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1.
Heliyon ; 6(5): e04039, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32478192

RESUMO

In this study, the architecture of a multilayer metallic material of iron-carbon alloys with an internal protector was developed based on theoretical studies. The operability of the proposed architecture was experimentally verified using gravimetry and electrochemical analysis. The internal position of the protector enabled the modification of the mechanism of corrosion. The stages of corrosion of the multilayer material were revealed; the material was observed as useable until the third layer was perforated. To demonstrate the obtained results, the authors conducted a set of experiments using X-ray microscopy and scanning electron microscopy with an electron probe analysis of the chemical composition. The cost of the developed material is within the same range as widely used corrosion-resistant stainless austenite steels; and in terms of corrosion resistance, this material is comparable to palladium, molybdenum, nickel, and Hastelloy.

2.
Data Brief ; 27: 104722, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31763390

RESUMO

The nitritation-anammox process, which involves partial aerobic oxidation of the ammonium to nitrite and following oxidation of ammonium by nitrite to molecular nitrogen, is an efficient and cost-effective approach for biological nitrogen removal from wastewater. To characterize the microbial communities involved in the nitrogen and carbon cycles in wastewater treatment bioreactors employing this process, we sequenced the metagenome of a sludge sample collected from the lab-scale nitritation-anammox sequencing-batch reactor. At the phylum level, Proteobacteria and Chloroflexi were the most numerous groups. Anammox bacteria belonged to the genus Candidatus Brocadia. The obtained data will help to investigate the taxonomical and functional diversity the microbial communities involved in nitritation-anammox process, and will be used for genome-based analysis of uncultured bacterial lineages. The raw sequencing data is available from the NCBI Sequence Read Archive (SRR9831403) database under the BioProject PRJN0A55627.

3.
Biochem Biophys Res Commun ; 509(3): 790-796, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30612734

RESUMO

Telomerase activity is regulated at the mRNA level by alternative splicing (AS) of its catalytic subunit hTERT. The aim of this study was to define the ability of splice-switching oligonucleotides (SSOs) that pair with hTERT pre-mRNA to induce AS and inhibit telomerase activity in human CD4+ T lymphocytes. SSOs that blocked the binding of a single splicing regulatory protein, SRp20 or SRp40, to its site within intron 8 of hTERT pre-mRNA demonstrated rather moderate capacities to induce AS and inhibit telomerase. However, a SSO that blocked the interaction of both SRp20 and SRp40 proteins with pre-mRNA was the most active. Cultivation of lymphocytes with spliced hTERT and inhibited telomerase resulted in the reduction of proliferative activity without significant induction of cell death. These results should facilitate further investigation of telomerase activity regulation, and antitelomerase SSOs could become promising agents for antiproliferative cell therapy.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Oligonucleotídeos/farmacologia , RNA Mensageiro/genética , Telomerase/genética , Adulto , Linfócitos T CD4-Positivos/metabolismo , Domínio Catalítico/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Oligonucleotídeos/administração & dosagem , Oligonucleotídeos/genética , Telomerase/química , Transfecção
4.
Biochimie ; 157: 158-176, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30521874

RESUMO

Apoptotic endonucleases act cooperatively to fragment DNA and ensure the irreversibility of apoptosis. However, very little is known regarding the potential regulatory links between endonucleases. Deoxyribonuclease 1 (DNase I) inactivation is caused by alternative splicing (AS) of DNase I pre-mRNA skipping exon 4, which occurs in response to EndoG overexpression in cells. The current study aimed to determine the role of EndoG in the regulation of DNase I mRNA AS and the modulation of its enzymatic activity. A strong correlation was identified between the EndoG expression levels and DNase I splice variants in human lymphocytes. EndoG overexpression in CD4+ T cells down-regulated the mRNA levels of the active full-length DNase I variant and up-regulated the levels of the non-active spliced variant, which acts in a dominant-negative fashion. DNase I AS was induced by the translocation of EndoG from mitochondria into nuclei during the development of apoptosis. The DNase I spliced variant was induced by recombinant EndoG or by incubation with EndoG-digested cellular RNA in an in vitro system with isolated cell nuclei. Using antisense DNA oligonucleotides, we identified a 72-base segment that spans the adjacent segments of exon 4 and intron 4 and appears to be responsible for the AS. DNase I-positive CD4+ T cells overexpressing EndoG demonstrated decreased progression towards bleomycin-induced apoptosis. Therefore, EndoG is an endonuclease with the unique ability to inactivate another endonuclease, DNase I, and to modulate the development of apoptosis.


Assuntos
Processamento Alternativo/fisiologia , Apoptose/fisiologia , Linfócitos T CD4-Positivos/enzimologia , Desoxirribonuclease I/biossíntese , Endodesoxirribonucleases/metabolismo , RNA Mensageiro/metabolismo , Adolescente , Adulto , Linfócitos T CD4-Positivos/citologia , Desoxirribonuclease I/genética , Endodesoxirribonucleases/genética , Feminino , Humanos , Masculino , RNA Mensageiro/genética
5.
Heliyon ; 4(8): e00731, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30128362

RESUMO

The paper estimates corrosion resistance of new multilayer metallic materials with internal protector against pitting. Using an electron microscope method, the mechanism of the layers' corrosive destruction has been experimentally substantiated. The authors have suggested chemical and electrochemical methods of accelerated corrosion tests allowing for determining the corrosion destruction rate. The electrochemical method reveals the limiting stage of the process and allows calculating the mass corrosion index and substantiating the choice of protector for the specific corrosive medium. The chemical method allows for quantitative assessment of the internal protector's effectiveness and for defining the multilayer/monometallic material corrosion resistance ratio.

6.
Mol Immunol ; 101: 229-244, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30025223

RESUMO

Regulatory T cells (Tregs) play a fundamental role in the maintenance of immunological tolerance by suppressing effector target T, B and NK lymphocytes. Contact-dependent suppression mechanisms have been well-studied, though contact-independent Treg activity is not fully understood. In the present study, we showed that human native Tregs, as well as induced ex vivo Tregs, can cause in vitro telomere-dependent senescence in target T, B and NK cells in a contact-independent manner. The co-cultivation of target cells with Tregs separated through porous membranes induced alternative splicing of the telomerase catalytic subunit hTERT (human Telomerase Reverse Transcriptase), which suppressed telomerase activity. Induction of the hTERT splicing variant was associated with increased expression of the apoptotic endonuclease EndoG, a splicing regulator. Inhibited telomerase in target cells co-cultivated with Tregs for a long period of time led to a decrease in their telomere lengths, cell cycle arrest, conversion of the target cells to replicative senescence and apoptotic death. Induced Tregs showed the ability to up-regulate EndoG expression, TERT alternative splicing and telomerase inhibition in mouse T, B and NK cells after in vivo administration. The results of the present study describe a novel mechanism of contact-independent Treg cell suppression that induces telomerase inhibition through the EndoG-provoked alternative splicing of hTERT and converts cells to senescence and apoptosis phenotypes.


Assuntos
Apoptose , Linfócitos T Reguladores/metabolismo , Telomerase/antagonistas & inibidores , Encurtamento do Telômero , Adulto , Processamento Alternativo , Animais , Morte Celular , Sobrevivência Celular , Feminino , Humanos , Camundongos Endogâmicos C57BL , Mucinas/metabolismo , Telomerase/metabolismo , Fatores de Tempo
7.
Cell Immunol ; 331: 146-160, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29935763

RESUMO

Regulatory T cells (Tregs) suppress the activity of effector T, B and NK lymphocytes and sustain immunological tolerance, but the proliferative activity of suppressed cells remains unexplored. In the present study, we report that mouse Tregs can induce replicative senescence and the death of responder mouse CD4+CD25- T cells, CD8+ T cells, B cells and NK cells in vitro and in vivo. Contact-independent in vitro co-cultivation with Tregs up-regulated endonuclease G (EndoG) expression and its translocation to the nucleus in responder cells. EndoG localization in the nucleus induced alternative mRNA splicing of the telomerase catalytic subunit Tert and telomerase inhibition. The lack of telomerase activity in proliferating cells led to telomere loss followed by the development of senescence and cell death. Injection of Tregs into mice resulted in EndoG-associated alternative splicing of Tert, telomerase inhibition, telomere loss, senescence development and increased cell death in vivo. The present study describes a novel contact-independent mechanism by which Tregs specify effector cell fate and provides new insights into cellular crosstalk related to immune suppression.


Assuntos
Apoptose/imunologia , Linfócitos B/imunologia , Células Matadoras Naturais/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Processamento Alternativo , Animais , Linfócitos B/metabolismo , Comunicação Celular/imunologia , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Cultivadas , Senescência Celular/genética , Senescência Celular/imunologia , Feminino , Células Matadoras Naturais/metabolismo , Camundongos Endogâmicos C57BL , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Telomerase/genética , Telomerase/imunologia , Telomerase/metabolismo , Telômero/genética , Telômero/imunologia , Telômero/metabolismo
8.
Environ Sci Pollut Res Int ; 25(8): 7315-7329, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29359248

RESUMO

Water is the most important and essential component of earth's ecosystem playing a vital role in the proper functioning of flora and fauna. But, our water resources are contaminating continuously. The whole world may be in great water scarcity after few decades. Graphene, a single-atom thick carbon nanosheet, and graphene nanomaterials have bright future in water treatment technologies due to their extraordinary properties. Only few papers describe the use of these materials in water treatment by adsorption, filtration, and photodegradation methods. This article presents a critical evaluation of the contribution of graphene nanomaterials in water treatment. Attempts have been made to discuss the future perspectives of these materials in water treatment. Besides, the efforts are made to discuss the nanotoxicity and hazards of graphene-based materials. The suggestions are given to explore the full potential of these materials along with precautions of nanotoxicity and its hazards. It was concluded that the future of graphene-based materials is quite bright.


Assuntos
Grafite/química , Nanoestruturas/química , Água , Purificação da Água
9.
Eur J Cell Biol ; 96(7): 653-664, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28886883

RESUMO

Telomerase activity is regulated by alternative splicing of its catalytic subunit human Telomerase Reverse Transcriptase (hTERT) mRNA. Induction of a non-active spliced hTERT leads to inhibition of telomerase activity. However, very little is known about the mechanism of hTERT mRNA alternative splicing. The aim of this study was to determine the role of the apoptotic endonuclease EndoG in alternative splicing of hTERT and telomerase activity. A strong correlation was identified between EndoG expression levels and hTERT splice variants in human CD4+ and CD8+ T lymphocytes. Overexpression of EndoG in CD4+ T cells down-regulated the expression of the active full-length hTERT variant and up-regulated expression of the non-active spliced variant. A reduction in full-length hTERT transcripts down-regulated telomerase activity. Long-term in vitro cultivation of EndoG-overexpressing CD4+ T cells led to dramatically shortened telomeres, conversion of cells into a replicative senescence state, and activation of the BCL2/BAX-associated apoptotic pathway finally leading to cell death. These data indicated the participation of EndoG in alternative mRNA splicing of the telomerase catalytic subunit hTERT, regulation of telomerase activity and determination of cell fate.


Assuntos
Processamento Alternativo/genética , Endonucleases/genética , Telomerase/genética , Telômero/genética , Apoptose/genética , Linfócitos T CD4-Positivos/metabolismo , Domínio Catalítico/genética , Regulação Enzimológica da Expressão Gênica , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , Proteína X Associada a bcl-2/genética
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