Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Appl Microbiol ; 132(1): 459-469, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34176204

RESUMO

AIMS: Dispersal effects on biofilms have not been adequately studied despite their strong potential impacts on biofilm development. We investigated the effects of dispersal on biofilm metacommunity. METHODS AND RESULTS: A bacterial consortium was allowed to form biofilms on 12 glass beads attached to disposable plates (compartmentalized or not), and biofilms were scrutinized on days 5, 10 and 15 using quantitative PCR and MiSeq sequencing. Biofilm population density was lesser by 2 orders of magnitude on day 5 when dispersal was allowed (p < 0.05). Then, the population rapidly increased by 4.4 orders with dispersal (p < 0.05) but did not change without dispersal. Community analyses revealed that dispersal increased the species diversity at all sampling times (p < 0.05). Dispersal affected the community structure and increased the homogeneity of local communities (p < 0.05). Distance-decay analysis showed that dispersal reduced the dissimilarity among local communities at all distance levels. Furthermore, dispersal reduced the variability of diversity, population and community structure. Network analysis revealed that dispersal increased the clustering coefficient, network density and connectivity. CONCLUSIONS: Dispersal increased the species diversity, population and interaction and reduced the variability of the diversity, population and structure among local communities. SIGNIFICANCE AND IMPACT OF STUDY: Our results suggest that dispersal can induce the niche complementarity and mass effects.


Assuntos
Biodiversidade , Ecossistema , Bactérias/genética , Biofilmes
2.
Int J Mol Sci ; 23(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36430156

RESUMO

The mRNA destabilizing factor tristetraprolin (TTP) functions as a tumor suppressor by down-regulating cancer-associated genes. TTP expression is significantly reduced in various cancers, which contributes to cancer processes. Enforced expression of TTP impairs tumorigenesis and abolishes maintenance of the malignant state, emphasizing the need to identify a TTP inducer in cancer cells. To search for novel candidate agents for inducing TTP in cancer cells, we screened a library containing 1019 natural compounds using MCF-7 breast cancer cells transfected with a reporter vector containing the TTP promoter upstream of the luciferase gene. We identified one molecule, of which the enantiomers are betamethasone 21-phosphate (BTM-21-P) and dexamethasone 21-phosphate (BTM-21-P), as a potent inducer of TTP in cancer cells. We confirmed that BTM-21-P, DXM-21-P, and dexamethasone (DXM) induced the expression of TTP in MDA-MB-231 cells in a glucocorticoid receptor (GR)-dependent manner. To identify potential pathways linking BTM-21-P and DXM-21-P to TTP induction, we performed an RNA sequencing-based transcriptome analysis of MDA-MB-231 cells at 3 h after treatment with these compounds. A heat map analysis of FPKM expression showed a similar expression pattern between cells treated with the two compounds. The KEGG pathway analysis results revealed that the upregulated DEGs were strongly associated with several pathways, including the Hippo signaling pathway, PI3K-Akt signaling pathway, FOXO signaling pathway, NF-κB signaling pathway, and p53 signaling pathway. Inhibition of the FOXO pathway using a FOXO1 inhibitor blocked the effects of BTM-21-P and DXM-21-P on the induction of TTP in MDA-MB-231 cells. We found that DXM enhanced the binding of FOXO1 to the TTP promoter in a GR-dependent manner. In conclusion, we identified a natural compound of which the enantiomers are DXM-21-P and BTM-21-P as a potent inducer of TTP in breast cancer cells. We also present new insights into the role of FOXO1 in the DXM-21-P- and BTM-21-P-induced expression of TTP in cancer cells.


Assuntos
Neoplasias , Tristetraprolina , Tristetraprolina/genética , Glucocorticoides/farmacologia , Fosfatidilinositol 3-Quinases , Receptores de Glucocorticoides/genética
3.
Microb Ecol ; 81(2): 549-552, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32948906

RESUMO

Interspecies interactions have a profound influence on spatial distribution of coexisting microbial species. We explored whether spatial variance of species distribution (SVSD) predicts the degree of interspecies interactions within a microbial metacommunity. Simulations were used to determine the relationships from random, lake, soil, and biofilm metacommunity datasets (1,000 times). All of the bacterial datasets showed a negative correlation between the habitat breadth (inverse to SVSD) and the numbers of total, positive, and negative interspecies interactions (P < 0.05); the only exception was the relationship between habitat breadth and negative interactions in the biofilm dataset. The random dataset had no significant relationships (P > 0.05). We repeated the simulations to determine the degree of correlation and reproducibility (100 times). Habitat breadth was negatively correlated with the total and positive interactions in all of the real datasets (P < 0.05), and the negative relationships persisted across repetitions. Despite variability in the slope of total interactions, the slope values of positive interactions were similar for the real datasets (- 19.9, - 19.2, and - 25.8 for lake, soil, and biofilm, respectively). In conclusion, our results demonstrate the patterns of species interaction-distribution and show that interspecies interactions are positively correlated with the SVSD.


Assuntos
Ecossistema , Interações Microbianas , Microbiota , Bactérias , Biofilmes , Lagos/microbiologia , Reprodutibilidade dos Testes , Microbiologia do Solo
4.
Microb Ecol ; 81(3): 657-672, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33094372

RESUMO

Plants may influence different aspects of the belowground microorganisms, including abundance, distribution, and interaction, in wetlands. Microbial communities were scrutinized in a 4-year-old restored wetland ecosystem with 5 distinct sites: a bare-soil site (10 local patches) and sites dominated by Miscanthus, Phragmites, Typha, and Zizania (20 patches per site). Ordination analysis revealed that plant-induced attributes (e.g., organic matter and total carbon and nitrogen) could explain the total environmental variance. Community comparisons showed that all groups (Bacteria, Fungi, Protista, and Metazoa) differed in community structure among the 5 sites (P < 0.05). Comparisons between the community and environmental ordination plots revealed that community structural variation among the sites correlated with the environmental change across all groups (R2 ≥ 0.61). This indicates that all groups were primarily influenced by plant detritus. In addition, correlation networks markedly varied in topology and composition among the sites across all groups. There was a strong coupling between the metacommunity and correlation network for both Bacteria and Fungi (R2 ≥ 0.58), indicating that the plants determined the spatial covariation patterns of microbial populations. Multi-group networks and group synchrony results revealed that Bacteria, Fungi, and Protista were synchronized with each other (R2 ≥ 0.52) as the key founders of the microbial systems, while Metazoa participated in the system only under Miscanthus. Our findings concluded that the plants shaped the communities by controlling the abundance and interaction of their populations.


Assuntos
Microbiota , Áreas Alagadas , Fungos/genética , Plantas , Solo , Microbiologia do Solo
5.
Biochem Biophys Res Commun ; 521(2): 389-394, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31668919

RESUMO

The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases 3 (PFKFB3) catalyzes the first committed rate-limiting step of glycolysis and is upregulated in cancer cells. The mechanism of PFKFB3 expression upregulation in cancer cells has not been fully elucidated. The PFKFB3 3'-UTR is reported to contain AU-rich elements (AREs) that are important for regulating PFKFB3 mRNA stability. However, the mechanisms by which PFKFB3 mRNA stability is determined by its 3'-UTR are not well known. We demonstrated that tristetraprolin (TTP), an ARE-binding protein, has a critical function regulating PFKFB3 mRNA stability. Our results showed that PFKFB3 mRNA contains three AREs in the 3'-UTR. TTP bound to the 3rd ARE and enhanced the decay of PFKFB3 mRNA. Overexpression of TTP decreased PFKFB3 expression and ATP levels but increased GSH level in cancer cells. Overexpression of PFKFB3 cDNA without the 3'-UTR rescued ATP level and GSH level in TTP-overexpressing cells. Our results suggested that TTP post-transcriptionally downregulated PFKFB3 expression and that overexpression of TTP may contribute to suppression of glycolysis and energy production of cancer cells in part by downregulating PFKFB3 expression.


Assuntos
Regulação para Baixo , Neoplasias/patologia , Fosfofrutoquinase-2/metabolismo , Tristetraprolina/fisiologia , Elementos Ricos em Adenilato e Uridilato , Glicólise , Humanos , Neoplasias/metabolismo , Fosfofrutoquinase-2/genética , Estabilidade de RNA , RNA Mensageiro , Transcrição Gênica , Tristetraprolina/metabolismo , Células Tumorais Cultivadas
6.
Biochem Biophys Res Commun ; 522(2): 402-407, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31767150

RESUMO

Recent research revealed that doxorubicin (DOX) decreased expression of programmed death-ligand 1 (PD-L1) in cancer cells. However, the detailed mechanisms underlying this effect are not well established. Here, we demonstrate that doxorubicin down-regulates PD-L1 expression through induction of AU-rich element (ARE) binding protein tristetraprolin (TTP) in cancer cells. PD-L1 mRNA contain three AREs within its 3'UTR. Doxorubicin induced expression of TTP, increased TTP binding to the 3rd ARE of the PD-L1 3'UTR, and increased decay of PD-L1 mRNA. Inhibition of TTP abrogates the inhibitory effect of doxorubicin on PD-L1 expression. Our data suggest that TTP plays a key role in doxorubicin-mediated down-regulation of PD-L1 by enhancing degradation of PD-L1 mRNA in cancer cells.


Assuntos
Antígeno B7-H1/genética , Doxorrubicina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Estabilidade de RNA/efeitos dos fármacos , Tristetraprolina/metabolismo , Regiões 3' não Traduzidas/genética , Elementos de Resposta Antioxidante/genética , Antígeno B7-H1/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo/genética , Humanos , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
7.
Microb Ecol ; 79(1): 84-97, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31250076

RESUMO

Quorum quenching (QQ) has received attention for the control of biofilms, e.g., biofilms that cause biofouling in membrane bioreactors (MBRs). Despite the efficacy of QQ on biofouling, it is elusive how QQ influences biofilm formation on membranes. A pilot-scale QQ-MBR and non-QQ-MBR were identically operated for 4 days and 8 days to destructively sample the membranes. QQ prolonged the membrane filterability by 43% with no harmful influence on MBR performance. qPCR showed no effect of QQ on microbial density during either of these time periods. Community comparisons revealed that QQ influenced the bacterial and fungal community structures, and the fungal structure corresponded with the bacterial structure. Metacommunity and spatial analyses showed that QQ induced structural variation rather than compositional variation of bacteria and fungi. Moreover, QQ considerably enhanced the bacterial dispersal across membrane during the early development. As the dispersal enhancement by QQ counteracted the ecological drift, it eliminated the distance-decay relationship, reflecting a neutral theory archetype of metacommunity. Network analyses showed that QQ substantially reduced the amount and magnitude of interactions, e.g., competition and cooperation, for bacteria and fungi, and weakened their network structures, irrespective of time. Additionally, QQ suppressed the growth of specific microbial species (e.g., Acinetobacter), abundant and widespread at the early stage. These findings suggest that QQ influenced the community dynamics at the regional and local levels, correspondingly the ecological selection and dispersal processes, during the biofilm development.


Assuntos
Biofilmes , Reatores Biológicos/microbiologia , Fungos/fisiologia , Percepção de Quorum , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Fenômenos Fisiológicos Bacterianos , Fungos/classificação , Fungos/genética , Fungos/crescimento & desenvolvimento , Membranas Artificiais
8.
Microb Ecol ; 79(4): 801-814, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31705158

RESUMO

Freshwater planktonic communities comprise a tremendous diversity of microorganisms. This study investigated the distribution patterns of microbial kingdoms (bacteria, fungi, protists, and microbial metazoans) within a lake ecosystem. Water samples were collected from 50 sites along the shoreline in a lake during an early eutrophication period, and MiSeq sequencing was performed with different marker genes. Metacommunity analyses revealed a bimodal occupancy-frequency distribution and a Clementsian gradient persisting throughout all microbial kingdoms, suggesting similar regional processes in all kingdoms. Variation partitioning revealed that environmental characteristics, macrophyte/macroinvertebrate composition, space coordinates, and distance-based Moran's eigenvector maps (dbMEM) together could explain up to 29% of the community variances in microbial kingdoms. Kingdom synchrony results showed strong couplings between kingdoms (R2 ≥ 0.31), except between Fungi and Metazoa (R2 = 0.09). Another variation partitioning revealed that microbial kingdoms could well explain their community variances up to 73%. Interestingly, the kingdom Protista was best synchronized with the other kingdoms. A correlation network showed that positive associations between kingdoms outnumbered the negative ones and that the kingdom Protista acted as a hub among kingdoms. Module analysis showed that network modules included multi-kingdom associations that were prevalent. Our findings suggest that protists coordinate community assembly and distribution of other kingdoms, and inter-kingdom interactions are a key determinant in shaping their community structures in a freshwater lake.


Assuntos
Lagos/microbiologia , Microbiota , Animais , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Lagos/parasitologia , República da Coreia , Análise Espacial
9.
Environ Res ; 183: 109230, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32058145

RESUMO

Particulate matter (PM), the collection of all liquid and solid particles suspended in air, includes both organic and inorganic particles, many of which are health-hazards. PM particles with a diameter equal to or less than 2.5 µm (PM2.5) is a form of air pollutant that causes significant lung damage when inhaled. Maslinic acid (MA) prevents oxidative stress and pro-inflammatory cytokine generation, but there is little information available regarding its role in PM-induced lung injury. Therefore, the purpose of this study was to determine the protective activity of MA against PM2.5-induced lung injury. The mice were divided into seven groups (n = 10 each): a mock control group, an MA control (0.8 mg/kg mouse body weight) group, an opted PM2.5 produced from diesel (10 mg/kg mouse body weight) group, a diesel PM2.5+MA (0.2, 0.4, 0.6, and 0.8 mg/kg mouse body weight) groups. Mice were treated with MA via tail-vein injection 30 min after the intratracheal instillation of a diesel PM2.5. Changes in the wet/dry weight ratio of the lung tissue, total protein/total cell and lymphocyte counts, inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), vascular permeability, and histology were monitored in diesel PM2.5-treated mice. The results showed that MA reduced pathological lung injury, the wet/dry weight ratio of the lung tissue, and hyperpermeability caused by diesel PM2.5. MA also inhibited diesel PM2.5-induced myeloperoxidase (MPO) activity in the lung tissue, decreased the levels of diesel PM2.5-induced inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, reduced nitric oxide (NO) and total protein in the BALF, and effectively attenuated diesel PM2.5-induced increases in the number of lymphocytes in the BALF. In addition, MA increased the protein phosphorylation of the mammalian target of rapamycin (mTOR) and dramatically suppressed diesel PM2.5-stimulated expression of toll-like receptor 4 (TLR4), MyD88, and the autophagy-related proteins LC3 II and Beclin 1. In conclusion, these findings indicate that MA has a critical anti-inflammatory effect due to its ability to regulate both the TLR4-MyD88 and mTOR-autophagy pathways and may thus be a potential therapeutic agent against diesel PM2.5-induced lung injury.


Assuntos
Autofagia , Lesão Pulmonar , Material Particulado , Transdução de Sinais , Serina-Treonina Quinases TOR , Receptor 4 Toll-Like , Triterpenos , Animais , Líquido da Lavagem Broncoalveolar , Citocinas , Pulmão/efeitos dos fármacos , Camundongos , Material Particulado/toxicidade , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/efeitos dos fármacos , Receptor 4 Toll-Like/efeitos dos fármacos , Triterpenos/farmacologia
10.
J Asian Nat Prod Res ; 22(4): 386-396, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30821482

RESUMO

The aim of this study was to investigate the effects of sulforaphane (SFN) on lipopolysaccharide (LPS)-induced liver failure, and to elucidate underlying mechanisms. SFN, a natural isothiocyanate present in cruciferous vegetables such as broccoli and cabbage, is effective in preventing carcinogenesis, diabetes, and inflammatory responses. Mice were treated intravenously with SFN at 12 h after LPS treatment. LPS significantly increased mortality, serum levels of liver damage markers, and inflammatory cytokines, and toll-like receptor 4 (TLR4) protein expression, which were reduced by SFN. Our results suggest that SFN protects against LPS-induced liver damage, indicating its potential to treat liver diseases.


Assuntos
Isotiocianatos , Lipopolissacarídeos , Animais , Fígado , Camundongos , Estrutura Molecular , Sulfóxidos
11.
J Cell Biochem ; 120(1): 928-939, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30160785

RESUMO

Ferroptosis is considered genetically and biochemically distinct from other forms of cell death. In this study, we examined whether ferroptosis shares cell death pathways with other types of cell death. When human colon cancer HCT116, CX-1, and LS174T cells were treated with ferroptotic agents such as sorafenib (SRF), erastin, and artesunate, data from immunoblot assay showed that ferroptotic agents induced endoplasmic reticulum (ER) stress and the ER stress response-mediated expression of death receptor 5 (DR5), but not death receptor 4. An increase in the level of DR5, which is activated by binding to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and initiates apoptosis, was probably responsible for synergistic apoptosis when cells were treated with ferroptotic agent in combination with TRAIL. This collateral effect was suppressed in C/EBP (CCAAT-enhancer-binding protein)-homologous protein (CHOP)-deficient mouse embryonic fibroblasts or DR5 knockdown HCT116 cells, but not in p53-deficient HCT116 cells. The results from in vitro studies suggest the involvement of the p53-independent CHOP/DR5 axis in the synergistic apoptosis during the combinatorial treatment of ferroptotic agent and TRAIL. The synergistic apoptosis and regression of tumor growth were also observed in xenograft tumors when SRF and TRAIL were administered to tumor-bearing mice.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Ferroptose/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Regulação para Cima/efeitos dos fármacos , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Artesunato/farmacologia , Neoplasias do Colo/patologia , Sinergismo Farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Feminino , Técnicas de Silenciamento de Genes , Células HCT116 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Sorafenibe/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Fator de Transcrição CHOP/metabolismo , Carga Tumoral/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
J Toxicol Environ Health A ; 82(12): 727-740, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31342870

RESUMO

Particulate matter 2.5 (PM2.5), with an aerodynamic diameter of ≤2.5 µm, is the primary air pollutant that plays a key role associated with lung injury produced by loss of vascular barrier integrity. Dioscorea batatas Decne (Chinese yam), a perennial plant belonging to Dioscoreaceae family, is widely cultivated in tropical and subtropical regions across Asia. Both aerial parts and root of D. batatas are consumed for nutritional and medicinal purposes. The aim of this study was to (1) identify the bioactive compounds present in D. batatas peel which may be responsible for inhibition of PM2.5-induced pulmonary inflammation in mice and (2) examine in vitro mechanisms underlying the observed effects of these compounds on mouse lung microvascular endothelial cells. The measured parameters include permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology. Two phenanthrene compounds, 2,7-dihydroxy-4,6-dimethoxyphenanthrene (1) and 6,7-dihydroxy-2,4-dimethoxyphenanthrene (2) were isolated from D. batatas peels. Both these phenanthrene compounds exhibited significant scavenging activity against PM2.5-induced ROS and inhibited ROS-induced activation of p38 mitogen-activated protein kinase. In addition, enhancement of Akt pathway, involved in the maintenance of endothelial integrity, was noted. These phenanthrene compounds also reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid obtained from PM2.5-induced lung tissues. Evidence thus indicates that phenanthrene compounds derived from D. batatas may exhibit protective effects against PM2.5-induced inflammatory lung injury and vascular hyperpermeability in mice.


Assuntos
Dioscorea/química , Lesão Pulmonar/induzido quimicamente , Material Particulado/toxicidade , Fenantrenos/farmacologia , Extratos Vegetais/farmacologia , Animais , Líquido da Lavagem Broncoalveolar , Frutas/química , Regulação da Expressão Gênica/efeitos dos fármacos , Lesão Pulmonar/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Tamanho da Partícula , Fenantrenos/química , Fenantrenos/uso terapêutico , Fosforilação , Extratos Vegetais/química , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
13.
Chemistry ; 23(20): 4803-4809, 2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28009932

RESUMO

With regard to fluorescence quenching commonly observed during metal-ion detection, "turn-on" chemical sensing has been rarely reported, but could be extremely important because it facilitates the selective recognition of target objects of interest against a dark background. A metal-organic framework (MOF) chemosensor has been prepared that serves as an efficient platform for the selective detection of Cu2+ and Cd2+ ions over other metal ions. In particular, this framework shows the highest fluorescence enhancement (≈60-fold relative to Cd-free MOF) for the hazardous metal ion Cd2+ among luminescent MOFs and displays excellent reusability in repeated cycles. The direct diffusion of Cd2+ into the crystal pores has also been visualized for the first time.

14.
Appl Microbiol Biotechnol ; 99(1): 445-58, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25117548

RESUMO

Droplet digital PCR (ddPCR) is a new DNA quantification platform without an external DNA calibrator. This study examined methanogen communities in four full-scale anaerobic digesters treating municipal sewage sludge, using ddPCR with taxon-specific primer/TaqMan probe sets (5 orders, 11 families, and 13 genera), many of which were developed in this study. Total methanogen abundance was positively correlated with hydraulic retention time (HRT) and temperature (p < 0.05), though the effect of HRT was stronger (r = 0.864 vs. 0.682, respectively). Moreover, total abundance was strongly correlated with biogas production rate (r = 0.896). HRT was positively correlated with seven methanogenic taxa, while temperature was positively or negatively correlated with 13 taxa (p < 0.05). For instance, the predominant genera Methanosaeta and Methanosarcina were negatively and positively associated, respectively, with temperature only (p < 0.05). Redundancy analysis and principal component analysis using the absolute-abundance dataset indicated that only temperature explained the variability in the methanogen communities at all classification levels. Therefore, HRT was the most important operational factor to influence net methanogen abundance and activity, while temperature governed the composition of the methanogen community. ddPCR enabled absolute quantification of methanogens without the external DNA standards and linked methanogen communities and operational factors, suggesting that it is a promising tool for analyzing the microbial ecology of anaerobic digestion.


Assuntos
Archaea/isolamento & purificação , Reatores Biológicos/microbiologia , Biota , Metano/metabolismo , Técnicas Microbiológicas/métodos , Reação em Cadeia da Polimerase/métodos , Esgotos/microbiologia , Anaerobiose , Archaea/classificação , Archaea/genética , Biocombustíveis , Temperatura , Fatores de Tempo
15.
Appl Microbiol Biotechnol ; 98(13): 6105-13, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24831026

RESUMO

The newly developed droplet digital PCR (DD-PCR) has shown promise as a DNA quantification technology in medical diagnostic fields. This study evaluated the applicability of DD-PCR as a quantitative tool for soil DNA using quantitative real-time PCR (qRT-PCR) as a reference technology. Cupriavidus sp. MBT14 and Sphingopyxis sp. MD2 were used, and a primer/TaqMan probe set was designed for each (CupMBT and SphMD2, respectively). Standard curve analyses on tenfold dilution series showed that both qRT-PCR and DD-PCR exhibited excellent linearity (R (2) = 1.00) and PCR efficiency (≥92 %) across their detectable ranges. However, DD-PCR showed a tenfold greater sensitivity than qRT-PCR. MBT14 and MD2 were added to non-sterile soil at 0 ~ 5 × 10(8) and 0 ~ 5 × 10(7) cells per gram of soil, respectively (n = 5). This bacterial load test indicated that DD-PCR was more sensitive and discriminating than qRT-PCR. For instance, DD-PCR showed a gradual DNA increase from 14 to 141,160 MBT14 rDNA copies µL DNA extract(-1) as the bacterial load increased, while qRT-PCR could quantify the DNA (6,432 copies µL DNA(-1)) at ≥5 × 10(5) MBT14 per gram of soil. When temporal DNA changes were monitored for 3 weeks in the amended soils, the two technologies exhibited nearly identical changes over time. Linearity tests (y = a · x) revealed excellent quantitative agreement between the two technologies (a = 0.98, R (2) = 0.97 in the CupMBT set and a = 0.90, R (2) = 0.94 in the SphMD2 set). These results suggest that DD-PCR is a promising tool to examine temporal dynamics of microorganisms in complex environments.


Assuntos
Carga Bacteriana/métodos , Cupriavidus/crescimento & desenvolvimento , Reação em Cadeia da Polimerase/métodos , Microbiologia do Solo , Sphingomonadaceae/crescimento & desenvolvimento , Cupriavidus/genética , Dinâmica Populacional , Sensibilidade e Especificidade , Sphingomonadaceae/genética
16.
Appl Microbiol Biotechnol ; 98(7): 3275-86, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24287932

RESUMO

Temporal microbial succession was investigated in relation to the performance of a methane biofilter. A laboratory-scale biofilter packed with perlite was operated for 108 days, without a deliberate biomass control. The system performance was stable over the period with a mean elimination capacity of 1,563 g m(-3) day(-1), despite a temporal deterioration (45-56 days). Ribosomal-tag pyrosequencing showed that bacterial communities at days 14-28 were distinct from those of days 68-108. The accumulation of nonviable substances strongly coincided with the community change (R (2) > 0.97). Rhodobacter, Hydrogenophaga, and Methylomonas were dominated in the earlier period, while Methylocaldum and Methylococcus were abundant in the later period. The methanotrophic proportion gradually increased to 41 %, and type I methanotrophs became predominant over time. However, community structure and methanotrophic population density stably retained over time, allowing the system to keep the similar performance. Therefore, the perlite biofilter system was functionally rigid against the temporal microbial succession.


Assuntos
Bactérias/classificação , Biofilmes/crescimento & desenvolvimento , Biota , Filtração/métodos , Metano/metabolismo , Bactérias/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Recuperação e Remediação Ambiental/métodos , Dados de Sequência Molecular , Análise de Sequência de DNA
17.
Nat Commun ; 15(1): 2102, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453901

RESUMO

Nicotinamide adenine dinucleotide (NAD)+ serves as a crucial coenzyme in numerous essential biological reactions, and its cellular availability relies on the activity of the nicotinamide phosphoribosyltransferase (NAMPT)-catalyzed salvage pathway. Here we show that treatment with saturated fatty acids activates the NAD+ salvage pathway in hypothalamic astrocytes. Furthermore, inhibition of this pathway mitigates hypothalamic inflammation and attenuates the development of obesity in male mice fed a high-fat diet (HFD). Mechanistically, CD38 functions downstream of the NAD+ salvage pathway in hypothalamic astrocytes burdened with excess fat. The activation of the astrocytic NAMPT-NAD+-CD38 axis in response to fat overload induces proinflammatory responses in the hypothalamus. It also leads to aberrantly activated basal Ca2+ signals and compromised Ca2+ responses to metabolic hormones such as insulin, leptin, and glucagon-like peptide 1, ultimately resulting in dysfunctional hypothalamic astrocytes. Our findings highlight the significant contribution of the hypothalamic astrocytic NAD+ salvage pathway, along with its downstream CD38, to HFD-induced obesity.


Assuntos
Gorduras na Dieta , NAD , Masculino , Camundongos , Animais , NAD/metabolismo , Gorduras na Dieta/metabolismo , Astrócitos/metabolismo , Obesidade/metabolismo , Hipotálamo/metabolismo , Citocinas/metabolismo
18.
J Microbiol Biotechnol ; 33(3): 348-355, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36746918

RESUMO

Epifluorescence microscopy with image analysis was evaluated as a biofilm quantification method (i.e., quantification of surface area colonized by biofilms), in comparison with crystal violet (CV) staining. We performed different experiments to generate multispecies biofilms with natural and artificial bacterial assemblages. First, four species were inoculated daily in 16 different sequences to form biofilms (surface colonization, 0.1%-56.6%). Second, a 9-species assemblage was allowed to form biofilms under 10 acylase treatment episodes (33.8%-55.6%). The two methods comparably measured the quantitative variation in biofilms, exhibiting a strong positive relationship (R2 ≥ 0.7). Moreover, the two methods exhibited similar levels of variation coefficients. Finally, six synthetic and two natural consortia were allowed to form biofilms for 14 days, and their temporal dynamics were monitored. The two methods were comparable in quantifying four biofilms colonizing ≥18.7% (R2 ≥ 0.64), but not for the other biofilms colonizing ≤ 3.7% (R2 ≤ 0.25). In addition, the two methods exhibited comparable coefficients of variation in the four biofilms. Microscopy and CV staining comparably measured the quantitative variation of biofilms, exhibiting a strongly positive relationship, although microscopy cannot appropriately quantify the biofilms below the threshold colonization. Microscopy with image analysis is a promising approach for easily and rapidly estimating absolute quantity of multispecies biofilms.


Assuntos
Biofilmes , Microscopia , Bactérias
19.
Int J Womens Health ; 15: 1757-1769, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38020943

RESUMO

Background: Bochdalek hernia (BH) of congenital diaphragm hernia is infrequently seen in adults. Strangulation of the diaphragm hernia has been recognized as a severe complication. Among several factors, pregnancy is an important cause of diaphragm hernia's deterioration. However, nausea, vomiting, and upper abdominal pain are often considered non-specific pregnancy-related symptoms. Case Presentation: We report a case of a 39-year-old (gravida II, para I) multigravida woman with a delayed diagnosis of strangulated herniated viscera complicating total gastric gangrene at 26+1 weeks' gestation. The preoperative diagnosis was confirmed by an X-ray examination and magnetic resonance imaging (MRI). After identifying the size and severity of the herniated contents through video-assisted thoracoscopy (VAT), we immediately converted to abdominal laparotomy. Antenatal corticosteroids were administered simultaneously with diagnosis to promote fetal maturity. The fetal condition was maintained well in the maternal uterus during the operation. Careful monitoring of the fetus and the mother's clinical conditions should be performed during expectant management to achieve delayed delivery after maternal surgical correction. Delivery was completed through cesarean delivery at 27+1 weeks of gestation. Conclusion: Despite the rarity of maternal Bochdalek hernias during pregnancy, early diagnosis and appropriate treatment via multidisciplinary care are essential for maternal and fetal outcomes.

20.
Nat Commun ; 14(1): 1994, 2023 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-37031230

RESUMO

Nicotinamide adenine dinucleotide (NAD+) is an essential cofactor of critical enzymes including protein deacetylase sirtuins/SIRTs and its levels in mammalian cells rely on the nicotinamide phosphoribosyltransferase (NAMPT)-mediated salvage pathway. Intracellular NAMPT (iNAMPT) is secreted and found in the blood as extracellular NAMPT (eNAMPT). In the liver, the iNAMPT-NAD+ axis oscillates in a circadian manner and regulates the cellular clockwork. Here we show that the hypothalamic NAD+ levels show a distinct circadian fluctuation with a nocturnal rise in lean mice. This rhythm is in phase with that of plasma eNAMPT levels but not with that of hypothalamic iNAMPT levels. Chemical and genetic blockade of eNAMPT profoundly inhibit the nighttime elevations in hypothalamic NAD+ levels as well as those in locomotor activity (LMA) and energy expenditure (EE). Conversely, elevation of plasma eNAMPT by NAMPT administration increases hypothalamic NAD+ levels and stimulates LMA and EE via the hypothalamic NAD+-SIRT-FOXO1-melanocortin pathway. Notably, obese animals display a markedly blunted circadian oscillation in blood eNAMPT-hypothalamic NAD+-FOXO1 axis as well as LMA and EE. Our findings indicate that the eNAMPT regulation of hypothalamic NAD+ biosynthesis underlies circadian physiology and that this system can be significantly disrupted by obesity.


Assuntos
Citocinas , NAD , Camundongos , Animais , NAD/metabolismo , Citocinas/metabolismo , Fígado/metabolismo , Metabolismo Energético , Ritmo Circadiano , Locomoção , Mamíferos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA