina/efectos adversos , Enfermedades Cardiovasculares/prevención & control , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Factores de Riesgo , Estudios Transversales , Accidente Cerebrovascular/tratamiento farmacológico , Factores de Riesgo de Enfermedad Cardiaca , Resultado del Tratamiento
18.
Am J Physiol Heart Circ Physiol ; 324(5): H610-H623, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36867447

RESUMEN

Microvascular hyperpermeability is a hallmark of inflammation. Many negative effects of hyperpermeability are due to its persistence beyond what is required for preserving organ function. Therefore, we propose that targeted therapeutic approaches focusing on mechanisms that terminate hyperpermeability would avoid the negative effects of prolonged hyperpermeability while retaining its short-term beneficial effects. We tested the hypothesis that inflammatory agonist signaling leads to hyperpermeability and initiates a delayed cascade of cAMP-dependent pathways that causes inactivation of hyperpermeability. We applied platelet-activating factor (PAF) and vascular endothelial growth factor (VEGF) to induce hyperpermeability. We used an Epac1 agonist to selectively stimulate exchange protein activated by cAMP (Epac1) and promote inactivation of hyperpermeability. Stimulation of Epac1 inactivated agonist-induced hyperpermeability in the mouse cremaster muscle and in human microvascular endothelial cells (HMVECs). PAF induced nitric oxide (NO) production and hyperpermeability within 1 min and NO-dependent increased cAMP concentration in about 15-20 min in HMVECs. PAF triggered phosphorylation of vasodilator-stimulated phosphoprotein (VASP) in a NO-dependent manner. Epac1 stimulation promoted cytosol-to-membrane eNOS translocation in HMVECs and in myocardial microvascular endothelial (MyEnd) cells from wild-type mice, but not in MyEnd cells from VASP knockout mice. We demonstrate that PAF and VEGF cause hyperpermeability and stimulate the cAMP/Epac1 pathway to inactivate agonist-induced endothelial/microvascular hyperpermeability. Inactivation involves VASP-assisted translocation of eNOS from the cytosol to the endothelial cell membrane. We demonstrate that hyperpermeability is a self-limiting process, whose timed inactivation is an intrinsic property of the microvascular endothelium that maintains vascular homeostasis in response to inflammatory conditions.NEW & NOTEWORTHY Termination of microvascular hyperpermeability has been so far accepted to be a passive result of the removal of the applied proinflammatory agonists. We provide in vivo and in vitro evidence that 1) inactivation of hyperpermeability is an actively regulated process, 2) proinflammatory agonists (PAF and VEGF) stimulate microvascular hyperpermeability and initiate endothelial mechanisms that terminate hyperpermeability, and 3) eNOS location-translocation is critical in the activation-inactivation cascade of endothelial hyperpermeability.


Asunto(s)
Células Endoteliales , Factor A de Crecimiento Endotelial Vascular , Ratones , Humanos , Animales , Células Endoteliales/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Inflamación/metabolismo , Factor de Activación Plaquetaria/metabolismo , Factor de Activación Plaquetaria/farmacología , Ratones Noqueados , Endotelio/metabolismo , Permeabilidad Capilar , Endotelio Vascular/metabolismo
19.
J Gen Intern Med ; 38(10): 2318-2325, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36800147

RESUMEN

BACKGROUND: At some US Academic Health Centers (AHCs), patients with predominantly Medicaid insurance are seen in one clinic and patients with other insurance are seen in another. The extent of this practice and implications are unknown. OBJECTIVE: To estimate the proportion of AHCs that have at least two primary care internal medicine clinics that differ substantially in proportion of patients with Medicaid and to compare patient demographic, staffing, and operational features. PARTICIPANTS: General internal medicine chiefs and clinic directors at 40 randomly selected US AHCs plus the top 10 AHCs in terms of NIH funding. MAIN MEASURE: An AHC was classified as maintaining clinics that differed substantially in the proportion of patients with Medicaid if any two differed by ≥ 40% (absolute). Other criteria were used for pre-specified secondary analyses (e.g., ≥ 30%). KEY RESULTS: Thirty-nine of 50 AHCs (78%) participated. Four of 39 (10%; 95% CI, 3 to 24%) had two clinics differing by ≥ 40% in the proportion of patients with Medicaid, eight (21%; 95% CI, 9 to 36%) had clinics differing by ≥ 30%, and 15 (38%; 95% CI, 23 to 55%) had clinics differing by ≥ 20%. Clinics with more patients with Medicaid by any of the three criteria were more likely to employ resident physicians as providers of longitudinal care (with faculty supervision) and more likely to have patients who were Black or Hispanic. CONCLUSIONS: Some US AHCs maintain separate clinics defined by the proportion of patients with Medicaid. Clinics with a higher proportion of patients insured by Medicaid are more likely to employ residents (with faculty oversight), feature residents as providers of longitudinal care, and serve patients who are Black and Hispanic. Further research is needed to understand why some AHCs have primary care clinics distinguishable by insurance mix with the goal of ensuring that racism and discrimination are not root causes.


Asunto(s)
Seguro de Salud , Medicaid , Estados Unidos , Humanos , Estudios Transversales , Instituciones de Atención Ambulatoria , Atención Primaria de Salud
20.
Proc Natl Acad Sci U S A ; 117(3): 1457-1467, 2020 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-31900363

RESUMEN

Many proteins are refractory to targeting because they lack small-molecule binding pockets. An alternative to drugging these proteins directly is to target the messenger (m)RNA that encodes them, thereby reducing protein levels. We describe such an approach for the difficult-to-target protein α-synuclein encoded by the SNCA gene. Multiplication of the SNCA gene locus causes dominantly inherited Parkinson's disease (PD), and α-synuclein protein aggregates in Lewy bodies and Lewy neurites in sporadic PD. Thus, reducing the expression of α-synuclein protein is expected to have therapeutic value. Fortuitously, the SNCA mRNA has a structured iron-responsive element (IRE) in its 5' untranslated region (5' UTR) that controls its translation. Using sequence-based design, we discovered small molecules that target the IRE structure and inhibit SNCA translation in cells, the most potent of which is named Synucleozid. Both in vitro and cellular profiling studies showed Synucleozid directly targets the α-synuclein mRNA 5' UTR at the designed site. Mechanistic studies revealed that Synucleozid reduces α-synuclein protein levels by decreasing the amount of SNCA mRNA loaded into polysomes, mechanistically providing a cytoprotective effect in cells. Proteome- and transcriptome-wide studies showed that the compound's selectivity makes Synucleozid suitable for further development. Importantly, transcriptome-wide analysis of mRNAs that encode intrinsically disordered proteins revealed that each has structured regions that could be targeted with small molecules. These findings demonstrate the potential for targeting undruggable proteins at the level of their coding mRNAs. This approach, as applied to SNCA, is a promising disease-modifying therapeutic strategy for PD and other α-synucleinopathies.


Asunto(s)
Proteínas Intrínsecamente Desordenadas/genética , Inhibidores de la Síntesis de la Proteína/farmacología , ARN Mensajero/metabolismo , Elementos de Respuesta , alfa-Sinucleína/genética , Regiones no Traducidas 3' , Animales , Línea Celular Tumoral , Humanos , Proteínas Intrínsecamente Desordenadas/metabolismo , Ratones , Biosíntesis de Proteínas/efectos de los fármacos , Inhibidores de la Síntesis de la Proteína/química , ARN Mensajero/química , ARN Mensajero/genética , alfa-Sinucleína/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA