Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 103
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Genes Dev ; 33(19-20): 1367-1380, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31488578

RESUMO

Fat storage in adult mammals is a highly regulated process that involves the mobilization of adipocyte progenitor cells (APCs) that differentiate to produce new adipocytes. Here we report a role for the broadly conserved miR-26 family of microRNAs (miR-26a-1, miR-26a-2, and miR-26b) as major regulators of APC differentiation and adipose tissue mass. Deletion of all miR-26-encoding loci in mice resulted in a dramatic expansion of adipose tissue in adult animals fed normal chow. Conversely, transgenic overexpression of miR-26a protected mice from high-fat diet-induced obesity. These effects were attributable to a cell-autonomous function of miR-26 as a potent inhibitor of APC differentiation. miR-26 blocks adipogenesis, at least in part, by repressing expression of Fbxl19, a conserved miR-26 target without a previously known role in adipocyte biology that encodes a component of SCF-type E3 ubiquitin ligase complexes. These findings have therefore revealed a novel pathway that plays a critical role in regulating adipose tissue formation in vivo and suggest new potential therapeutic targets for obesity and related disorders.


Assuntos
Adipogenia/genética , Diferenciação Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , MicroRNAs/metabolismo , Obesidade/genética , Células-Tronco/citologia , Animais , Dieta Hiperlipídica , Expressão Gênica , Técnicas de Silenciamento de Genes , Camundongos , MicroRNAs/genética
2.
EMBO J ; 39(7): e103304, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32104923

RESUMO

Beneficial effects of resistance exercise on metabolic health and particularly muscle hypertrophy and fat loss are well established, but the underlying chemical and physiological mechanisms are not fully understood. Here, we identified a myometabolite-mediated metabolic pathway that is essential for the beneficial metabolic effects of resistance exercise in mice. We showed that substantial accumulation of the tricarboxylic acid cycle intermediate α-ketoglutaric acid (AKG) is a metabolic signature of resistance exercise performance. Interestingly, human plasma AKG level is also negatively correlated with BMI. Pharmacological elevation of circulating AKG induces muscle hypertrophy, brown adipose tissue (BAT) thermogenesis, and white adipose tissue (WAT) lipolysis in vivo. We further found that AKG stimulates the adrenal release of adrenaline through 2-oxoglutarate receptor 1 (OXGR1) expressed in adrenal glands. Finally, by using both loss-of-function and gain-of-function mouse models, we showed that OXGR1 is essential for AKG-mediated exercise-induced beneficial metabolic effects. These findings reveal an unappreciated mechanism for the salutary effects of resistance exercise, using AKG as a systemically derived molecule for adrenal stimulation of muscle hypertrophy and fat loss.


Assuntos
Ácidos Cetoglutáricos/sangue , Atrofia Muscular/genética , Receptores Purinérgicos P2/genética , Treinamento Resistido/métodos , Adulto , Idoso , Animais , Linhagem Celular , Feminino , Técnicas de Inativação de Genes , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Modelos Animais , Atrofia Muscular/metabolismo , Receptores Purinérgicos P2/metabolismo
3.
Mol Cell Biochem ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38430300

RESUMO

While P21-activated kinase-1 (PAK1) has been extensively studied in relation to cardiovascular health and glucose metabolism, its roles within adipose tissue and cardiometabolic diseases are less understood. In this study, we explored the effects of PAK1 deletion on energy balance, adipose tissue homeostasis, and cardiac function utilizing a whole-body PAK1 knockout (PAK1-/-) mouse model. Our findings revealed that body weight differences between PAK1-/- and WT mice emerged at 9 weeks of age, with further increases observed at 12 weeks. Furthermore, PAK1-/- mice displayed increased fat mass and decreased lean mass at 12 weeks, indicating a shift towards adiposity. In conjunction with the increased body weight, PAK1-/- mice had increased food intake and reduced energy expenditure. At a mechanistic level, PAK1 deletion boosted the expression of lipogenic markers while diminishing thermogenic markers expression in adipose tissues, contributing to reduced energy expenditure and the overall obesogenic phenotype. Moreover, our findings highlighted a significant impact on cardiac function following PAK1 deletion, including alterations in calcium kinetics and compromised systolic and lusitropy functions. In summary, our study emphasizes the significant role of PAK1 in weight regulation and cardiac function, enriching our comprehension of heart health and metabolism. These findings could potentially facilitate the identification of novel therapeutic targets in cardiometabolic diseases.

4.
Molecules ; 29(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38893567

RESUMO

Curcumin (Cur) is a phytochemical with various beneficial properties, including antioxidant, anti-inflammatory, and anticancer activities. However, its hydrophobicity, poor bioavailability, and stability limit its application in many biological approaches. In this study, a novel amphiphilic chitosan wall material was synthesized. The process was carried out via grafting chitosan with succinic anhydride (SA) as a hydrophilic group and deoxycholic acid (DA) as a hydrophobic group; 1H-NMR, FTIR, and XRD were employed to characterize the amphiphilic chitosan (CS-SA-DA). Using a low-cost, inorganic solvent-based procedure, CS-SA-DA was self-assembled to load Cur nanomicelles. This amphiphilic polymer formed self-assembled micelles with a core-shell structure and a critical micelle concentration (CMC) of 0.093 mg·mL-1. Cur-loaded nanomicelles were prepared by self-assembly and characterized by the Nano Particle Size Potential Analyzer and transmission electron microscopy (TEM). The mean particle size of the spherical Cur-loaded micelles was 770 nm. The drug entrapment efficiency and loading capacities were up to 80.80 ± 0.99% and 19.02 ± 0.46%, respectively. The in vitro release profiles of curcumin from micelles showed a constant release of the active drug molecule. Cytotoxicity studies and toxicity tests for zebrafish exhibited the comparable efficacy and safety of this delivery system. Moreover, the results showed that the entrapment of curcumin in micelles improves its stability, antioxidant, and anti-inflammatory activity.


Assuntos
Antioxidantes , Quitosana , Curcumina , Micelas , Curcumina/farmacologia , Curcumina/química , Quitosana/química , Antioxidantes/farmacologia , Antioxidantes/química , Nanopartículas/química , Animais , Peixe-Zebra , Portadores de Fármacos/química , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Tensoativos/química
5.
BMC Infect Dis ; 23(1): 22, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36635681

RESUMO

BACKGROUND: At present, the pathogenesis of post-treatment Lyme disease (PTLDS) is not clear, so the treatment scheme of PTLDS, especially antibiotic treatment, is still controversial. This study aims to evaluate the efficacy of antibiotics in the treatment of PTLDS using network meta-analysis (NMA). METHODS: Following PRISMA guidelines, a systematic literature search was conducted on randomized controlled trials in PubMed, EMBASE, Web of Science and Cochrane Library (the literature was published from database inception through December 16, 2022). Using random effect model and fixed effect model. STATA17.0 software was used to evaluate the quality and heterogeneity of the included research literature. RESULTS: The system included 4 randomized controlled trials (485 subjects). The network meta-analysis showed that ceftriaxone had better results than placebo [Mean = 0.87, 95% CI (0.02, 1.71)] and doxycycline [Mean = 1.01, 95% CI (0.03, 1.98)] in FSS scale scores. There was no statistical difference in FSS scale scores of other drugs after treatment. In terms of FSS score results, Ceftriaxone was the best intervention according to the SUCRA value of each treatment (97.7). The analysis of outcome indicators such as Beck Depression Inventory (BDI), Mental-health Scale and Physical-functioning scale showed that there was no statistically significant difference between the antibiotic group and placebo group. CONCLUSION: Ceftriaxone treatment may be the best choice for antibiotic treatment of PTLD, which provides useful guidance for antibiotic treatment of PTLD in the future.


Assuntos
Antibacterianos , Ceftriaxona , Doença de Lyme , Humanos , Antibacterianos/efeitos adversos , Ceftriaxona/uso terapêutico , Doxiciclina/uso terapêutico , Doença de Lyme/complicações , Doença de Lyme/tratamento farmacológico , Metanálise em Rede , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
6.
Sensors (Basel) ; 24(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38202919

RESUMO

The deposition of dust and condensation of fog will block the scattering and transmission of light, thus affecting the performance of optical devices. In this work, flexible polyethylene terephthalate (PET) foil functionalized by active dust removal and anti-fogging characteristics is realized which combines electrodynamic screen (EDS) and electro-heating devices. In lieu of traditional measurement methods of dust removal efficiency, the PSNR is employed to characterize the dust removal efficiency of the film for the first time. The results show that both dust removal and anti-fogging improve the image quality, in which the dust removal increases the PSNR from 28.1 dB to 34.2 dB and the anti-fogging function realizes a film temperature rise of 16.7 ∘C in 5 min, reaching a maximum of 41.3 ∘C. According to the high sensitivity of the PSNR, we propose a fully automatic CIS film-driven algorithm, and its feasibility has been demonstrated.

7.
J Antimicrob Chemother ; 77(5): 1286-1295, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35296898

RESUMO

OBJECTIVES: To investigate the prevalence and molecular characteristics of fosA3 and fosA7 among Salmonella isolates. METHODS: Five hundred and fifty-one Salmonella isolates collected from food animals in China during 2016-19 were screened for fos genes. The drug resistance, serovars, clonal relationships and genetic environments of fosA were compared between fosA7- and fosA3-positive Salmonella. RESULTS: A relatively high prevalence of fosA7 (9.26%) and fosA3 (6.53%) was identified. fosA3 was associated with high-level fosfomycin resistance (≥512 mg/L), while fosA7 conferred relatively low-level resistance that was independent of the presence of glucose-6-phosphate. Additionally, fosA7 could facilitate Salmonella survival under oxidative stress. Both fosA3 and fosA7 were found in diverse serovars and STs, but segregated into distinct groups. The fosA3-positive Salmonella Typhimurium/Salmonella Indiana strains showed close genetic relationships, while fosA7-positive Salmonella Meleagridis/Salmonella Agona/Salmonella Derby showed a relatively high degree of whole-genome sequence heterogeneity. fosA3 was located on conjugative IncHI2 plasmids or chromosomes, while fosA7 was strictly chromosomal. Furthermore, two strains carried large chromosomal fosA7 regions within genomic islands. The fosA3 and fosA7 contigs from our isolates and the NCBI could be segregated into four primary and distinct genomic backbones. IS26 and the antibiotic resistance genes (ARGs) blaCTX-M, blaTEM-1B and rmtB were frequently adjacent to fosA3, while fosA7-carrying contigs generally lacked mobile elements and ARGs. CONCLUSIONS: fosA3 and fosA7 were the primary factors contributing to reduced fosfomycin susceptibility, to different degrees, in these Salmonella isolates. The distinct distributions and molecular characteristics of fosA7 and fosA3 indicated that their origin and evolution in Salmonella were most likely distinct.


Assuntos
Fosfomicina , Animais , Antibacterianos/farmacologia , China/epidemiologia , Escherichia coli/genética , Testes de Sensibilidade Microbiana , Plasmídeos , Prevalência , Salmonella/genética , beta-Lactamases/genética
9.
Appl Microbiol Biotechnol ; 106(24): 8183-8194, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36404356

RESUMO

The nucleic acid test is still the standard assessment for the diagnosis of coronavirus disease 2019 (COVID-19), which is caused by human infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to supporting the confirmation of disease cases, serological assays are used for the analysis of antibody status and epidemiological surveys. In this study, a single Western blot strip (WBS) coated with multiple Escherichia coli (E. coli)-expressed SARS-CoV-2 antigens was developed for comprehensive studies of antibody profiles in COVID-19 patient sera. The levels of specific antibodies directed to SARS-CoV-2 spike (S), S2, and nucleocapsid (N) proteins were gradually increased with the same tendency as the disease progressed after hospitalization. The signal readouts of S, S2, and N revealed by the multi-antigen-coated WBS (mWBS)-based serological assay (mWBS assay) also demonstrated a positive correlation with the SARS-CoV-2 neutralizing potency of the sera measured by the plaque reduction neutralization test (PRNT) assays. Surprisingly, the detection signals against the unstructured receptor-binding domain (RBD) purified from E. coli inclusion bodies were not observed, although the COVID-19 patient sera exhibited strong neutralizing potency in the PRNT assays, suggesting that the RBD-specific antibodies in patient sera mostly recognize the conformational epitopes. Furthermore, the mWBS assay identified a unique and major antigenic epitope at the residues 1148, 1149, 1152, 1155, and 1156 located within the 1127-1167 fragment of the S2 subunit, which was specifically recognized by the COVID-19 patient serum. The mWBS assay can be finished within 14-16 min by using the automatic platform of Western blotting by thin-film direct coating with suction (TDCS WB). Collectively, the mWBS assay can be applied for the analysis of antibody responses, prediction of the protective antibody status, and identification of the specific epitope. KEY POINTS: • A Western blot strip (WBS) coated with multiple SARS-CoV-2 antigens was developed for the serological assay. • The multi-antigen-coated WBS (mWBS) can be utilized for the simultaneous detection of antibody responses to multiple SARS-CoV-2 antigens. • The mWBS-based serological assay (mWBS assay) identified a unique epitope recognized by the COVID-19 patient serum.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Formação de Anticorpos , COVID-19/diagnóstico , Escherichia coli/genética , Western Blotting
10.
Mar Drugs ; 20(8)2022 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-36005539

RESUMO

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has excellent biological activities such as antibacterial, antioxidant, and hemostasis. In recent years, the demand has increased significantly in many fields and has huge application potential. Due to the poor water solubility of chitosan, its wide application is limited. However, chemical modification of the chitosan matrix structure can improve its solubility and biological activity, thereby expanding its application range. The review covers the period from 1996 to 2022 and was elaborated by searching Google Scholar, PubMed, Elsevier, ACS publications, MDPI, Web of Science, Springer, and other databases. The various chemical modification methods of chitosan and its main activities and application research progress were reviewed. In general, the modification of chitosan and the application of its derivatives have had great progress, such as various reactions, optimization of conditions, new synthetic routes, and synthesis of various novel multifunctional chitosan derivatives. The chemical properties of modified chitosan are usually better than those of unmodified chitosan, so chitosan derivatives have been widely used and have more promising prospects. This paper aims to explore the latest progress in chitosan chemical modification technologies and analyze the application of chitosan and its derivatives in various fields, including pharmaceuticals and textiles, thus providing a basis for further development and utilization of chitosan.


Assuntos
Quitosana , Antibacterianos/química , Antibacterianos/farmacologia , Quitina/química , Quitosana/química , Solubilidade
11.
Traffic ; 20(4): 267-283, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30740854

RESUMO

Chromatin remodeling regulates gene expression in response to the accumulation of misfolded polyQ proteins associated with Huntington's disease (HD). Tra1 is an essential component of both the SAGA/SLIK and NuA4 transcription co-activator complexes and is linked to multiple cellular processes, including protein trafficking and signaling pathways associated with misfolded protein stress. Cells with compromised Tra1 activity display phenotypes distinct from deletions encoding components of the SAGA and NuA4 complexes, indicating a potentially unique regulatory role of Tra1 in the cellular response to protein misfolding. Here, we employed a yeast model to define how the expression of toxic polyQ expansion proteins affects Tra1 expression and function. Expression of expanded polyQ proteins mimics deletion of SAGA/NuA4 components and results in growth defects under stress conditions. Moreover, deleting genes encoding SAGA and, to a lesser extent, NuA4 components exacerbates polyQ toxicity. Also, cells carrying a mutant Tra1 allele displayed increased sensitivity to polyQ toxicity. Interestingly, expression of polyQ proteins upregulated the expression of TRA1 and other genes encoding SAGA components, revealing a feedback mechanism aimed at maintaining Tra1 and SAGA functional integrity. Moreover, deleting the TORC1 (Target of Rapamycin) effector SFP1 abolished upregulation of TRA1 upon expression of polyQ proteins. While Sfp1 is known to adjust ribosome biogenesis and cell size in response to stress, we identified a new role for Sfp1 in the control of TRA1 expression, linking TORC1 and cell growth regulation to the SAGA acetyltransferase complex during misfolded protein stress.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Histona Acetiltransferases/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Peptídeos/toxicidade , Proteínas de Saccharomyces cerevisiae/metabolismo , Resposta a Proteínas não Dobradas , Processos de Crescimento Celular , Proteínas de Ligação a DNA/genética , Exorribonucleases/genética , Exorribonucleases/metabolismo , Histona Acetiltransferases/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Peptídeos/genética , Peptídeos/metabolismo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética
12.
Am J Physiol Cell Physiol ; 321(3): C585-C595, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34378991

RESUMO

Defined as the dysfunction and/or cell death caused by toxic lipids accumulation in hepatocytes, hepatic lipotoxicity plays a pathological role in nonalcoholic fatty liver disease. The cellular and molecular mechanisms underlying lipotoxicity remain to be elucidated. In this study, using AML12 cells, a nontransformed murine hepatocyte cell line, exposed to palmitate (a 16-C saturated fatty acid) as an experimental model, we investigated the role and mechanisms of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing nicotinamide methylation and degradation, in hepatic lipotoxicity. We initially identified activating transcription factor 4 (ATF4) as a major transcription factor for hepatic NNMT expression. Here, we demonstrated that palmitate upregulates NNMT expression via activating ATF4 in a mechanistic target of rapamycin complex 1 (mTORC1)-dependent mechanism in that mTORC1 inhibition by both Torin1 and rapamycin attenuated ATF4 activation and NNMT upregulation. We further demonstrated that the mTORC1-dependent ATF4 activation is an integral signaling event of unfolded protein response (UPR) as both ATF4 activation and NNMT upregulation by tunicamycin, a well-documented endoplasmic reticulum (ER) stress inducer, are blunted when hepatocytes were pretreated with Torin1. Importantly, our data uncovered that NNMT upregulation contributes to palmitate-induced hepatotoxicity as NNMT inhibition, via either pharmacological (NNMT inhibitors) or genetic approach (siRNA transfection), provided protection against palmitate lipotoxicity. Our further mechanistic exploration identified protein kinase A (PKA) activation to contribute, at least, partially to the protective effect of NNMT inhibition against lipotoxicity. Collectively, our data demonstrated that NNMT upregulation by the mTORC1-ATF4 pathway activation contributes to the development of lipotoxicity in hepatocytes.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Hepatócitos/efeitos dos fármacos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Nicotinamida N-Metiltransferase/metabolismo , Palmitatos/toxicidade , Fator 4 Ativador da Transcrição/genética , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hepatócitos/enzimologia , Hepatócitos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nicotinamida N-Metiltransferase/genética , Transdução de Sinais , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Regulação para Cima , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismo
13.
Am J Physiol Gastrointest Liver Physiol ; 321(3): G335-G343, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34405732

RESUMO

Obesity is associated with gastroesophageal reflux disease (GERD) and its complications including reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Traditionally, these associations have been attributed to the mechanical effect of abdominal fat in increasing intra-abdominal pressure, thereby promoting gastroesophageal reflux and causing disruption of antireflux mechanisms at the esophagogastric junction. However, recent studies suggest that visceral adipose tissue (VAT) produces numerous cytokines that can cause esophageal inflammation and impair esophageal mucosal barrier integrity through reflux-independent mechanisms that render the esophageal mucosa especially susceptible to GERD-induced injury. In this report, we review mechanisms of esophageal mucosal defense, the genesis and remodeling of visceral adipose tissue during obesity, and the potential role of substances produced by VAT, especially the VAT that encircles the esophagogastric junction, in the impairment of esophageal mucosal barrier integrity that leads to the development of GERD complications.


Assuntos
Esôfago de Barrett/patologia , Mucosa Esofágica/metabolismo , Refluxo Gastroesofágico/patologia , Obesidade/patologia , Esôfago de Barrett/metabolismo , Mucosa Esofágica/patologia , Esofagite Péptica/metabolismo , Esofagite Péptica/patologia , Esôfago/patologia , Refluxo Gastroesofágico/metabolismo , Humanos , Obesidade/metabolismo
14.
Appl Environ Microbiol ; 87(10)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33674440

RESUMO

We investigated the prevalence and transmission of NDM-producing Enterobacteriaceae in fecal samples of geese and environmental samples from a goose farm in southern China. The samples were cultivated on MacConkey agar plates supplemented with meropenem. Individual colonies were examined for blaNDM, and blaNDM-positive bacteria were characterized based on whole-genome sequencing (WGS) data from the Illumina and Oxford Nanopore Technologies (ONT) platforms. Of 117 samples analyzed, the carriage rates for New Delhi metallo-ß-lactamase (NDM)-positive Enterobacteriaceae were 47.1, 18, and 50% in geese, inanimate environments (sewage, soil, fodder, and dust), and mouse samples, respectively. Two variants (blaNDM-1 and blaNDM-5, in 4 and 40 isolates, respectively) were found among 44 blaNDM-positive Enterobacteriaceae; these variants belonged to eight species, and Escherichia coli was the most prevalent (50%). WGS analysis revealed that blaNDM coexisted with diverse antibiotic resistance genes (ARGs). Population structure analysis showed that most E. coli and Enterobacter sp. isolates were highly heterogeneous, while most Citrobacter sp. and P. stuartii isolates possessed extremely high genetic similarities. In addition, blaNDM-5-positive ST4358/ST48 E. coli isolates were found to be clonally spread between geese and the environment and were highly genetically similar to those reported from ducks, farm environments, and humans in China. Plasmid analysis indicated that IncX3 pHNYX644-1-like (n = 40) and untypeable pM2-1-like plasmids (n = 4) mediated blaNDM spread. pM2-1-like plasmids possessed diverse ARGs, including blaNDM-1, the arsenical and mercury resistance operons, and the maltose operon. Our findings revealed that the goose farm is a reservoir for NDM-positive Enterobacteriaceae The blaNDM contamination of wild mice and the novel pM2-1-like plasmid described here likely adds to the risk for dissemination of blaNDM and associated resistance genes.IMPORTANCE Carbapenem-resistant bacteria, in particular NDM-producing Enterobacteriaceae, have become a great threat to global public. These bacteria have been found not only in hospital and community environments but also among food animal production chains, which are recognized as reservoirs for NDM-producing Enterobacteriaceae However, the dissemination of NDM-producing bacteria in waterfowl farms has been less well explored. Our study demonstrates that the horizontal spread of blaNDM-carrying plasmids and the partial clonal spread of blaNDM-positive Enterobacteriaceae contribute to the widespread contamination of blaNDM in the goose farm ecosystem, including mice. Furthermore, we found a novel and transferable blaNDM-1-carrying multidrug resistance (MDR) plasmid that possessed multiple environmental adaptation-related genes. The outcomes of this study contribute to a better understanding of the prevalence and transmission of blaNDM-carrying Enterobacteriaceae among diverse niches in the farm ecosystem.


Assuntos
Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/isolamento & purificação , Gansos/microbiologia , Doenças das Aves Domésticas/microbiologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , China , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/veterinária , Fazendas , Fezes/microbiologia , Fômites/microbiologia , Camundongos , Testes de Sensibilidade Microbiana
15.
J Integr Plant Biol ; 63(4): 772-786, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33615694

RESUMO

Active DNA demethylation is critical for altering DNA methylation patterns and regulating gene expression. The 5-methylcytosine DNA glycosylase/lyase ROS1 initiates a base-excision repair pathway for active DNA demethylation and is required for the prevention of DNA hypermethylation at 1 000s of genomic regions in Arabidopsis. How ROS1 is regulated and targeted to specific genomic regions is not well understood. Here, we report the discovery of an Arabidopsis protein complex that contains ROS1, regulates ROS1 gene expression, and likely targets the ROS1 protein to specific genomic regions. ROS1 physically interacts with a WD40 domain protein (RWD40), which in turn interacts with a methyl-DNA binding protein (RMB1) as well as with a zinc finger and homeobox domain protein (RHD1). RMB1 binds to DNA that is methylated in any sequence context, and this binding is necessary for its function in vivo. Loss-of-function mutations in RWD40, RMB1, or RHD1 cause DNA hypermethylation at several tested genomic regions independently of the known ROS1 regulator IDM1. Because the hypermethylated genomic regions include the DNA methylation monitoring sequence in the ROS1 promoter, plants mutated in RWD40, RMB1, or RHD1 show increased ROS1 expression. Importantly, ROS1 binding to the ROS1 promoter requires RWD40, RMB1, and RHD1, suggesting that this complex dictates ROS1 targeting to this locus. Our results demonstrate that ROS1 forms a protein complex with RWD40, RMB1, and RHD1, and that this novel complex regulates active DNA demethylation at several endogenous loci in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Desmetilação do DNA , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/fisiologia , Proteínas Proto-Oncogênicas/genética
17.
J Antimicrob Chemother ; 75(7): 1756-1765, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32274508

RESUMO

OBJECTIVES: To investigate the prevalence and transmission of mcr-3 among Salmonella enterica serotype Typhimurium and 1,4,[5],12:i:-. METHODS: A total of 4724 clinical Salmonella isolates were screened for the presence of mcr-3 in China during 2014-19. The clonal relationship of the mcr-3-positive isolates and their plasmid contents and complete sequence were also characterized based on WGS data from the Illumina and MinION platforms. RESULTS: We identified 10 mcr-3-positive isolates, and all were MDR, mostly resistant to colistin, cefotaxime, ciprofloxacin, doxycycline and florfenicol. mcr-3 was co-present with blaCTX-M-55-qnrS1 on hybrid ST3-IncC-FII conjugatable plasmids (n = 6) and an ST3-IncC non-conjugatable plasmid (n = 1) and embedded into a pCHL5009T-like IncFII plasmid on the Salmonella chromosome (n = 3). Four distinctive genetic contexts surrounded mcr-3 and all but one were closely related to each other and to the corresponding region of IncFII plasmid pCHL5009T. IS15DI was most likely the vehicle for integration of mcr-3-carrying IncFII plasmids into ST3-IncC plasmids and the chromosome and for shaping the MDR regions. In addition, a phylogenetic tree based on the core genome revealed a unique Salmonella lineage (≤665 SNPs) that contained these 10 mcr-3-positive isolates and another 38 (33 from patients) mcr-3-positive Salmonella from five countries. In particular, most of the 51 mcr-3-positive isolates belonged to ST34 and harboured diverse antibiotic resistance genes (ARGs), including mcr-3-blaCTX-M-55-qnrS1, and possessed similar ARG profiles. CONCLUSIONS: Our findings revealed global clonal spread of MDR ST34 Salmonella from clinical isolates co-harbouring mcr-3 with blaCTX-M-55 and qnrS1 and a flexibility of mcr-3 co-transmittance with other ARGs mediated by mobile genetic elements.


Assuntos
Antibacterianos , Salmonella typhimurium , Antibacterianos/farmacologia , China/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Plasmídeos/genética , Salmonella typhimurium/genética , Sorogrupo
18.
Acta Radiol ; 61(10): 1431-1440, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32008343

RESUMO

BACKGROUND: There is still little research about histogram analysis of diffusion kurtosis imaging (DKI) using in prostate cancer at present. PURPOSE: To verify the utility of histogram analysis of DKI model in detection and assessment of aggressiveness of prostate cancer, compared with monoexponential model (MEM). MATERIAL AND METHODS: Twenty-three patients were enrolled in this study. For DKI model and MEM, the Dapp, Kapp, and apparent diffusion coefficient (ADC) were obtained by using single-shot echo-planar imaging sequence. The pathologies were confirmed by in-bore magnetic resonance (MR)-guided biopsy. Regions of interest (ROI) were drawn manually in the position where biopsy needle was put. The mean values and histogram parameters in cancer and noncancerous foci were compared using independent-samples T test. Receiver operating characteristic curves were used to investigate the diagnostic efficiency. Spearman's test was used to evaluate the correlation of parameters and Gleason scores. RESULTS: The mean, 10th, 25th, 50th, 75th, and 90th percentiles of ADC and Dapp were significantly lower in prostate cancer than non-cancerous foci (P < 0.001). The mean, 50th, 75th, and 90th percentiles of Kapp were significantly higher in prostate cancer (P < 0.05). There was no significant difference between the AUCs of two models (0.971 vs. 0.963, P > 0.05). With the increasing Gleason scores, the 10th ADC decreased (ρ = -0.583, P = 0.018), but the 90th Kapp increased (ρ = 0.642, P = 0.007). CONCLUSION: Histogram analysis of DKI model is feasible for diagnosing and grading prostate cancer, but it has no significant advantage over MEM.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Imagem Ecoplanar , Humanos , Biópsia Guiada por Imagem , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Gradação de Tumores , Neoplasias da Próstata/patologia
19.
Phytother Res ; 34(11): 3063-3077, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32583938

RESUMO

Schisandra chinensis fruit has been shown to restore carbohydrate- and lipid-metabolic disorders and has anti-hepatotoxicity and anti-hepatitis activities. However, the molecular targets mediating the pharmacological properties of S. chinensis fruit have not been clarified. Here, we assayed the effects of S. chinensis fruit ethanol extract (SCE) on farnesoid X receptor (FXR) transactivity. The pharmacological effects of SCE (1 g/100 g diet) were assessed in high-fat diet (HFD)-fed C57BL/6 mice and ob/ob mice. The FXR and Fgf15 signalling pathways were evaluated by FXR silencing, ELISA, Western blot and RT-PCR analyses. The results showed that SCE treatment increased FXR transcription activity and improved obesity, hypercholesteremia and fatty liver in HFD-fed mice, while it had limited effects on ob/ob mice. Our study suggests that SCE treatment may improve HFD-induced metabolic disorders through pharmacological activation of FXR/Fgf15 signalling, and such beneficial effects of SCE may require leptin participation.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Frutas/química , Doenças Metabólicas/tratamento farmacológico , Extratos Vegetais/química , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Schisandra/química , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos
20.
Traffic ; 18(1): 58-70, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27734565

RESUMO

The palette of fluorescent proteins (FPs) available for live-cell imaging contains proteins that strongly differ in their biophysical properties. FPs cannot be assumed to be equivalent and in certain cases could significantly perturb the behavior of fluorescent reporters. We employed Saccharomyces cerevisiae to comprehensively study the impact of FPs on the toxicity of polyglutamine (polyQ) expansion proteins associated with Huntington's disease. The toxicity of polyQ fusion constructs is highly dependent on the sequences flanking the polyQ repeats. Thus, they represent a powerful tool to study the impact of fluorescent fusion partners. We observed significant differences on polyQ aggregation and toxicity between commonly used FPs. We generated a novel series of vectors with latest yeast-optimized FPs for investigation of Htt toxicity, including a newly optimized blue FP for expression in yeast. Our study highlights the importance of carefully choosing the optimal FPs when designing tagging strategies.


Assuntos
Proteínas Luminescentes/metabolismo , Peptídeos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Humanos , Doença de Huntington/metabolismo , Fenótipo
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa