Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.478
Filtrar
1.
Cell ; 187(16): 4272-4288.e20, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39013469

RESUMO

Vesicle trafficking is a fundamental process that allows for the sorting and transport of specific proteins (i.e., "cargoes") to different compartments of eukaryotic cells. Cargo recognition primarily occurs through coats and the associated proteins at the donor membrane. However, it remains unclear whether cargoes can also be selected at other stages of vesicle trafficking to further enhance the fidelity of the process. The WDR11-FAM91A1 complex functions downstream of the clathrin-associated AP-1 complex to facilitate protein transport from endosomes to the TGN. Here, we report the cryo-EM structure of human WDR11-FAM91A1 complex. WDR11 directly and specifically recognizes a subset of acidic clusters, which we term super acidic clusters (SACs). WDR11 complex assembly and its binding to SAC-containing proteins are indispensable for the trafficking of SAC-containing proteins and proper neuronal development in zebrafish. Our studies thus uncover that cargo proteins could be recognized in a sequence-specific manner downstream of a protein coat.


Assuntos
Microscopia Crioeletrônica , Transporte Proteico , Peixe-Zebra , Humanos , Animais , Endossomos/metabolismo , Células HEK293 , Células HeLa , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/química , Ligação Proteica
2.
Cell ; 171(3): 628-641.e26, 2017 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-29053969

RESUMO

Ferroptosis is a form of programmed cell death that is pathogenic to several acute and chronic diseases and executed via oxygenation of polyunsaturated phosphatidylethanolamines (PE) by 15-lipoxygenases (15-LO) that normally use free polyunsaturated fatty acids as substrates. Mechanisms of the altered 15-LO substrate specificity are enigmatic. We sought a common ferroptosis regulator for 15LO. We discovered that PEBP1, a scaffold protein inhibitor of protein kinase cascades, complexes with two 15LO isoforms, 15LO1 and 15LO2, and changes their substrate competence to generate hydroperoxy-PE. Inadequate reduction of hydroperoxy-PE due to insufficiency or dysfunction of a selenoperoxidase, GPX4, leads to ferroptosis. We demonstrated the importance of PEBP1-dependent regulatory mechanisms of ferroptotic death in airway epithelial cells in asthma, kidney epithelial cells in renal failure, and cortical and hippocampal neurons in brain trauma. As master regulators of ferroptotic cell death with profound implications for human disease, PEBP1/15LO complexes represent a new target for drug discovery.


Assuntos
Injúria Renal Aguda/patologia , Asma/patologia , Lesões Encefálicas Traumáticas/patologia , Morte Celular , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Injúria Renal Aguda/metabolismo , Animais , Apoptose , Asma/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Isoenzimas/metabolismo , Lipoxigenase/química , Lipoxigenase/metabolismo , Camundongos , Modelos Moleculares , Oxazolidinonas/farmacologia , Oxirredução , Proteína de Ligação a Fosfatidiletanolamina/química
3.
Nat Rev Mol Cell Biol ; 19(10): 654-672, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30104701

RESUMO

The cause of insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is not limited to impaired insulin signalling but also involves the complex interplay of multiple metabolic pathways. The analysis of large data sets generated by metabolomics and lipidomics has shed new light on the roles of metabolites such as lipids, amino acids and bile acids in modulating insulin sensitivity. Metabolites can regulate insulin sensitivity directly by modulating components of the insulin signalling pathway, such as insulin receptor substrates (IRSs) and AKT, and indirectly by altering the flux of substrates through multiple metabolic pathways, including lipogenesis, lipid oxidation, protein synthesis and degradation and hepatic gluconeogenesis. Moreover, the post-translational modification of proteins by metabolites and lipids, including acetylation and palmitoylation, can alter protein function. Furthermore, the role of the microbiota in regulating substrate metabolism and insulin sensitivity is unfolding. In this Review, we discuss the emerging roles of metabolites in the pathogenesis of insulin resistance and T2DM. A comprehensive understanding of the metabolic adaptations involved in insulin resistance may enable the identification of novel targets for improving insulin sensitivity and preventing, and treating, T2DM.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Resistência à Insulina/fisiologia , Animais , Transtornos do Metabolismo de Glucose/metabolismo , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , Redes e Vias Metabólicas , Metabolômica/métodos , Obesidade , Receptor de Insulina/metabolismo , Transdução de Sinais
4.
Cell ; 149(3): 630-41, 2012 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-22541433

RESUMO

In female mouse embryos, somatic cells undergo a random form of X chromosome inactivation (XCI), whereas extraembryonic trophoblast cells in the placenta undergo imprinted XCI, silencing exclusively the paternal X chromosome. Initiation of imprinted XCI requires a functional maternal allele of the X-linked gene Rnf12, which encodes the ubiquitin ligase Rnf12/RLIM. We find that knockout (KO) of Rnf12 in female mammary glands inhibits alveolar differentiation and milk production upon pregnancy, with alveolar cells that lack RLIM undergoing apoptosis as they begin to differentiate. Genetic analyses demonstrate that these functions are mediated primarily by the paternal Rnf12 allele due to nonrandom maternal XCI in mammary epithelial cells. These results identify paternal Rnf12/RLIM as a critical survival factor for milk-producing alveolar cells and, together with population models, reveal implications of transgenerational epigenetic inheritance.


Assuntos
Sobrevivência Celular , Glândulas Mamárias Animais/citologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Epigênese Genética , Feminino , Impressão Genômica , Masculino , Glândulas Mamárias Animais/fisiologia , Camundongos , Gravidez , Ubiquitina-Proteína Ligases/genética , Inativação do Cromossomo X
5.
Hum Mol Genet ; 33(10): 884-893, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38340456

RESUMO

Patent ductus arteriosus (PDA) is a common form of congenital heart disease. The MYH6 gene has important effects on cardiovascular growth and development, but the effect of variants in the MYH6 gene promoter on ductus arteriosus is unknown. DNA was extracted from blood samples of 721 subjects (428 patients with isolated and sporadic PDA and 293 healthy controls) and analyzed by sequencing for MYH6 gene promoter region variants. Cellular function experiments with three cell lines (HEK-293, HL-1, and H9C2 cells) and bioinformatics analyses were performed to verify their effects on gene expression. In the MYH6 gene promoter, 11 variants were identified. Four variants were found only in patients with PDA and 2 of them (g.3434G>C and g.4524C>T) were novel. Electrophoretic mobility shift assay showed that the transcription factors bound by the promoter variants were significantly altered in comparison to the wild-type in all three cell lines. Dual luciferase reporter showed that all the 4 variants reduced the transcriptional activity of the MYH6 gene promoter (P < 0.05). Prediction of transcription factors bound by the variants indicated that these variants alter the transcription factor binding sites. These pathological alterations most likely affect the contraction of the smooth muscle of ductus arteriosus, leading to PDA. This study is the first to focus on variants at the promoter region of the MYH6 gene in PDA patients with cellular function tests. Therefore, this study provides new insights to understand the genetic basis and facilitates further studies on the mechanism of PDA formation.


Assuntos
Miosinas Cardíacas , Permeabilidade do Canal Arterial , Cadeias Pesadas de Miosina , Regiões Promotoras Genéticas , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Miosinas Cardíacas/genética , Estudos de Casos e Controles , Linhagem Celular , Permeabilidade do Canal Arterial/genética , Permeabilidade do Canal Arterial/patologia , Células HEK293 , Cadeias Pesadas de Miosina/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Mol Cell ; 69(1): 126-135.e6, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29304330

RESUMO

N6-methyladenosine (m6A) and adenosine-to-inosine (A-to-I) editing are two of the most abundant RNA modifications, both at adenosines. Yet, the interaction of these two types of adenosine modifications is largely unknown. Here we show a global A-to-I difference between m6A-positive and m6A-negative RNA populations. Both the presence and extent of A-to-I sites in m6A-negative RNA transcripts suggest a negative correlation between m6A and A-to-I. Suppression of m6A-catalyzing enzymes results in global A-to-I RNA editing changes. Further depletion of m6A modification increases the association of m6A-depleted transcripts with adenosine deaminase acting on RNA (ADAR) enzymes, resulting in upregulated A-to-I editing on the same m6A-depleted transcripts. Collectively, the effect of m6A on A-to-I suggests a previously underappreciated interplay between two distinct and abundant RNA modifications, highlighting a complex epitranscriptomic landscape.


Assuntos
Adenosina/análogos & derivados , Adenosina/química , Inosina/química , Edição de RNA/genética , RNA/genética , Adenosina Desaminase/genética , Adenosina Desaminase/metabolismo , Linhagem Celular Tumoral , Regulação da Expressão Gênica/genética , Células HEK293 , Células HeLa , Humanos , Metiltransferases/genética , Metiltransferases/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
7.
Nucleic Acids Res ; 52(2): 831-843, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38084901

RESUMO

The large dsDNA viruses replicate their DNA as concatemers consisting of multiple covalently linked genomes. Genome packaging is catalyzed by a terminase enzyme that excises individual genomes from concatemers and packages them into preassembled procapsids. These disparate tasks are catalyzed by terminase alternating between two distinct states-a stable nuclease that excises individual genomes and a dynamic motor that translocates DNA into the procapsid. It was proposed that bacteriophage λ terminase assembles as an anti-parallel dimer-of-dimers nuclease complex at the packaging initiation site. In contrast, all characterized packaging motors are composed of five terminase subunits bound to the procapsid in a parallel orientation. Here, we describe biophysical and structural characterization of the λ holoenzyme complex assembled in solution. Analytical ultracentrifugation, small angle X-ray scattering, and native mass spectrometry indicate that 5 subunits assemble a cone-shaped terminase complex. Classification of cryoEM images reveals starfish-like rings with skewed pentameric symmetry and one special subunit. We propose a model wherein nuclease domains of two subunits alternate between a dimeric head-to-head arrangement for genome maturation and a fully parallel arrangement during genome packaging. Given that genome packaging is strongly conserved in both prokaryotic and eukaryotic viruses, the results have broad biological implications.


Assuntos
Empacotamento do Genoma Viral , Montagem de Vírus , Montagem de Vírus/genética , Bacteriófago lambda/genética , Endodesoxirribonucleases/metabolismo , DNA , DNA Viral/metabolismo , Empacotamento do DNA
8.
Plant Physiol ; 195(1): 671-684, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38345859

RESUMO

The phytohormone abscisic acid (ABA) plays a central role in regulating stomatal movements under drought conditions. The root-derived peptide CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 25 (CLE25) moves from the root to shoot for activating ABA biosynthesis under drought conditions. However, the root-to-shoot translocation of root-derived ABA and its regulation of stomatal movements in the shoot remain to be clarified. Here, we reveal that the ABA transporter ATP-binding cassette subfamily G member 25 (AtABCG25) mediates root-to-shoot translocation of ABA and ABA-glucosyl ester (ABA-GE) in Arabidopsis (Arabidopsis thaliana). Isotope-labeled ABA tracer experiments and hormone quantification in xylem sap showed that the root-to-shoot translocation of ABA and ABA-GE was substantially impaired in the atabcg25 mutant under nondrought and drought conditions. However, the contents of ABA and ABA-GE in the leaves were lower in the atabcg25 mutant than in the wild type (WT) under nondrought but similar under drought conditions. Consistently, the stomatal closure was suppressed in the atabcg25 mutant under nondrought but not under drought conditions. The transporter activity assays showed that AtABCG25 directly exported ABA and ABA-GE in planta and in yeast (Saccharomyces cerevisiae) cells. Thus, we proposed a working model in which root-derived ABA transported by AtABCG25 via xylem mediates stomatal movements in the shoot under nondrought conditions but might exhibit little effect on stomatal movements under drought conditions. These findings extend the functions of AtABCG25 and provide insights into the long-distance translocation of ABA and its role in stomatal movements.


Assuntos
Ácido Abscísico , Proteínas de Arabidopsis , Arabidopsis , Raízes de Plantas , Brotos de Planta , Estômatos de Plantas , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ácido Abscísico/metabolismo , Estômatos de Plantas/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Brotos de Planta/metabolismo , Brotos de Planta/genética , Transporte Biológico , Secas , Mutação/genética , Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Reguladores de Crescimento de Plantas/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética
9.
Syst Biol ; 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39051673

RESUMO

Polyploidy is a significant mechanism in eukaryotic evolution and is particularly prevalent in the plant kingdom. However, our knowledge about this phenomenon and its effects on evolution remains limited. A major obstacle to the study of polyploidy is the great difficulty in untangling the origins of allopolyploids. Due to the drastic genome changes and the erosion of allopolyploidy signals caused by the combined effects of hybridization and complex post-polyploid diploidization processes, resolving the origins of allopolyploids has long been a challenging task. Here we revisit this issue with the interesting case of subtribe Tussilagininae (Asteraceae: Senecioneae) and by developing HomeoSorter, a new pipeline for network inferences by phasing homeologs to parental subgenomes. The pipeline is based on the basic idea of a previous study but with major changes to address the scaling problem and implement some new functions. With simulated data, we demonstrate that HomeoSorter works efficiently on genome-scale data and has high accuracy in identifying polyploid patterns and assigning homeologs. Using HomeoSorter, the maximum pseudo-likelihood model of Phylonet, and genome-scale data, we further address the complex origin of Tussilagininae, a speciose group (ca. 45 genera and 710 species) characterized by having high base chromosome numbers (mainly x = 30, 40). In particular, the inferred patterns are strongly supported by the chromosomal evidence. Tussilagininae is revealed to comprise two large groups with successive allopolyploid origins: Tussilagininae s.s. (mainly x = 30) and the Gynoxyoid group (x = 40). Two allopolyploidy events first give rise to Tussilagininae s.s., with the first event occurring between the ancestor of subtribe Senecioninae (x = 10) and a lineage (highly probably with x = 10) related to the Brachyglottis alliance, and the resulting hybrid lineage crossing with the ancestor of Chersodoma (x = 10) and leading to Tussilagininae s.s. Then, after early diversification, the Central American group (mainly x = 30) of Tussilagininae s.s., is involved in a third allopolyploidy event with, again, the Chersodoma lineage and produces the Gynoxyoid group. Our study highlights the value of HomeoSorter and the homeolog-sorting approach in polyploid phylogenetics. With rich species diversity and clear evolutionary patterns, Tussilagininae s.s. and the Gynoxyoid group are also excellent models for future investigations of polyploidy.

10.
J Proteome Res ; 23(6): 2186-2194, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38664393

RESUMO

Tandem mass tags (TMT) are widely used in proteomics to simultaneously quantify multiple samples in a single experiment. The tags can be easily added to the primary amines of peptides/proteins through chemical reactions. In addition to amines, TMT reagents also partially react with the hydroxyl groups of serine, threonine, and tyrosine residues under alkaline conditions, which significantly compromises the analytical sensitivity and precision. Under alkaline conditions, reducing the TMT molar excess can partially mitigate overlabeling of histidine-free peptides, but has a limited effect on peptides containing histidine and hydroxyl groups. Here, we present a method under acidic conditions to suppress overlabeling while efficiently labeling amines, using only one-fifth of the TMT amount recommended by the manufacturer. In a deep-scale analysis of a yeast/human two-proteome sample, we systematically evaluated our method against the manufacturer's method and a previously reported TMT-reduced method. Our method reduced overlabeled peptides by 9-fold and 6-fold, respectively, resulting in the substantial enhancement in peptide/protein identification rates. More importantly, the quantitative accuracy and precision were improved as overlabeling was reduced, endowing our method with greater statistical power to detect 42% and 12% more statistically significant yeast proteins compared to the standard and TMT-reduced methods, respectively. Mass spectrometric data have been deposited in the ProteomeXchange Consortium via the iProX partner repository with the data set identifier PXD047052.


Assuntos
Aminas , Proteoma , Proteômica , Espectrometria de Massas em Tandem , Proteoma/análise , Proteoma/química , Proteômica/métodos , Humanos , Aminas/química , Espectrometria de Massas em Tandem/métodos , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/química , Peptídeos/química , Peptídeos/análise , Análise Custo-Benefício , Proteínas de Saccharomyces cerevisiae/análise , Proteínas de Saccharomyces cerevisiae/química , Coloração e Rotulagem/métodos
11.
J Cell Mol Med ; 28(19): e70076, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39392103

RESUMO

Non-small cell lung cancer (NSCLC) is a lethal malignancy. There is mounting evidence indicating that lncRNAs are crucial players with dual roles as both biomarkers and regulators across various cancers. It was reported that LINC00941 plays a cancer-promoting role in NSCLC. However, its impact on tumour autophagy remains poorly understood. In this study, we developed a risk assessment model and identified an autophagy-related lncRNA LINC00941, which has independent predictive and early diagnostic potential. Using RT-qPCR analysis, we confirmed the upregulation of LINC00941 in tumour tissues and cell lines of human lung adenocarcinoma (LUAD). Functional assays, such as CCK8, colony formation and xenograft models, demonstrated the cancer-promoting activity of LINC00941 both in vitro and in vivo. Further analysis using Western blotting analysis, mRFP-GFP-LC3 double fluorescence lentivirus vector and transmission electron microscopy (TEM) confirmed that the knockdown of LINC00941 triggered autophagy. These results indicate that knockdown of LINC00941 induces autophagy and impairs the proliferation of LUAD. Therefore, we propose LINC00941 as an independent biomarker for early diagnosis as well as a therapeutic target in LUAD.


Assuntos
Adenocarcinoma de Pulmão , Autofagia , Biomarcadores Tumorais , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , RNA Longo não Codificante , Humanos , Autofagia/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/diagnóstico , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Animais , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Proliferação de Células/genética , Linhagem Celular Tumoral , Carcinogênese/genética , Carcinogênese/patologia , Camundongos , Feminino , Masculino , Camundongos Nus , Pessoa de Meia-Idade
12.
J Hepatol ; 80(3): 454-466, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37952766

RESUMO

BACKGROUND & AIMS: Hereditary tyrosinemia type 1 (HT1) results from the loss of fumarylacetoacetate hydrolase (FAH) activity and can lead to lethal liver injury. Therapeutic options for HT1 remain limited. In this study, we aimed to construct an engineered bacterium capable of reprogramming host metabolism and thereby provide a potential alternative approach for the treatment of HT1. METHODS: Escherichia coli Nissle 1917 (EcN) was engineered to express genes involved in tyrosine metabolism in the anoxic conditions that are characteristic of the intestine (EcN-HT). Bodyweight, survival rate, plasma (tyrosine/liver function), H&E staining and RNA sequencing were used to assess its ability to degrade tyrosine and protect against lethal liver injury in Fah-knockout (KO) mice, a well-accepted model of HT1. RESULTS: EcN-HT consumed tyrosine and produced L-DOPA (levodopa) in an in vitro system. Importantly, in Fah-KO mice, the oral administration of EcN-HT enhanced tyrosine degradation, reduced the accumulation of toxic metabolites, and protected against lethal liver injury. RNA sequencing analysis revealed that EcN-HT rescued the global gene expression pattern in the livers of Fah-KO mice, particularly of genes involved in metabolic signaling and liver homeostasis. Moreover, EcN-HT treatment was found to be safe and well-tolerated in the mouse intestine. CONCLUSIONS: This is the first report of an engineered live bacterium that can degrade tyrosine and alleviate lethal liver injury in mice with HT1. EcN-HT represents a novel engineered probiotic with the potential to treat this condition. IMPACT AND IMPLICATIONS: Patients with hereditary tyrosinemia type 1 (HT1) are characterized by an inability to metabolize tyrosine normally and suffer from liver failure, renal dysfunction, neurological impairments, and cancer. Given the overlap and complementarity between the host and microbial metabolic pathways, the gut microbiome provides a potential chance to regulate host metabolism through degradation of tyrosine and reduction of byproducts that might be toxic. Herein, we demonstrated that an engineered live bacterium, EcN-HT, could enhance tyrosine breakdown, reduce the accumulation of toxic tyrosine byproducts, and protect against lethal liver injury in Fah-knockout mice. These findings suggested that engineered live biotherapeutics that can degrade tyrosine in the gut may represent a viable and safe strategy for the prevention of lethal liver injury in HT1 as well as the mitigation of its associated pathologies.


Assuntos
Tirosinemias , Humanos , Camundongos , Animais , Tirosinemias/complicações , Tirosinemias/genética , Tirosinemias/metabolismo , Fígado/patologia , Modelos Animais de Doenças , Camundongos Knockout , Tirosina/metabolismo , Escherichia coli/genética
13.
Biochem Biophys Res Commun ; 729: 150343, 2024 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-38986259

RESUMO

Pathological cardiac hypertrophy is associated with adverse cardiovascular events and can gradually lead to heart failure, arrhythmia, and even sudden death. However, the current development of treatment strategies has been unsatisfactory. Therefore, it is of great significance to find new and effective drugs for the treatment of myocardial hypertrophy. We found that carnosol can inhibit myocardial hypertrophy induced by PE stimulation, and the effect is very significant at 5 µM. Moreover, we demonstrated that 50 mg/kg of carnosol protect against cardiac hypertrophy and fibrosis induced by TAC surgery in mice. Mechanically, we proved that the inhibitory effect of carnosol on cardiac hypertrophy depends on its regulation on the phosphorylation activation of AMPK. In conclusion, our study suggested that carnosol may be a novel drug component for the treatment of pathological cardiac hypertrophy.


Assuntos
Proteínas Quinases Ativadas por AMP , Abietanos , Cardiomegalia , Camundongos Endogâmicos C57BL , Miócitos Cardíacos , Animais , Abietanos/farmacologia , Abietanos/uso terapêutico , Cardiomegalia/tratamento farmacológico , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/prevenção & controle , Proteínas Quinases Ativadas por AMP/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Masculino , Camundongos , Transdução de Sinais/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos
14.
J Comput Chem ; 45(21): 1846-1869, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38682874

RESUMO

Advanced vibrational spectroscopic experiments have reached a level of sophistication that can only be matched by numerical simulations in order to provide an unequivocal analysis, a crucial step to understand the structure-function relationship of biomolecules. While density functional theory (DFT) has become the standard method when targeting medium-size or larger systems, the problem of its reliability and accuracy are well-known and have been abundantly documented. To establish a reliable computational protocol, especially when accuracy is critical, a tailored benchmark is usually required. This is generally done over a short list of known candidates, with the basis set often fixed a priori. In this work, we present a systematic study of the performance of DFT-based hybrid and double-hybrid functionals in the prediction of vibrational energies and infrared intensities at the harmonic level and beyond, considering anharmonic effects through vibrational perturbation theory at the second order. The study is performed for the six-lowest energy glycine conformers, utilizing available "state-of-the-art" accurate theoretical and experimental data as reference. Focusing on the most intense fundamental vibrations in the mid-infrared range of glycine conformers, the role of the basis sets is also investigated considering the balance between computational cost and accuracy. Targeting larger systems, a broad range of hybrid schemes with different computational costs is also tested.

15.
Small ; 20(23): e2309568, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38461520

RESUMO

Wounds in harsh environments can face long-term inflammation and persistent infection, which can slow healing. Wound spray is a product that can be rapidly applied to large and irregularly dynamic wounds, and can quickly form a protective film in situ to inhibit external environmental infection. In this study, a biodegradable A and B combined multi-functional spray hydrogel is developed with methacrylate-modified chitosan (CSMA1st) and ferulic acid (FA) as type A raw materials and oxidized Bletilla striata polysaccharide (OBSP) as type B raw materials. The precursor CSMA1st-FA/OBSP (CSOB-FA1st) hydrogel is formed by the self-cross-linking of dynamic Schiff base bonds, the CSMA-FA/OBSP (CSOB-FA) hydrogel is formed quickly after UV-vis light, so that the hydrogel fits with the wound. Rapid spraying and curing provide sufficient flexibility and rapidity for wounds and the hydrogel has good injectability, adhesive, and mechanical strength. In rats and miniature pigs, the A and B combined spray hydrogel can shrink wounds and promote healing of infected wounds, and promote the enrichment of fibrocyte populations. Therefore, the multifunctional spray hydrogel combined with A and B can protect irregular dynamic wounds, prevent wound infection and secondary injury, and be used for safe and effective wound treatment, which has a good prospect for development.


Assuntos
Quitosana , Hidrogéis , Cicatrização , Cicatrização/efeitos dos fármacos , Animais , Hidrogéis/química , Quitosana/química , Ratos , Suínos , Reagentes de Ligações Cruzadas/química , Ratos Sprague-Dawley , Porco Miniatura , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia
16.
Small ; : e2404983, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113343

RESUMO

The kinetically retarded sulfur evolution reactions and notorious lithium dendrites as the major obstacles hamper the practical implementation of lithium-sulfur batteries (LSBs). Dual metal atom catalysts as a new model are expected to show higher activity by their rational coupling. Herein, the dual-atom catalyst with coupled Ni─Co atom pairs (Ni/Co-DAC) is designed successfully by programmed approaches. The Ni─Co atom pairs alter the local electron structure and optimize the coordination configuration of Ni/Co-DAC, leading to the coupling effect for promoting the interconversion of sulfur and guiding lithium plating/striping. The LSB delivers a remarkable capacity of 818 mA h g-1 at 3.0 C and a low degeneration rate of 0.053% per cycle over 500 cycles. Moreover, the LSB with a high sulfur mass loading of 6.1 mg cm-2 and lean electrolyte dosage of 6.0 µL mgS -1 shows a remarkable areal capacity of 5.7 mA h cm-2.

17.
Mamm Genome ; 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39400603

RESUMO

Atherosclerosis (AS) is a predominant etiological factor in numerous cardiovascular diseases, with its associated complications such as myocardial infarction and stroke serving as major contributors to worldwide mortality rates. Here, we devised dependable AS-related biomarkers through the utilization of single-cell RNA sequencing, weighted co-expression network (WGCNA), and differential expression analysis. Furthermore, we employed various machine learning techniques (LASSO and SVM-RFE) to enhance the identification of AS biomarkers, subsequently validating them using the GEO dataset. Following this, CIBERSORT was employed to investigate the correlation between biomarkers and infiltrating immune cells. Consequently, 256 differentially expressed genes (DEGs) were selected in samples of AS and normal. GO and KEGG analyses indicated that these DEGs may be related to the negative regulation of leukocyte-mediated immunity, leukocyte cell-cell adhesion, and immune system processes. Notably, C1QC and COL1A1 were pinpointed as potential diagnostic markers for AS, a finding that was further validated in the GSE21545 dataset. Moreover, the area under the curve (AUC) values for these markers exceeded 0.8, underscoring their diagnostic utility. Analysis of immune cell infiltration revealed that the expression of C1QC was correlated with M0 macrophages, gamma delta T cells, activated mast cells and memory B cells. Similarly, COL1A1 expression was linked to M0 macrophages, memory B cells, activated mast cells, gamma delta T cells, and CD4 native T cells. Finally, these results were validated using mice and human samples through immunofluorescence, immunohistochemistry, and ELISA analysis. Overall, C1QC and COL1A1 would be potential biomarkers for AS diagnosis, and that would provides novel perspectives on the diagnosis and treatment of AS.

18.
J Antimicrob Chemother ; 79(10): 2528-2533, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39086116

RESUMO

OBJECTIVES: To identify novel genetic elements facilitating the horizontal transfer of the oxazolidinone/phenicol resistance gene optrA and the pleuromutilin-lincosamide-streptogramin A resistance gene lsa(E) in Streptococcus suis. METHODS: The complete genomes of S. suis HB18 and two transconjugants were obtained using both the Illumina and Nanopore platforms. MICs were determined by broth microdilution. Inverse PCR was performed to identify circular forms of the novel unconventional circularizable structure (UCS), genomic island (GI) and integrative and conjugative element (ICE). Conjugation experiments assessed the transferability of optrA and lsa(E) genes in S. suis. RESULTS: S. suis HB18 carried a multiresistance gene cluster optrA-lsa(E)-lnu(B)-aphA-aadE-spw. This gene cluster, flanked by intact and truncated erm(B) in the same orientation, resided on a novel ICESsuHB18. Inverse PCR revealed the existence of a novel UCS, named UCS-optrA + lsa(E), which could excise the gene cluster optrA-lsa(E)-lnu(B)-aphA-aadE-spw and one copy of erm(B) from ICESsuHB18. Two transconjugants with different characteristics were obtained. In transconjugant T-JH-GI, UCS-optrA + lsa(E) excised from ICESsuHB18 inserted into the erm(B)-positive GI, designated GISsuHB18, generating the novel GISsuHB18-1. Meanwhile, in T-JH-ICE, genetic rearrangement events occurred in ICESsuHB18 and GISsuHB18, forming the novel ICESsuHB18-1. CONCLUSIONS: This is the first report demonstrating the functionally active UCS-optrA + lsa(E) excising from ICESsuHB18 and inserting into the erm(B)-positive GISsuHB18 during the conjugation process. The location of optrA and lsa(E) on a multiresistance UCS enhances its persistence and dissemination.


Assuntos
Antibacterianos , Conjugação Genética , Farmacorresistência Bacteriana Múltipla , Transferência Genética Horizontal , Testes de Sensibilidade Microbiana , Família Multigênica , Streptococcus suis , Streptococcus suis/genética , Streptococcus suis/efeitos dos fármacos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Conjugação Genética/genética , Genoma Bacteriano , Ilhas Genômicas/genética , Lincosamidas/farmacologia , Pleuromutilinas , Diterpenos/farmacologia , Compostos Policíclicos , Infecções Estreptocócicas/microbiologia , Genes Bacterianos , Estreptogramina A/farmacologia
19.
J Antimicrob Chemother ; 79(8): 1919-1928, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946304

RESUMO

OBJECTIVES: Polymyxin-induced nephrotoxicity (PIN) is a major safety concern and challenge in clinical practice, which limits the clinical use of polymyxins. This study aims to investigate the risk factors and to develop a scoring tool for the early prediction of PIN. METHODS: Data on critically ill patients who received intravenous polymyxin B or colistin sulfate for over 24 h were collected. Logistic regression with the least absolute shrinkage and selection operator (LASSO) was used to identify variables that are associated with outcomes. The eXtreme Gradient Boosting (XGB) classifier algorithm was used to further visualize factors with significant differences. A prediction model for PIN was developed through binary logistic regression analysis and the model was assessed by temporal validation and external validation. Finally, a risk-scoring system was developed based on the prediction model. RESULTS: Of 508 patients, 161 (31.6%) patients developed PIN. Polymyxin type, loading dose, septic shock, concomitant vasopressors and baseline blood urea nitrogen (BUN) level were identified as significant predictors of PIN. All validation exhibited great discrimination, with the AUC of 0.742 (95% CI: 0.696-0.787) for internal validation, of 0.708 (95% CI: 0.605-0.810) for temporal validation and of 0.874 (95% CI: 0.759-0.989) for external validation, respectively. A simple risk-scoring tool was developed with a total risk score ranging from -3 to 4, corresponding to a risk of PIN from 0.79% to 81.24%. CONCLUSIONS: This study established a prediction model for PIN. Before using polymyxins, the simple risk-scoring tool can effectively identify patients at risk of developing PIN within a range of 7% to 65%.


Assuntos
Antibacterianos , Humanos , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Antibacterianos/efeitos adversos , Idoso , Fatores de Risco , Polimixina B/efeitos adversos , Polimixina B/administração & dosagem , Projetos Piloto , Estado Terminal , Medição de Risco/métodos , Polimixinas/efeitos adversos , Colistina/efeitos adversos , Colistina/administração & dosagem , Modelos Logísticos , Adulto , Nefropatias/induzido quimicamente
20.
Int Arch Allergy Immunol ; : 1-17, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39260358

RESUMO

INTRODUCTION: Asthma is a common chronic respiratory disease characterized by chronic airway inflammation and abnormal airway remodeling. The RhoA/ROCK pathway and myocardin-related transcription factor A (MRTF-A) demonstrate significant associations with the proliferation of airway smooth muscle cells (ASCMs), which tightly correlates with the process of airway remodeling. MYOCD, which is homologous to MRTF-A but specifically expressed in smooth muscle cells, potentially regulates RhoA/ROCK activated cell proliferation and subsequent airway remodeling. METHODS: The RhoA/ROCK overexpression and silencing cell lines were constructed in vitro, as well as MYOCD overexpression/silencing. The cytoskeleton alterations induced by RhoA/ROCK pathway were identified by the measuring of globular actin and filamentous actin. RESULTS: The comparison between controls for overexpression/silencing and ROCK overexpression/silencing revealed that MYOCD presented consistent change trends with cytoskeleton and RhoA/ROCK pathway. The ROCK1 facilitates the proliferation and migration of ASCMs. The MYOCD enhanced the proliferation and migration of HASMCs. CONCLUSION: Our study indicates that Rho/ROCK/MYOCD is a key pathway involved in the migration and proliferation of airway smooth muscle cells. Inhibition of Rho/ROCK may be an effective approach to breaking the vicious cycle of asthmatic ASCMs proliferation, providing a novel strategy in treating asthma airway remodeling.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA