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1.
BMC Genomics ; 24(1): 57, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36721086

RESUMO

OBJECTIVES: To explore the causes of sudden unexpected death (SUD) and to search for high-risk people, whole exome sequencing (WES) was performed in families with SUDs.  METHODS: Whole exome sequencing of 25 people from 14 SUD families were screened based on cardiac disease-associated gene variants, and their echocardiograms and electrocardiograms (ECG) were also examined. The protein function of mutated genes was predicted by SIFT, PolyPhen2 and Mutation Assessor. RESULTS: In the group of 25 people from 14 SUD families, 49 single nucleotide variants (SNVs) of cardiac disease-associated genes were found and verified by Sanger sequencing. 29 SNVs of 14 cardiac disorder-related genes were predicted as pathogens by software. Among them, 7 SNVs carried by two or more members were found in 5 families, including SCN5A (c.3577C > T), IRX4 (c.230A > G), LDB3 (c.2104 T > G), MYH6 (c.3G > A), MYH6 (c.3928 T > C), TTN (c.80987C > T) and TTN (c.8069C > T). 25 ECGs were collected. In summary, 4 people had J-point elevation, 2 people had long QT syndrome (LQTS), 4 people had prolonged QT interval, 3 people had T-wave changes, 3 people had sinus tachycardia, 4 people had sinus bradycardia, 4 people had left side of QRS electrical axis, and 3 people had P wave broadening. Echocardiographic results showed that 1 person had atrial septal defect, 1 person had tricuspid regurgitation, and 2 people had left ventricular diastolic dysfunction. CONCLUSIONS: Of the 14 heart disease-associated genes in 14 SUDs families, there are 7 possible pathological SNVS may be associated with SUDs. Our results indicate that people with ECG abnormalities, such as prolonged QT interval, ST segment changes, T-wave change and carrying the above 7 SNVs, should be the focus of prevention of sudden death.


Assuntos
Cardiopatias , Humanos , Sequenciamento do Exoma , China , Morte Súbita , Mutação
2.
Molecules ; 28(11)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37298817

RESUMO

Pulmonary fibrosis is a chronic, progressive, and fatal disease of the interstitial lung. There is currently a lack of efficient therapy to reverse the prognosis of patients. In this study, a fucoidan from Costaria costata was isolated, and its anti-idiopathic fibrosis activity was investigated both in vitro and in vivo. The chemical composition analysis showed that C. costata polysaccharide (CCP) consists of galactose and fucose as the main monosaccharides with a sulfate group content of 18.54%. Further study found that CCP could resist TGF-ß1-induced epithelial-mesenchymal transition (EMT) in A549 cells by inhibiting the TGF-ß/Smad and PI3K/AKT/mTOR signaling pathways. Moreover, in vivo study found that CCP treatment alleviated bleomycin (BLM)-stimulated fibrosis and inflammation in mice lung tissue. In conclusion, the present study suggests that CCP could protect the lung from fibrosis by relieving the EMT process and inflammation in lung cells.


Assuntos
Fibrose Pulmonar Idiopática , Fosfatidilinositol 3-Quinases , Camundongos , Animais , Fosfatidilinositol 3-Quinases/metabolismo , Pulmão/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Polissacarídeos/metabolismo , Fibrose , Fibrose Pulmonar Idiopática/metabolismo , Transição Epitelial-Mesenquimal , Inflamação/metabolismo , Bleomicina
3.
Ecotoxicol Environ Saf ; 188: 109756, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31711776

RESUMO

Soil co-contaminated with heavy metals and organics is often difficult to remediate. In this study, pot experiments were conducted to investigate the concurrent removal of cadmium (Cd, two levels: CdL [10 mg kg-1] and CdH [50 mg kg-1]) and trichlorfon (TCF, 100 mg kg-1) from co-contaminated soil by comparing the following remediation methods: natural remediation (NR), soil inoculated with Aspergillus sydowii (AS), soil planted with Brassica juncea (BJ), and soil planted with B. juncea and inoculated with A. sydowii (BJ-AS). The physiological responses of B. juncea and soil enzyme activities after remediation were also studied. B. juncea grew well in co-contaminated soil at both Cd levels. The biomass and chlorophyll content of B. juncea in CdH soil were lower than those in CdL soil, whereas the malondialdehyde content and activities of catalase, peroxidase and superoxide dismutase of B. juncea in CdH soil were higher than those in CdL soil. Cd accumulation in B. juncea was high in CdH soil, whereas high Cd removal efficiency was observed in CdL soil. TCF could be thoroughly degraded within 35 days in NR at both Cd-level soils. AS, BJ and BJ-AS promoted TCF degradation and enhanced the activities of catalase, urease, sucrase and alkaline phosphatase in soil compared with the NR. BJ-AS showed the highest phytoextraction ratio (3.32% in CdL and 1.34% in CdH soil) and TCF degradation rate (half-life of 2.18 and 2.37 days in CdL and CdH soil, respectively). These results demonstrate that BJ-AS could effectively remove Cd and TCF from soil and is thus a feasible technology for the bioremediation of these co-contaminated soil.


Assuntos
Aspergillus/crescimento & desenvolvimento , Cádmio/análise , Mostardeira/crescimento & desenvolvimento , Poluentes do Solo/análise , Solo/química , Triclorfon/análise , Aspergillus/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Catalase/metabolismo , Malondialdeído/metabolismo , Mostardeira/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Triclorfon/metabolismo
4.
Ecotoxicol Environ Saf ; 198: 110648, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32388188

RESUMO

Microalgae have been used for the removal of heavy metals or synthetic organics; however, the simultaneous removal of both types of compounds is always technically difficult. In this study, a green algae, Chlamydomonas reinhardtii, was first used to simultaneously remove hexavalent chromium [Cr(VI)] and o-nitrophenol (ONP), and the balance among biomass, oxidative damage and removal rate was also investigated. The results showed that treatment with Cr(VI) or ONP decreased the photosynthetic and superoxide dismutase activities and increased the production of reactive oxygen species (ROS) and malondialdehyde content. However, combined treatment with Cr(VI) (≤4 mg/L) and ONP (≤15 mg/L) significantly decreased ROS generation and alleviated cell damage in C. reinhardtii. In addition, the removal rates of Cr(VI) and ONP by C. reinhardtii cells significantly increased from 37.4% to 54.9% and from 35.8% to 45.9%, respectively, and the cells could be reused at least four times. Moreover, the increased acidity in the medium and Cr(VI) reductase content in C. reinhardtii caused Cr(VI) to be reduced to Cr(III). The addition of an exogenous antioxidant decreased the removal rates of Cr(VI) and ONP. These results indicated that the presence of Cr(VI) could induce ROS generation in C. reinhardtii and enhance ONP degradation, which consumed ROS, alleviated cell damage, and thus benefited Cr(VI) reduction. As a result, C. reinhardtii could be used as a theoretical candidate for the simultaneous removal of combined Cr(VI) and ONP contamination.


Assuntos
Biodegradação Ambiental , Chlamydomonas reinhardtii/metabolismo , Cromo/metabolismo , Poluentes Ambientais/metabolismo , Nitrofenóis/metabolismo , Biomassa , Metais Pesados/metabolismo
5.
Ecotoxicol Environ Saf ; 178: 195-201, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31009925

RESUMO

The increased anthropogenic activities in the Tibetan Plateau may threaten the river environmental safety. However, limited information is available on the Lhasa River in the Tibetan Plateau, which is known as the remaining pure land on Earth. Here, we firstly investigated the distribution patterns of bacterial and archaeal communities in sediments in response to dam construction and sewage discharge along the reaches of the Lhasa River. The total organic carbon, total Nitrogen (N), nitrate and ammonium contents and the relative abundance of bacteria and archaea significantly increased in reservoir sites in comparison with sites below dam, and they also gradually increased from upstream to downstream in sewage discharge sites. By contrast, the diversity of sediment bacteria and archaea in reservoir sites were significantly less than that in sites below dam and sewage discharge sites at Operational Taxonomic Units (OTUs) level. The dominant species were water-bloom cyanobacteria in the reservoir area of Zhikong Dam and Proteobacteria in the sewage discharge sites, which were significantly correlated with the nutrient concentration. The abundance of nitrogen functional genes significantly also increased in reservoir sites and the downstream of sewage discharge areas. These results suggested that dam construction and sewage discharge caused the increase of sediment bacterial communities and nutrient levels and potentially induced eutrophication in the Lhasa River.


Assuntos
Archaea/isolamento & purificação , Sedimentos Geológicos/microbiologia , Proteobactérias/isolamento & purificação , Rios/química , Rios/microbiologia , Esgotos/microbiologia , Compostos de Amônio/análise , Archaea/genética , Eutrofização , Nitrogênio/análise , Proteobactérias/genética , RNA Ribossômico 16S/genética , Tibet , Poluentes Químicos da Água/análise
6.
Nucleic Acids Res ; 44(19): 9131-9141, 2016 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-27365050

RESUMO

Linker histones are an integral component of chromatin but how these proteins promote assembly of chromatin fibers and higher order structures and regulate gene expression remains an open question. Using Förster resonance energy transfer (FRET) approaches we find that association of a linker histone with oligonucleosomal arrays induces condensation of the intrinsically disordered H1 CTD in a manner consistent with adoption of a defined fold or ensemble of folds in the bound state. However, H1 CTD structure when bound to nucleosomes in arrays is distinct from that induced upon H1 association with mononucleosomes or bare double stranded DNA. Moreover, the H1 CTD becomes more condensed upon condensation of extended nucleosome arrays to the contacting zig-zag form found in moderate salts, but does not detectably change during folding to fully compacted chromatin fibers. We provide evidence that linker DNA conformation is a key determinant of H1 CTD structure and that constraints imposed by neighboring nucleosomes cause linker DNAs to adopt distinct trajectories in oligonucleosomes compared to H1-bound mononucleosomes. Finally, inter-molecular FRET between H1s within fully condensed nucleosome arrays suggests a regular spatial arrangement for the H1 CTD within the 30 nm chromatin fiber.


Assuntos
Cromatina/química , DNA/química , Histonas/química , Conformação de Ácido Nucleico , Conformação Proteica , Animais , Cromatina/metabolismo , DNA/metabolismo , Transferência Ressonante de Energia de Fluorescência , Histonas/genética , Histonas/metabolismo , Nucleossomos/química , Nucleossomos/genética , Nucleossomos/metabolismo , Ligação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
7.
Nucleic Acids Res ; 43(17): e111, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26013809

RESUMO

Structural dynamics of nucleic acid and protein is an important physical basis of their functions. These motions are often very difficult to synchronize and too fast to be clearly resolved with the currently available single molecule methods. Here we demonstrate a novel hybrid single molecule approach combining stochastic data analysis with fluorescence correlation that enables investigations of sub-ms unsynchronized structural dynamics of macromolecules. Based on the method, we report the first direct evidence of spontaneous DNA motions at the nucleosome termini. The nucleosome, comprising DNA and a histone core, is the fundamental packing unit of eukaryotic genes that must be accessed during various genome transactions. Spontaneous DNA opening at the nucleosome termini has long been hypothesized to enable gene access in the nucleosome, but has yet to be directly observed. Our approach reveals that DNA termini in the nucleosome open and close repeatedly at 0.1-1 ms(-1). The kinetics depends on salt concentration and DNA-histone interactions but not much on DNA sequence, suggesting that this dynamics is universal and imposes the kinetic limit to gene access. These results clearly demonstrate that our method provides an efficient and robust means to investigate unsynchronized structural changes of DNA at a sub-ms time resolution.


Assuntos
DNA/química , Transferência Ressonante de Energia de Fluorescência/métodos , Nucleossomos/química , Corantes Fluorescentes , Funções Verossimilhança , Movimento (Física) , Fótons
8.
Biochemistry ; 55(14): 2069-77, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-27010485

RESUMO

Linker histone H1 regulates chromatin structure and gene expression. Investigating the dynamics and stoichiometry of binding of H1 to DNA and the nucleosome is crucial to elucidating its functions. Because of the abundant positive charges and the strong self-affinity of H1, quantitative in vitro studies of its binding to DNA and the nucleosome have generated results that vary widely and, therefore, should be interpreted in a system specific manner. We sought to overcome this limitation by developing a specially passivated microscope slide surface to monitor binding of H1 to DNA and the nucleosome at a single-molecule level. According to our measurements, the stoichiometry of binding of H1 to DNA and the nucleosome is very heterogeneous with a wide distribution whose averages are in reasonable agreement with previously published values. Our study also revealed that H1 does not dissociate from DNA or the nucleosome on a time scale of tens of minutes. We found that histone chaperone Nap1 readily dissociates H1 from DNA and superstoichiometrically bound H1 from the nucleosome, supporting a hypothesis whereby histone chaperones contribute to the regulation of the H1 profile in chromatin.


Assuntos
DNA/química , Histonas/química , Modelos Moleculares , Proteína 1 de Modelagem do Nucleossomo/química , Nucleossomos/química , Proteínas de Xenopus/química , Substituição de Aminoácidos , Animais , Ligação Competitiva , DNA/metabolismo , Histonas/genética , Histonas/metabolismo , Proteínas Imobilizadas/química , Proteínas Imobilizadas/genética , Proteínas Imobilizadas/metabolismo , Cinética , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Lipossomos , Mutação , Conformação de Ácido Nucleico , Proteína 1 de Modelagem do Nucleossomo/genética , Proteína 1 de Modelagem do Nucleossomo/metabolismo , Nucleossomos/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Multimerização Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis
9.
J Biol Chem ; 289(49): 33827-37, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25294883

RESUMO

The structure of eukaryotic chromatin directly influences gene function, and is regulated by chemical modifications of the core histone proteins. Modification of the human histone H4 N-terminal tail region by the small ubiquitin-like modifier protein, SUMO-3, is associated with transcription repression. However, the direct effect of sumoylation on chromatin structure and function remains unknown. Therefore, we employed a disulfide-directed strategy to generate H4 homogenously and site-specifically sumoylated at Lys-12 (suH4ss). Chromatin compaction and oligomerization assays with nucleosomal arrays containing suH4ss established that SUMO-3 inhibits array folding and higher order oligomerization, which underlie chromatin fiber formation. Moreover, the effect of sumoylation differed from that of acetylation, and could be recapitulated with the structurally similar protein ubiquitin. Mechanistic studies at the level of single nucleosomes revealed that, unlike acetylation, the effect of SUMO-3 arises from the attenuation of long-range internucleosomal interactions more than from the destabilization of a compacted dinucleosome state. Altogether, our results present the first insight on the direct structural effects of histone H4 sumoylation and reveal a novel mechanism by which SUMO-3 inhibits chromatin compaction.


Assuntos
Histonas/química , Lisina/química , Nucleossomos/química , Processamento de Proteína Pós-Traducional , Ubiquitina/química , Acetilação , Montagem e Desmontagem da Cromatina , Dissulfetos/química , Escherichia coli/genética , Escherichia coli/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Cinética , Lisina/metabolismo , Modelos Moleculares , Nucleossomos/genética , Nucleossomos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Sumoilação , Transcrição Gênica , Ubiquitina/genética , Ubiquitina/metabolismo
10.
Sci Total Environ ; 857(Pt 3): 159690, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36302410

RESUMO

The ecotoxicological effects of microplastics, a new and widespread ecosystem pollutant, have been extensively reported. However, it remains unclear whether soil fauna transfer microplastics and whether migration behaviours influence subsequent ecological functions in terrestrial ecosystems. We investigated the transfer patterns of microplastics and their adsorbed substances by soil animals (the springtail, Folsomia candida) and the effect of the transfer on the decomposition of soil organic matter through a standardized cotton strip assay. The results showed that springtails had a strong ability to transfer microplastics into the soil. The adsorbed nutrient (nitrogen; N), pollutant (cadmium; Cd), and green fluorescent Escherichia coli (GFP-E. coli) were also transferred with the microplastics. In addition, cotton strip decomposition was accelerated when the microplastics adsorbed N, but the adsorption of Cd decreased decomposition. These ecological effects were particularly strong for small microplastics. Microplastic transfer regulated soil bacterial communities, promoting the growth of Ascomycota fungi and inhibiting that of Basidiomycota, leading to cotton strip decomposition. Thus, microplastic pollution may occur at one site, but microplastics can be transferred anywhere in terrestrial ecosystems by soil animals and adsorb other substances, including nutrients and pollutants, that affect ecosystem function. Therefore, more studies on the migration behaviour of microplastics are necessary.


Assuntos
Microplásticos , Poluentes do Solo , Animais , Solo , Plásticos , Ecossistema , Poluentes do Solo/toxicidade , Cádmio , Escherichia coli
11.
Artigo em Inglês | MEDLINE | ID: mdl-36901319

RESUMO

Spartina alterniflora is considered an invasive species that has affected the biogeochemical circle of carbon in coastal wetlands around the world. Nevertheless, it is still unclear how S. alternation invasion affects the carbon storage capacity of coastal wetlands as carbon pools through bacterial changes. Herein, bacterial communities and soil carbon content in coastal wetland native areas and S. alterniflora invasion areas were detected. It was found that an S. alterniflora invasion brought more organic carbon and resulted in the increase in Proteobacteria in bare flats and Sueada salsa areas. When decomposition capacity was not sufficient, large amounts of organic carbon may be stored in specific chemical forms, such as monosaccharides, carboxylic acids, alcohols, etc. The results have also shown that soil bacterial communities were highly similar between the bare flat and S. alterniflora invasion area, which is extremely conducive to the rapid growth of S. alterniflora. However, an S. alterniflora invasion would decrease total carbon contents and inorganic carbon contents in the Sueada salsa area. This is not conducive to the stability of the soil carbon pool and soil health. These findings may complement, to some extent, the shortcomings of the interaction between S. alterniflora and bacterial communities, and their joint effect on soil carbon storage.


Assuntos
Solo , Áreas Alagadas , Solo/química , Carbono/análise , Poaceae , Espécies Introduzidas , Bactérias , China
12.
J Biol Chem ; 286(13): 11099-109, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21282115

RESUMO

We characterized the effect of histone acetylation on the structure of a nucleosome and the interactions between two nucleosomes. In this study, nucleosomes reconstituted with the Selex "Widom 601" sequence were acetylated with the Piccolo NuA4 complex, which acetylates mainly H4 N-terminal tail lysine residues and some H2A/H3 N-terminal tail lysine residues. Upon the acetylation, we observed directional unwrapping of nucleosomal DNA that accompanies topology change of the DNA. Interactions between two nucleosomes in solution were also monitored to discover multiple transient dinucleosomal states that can be categorized to short-lived and long-lived (∼1 s) states. The formation of dinucleosomes is strongly Mg(2+)-dependent, and unacetylated nucleosomes favor the formation of long-lived dinucleosomes 4-fold as much as the acetylated ones. These results suggest that the acetylation of histones by Piccolo NuA4 disturbs not only the structure of a nucleosome but also the interactions between two nucleosomes. Lastly, we suggest a structural model for a stable dinucleosomal state where the two nucleosomes are separated by ∼2 nm face-to-face and rotated by 34° with respect to each other.


Assuntos
DNA/metabolismo , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Magnésio/metabolismo , Complexos Multiproteicos/metabolismo , Nucleossomos/metabolismo , Acetilação , Animais , Histona Acetiltransferases/genética , Histonas/genética , Humanos , Complexos Multiproteicos/genética , Nucleossomos/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Xenopus
13.
Environ Sci Pollut Res Int ; 29(10): 13835-13844, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34599447

RESUMO

This study investigated the characteristics of the proliferation process of Microcystis aeruginosa and its changes to environmental pH values under different initial pH values and different initial inoculation densities. The results showed that although the initial pH value or the initial inoculation density was different, the pH values of the culture systems fluctuated up and down throughout the proliferation of M. aeruginosa, both on a daily and hourly time scale, and then tended to stabilize around the same value of 10.0 at the end of proliferation. The optimal pH value for the proliferation of M. aeruginosa was 9.55. This study creatively proposes that the period when the environmental pH value starts to rise rapidly toward 9.0 could be selected as an early warning period for a cyanobacterial outbreak, and the environmental pH value could be adjusted to below 8.0 to delay the outbreak. These results provide a scientific basis for further understanding the mechanism of cyanobacterial blooms and formulating pH-based control strategies.


Assuntos
Cianobactérias , Microcystis , Proliferação de Células , Concentração de Íons de Hidrogênio
14.
J Genet ; 1012022.
Artigo em Inglês | MEDLINE | ID: mdl-36226343

RESUMO

A novel missense variant (NM_005327.7: c.99C>G, p.Ile33Met) was discovered in 3-hydroxyacyl-CoA dehydrogenase (HADH), which is involved in congenital hyperinsulinism (CHI). This variant may be damaging or deleterious, as assessed using protein prediction software. This study aimed at the impact of this variant on islets and if it caused the leu-sensitive insulin secretion. The adenoassociated virus containing the HADH missense variant (p.Ile33Met), wild-type (WT) HADH or empty vector (EV) was constructed, and the rats were infected with it. Three weeks after the transfection, 15 rats were dissected to observe the effect of the variant on the islet tissue. Then we treated the remaining rats with leucine or sodium carboxymethyl cellulose (CMC-Na) by gavage and drew blood from the rat tail vein to detect the variations in blood glucose, serum insulin and serum glucagon. Further, we dissected the rats to observe the fluctuation of insulin and glucagon contents in pancreatic islets under the combined action of leucine and p.Ile33Met. Insulin and glucagon were observed in the islet tissue under an inverted fluorescence microscope, serum insulin and glucagon were detected by ELISA, and the blood glucose value was determined using a Roche glucometer. The positive area and average gray value of islet fluorescence pictures were analysed using the software Image J (USA). Rats expressing p.Ile33Met showed significantly higher insulin and glucagon content, as well as the islet area, compared to WT and EV rats. Moreover, after intragastric administration of leucine, the serum insulin content of the variant rats increased but the blood sugar level decreased significantly. Meanwhile, there was an appreciable decrease in the insulin content in rat pancreatic islet tissues. Our results suggest that the variant NM_005327.7: c.99C>G promotes the proliferation of pancreatic islets, enhances the secretion of insulin, and induces leu-sensitive hyperinsulinaemia.


Assuntos
Hiperinsulinismo , Ilhotas Pancreáticas , 3-Hidroxiacil-CoA Desidrogenase/metabolismo , Animais , Glicemia/metabolismo , Carboximetilcelulose Sódica/metabolismo , Carboximetilcelulose Sódica/farmacologia , Proliferação de Células , Glucagon/metabolismo , Glucagon/farmacologia , Glucose/metabolismo , Glucose/farmacologia , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Insulina , Ilhotas Pancreáticas/metabolismo , Leucina/metabolismo , Leucina/farmacologia , Ratos , Sódio/metabolismo , Sódio/farmacologia
15.
Environ Technol ; 42(28): 4405-4414, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32324107

RESUMO

The biodegradation of benzene series compounds is a difficult problem in environment pollution control, which is attributed to the deficiency of high efficiency bacteria and suitable embedding materials. In this study, the immobilized cells Rhodococcussp. strain PB-1 was used to synchronously biodegrade phenol and aniline by entrapped in sodium alginate (SA)-bamboo charcoal (BC)-chitosan acetate (CA) beads. The free cells of the strain PB-1 could completely degrade 1500 mg/L phenol or 800 mg/L aniline within 48 h, while the degradation rate of 2000 mg/L phenol and 1500 mg/L aniline was 35.76% and 68.06% at 72 h, respectively. The ortho-cleavage pathway was used to degrade phenol and aniline by strain PB-1. However, after entrapped with SA-BC-CA beads,the removal rate of 2000 mg/L phenol was 100% at 108 h, 1500 mg/L aniline was 100% at 62 h and 2000-3000 mg/L total toxic compounds was over 95% at 120 h. These beads could be used four times and were more effective than SA or SA-BC beads. The SA-BC-CA beads could remarkably improve the stability and degradation efficiency of strain PB-1, and thus provide a potential application in the removal of phenol and aniline in wastewater.


Assuntos
Quitosana , Rhodococcus , Alginatos , Compostos de Anilina , Carvão Vegetal , Fenol , Fenóis
16.
J Am Chem Soc ; 132(6): 1782-3, 2010 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-20095602

RESUMO

Cytosine methylation on CpG dinucleotides is an essential epigenetic modification in eukaryotes. How DNA methylation modulates nucleosome structure and dynamics has been a long-standing question. We implemented a single-molecule method to monitor the effects of DNA methylation on the structure and dynamics of mononucleosomes. Our studies show that DNA methylation induces a more compact and rigid nucleosome structure, providing a physical basis for how DNA methylation might contribute to regulating chromatin structure.


Assuntos
Metilação de DNA , Nucleossomos/química , Nucleossomos/metabolismo , Sequência de Bases , Ilhas de CpG , DNA/química , DNA/genética , DNA/metabolismo , Transferência Ressonante de Energia de Fluorescência , Modelos Moleculares , Dados de Sequência Molecular , Conformação de Ácido Nucleico
17.
Environ Sci Pollut Res Int ; 26(26): 26844-26854, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300993

RESUMO

Co-contamination with heavy metals and pesticides is a severe environmental problem, but little information is available regarding the simultaneous removal of these pollutants. In this study, we showed that Aspergillus sydowii strain PA F-2 isolated from soil contaminated with heavy metal and pesticides can simultaneously degrade trichlorfon (TCF) and adsorb Cd(II) from mineral salt medium. The maximum removal rates for TCF and Cd(II) were 55.52% and 57.90%, respectively, in the treatment containing 100 mg L-1 TCF and 2 mg L-1 Cd(II). As the initial Cd(II) concentration increased (2, 5, and 10 mg L-1), the PA F-2 biomass, TCF degradation rate, and Cd(II) adsorption efficiency decreased, whereas the Cd(II) adsorption capacity by PA F-2 increased. The addition of exogenous glucose and sucrose significantly increased the PA F-2 biomass as well as the removal of TCF and Cd(II). Moreover, the TCF degradation pathway and Cd(II) adsorption mechanism were investigated by gas chromatography-mass spectrometry, scanning electron microscopy, and Fourier transform infrared spectroscopy. These results suggest that PA F-2 has potential applications in the bioremediation of TCF and Cd(II) co-contamination.


Assuntos
Aspergillus/metabolismo , Cádmio/metabolismo , Triclorfon/metabolismo , Adsorção , Aspergillus/isolamento & purificação , Biodegradação Ambiental , Cádmio/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Glucose/metabolismo , Microscopia Eletrônica de Varredura , Microbiologia do Solo , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/metabolismo
18.
Aquat Toxicol ; 203: 172-178, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30138801

RESUMO

The co-contamination discharge of Phthalate esters (PAEs) by human activities and the increased UV radiation is increasing in aquatic ecosystems. However, little information is available about the combined detrimental effects of UV and PAEs on phytoplankton. In this study, the combined effects of UV-B irradiation and di-(2-ethylhexyl) phthalate (DEHP) on photosynthesis and antioxidant system of Scenedesmus acuminatus, and the DEHP degradation were investigated. Results showed that UV-B radiation decreased the chlorophyll a fluorescence yield, photosynthetic activity (Fv/Fm), pigment content and superoxide dismutase activity. This radiation also increased the reactive oxygen species (ROS) production and soluble protein and malondialdehyde contents. UV-B radiation with 10 mg L-1 DEHP improved the Fv/Fm and alleviated the cell damage of S. acuminatus, and the addition of high DEHP concentration (≥50 mg L-1) aggravated cell damage. The ROS generation also decreased with the increased DEHP concentration. UV-B radiation can effectively promote the DEHP degradation, with the highest degradation rate of 89.9% at an initial DEHP concentration of 10 mg L-1 within 6 h. This result may be attributed to that UV-B irradiance induced DEHP degradation under the regulation of ROS generated by S. acuminatus. Our findings will contribute to the understanding of the combined toxic mechanisms of UV-B and DEHP and in the evaluation of ecological environment risks for primary producers in aquatic ecosystems.


Assuntos
Dietilexilftalato/toxicidade , Recuperação e Remediação Ambiental , Scenedesmus/metabolismo , Raios Ultravioleta , Clorofila/metabolismo , Clorofila A , Fluorescência , Humanos , Malondialdeído/metabolismo , Oxirredução , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Scenedesmus/efeitos dos fármacos , Solubilidade , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
19.
J Phys Chem B ; 120(34): 8925-31, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27487198

RESUMO

Structural dynamics of a protein molecule is often critical to its function. Single-molecule methods provide efficient ways to investigate protein dynamics, although it is very challenging to achieve a millisecond or higher temporal resolution. Here we report spontaneous structural dynamics of the histone protein core in the nucleosome based on a single-molecule method that can reveal submillisecond dynamics by combining maximum likelihood estimation and fluorescence correlation spectroscopy. The nucleosome, comprising ∼147 bp DNA and an octameric histone protein core consisting of H2A, H2B, H3, and H4, is the fundamental packing unit of the eukaryotic genome. The nucleosome imposes a physical barrier that should be overcome during various DNA-templated processes. Structural fluctuation of the nucleosome in the histone core has been hypothesized to be required for nucleosome disassembly but has yet to be directly probed. Our results indicate that at 100 mM NaCl the histone H2A-H2B dimer dissociates from the histone core transiently once every 3.6 ± 0.6 ms and returns to its position within 2.0 ± 0.3 ms. We also found that the motion is facilitated upon H3K56 acetylation and inhibited upon replacing H2A with H2A.Z. These results provide the first direct examples of how a localized post-translational modification or an epigenetic variation affects the kinetic and thermodynamic stabilities of a macromolecular protein complex, which may directly contribute to its functions.


Assuntos
Nucleossomos/química , Proteínas/química , Proteínas/metabolismo , Imagem Individual de Molécula , Termodinâmica , Histonas/química , Histonas/metabolismo , Cinética
20.
J Hazard Mater ; 299: 702-10, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26282088

RESUMO

The pollution risk of dilute acidic sulfate effluent (DASE),which is discharged from titanium dioxide factories heavily every year, has sparked the recycling of sulfuric acid, iron and water. In this study, a new green recovery process for the DASE is proposed based on coupling solventextraction-oxidation-hydrolysis. Compared to the conventional ways, this innovative method allows the effective extraction of sulfuric acid and the precipitation of FexOy·nH2O in onestep without adding inorganic neutralizer or precipitant. Trioctylamine (TOA) in kerosene (20-50%) was used as an organic phase for solvent extraction. The hydrolytic productions and the raffinate purified by a cation exchange were evaluated using XRD and ICP-OES, respectively. The initial pH of 0.63 and Fe(II) concentration of 0.1 mol/L in the DASE, the volume ratio of organic toaqueous phase (O/A) of 3/1, and reaction temperature of 25 °C were determined as the optimal conditions. Under this conditions, Fe(II) was transformed as yellow precipitation which was characterized as α-FeOOH, and pH of raffinate was in the range of 3.6-3.8.

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