RESUMEN
N6-methyladenosine (m6A) is an abundant modification in eukaryotic mRNA, regulating mRNA dynamics by influencing mRNA stability, splicing, export, and translation. However, the precise m6A regulating machinery still remains incompletely understood. Here we demonstrate that ZC3H13, a zinc-finger protein, plays an important role in modulating RNA m6A methylation in the nucleus. We show that knockdown of Zc3h13 in mouse embryonic stem cell significantly decreases global m6A level on mRNA. Upon Zc3h13 knockdown, a great majority of WTAP, Virilizer, and Hakai translocate to the cytoplasm, suggesting that Zc3h13 is required for nuclear localization of the Zc3h13-WTAP-Virilizer-Hakai complex, which is important for RNA m6A methylation. Finally, Zc3h13 depletion, as does WTAP, Virilizer, or Hakai, impairs self-renewal and triggers mESC differentiation. Taken together, our findings demonstrate that Zc3h13 plays a critical role in anchoring WTAP, Virilizer, and Hakai in the nucleus to facilitate m6A methylation and to regulate mESC self-renewal.
Asunto(s)
Adenosina/análogos & derivados , Núcleo Celular/metabolismo , Proliferación Celular , Autorrenovación de las Células , Células Madre Embrionarias de Ratones/metabolismo , Proteínas Nucleares/metabolismo , Procesamiento Postranscripcional del ARN , ARN Mensajero/metabolismo , Regiones no Traducidas 3' , Transporte Activo de Núcleo Celular , Adenosina/metabolismo , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación del Desarrollo de la Expresión Génica , Células HEK293 , Humanos , Metilación , Ratones , Proteínas Nucleares/genética , Factores de Empalme de ARN , Estabilidad del ARN , ARN Mensajero/genética , Proteínas de Unión al ARN , Transducción de Señal , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Methicillin-resistant Staphylococcus aureus (MRSA) acquires high-level resistance against ß-lactam antibiotics by expressing penicillin-binding protein 2a (PBP2a). PBP2a is a cell wall-synthesizing protein whose closed active site exhibits a reduced binding affinity toward ß-lactam antibiotics. Ceftaroline (CFT), a fifth-generation cephalosporin, can effectively inhibit the PBP2a activity by binding to an allosteric site to trigger the active site opening, allowing a second CFT to access the active site. However, the essential mechanism behind the allosteric behavior of PBP2a remains unclear. Herein, computational simulations are employed to elucidate how CFT allosterically regulates the conformation and dynamics of the active site of PBP2a. While CFT stabilizes the allosteric domain surrounding it, it simultaneously enhances the dynamics of the catalytic domain. Specifically, the study successfully captured the opening process of the active pocket in the allosteric CFT-bound systems and discovered that CFT alters the potential signal-propagating pathways from the allosteric site to the active site. These findings reveal the implied mechanism of the CFT-mediated allostery in PBP2a and provide new insights into dual-site drug design or combination therapy against MRSA targeting PBP2a.
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Antibacterianos , Staphylococcus aureus Resistente a Meticilina , Antibacterianos/química , Proteínas de Unión a las Penicilinas , Regulación Alostérica , Proteínas Bacterianas/metabolismo , Pruebas de Sensibilidad MicrobianaRESUMEN
BS69 (also called ZMYND11) contains tandemly arranged PHD, BROMO, and PWWP domains, which are chromatin recognition modalities. Here, we show that BS69 selectively recognizes histone variant H3.3 lysine 36 trimethylation (H3.3K36me3) via its chromatin-binding domains. We further identify BS69 association with RNA splicing regulators, including the U5 snRNP components of the spliceosome, such as EFTUD2. Remarkably, RNA sequencing shows that BS69 mainly regulates intron retention (IR), which is the least understood RNA alternative splicing event in mammalian cells. Biochemical and genetic experiments demonstrate that BS69 promotes IR by antagonizing EFTUD2 through physical interactions. We further show that regulation of IR by BS69 also depends on its binding to H3K36me3-decorated chromatin. Taken together, our study identifies an H3.3K36me3-specific reader and a regulator of IR and reveals that BS69 connects histone H3.3K36me3 to regulated RNA splicing, providing significant, important insights into chromatin regulation of pre-mRNA processing.
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Empalme Alternativo , Proteínas Portadoras/metabolismo , Cromatina/metabolismo , Histonas/metabolismo , Precursores del ARN/genética , ARN Mensajero/genética , Secuencia de Bases , Proteínas Portadoras/genética , Proteínas de Ciclo Celular , Línea Celular Tumoral , Cromatina/genética , Proteínas Co-Represoras , Metilación de ADN/genética , Proteínas de Unión al ADN , Células HeLa , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/genética , Humanos , Intrones/genética , Lisina/genética , Lisina/metabolismo , Factores de Elongación de Péptidos/antagonistas & inhibidores , Factores de Elongación de Péptidos/genética , Factores de Elongación de Péptidos/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Interferencia de ARN , Procesamiento Postranscripcional del ARN/genética , ARN Interferente Pequeño , Ribonucleoproteína Nuclear Pequeña U5/antagonistas & inhibidores , Ribonucleoproteína Nuclear Pequeña U5/genética , Ribonucleoproteína Nuclear Pequeña U5/metabolismo , Análisis de Secuencia de ARN , Empalmosomas/genéticaRESUMEN
AIM: To report the health resource use and estimate the direct medical costs among patients with diabetes mellitus (DM) in the year of mortality and the year preceding the year of mortality. MATERIALS AND METHODS: We analysed data from a population-based, retrospective cohort study including all adults with a DM diagnosis in Hong Kong between 2009 and 2013, and who died between January 1, 2010 and December 31, 2013. The annual direct medical costs in the year of mortality and the year preceding the year of mortality were determined by summing the costs of health services utilized within the respective year. The costs were analysed by gender, the presence of comorbidities, diabetic complications and primary cause of death. RESULTS: A total of 10 649 patients met the eligibility criteria for analysis. On average, the direct medical costs in the year of death were 1.947 times higher than those in the year before death. Men and women with DM incurred similar costs in the year preceding the year of mortality and in the mortality year. Patients with any diabetic complications incurred greater costs in the year of mortality and the year before mortality than those without. CONCLUSIONS: This analysis provides new evidence on incorporating additional direct medical costs in the mortality year, and refining the structure of total cost estimates for use in costing and cost-effectiveness analyses of interventions for DM.
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Diabetes Mellitus Tipo 1/economía , Diabetes Mellitus Tipo 2/economía , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/mortalidad , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/mortalidad , Costos Directos de Servicios , Utilización de Instalaciones y Servicios , Femenino , Gastos en Salud , Servicios de Salud/economía , Servicios de Salud/estadística & datos numéricos , Hong Kong/epidemiología , Hospitalización/economía , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Estudios Retrospectivos , Factores de TiempoRESUMEN
A new porcine circovirus-like virus P1 mutant was isolated and sequenced in China in 2015. This P1 mutant has a mutation in its ORF1-encoded capsid protein that results in its elongation by eight amino acids.
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Proteínas de la Cápside/genética , Infecciones por Circoviridae/veterinaria , Circovirus/genética , ADN Viral/genética , Genoma Viral , Enfermedades de los Porcinos/virología , Secuencia de Aminoácidos , Animales , China/epidemiología , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/patología , Infecciones por Circoviridae/virología , Circovirus/clasificación , Circovirus/aislamiento & purificación , Tamaño del Genoma , Mutación , Sistemas de Lectura Abierta , Filogenia , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/patologíaRESUMEN
BACKGROUND: Health-related quality of life (HRQoL) and health preference of patients with diabetes mellitus (DM) are essential in health economic evaluations but data on Chinese population is rare. This study aims to evaluate HRQoL and health preference of diabetic patients with different diabetic complications in Chinese population. METHODS: A cross-sectional study was conducted in 1275 patients with DM, including 518 subjects with various DM-related complications. HRQoL and health preference were estimated using SF-12 and SF-6D questionnaires, respectively. Disease status of DM and complications were identified from documented clinical diagnosis. Multivariable regression was used to investigate the effects of specific complications on HRQoL and health preference, adjusting for socio-demographic and clinical parameters. RESULTS: The presence of any diabetic complication was associated with lower physical component summary (-3.81 points, P < 0.01), and end-stage renal disease (ESRD) showed greatest reduction (-7.05 points, P < 0.01). Mental component summary and mental health (MH) scores were not decreased in any of the diabetic complications. The health preference score for diabetic subjects without complications was 0.882 (95% CI, 0.778 to 0.989). The reductions of health preference score were significant for stroke (-0.042, 95% CI -0.072 to -0.012), ESRD (-0.055, 95% CI -0.093 to -0.017), and sight-threatening diabetic retinopathy (STDR) (-0.043, 95% CI -0.075 to -0.010), while heart disease had an insignificant reduction (-0.017, 95% CI -0.042 to 0.008). CONCLUSIONS: The presence of any of the four major diabetic complications (heart disease, stroke, ESRD and STDR) was associated with lower HRQoL and health preference scores. Findings of this study facilitated the cost-effectiveness studies of alternative management strategies for prevention of diabetic complications in Chinese population.
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Complicaciones de la Diabetes/psicología , Calidad de Vida/psicología , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Atención Primaria de Salud , Atención Secundaria de Salud , Encuestas y CuestionariosRESUMEN
BACKGROUND: Many factors influence whether the first-line oral anti-diabetic drug, metformin, should be initiated to a patient with type 2 diabetes mellitus (T2DM) early in the course of management in addition to lifestyle modifications. This study aims to evaluate the net effects of metformin monotherapy (MM) on the all-cause mortality and cardiovascular disease (CVD) events. METHODS: A retrospective 5-year follow-up cohort study was conducted on Chinese adult patients with T2DM and without any CVD history under public primary care. Cox proportional hazard regressions were performed to compare the risk of all-cause mortality and CVD events (CHD, stroke, heart failure) between patients receiving lifestyle modifications plus MM (MM groups) and those with lifestyle modifications alone (control groups). RESULTS: 3400 pairs of matched patients were compared. MM group had an incidence rate of 7.5 deaths and 11.3 CVD events per 1000 person-years during a median follow-up period of 62.5 months whereas control group had 11.1 deaths and 16.3 per 1000 person-years during a median follow-up period of 43.5-44.5 months. MM group showed a 29.5 and 30-35% risk reduction of all-cause mortality and CVD events (except heart failure) than control group (P < 0.001). MM group was more prone to progress to chronic kidney disease but this was not statistically significant. CONCLUSIONS: Type 2 diabetic patients who were started on metformin monotherapy showed improvement in many of the clinical parameters and a reduction in all-cause mortality and CVD events than lifestyle modifications alone. If there is no contraindication and if tolerated, diabetic patients should be prescribed with metformin early in the course of the diabetic management to minimize their risk of having the cardiovascular events and mortality in the long run.
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Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Metformina/uso terapéutico , Anciano , Pueblo Asiatico , Estudios de Cohortes , Enfermedad Coronaria/epidemiología , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/epidemiología , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Mortalidad , Modelos de Riesgos Proporcionales , Insuficiencia Renal Crónica/epidemiología , Estudios Retrospectivos , Conducta de Reducción del Riesgo , Accidente Cerebrovascular/epidemiología , Resultado del TratamientoRESUMEN
BACKGROUND: Studies on the long-term effectiveness of multidisciplinary risk-stratification based management in Chinese population were rare. This study aimed to evaluate the effectiveness of a multidisciplinary risk assessment and management program for patients with diabetes mellitus (RAMP-DM) in reducing the risks of cardiovascular complications and all-cause mortality. METHODS: A prospective cohort study was conducted in 18,188 propensity score matched RAMP-DM participants and subjects with diabetes under usual primary care (9,094 subjects in each group). The study endpoints were the first occurrence of coronary heart disease (CHD), stroke, heart failure (HF), total cardiovascular disease (CVD) and all-cause mortality. We constructed multivariable Cox proportional hazard regressions to estimate the association between the RAMP-DM intervention and the first occurrence of study endpoints. RESULTS: The median follow-up period was 36 months. Three hundred and ninety-nine CVD events occurred in the RAMP-DM group, as compared with 608 in the control group [adjusted hazard ratio, 0.629; 95% confidence interval (CI) 0.554-0.715; P < 0.001]. The total number of all-cause deaths in RAMP-DM group was less than half that of control group (202 vs 552, adjusted hazard ratio, 0.363; 95% CI, 0.308-0.428; P < 0.001). The adjusted hazard ratios of the RAMP-DM group for CHD, stroke, and HF were 0.570 (95% CI, 0.470-0.691; P < 0.001), 0.652 (95% CI, 0.546-0.780; P < 0.001), and 0.598 (95%CI, 0.446-0.802; P = 0.001), respectively. CONCLUSIONS: The RAMP-DM intervention was associated with lower incidences of individual and total cardiovascular complications, as well as all-cause mortality over 3 years follow-up. The encouraging results provided evidence to support that the structured risk-stratification management leading by a multidisciplinary clinical team was an effective approach to reduce future cardiovascular complications in people with diabetes. CLINICAL TRIAL REGISTRY: NCT02034695, http://www.ClinicalTrials.gov.
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Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus/terapia , Servicios Preventivos de Salud , Anciano , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/mortalidad , Causas de Muerte , Distribución de Chi-Cuadrado , Investigación sobre la Eficacia Comparativa , Enfermedad Coronaria/mortalidad , Enfermedad Coronaria/prevención & control , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidad , Femenino , Conocimientos, Actitudes y Práctica en Salud , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/prevención & control , Hong Kong/epidemiología , Humanos , Incidencia , Análisis de Intención de Tratar , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Grupo de Atención al Paciente , Educación del Paciente como Asunto , Atención Primaria de Salud , Evaluación de Programas y Proyectos de Salud , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Conducta de Reducción del Riesgo , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/prevención & control , Factores de Tiempo , Resultado del TratamientoRESUMEN
Protein arginine methyltransferases (PRMTs), catalyzing methylation of both histones and other cellular proteins, have emerged as key regulators of various cellular processes. This study aimed to identify key PRMTs involved in Ag-induced pulmonary inflammation (AIPI), a rat model for asthma, and to explore the role of PRMT1 in the IL-4-induced eosinophil infiltration process. E3 rats were i.p. sensitized with OVA/alum and intranasally challenged with OVA to induce AIPI. The expressions of PRMT1-6, eotaxin-1, and CCR3 in lungs were screened by real-time quantitative PCR. Arginine methyltransferase inhibitor 1 (AMI-1, a pan-PRMT inhibitor) and small interfering RNA-PRMT1 were used to interrupt the function of PRMT1 in A549 cells. In addition, AMI-1 was administrated intranasally to AIPI rats to observe the effects on inflammatory parameters. The results showed that PRMT1 expression was mainly expressed in bronchus and alveolus epithelium and significantly upregulated in lungs from AIPI rats. The inhibition of PRMTs by AMI-1 and the knockdown of PRMT1 expression were able to downregulate the expressions of eotaxin-1 and CCR3 with the IL-4 stimulation in the epithelial cells. Furthermore, AMI-1 administration to AIPI rats can also ameliorate pulmonary inflammation, reduce IL-4 production and humoral immune response, and abrogate eosinophil infiltration into the lungs. In summary, PRMT1 expression is upregulated in AIPI rat lungs and can be stimulated by IL-4. Intervention of PRMT1 activity can abrogate IL-4-dependent eotaxin-1 production to influence the pulmonary inflammation with eosinophil infiltration. The findings may provide experimental evidence that PRMT1 plays an important role in asthma pathogenesis.
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Antígenos/toxicidad , Quimiocina CCL11/biosíntesis , Células Epiteliales/metabolismo , Interleucina-4/farmacología , Proteína-Arginina N-Metiltransferasas/fisiología , Eosinofilia Pulmonar/inmunología , Animales , Asma/metabolismo , Quimiocina CCL11/genética , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Células Epiteliales/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Naftalenosulfonatos/farmacología , Naftalenosulfonatos/uso terapéutico , Ovalbúmina/toxicidad , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Proteína-Arginina N-Metiltransferasas/biosíntesis , Proteína-Arginina N-Metiltransferasas/genética , Eosinofilia Pulmonar/inducido químicamente , Eosinofilia Pulmonar/tratamiento farmacológico , Eosinofilia Pulmonar/enzimología , Interferencia de ARN , ARN Interferente Pequeño/farmacología , Ratas , Proteínas Recombinantes/farmacología , Sistema Respiratorio/citología , Organismos Libres de Patógenos Específicos , Urea/análogos & derivados , Urea/farmacología , Urea/uso terapéuticoRESUMEN
In heterostylous plants, short-tongued pollinators are often ineffective/inefficient owing to the limitations imposed by a long corolla tube. However, it is unclear how disassortative pollen transfer is achieved in small flowers. We investigated the pollination pattern and floral morph variation by analyzing heterostylous syndrome, pollinator groups, and pollen deposition after a single visitation in two Limonium myrianthum populations with short-corolla-tubular small flowers. The predominant pollinators in the Hutubi population were pollen-seeking short-tongued syrphids, which can only transfer pollen between high-level sexual organs. In the Xishan population, nectar-seeking short-tongued insects were efficient pollinators with symmetrical disassortative pollen transfer between high- and low-level sexual organs, whereas long-tongued pollinators had a low efficiency between high-level sexual organs due to the low contact probability with the stigma of long-styled flowers (L-morph), which no longer offered the same advantage observed in tubular flowers. Asymmetrical disassortative pollination may cause the female fitness of short-styled (S-morph) individuals in the Hutubi and L-morph individuals in the Xishan population to suffer greater selection pressure and exhibit a higher degree of floral morph variation. Limonium myrianthum exhibits an unusual pollination pattern in which the small flowers with short corolla tubes make it possible for short-tongued insects to become effective pollinators. However, factors such as the position of stigma-anther within the flower, pollinator species and their preference further caused asymmetrical disassortative pollen transfer. Therefore, more factors should be considered when evaluating the effectiveness of short- and long-tongued insects in pollination service.
RESUMEN
Abstract. Heterostyly, a genetic style polymorphism, is linked to symmetric pollen transfer, vital for its maintenance. Clonal growth typically impacts sexual reproduction by influencing pollen transfer. However, the floral morph variation remains poorly understood under the combined effects of pollinators and clonal growth in heterostyly characterized by negative frequency-dependent selection and disassortative mating. We estimated morph ratios, ramets per genet and heterostylous syndrome and quantified legitimate pollen transfer via clonal growth, pollinators and reciprocal herkogamy between floral morphs in Limonium otolepis, a fragmented population composed of five subpopulations in the desert environment of northwestern China, with small flower and large floral morph variation. All subpopulations but one exhibited pollen-stigma morphology dimorphism. The compatibility between mating types with different pollen-stigma morphologies remained consistent regardless of reciprocal herkogamy. Biased ratios and ramets per genet of the two mating types with distinct pollen-stigma morphologies caused asymmetric pollen flow and varying fruit sets in all subpopulations. Short-tongued insects were the primary pollinators due to small flower sizes. However, pollen-feeding Syrphidae sp. triggered asymmetry in pollen flow between high and low sex organs, with short-styled morphs having lower stigma pollen depositions and greater variation. Clonal growth amplified this variation by reducing intermorph pollen transfer. All in all, pollinators and clonal growth jointly drive floral morph variation. H-morphs with the same stigma-anther position and self-incompatibility, which mitigate the disadvantages of sunken low sex organs with differing from the classical homostyly, might arise from long- and short-styled morphs through a 'relaxed selection'. This study is the first to uncover the occurrence of the H-morph and its associated influencing factors in a distylous plant featuring clonal growth, small flowers and a fragmented population.
RESUMEN
5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS), as an indispensable enzyme in the shikimate pathway, is the specific target of grasser killer glyphosate (GPJ). GPJ is a competitive inhibitor of phosphoenolpyruvate (PEP), which is the natural substrate of EPSPS. A novel Ls-EPSPS gene variant discovered from Liliaceae, named ELs-EPSPS, includes five distal mutations, E112V, D142N, T351S, D425G, and R496G, endowing high GPJ insensitivity. However, the implicit molecular mechanism of the enhanced tolerance/insensitivity of GPJ in ELs-EPSPS is not fully understood. Herein, we try to interpret the hidden molecular mechanism using computational methods. Computational results reveal the enhanced flexibility of apo EPSPS upon mutations. The enhanced affinity of the initial binding substrate shikimate-3-phosphate (S3P), and the higher probability of second ligands PEP/GPJ entering the pocket are observed in the ELs-EPSPS-S3P system. Docking and MD results further confirmed the decreased GPJ-induced EPSPS inhibition upon mutations. And, the alterations of K98 and R179 side-chain orientations upon mutations are detrimental to GPJ binding at the active site. Additionally, the oscillation of side chain K98, in charge of PEP location, improves the proximity effect for substrates in the dual-substrate systems upon mutations. Our results clarify that the enhanced GPJ tolerance of EPSPS is achieved from decreased competitive inhibition of GPJ at the atomic perspective, and this finding further contributes to the cultivation of EPSPS genes with higher GPJ tolerance/insensitivity and a mighty renovation for developing glyphosate-resistant crops.Communicated by Ramaswamy H. Sarma.
RESUMEN
The production of penicillin-binding protein 2a (PBP2a), a cell wall synthesis protein, is primarily responsible for the high-level resistance observed in methicillin-resistant Staphylococcus aureus (MRSA). PBP2a exhibits a significantly reduced affinity for most ß-lactam antibiotics owing to its tightly closed active site. Quinazolinones (QNE), a novel class of non-ß-lactam antibiotics, could initiate the allosteric regulation of PBP2a, resulting in the opening of the initially closed active pocket. Based on our previous study, we have a basic understanding of the dual-site inhibitor ceftaroline (CFT) induced allosteric regulation of PBP2a. However, there are still limitations in the knowledge of how combining medicines, QNE and piperacillin (PIP), induce the allosteric response of PBP2a and inhibit its function. Herein, molecular dynamics (MD) simulations were performed to elucidate the intricate mechanisms underlying the combination mode of QNE and PIP. Our study successfully captured the opening process of the active pocket upon the binding of the QNE at the allosteric site, which alters the signaling pathways with a favorable transmission to the active site. Subsequent docking experiments with different conformational states of the active pocket indicated that all three inhibitors, PIP, QNE, and CFT, exhibited higher docking scores and more favorable docking poses to the open active pocket. These findings reveal the implied mechanism of QNE-mediated allostery underlying combination therapy and provide novel insights into developing innovative therapeutic modalities against MRSA.Communicated by Ramaswamy H. Sarma.
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This study assessed the impact of milk on the bioactive compounds, physicochemical properties, antioxidant activity, ROS inhibition, and volatile flavor compounds of fermented black mulberry juice (FBMJ). Firstly, the results showed that 25% concentration of milk was the most suitable for preparing FBMJ-Milk. Compared to the control group, the addition of milk significantly increased the SOD activity and antioxidant capacity, as well as enhanced the total phenolic content (TPC) and SOD storage stability. Secondly, HS-SPME-GC-MS combined with OPLS-DA analysis identified 49 compounds in FBMJM, including 12 esters, 6 acids, 1 ketone, 2 aldehydes, 19 alcohols and 9 other compounds. During the storage, the levels of ethyl ester compounds decreased significantly, while the degradation of ester produced some acid and alcohol compounds. The findings revealed that the addition of milk was beneficial for maintaining the antioxidant stability of FBMJM during storage and enhancing the richness of product flavor.
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The introduction of a self-adaptive molecular switch is an appealing strategy to achieve complete charge separation (CS) in donor-acceptor (D-A) systems. Here, we designed donor-switch-acceptor (D-S-A) systems using a platinum(II) terpyridyl complex as the acceptor, dimethyldihydropyrene/cyclophanediene (DHP/CPD) as the bridge, and methoxybenzene, thieno[3,2-b]thiophene, 2,2'-bifuran, and 4,8-dimethoxybenzo[1,2-b:4,5-b']difuran as donors, respectively. We then systematically studied the whole opto-electronic conversion process of the donor-DHP/CPD-acceptor (D-DHP/CPD-A) systems based on time-dependent density functional theory, time-dependent ultrafast electron evolution, and electron transport property calculations. We first found that the substitution of -CH3 by -H and -CN groups in DHP/CPD can enlarge the range of the adsorption wavenumber in opto-electric conversion. Then the light absorption induces the cationization of DHP switch, largely accelerating the forth-isomerization to CPD form. Once the D-CPD-A molecule is formed, the poor conjugation can realize the complete CS state by inhibiting the radiative and nonradiative charge recombinations. Finally, the repeatable and complete CS can be achieved through the automatic back-isomerization of CPD to DHP. The present work provides valuable insights into design of D-S-A systems for practical utilization of molecule-based solar harvesting.
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Exploring the mechanisms underlying the permeation of graphene quantum dots (GQDs) through different cell membranes is key for the practical application of GQDs in medicine. Here, the permeation process of GQDs through different lipid membranes was evaluated using molecular dynamics (MD) simulations. Our results showed that GQDs can easily permeate into 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) lipid membranes with low phospholipid molecule densities but cannot permeate into 1-palmitoyl-2-oleoyl phosphatidylethanolamine (POPE) lipid membranes with high phospholipid densities. Free energy calculation showed that a high-energy barrier exists on the surface of the POPE lipid membrane, which prevents GQDs from entering the cell membrane interior. Further analysis of the POPE membrane structure showed that sparsely arranged phospholipid molecules of the low-density lipid membrane facilitated the entry of GQDs into the interior of the membrane, compared to compactly arranged molecules in the high-density lipid membrane. Our simulation study provides new insights into the transmembrane transport of GQDs.
RESUMEN
Molecular photoswitch can effectively regulate charge separation (CS) and charge recombination (CR) in donor-acceptor (D-A) systems. However, deformation of the donor-switch-acceptor (D-S-A) systems caused by the switch isomerization will destroy the geometrical stability of the battery. Here we take the planar platinum(II) terpyridyl complex of [Pt(t Bu3 tpy)(-C≡C-Ph)n ]+ as the typical D-A model, designed six D-S-A systems using different photoswitches (dimethyldihydropyrene, fulgimide, arylazopyrazole, N-salicylideneaniline, spiropyran, and dithienylethene, denoted as D-S-A 1-6 hereafter). Our investigations show that the D-S-A 1-6 can absorb visible light of 799â nm, 673â nm, 527â nm, 568â nm, 616â nm, and 629â nm, facilitating electrons transfer from the donor and the switch to the acceptor through the Switch-on channel. Then cationic character of the photoswitch can undergo much more rapid isomerization than the neutral form due to the lower energy barrier. The Switch-off isomer breaks the conjugation of the D-S-A system, effectively turning off the CT channel and forming the CS state. Based on the evaluated conjugated backbone twist (CBT) angle, we found that D-S-A 1, 2, 4, 6 exhibit little configurational change and can be good candidates as the organic solar cell. The proposed D-S-A design controlled by the molecular switch may help to develop a solution for solar-harvesting practical applications.
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Many encapsulated bacteria use capsules to cause invasive diseases. However, it remains largely unknown how the capsules enhance bacterial virulence under in vivo infection conditions. Here we show that the capsules primarily target the liver to enhance bacterial survival at the onset of blood-borne infections. In a mouse sepsis model, the capsules enabled human pathogens Streptococcus pneumoniae and Escherichia coli to circumvent the recognition of liver-resident macrophage Kupffer cells (KCs) in a capsular serotype-dependent manner. In contrast to effective capture of acapsular bacteria by KCs, the encapsulated bacteria are partially (low-virulence types) or completely (high-virulence types) "untouchable" for KCs. We finally identified the asialoglycoprotein receptor (ASGR) as the first known capsule receptor on KCs to recognize the low-virulence serotype-7F and -14 pneumococcal capsules. Our data identify the molecular interplay between the capsules and KCs as a master controller of the fate and virulence of encapsulated bacteria, and suggest that the interplay is targetable for therapeutic control of septic infections.
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Macrófagos del Hígado , Infecciones Neumocócicas , Animales , Cápsulas Bacterianas , Cápsulas , Hígado , Ratones , Streptococcus pneumoniae , VirulenciaRESUMEN
BACKGROUND: There is no better treatment method towards paraquat-induced acute lung injury (ALI) at present. Ambroxol combined with methylprednisolone exhibits a significant improvement effect on ALI treatment, whereas their mechanism in ALI is still unclear. METHODS: 64 patients with ALI caused by paraquat poisoning brought to our hospital from January 2015 to January 2018 were selected. They were separated into a combined treatment group (CTG) and a routine treatment group (RTG) on the basis of different treatment methods. The survival of patients was observed after 7 days of treatment. Arterial blood gas, oxygen partial pressure (PaO2), partial pressure of carbon dioxide (PaCO2), oxygenation index (PaO2/FiO2), patient's spontaneous respiratory rate (RR), tidal volume (VT), and positive end-expiratory pressure (PEEP) were observed before and after treatment for 7 days. Interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were analyzed. The differences of indexes between the dead patients and the survivors were observed, and the potential predictive value of death was analyzed. RESULTS: After treatment, the indexes of patients were significantly improved in both groups compared with those before therapy. Further comparison showed that the improvement of PaO2, PaCO2, and PaO2/FiO2 in CTG was obviously higher than that in RTG (p < 0.05). The improvement of RR, PEEP, and VT in CTG was obviously higher than that in RTG (p < 0.05). The decreased degree of IL-6 and TNF-α in CTG was higher than that in RTG (p < 0.05). The 7-day mortality rate of 64 patients was 39.06%, and there was no obvious difference in the 7-day survival rate in both groups (p = 0.649). IL-6 and TNF-α were expected to be potential prediction indexes of paraquat-induced ALI. CONCLUSION: Ambroxol combined with methylprednisolone significantly improved the oxygen partial pressure and oxygenation index of patients with paraquat-induced ALI and inhibited the inflammatory response of patients.
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Lesión Pulmonar Aguda/tratamiento farmacológico , Ambroxol/efectos adversos , Ambroxol/uso terapéutico , Metilprednisolona/efectos adversos , Metilprednisolona/uso terapéutico , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/metabolismo , Adulto , Análisis de los Gases de la Sangre/métodos , Humanos , Interleucina-6/metabolismo , Masculino , Paraquat/farmacología , Presión Parcial , Respiración con Presión Positiva/métodos , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Síndrome de Dificultad Respiratoria/metabolismo , Volumen de Ventilación Pulmonar/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Sonication is one of the essential strategies of chromatin fragmentation in Chromatin immunoprecipitation (ChIP) assay. The impact of proteins with different molecular weights generated under different duration of sonication on the results of Chromatin immunoprecipitation sequencing (ChIP-seq) experiments involving the Polycomb Repressive Complex 2 (PRC2) related protein EZH2, which is a histone methyltransferase, and its product H3K27me3 was investigated. The results indicate that in the promoter region or nonpromoter region, there were hardly any differences among the H3K27me3 peaks annotated genes from different duration of sonication, which suggesting that the duration of sonication had little effect on histone ChIP-seq results. In contrast, in the promoter region newly gained EZH2 peaks annonated genes at 20 min sonication time were significantly clustered in the gene ontology (GO) pathways related to actin filament bundle compared with 10 min. In the nonpromoter region, compared with 10 min, the GO pathways of newly gained EZH2 peaks annonated genes at 20 min sonication time is much more than that of lost EZH2 peaks annonated genes. And in the nonpromoter region, compared with 20 min, the GO pathways of lost EZH2 peaks annonated genes at 30 min sonication time is much more than that of newly gained EZH2 peaks annonated genes. Most of these pathways are associated with RNA polymerase II (RNAPII), organ development and cell morphogenesis. These suggest that the genomic information of EZH2 will be lost if the duration of sonication is not enough or too long. Different duration of sonication mainly affect the EZH2 peaks in PRC2 unoccupied region and the bivalent promoter in the promoter region, as well as the PRC2 occupied region, PRC2 unoccupied region and the activated enhancer in the nonpromoter region. Therefore, the sonication for the chromatin related proteins with high molecular weights need to be optimized to make chromatin fragments size vary from 100 bp to 500 bp, which will yield relatively comprehensive genomic information of the target protein. For histones, which are of small molecular weights, duration of sonication has little effect on them.