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1.
J Nutr ; 154(3): 896-907, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301957

RESUMO

BACKGROUND: Metallothioneins (MTs) have a strong affinity for zinc (Zn) and remain at a sufficiently high level in mitochondria. As the avian embryo is highly susceptible to oxidative damage and relatively easy to manipulate in a naturally closed chamber, it is an ideal model of the effects of oxidative stress on mitochondrial function. However, the protective roles and molecular mechanisms of Zn-inducible protein expression on mitochondrial function in response to various stressors are poorly understood. OBJECTIVES: The study aimed to investigate the mechanisms by which Zn-induced MT4 expression protects mitochondrial function and energy metabolism subjected to oxidative stress using the avian embryo and embryonic primary hepatocyte models. METHODS: First, we investigated whether MT4 expression alters mitochondrial function. Then, we examined the effects of Zn-induced MT4 overexpression and MT4 silencing on embryonic primary hepatocytes from breeder hens fed a normal Zn diet subjected to a tert-butyl hydroperoxide (BHP) oxidative stress challenge during incubation. In vivo, the avian embryos from hens fed the Zn-deficient and Zn-adequate diets were used to determine the protective roles of Zn-induced MT4 expression on the function of mitochondria exposed to oxidative stress induced by in ovo BHP injection. RESULTS: An in vitro study revealed that Zn-induced MT4 expression reduced reactive oxygen species accumulation in primary hepatocytes. MT4 silencing exacerbated BHP-mediated mitochondrial dysfunction whereas Zn-inducible MT4 overexpression mitigated it. Another in vivo study disclosed that maternal Zn-induced MT4 expression protected mitochondrial function in chick embryo hepatocytes against oxidative stress by inhibiting the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)/peroxisome proliferators-activated receptor-γ (PPAR-γ) pathway. CONCLUSION: This study underscores the potential protective roles of Zn-induced MT4 expression via the downregulation of the PGC-1α/PPAR-γ pathway on mitochondrial function stimulated by the stress challenge in the primary hepatocytes in an avian embryo model. Our findings suggested that Zn-induced MT4 expression could provide a new therapeutic target and preventive strategy for repairing mitochondrial dysfunction in disease.


Assuntos
Doenças Mitocondriais , Zinco , Embrião de Galinha , Animais , Feminino , Zinco/farmacologia , Zinco/metabolismo , Galinhas/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/farmacologia , Mitocôndrias/metabolismo , Estresse Oxidativo , Doenças Mitocondriais/metabolismo
2.
Surg Endosc ; 38(2): 648-658, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38012440

RESUMO

BACKGROUND: Portal vein system thrombosis (PVST) is a potentially fatal complication after splenectomy with esophagogastric devascularization (SED) in cirrhotic patients with portal hypertension. However, the impact of portal vein velocity (PVV) on PVST after SED remains unclear. Therefore, this study aims to explore this issue. METHODS: Consecutive cirrhotic patients with portal hypertension who underwent SED at Tongji Hospital between January 2010 and June 2022 were enrolled. The patients were divided into two groups based on the presence or absence of PVST, which was assessed using ultrasound or computed tomography after the operation. PVV was measured by duplex Doppler ultrasound within one week before surgery. The independent risk factors for PVST were analyzed using univariate and multivariate logistic regression analysis. A nomogram based on these variables was developed and internally validated using 1000 bootstrap resamples. RESULTS: A total of 562 cirrhotic patients with portal hypertension who underwent SED were included, and PVST occurred in 185 patients (32.9%). Multivariate logistic regression analysis showed that PVV was the strongest independent risk factor for PVST. The incidence of PVST was significantly higher in patients with PVV ≤ 16.5 cm/s than in those with PVV > 16.5 cm/s (76.2% vs. 8.5%, p < 0.0001). The PVV-based nomogram was internally validated and showed good performance (optimism-corrected c-statistic = 0.907). Decision curve and clinical impact curve analyses indicated that the nomogram provided a high clinical benefit. CONCLUSION: A nomogram based on PVV provided an excellent preoperative prediction of PVST after splenectomy with esophagogastric devascularization.


Assuntos
Hipertensão Portal , Trombose Venosa , Humanos , Veia Porta/patologia , Esplenectomia/efeitos adversos , Cirrose Hepática/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/etiologia , Hipertensão Portal/cirurgia , Hipertensão Portal/complicações
3.
Chem Biodivers ; 21(4): e202301711, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38372187

RESUMO

Stored products are constantly infested by insects, so finding eco-friendly bioinsecticides for insect management is important. The work aimed to assess the insecticidal and repellent activity of essential oil (EO) from Hedychium glabrum S. Q. Tong, Hedychium coronarium Koen., and Hedychium yunnanense Gagnep. against Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila. Results showed that 88 chemical components were identified in the extracted Hedychium EOs, indicating that they exhibited diversity in components. According to principal component analysis (PCA), the composition of the EO from the H. yunnanense stem and leaf (EOHYSL) was significantly different from other EOs due to the different organs and species. The biological activity also varied continuously with plant species and organs. Only the EO of H. yunnanense (EOHY) showed strong fumigant toxicity. While in the contact tests, EOHGR showed the strongest toxicity effect on L. bostrychophila, with a LC50 value of 71.76 µg/cm2, which was closest to the positive control (Pyrethrin). All EOs had remarkable repellent activities against the three target insects, and repellency increased with concentration. According to the results of the comprehensive score, EOHY had the highest potential, which ranged from 0.7999 to 0.8689. Thus, Hedychium EOs possess potential biorational traits to be biological insecticides.


Assuntos
Besouros , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Tribolium , Zingiberaceae , Animais , Óleos Voláteis/toxicidade , Óleos Voláteis/química , Insetos , Inseticidas/química , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química
4.
Chem Biodivers ; 20(12): e202301206, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37840218

RESUMO

Storage is a crucial part during grain production for the massive spoilage caused by stored product insects. Essential oils (EOs) of plant origin have been highly recommended to combating insects which are biodegradable and safe mode of action. Hence, to make the fullest use of natural resources, essential oils of different parts from Piper yunnanense (the whole part, PYW; fruits, PYF; leaves, PYL) and Piper boehmeriifolium (leaves, PBL) were extracted by steam distillation method in the present study. Gas chromatography-mass spectrometry (GC-MS) characterization revealed bicyclogermacrene (PYW), γ-muurolene (PYF), δ-cadinene (PYL) and methyl 4,7,10,13,16,19-docosahexaenoate (PBL) as the principal compound of each essential oil. Sesquiterpene hydrocarbons were also recognized as the richest class accounting for 56.3 %-94.9 % of the total oil. Three storage pests, Tribolium castaneum, Lasioderma serricorne and Liposceis bostrychophila, were exposed to different concentrations of EOs to determine their insecticidal effects. All tested samples performed modest contact toxicity in contrast to a bioactive ingredient pyrethrin, among which the most substantial effects were observed in PYF EOs against T. castaneum (35.84 µg/adult), PBL EOs against L. serricorne (15.76 µg/adult) and PYW EOs against L. bostrychophila (57.70 µg/cm2 ). In terms of repellency tests, essential oils of PYF at 78.63 nL/cm2 demonstrated to have a remarkable repellence against T. castaneum at 2h and 4h post-exposure. The investigations indicate diverse variations in the chemical profiles and insecticidal efficacies of P. yunnanense and P. boehmeriifolium EOs, providing more experimental evidence for the use of the Piper plants.


Assuntos
Besouros , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Piper , Tribolium , Animais , Óleos Voláteis/química , Insetos , Repelentes de Insetos/farmacologia , Repelentes de Insetos/química , Inseticidas/química
5.
J Cell Mol Med ; 26(11): 3269-3280, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35510614

RESUMO

Pulmonary fibrosis (PF) is a progressive interstitial lung disease with limited treatment options. The incidence and prevalence of PF is increasing with age, cell senescence has been proposed as a pathogenic driver, the clearance of senescent cells could improve lung function in PF. FOXO4-D-Retro-Inverso (FOXO4-DRI), a synthesis peptide, has been reported to selectively kill senescent cells in aged mice. However, it remains unknown if FOXO4-DRI could clear senescent cells in PF and reverse this disease. In this study, we explored the effect of FOXO4-DRI on bleomycin (BLM)-induced PF mouse model. We found that similar as the approved medication Pirfenidone, FOXO4-DRI decreased senescent cells, downregulated the expression of senescence-associated secretory phenotype (SASP) and attenuated BLM-induced morphological changes and collagen deposition. Furthermore, FOXO4-DRI could increase the percentage of type 2 alveolar epithelial cells (AEC2) and fibroblasts, and decrease the myofibroblasts in bleomycin (BLM)-induced PF mouse model. Compared with mouse and human lung fibroblast cell lines, FOXO4-DRI is inclined to kill TGF-ß-induced myofibroblast in vitro. The inhibited effect of FOXO4-DRI on myofibroblast lead to a downregulation of extracellular matrix (ECM) receptor interaction pathway in BLM-induced PF. Above all, FOXO4-DRI ameliorates BLM-induced PF in mouse and may be served as a viable therapeutic option for PF.


Assuntos
Fibrose Pulmonar , Animais , Bleomicina/efeitos adversos , Proteínas de Ciclo Celular/metabolismo , Modelos Animais de Doenças , Fibroblastos/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos/metabolismo , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/metabolismo
6.
Inorg Chem ; 61(32): 12652-12661, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35921656

RESUMO

The synergy of multiphoton fluorescence imaging (MP-FI) and magnetic resonance imaging (MRI) provides an imaging platform with high resolution and unlimited penetration depth for early disease detection. Herein, two kinds of terpyridine-Mn(II) complexes (FD-Mn-O2NO and FD-Mn-FD) possessing seven and six coordination modes, respectively, were designed rationally for photodynamic therapy (PDT) guided by MP-FI/MRI. The complexes obtain different multiphoton fluorescence/magnetic resonance properties by adjusting the number of terpyridine ligands. Among them, FD-Mn-FD exhibits the following superiorities: (1) The optimal three-photon excitation wavelength of FD-Mn-FD falls at 1450 nm (NIR-II), which brings high sensitivity and deep tissue penetration in MP-FI. (2) FD-Mn-FD has effective longitudinal relaxation efficiency (r1 = 2.6 m M-1 s-1), which can be used for T1-weighted MRI, overcoming the problems of limited tissue penetration depth and low spatial resolution. (3) FD-Mn-FD generates endogenous 1O2 under irradiation by 808 nm light, thereby enhancing the PDT effect in vitro and in vivo. To the best of our knowledge, the complex FD-Mn-FD is the first complex to guide PDT through MP-FI/MRI, providing a blueprint for accurate and effective early detection and timely treatment of the complex in the early stages of cancer.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Neoplasias/tratamento farmacológico , Fótons , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
7.
Mol Carcinog ; 60(8): 556-566, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34061408

RESUMO

The epithelial-mesenchymal transition (EMT) is a pivotal step involved in cancer recurrence and metastasis. In addition, the activation of the EMT program can induce a cancer stem cell (CSC)-like phenotype and programmed death-ligand 1 (PD-L1) expression in head and neck squamous cell carcinoma (HNSCC). The CMTM family has reported as an important regulator in this process. Here, we investigated the role of CMTM4 in HNSCC. We indicated that CMTM4 was overexpressed in human and mouse HNSCC samples and in HNSCC cell lines by immunohistochemistry and Western blot. A high expression level of CMTM4 was correlated with advanced lymph node metastasis and a negative prognosis. CMTM4-knockdown by small interfering RNA downregulated the EMT process and inhibited the migration and invasion abilities of tumor cells. Moreover, knockdown of CMTM4 decreased CSC-associated markers via the protein kinase B pathway. Notably, CMTM4-knockdown inhibited the expression of interferon-γ induced PD-L1 in HNSCC cells. A positive correlation was found between CMTM4 expression and CD8+ and PD-1+ cell density in the stroma. Our findings indicated that CMTM4 may play an important role in regulating EMT/CSC phenotypes and PD-L1 expression. This study may reinforce the interest in CMTM4 as a potential target for the prognosis and treatment of HNSCC.


Assuntos
Antígeno B7-H1/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Proteínas com Domínio MARVEL/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Metástase Linfática , Proteínas com Domínio MARVEL/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Microambiente Tumoral/genética
8.
Analyst ; 147(1): 66-71, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34821886

RESUMO

Lipid droplets (LDs) are dynamic multifunctional organelles that participate in the regulation of many metabolic processes, visualization of which is necessary for biological research. In this work, a series of two-photon responsive fluorescent probes (C-H, C-Br, and C-I) based on carbazole units were designed and synthesized. Thereinto, an iodine-modified carbazole derivative C-I exhibited an exciting lipid droplet targeting ability due to its excellent lipophilicity. Meanwhile, benefiting from its larger Stokes shift and two-photon absorption cross-section, C-I was employed for two-photon confocal laser scanning microscopy (CLSM) and stimulated emission depletion (STED) microscopy imaging to observe LDs more accurately. In addition, given the heavy atom effect, C-I can effectively generate reactive oxygen species (ROS) leading to cancer cell apoptosis under near-infrared light irradiation. Notably, we explained the process of cell apoptosis through in vitro simulation experiments. This study provides a promising platform for visualization of lipid droplets.


Assuntos
Gotículas Lipídicas , Fotoquimioterapia , Carbazóis , Halogênios , Microscopia Confocal
9.
Angew Chem Int Ed Engl ; 59(27): 10732-10745, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31746521

RESUMO

Lithium-sulfur (Li-S) batteries are highly regarded as the next-generation energy-storage devices because of their ultrahigh theoretical energy density of 2600 Wh kg-1 . Sulfurized polyacrylonitrile (SPAN) is considered a promising sulfur cathode to substitute carbon/sulfur (C/S) composites to afford higher Coulombic efficiency, improved cycling stability, and potential high-energy-density Li-SPAN batteries. However, the instability of the Li-metal anode threatens the performances of Li-SPAN batteries bringing limited lifespan and safety hazards. Li-metal can react with most kinds of electrolyte to generate a protective solid electrolyte interphase (SEI), electrolyte regulation is a widely accepted strategy to protect Li-metal anodes in rechargeable batteries. Herein, the basic principles and current challenges of Li-SPAN batteries are addressed. Recent advances on electrolyte regulation towards stable Li-metal anodes in Li-SPAN batteries are summarized to suggest design strategies of solvents, lithium salts, additives, and gel electrolyte. Finally, prospects for future electrolyte design and Li anode protection in Li-SPAN batteries are discussed.

10.
Planta ; 247(5): 1077-1087, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29350280

RESUMO

MAIN CONCLUSION: Six types of lignin-carbohydrate complex (LCC) fractions were isolated from Eucalyptus. The acidic dioxane treatment applied significantly improved the yield of LCCs. The extraction conditions had a limited impact on the LCC structures and linkages. Characterization of the lignin-carbohydrate complex (LCC) structures and linkages promises to offer insight on plant cell wall chemistry. In this case, Eucalyptus LCCs were extracted by aqueous dioxane, and then precipitated sequentially by 70% ethanol, 100% ethanol, and acidic water (pH = 2). The composition and structure of the six LCC fractions obtained by selective precipitation were investigated by sugar analysis, molecular weight determination, and 2D HSQC NMR. It was found that the acidic (0.05-M HCl) dioxane treatment significantly improved the yield of LCCs (66.4% based on Klason lignin), which was higher than the neutral aqueous dioxane extraction, and the extraction condition showed limited impact on the LCC structures and linkages. In the fractionation process, the low-molecular-weight LCCs containing a high content of carbohydrates (60.3-63.2%) were first precipitated by 70% ethanol from the extractable solution. The phenyl glycoside (PhGlc) bonds (13.0-17.0 per 100Ar) and highly acetylated xylans were observed in the fractions recovered by the precipitation with 100% ethanol. On the other hand, such xylan-rich LCCs exhibited the highest frequency of ß-O-4 linkages. The benzyl ether (BE) bonds were only detected in the fractions obtained by acidic water precipitation.


Assuntos
Carboidratos/isolamento & purificação , Eucalyptus/metabolismo , Lignina/isolamento & purificação , Metabolismo dos Carboidratos , Carboidratos/química , Precipitação Química , Dioxanos/uso terapêutico , Lignina/química , Lignina/metabolismo , Espectroscopia de Ressonância Magnética , Peso Molecular
11.
Plant Physiol ; 174(2): 1260-1273, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28438793

RESUMO

Brassinosteroids (BRs) are essential phytohormones regulating various developmental and physiological processes during normal growth and development. cog1-3D (cogwheel1-3D) was identified as an activation-tagged genetic modifier of bri1-5, an intermediate BR receptor mutant in Arabidopsis (Arabidopsis thaliana). COG1 encodes a Dof-type transcription factor found previously to act as a negative regulator of the phytochrome signaling pathway. cog1-3D single mutants show an elongated hypocotyl phenotype under light conditions. A loss-of-function mutant or inducible expression of a dominant negative form of COG1 in the wild type results in an opposite phenotype. A BR profile assay indicated that BR levels are elevated in cog1-3D seedlings. Quantitative reverse transcription-polymerase chain reaction analyses showed that several key BR biosynthetic genes are significantly up-regulated in cog1-3D compared with those of the wild type. Two basic helix-loop-helix transcription factors, PIF4 and PIF5, were found to be transcriptionally up-regulated in cog1-3D Genetic analysis indicated that PIF4 and PIF5 were required for COG1 to promote BR biosynthesis and hypocotyl elongation. Chromatin immunoprecipitation and electrophoretic mobility shift assays indicated that COG1 binds to the promoter regions of PIF4 and PIF5, and PIF4 and PIF5 bind to the promoter regions of key BR biosynthetic genes, such as DWF4 and BR6ox2, to directly promote their expression. These results demonstrated that COG1 regulates BR biosynthesis via up-regulating the transcription of PIF4 and PIF5.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Brassinosteroides/biossíntese , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Vias Biossintéticas/genética , Metanossulfonato de Etila , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Modelos Biológicos , Fenótipo , Mutação Puntual/genética , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética , Supressão Genética , Fatores de Transcrição/genética , Regulação para Cima/genética
12.
Rheumatol Int ; 38(5): 801-811, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29442150

RESUMO

OBJECTIVE: The present study was performed to localize the articular deposition of monosodium urate (MSU) crystal in joints. We compare the detection efficiencies of dual-energy CT (DECT) and ultrasound scans. METHODS: Analyses by DECT and ultrasound were performed with 184 bilateral joints of the lower limbs of 54 consecutive gout patients. All joints were categorized into (1) knee, (2) ankle, (3) MTP1, and (4) MTP2, and sorted into those with and those without detectable MSU deposition. The comparison of the positive rate between DECT and ultrasound and the agreement was performed using the McNemar test and the Cohen's κ coefficient, respectively. Next, we listed the MSU crystal deposition as assessed by ultrasound between the DECT-positive and -negative joints according to their interior structure. We included tendons, synovia, cartilage, subcutaneous tissue, etc. RESULTS: Among all joints, the percentages with MSU crystal deposition detected by DECT (99/184, 53.8%) and ultrasound (106/184, 57.6%) were comparable (P = 0.530 > 0.05). For MTP1 (21/34, 61.8%; 12/34, 35.3%; P < 0.05) and MTP2-5 (17/34, 50.0%; 10/34, 29.4%, P < 0.05), ultrasound and DECT were more efficient, respectively. The data concordance in 46 of 50 joints (92.00%; κ = 0.769, P < 0.05) for knee; and 27 of 34 joints (79.41%; κ = 0.588, P < 0.05) for MTP2-5 and suggested that tendons were the most frequent anatomical location of MSU crystal deposition. CONCLUSIONS: The tendons are the most frequent anatomical location of MSU crystal depositions. The concordance rate of knee joints and MTP2-5 joints shows good agreement between DECT and ultrasound depending on the location.


Assuntos
Articulação do Tornozelo/diagnóstico por imagem , Gota/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Tendões/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Ultrassonografia , Ácido Úrico/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Articulação do Tornozelo/química , Cristalização , Feminino , Gota/metabolismo , Humanos , Articulação do Joelho/química , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Tendões/química , Adulto Jovem
13.
Environ Microbiol ; 19(8): 3268-3282, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28618142

RESUMO

This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (ß) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed.


Assuntos
Bactérias/metabolismo , Peixes/microbiologia , Microbioma Gastrointestinal , Sedimentos Geológicos/microbiologia , Microbiologia da Água , Animais , Bactérias/genética , Biodiversidade , Ecologia , Ecossistema , Meio Ambiente , Água
14.
Appl Environ Microbiol ; 83(14)2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28500044

RESUMO

Some bacteria are capable of forming flocs, in which bacterial cells become self-flocculated by secreted extracellular polysaccharides and other biopolymers. The floc-forming bacteria play a central role in activated sludge, which has been widely utilized for the treatment of municipal sewage and industrial wastewater. Here, we use a floc-forming bacterium, Aquincolatertiaricarbonis RN12, as a model to explore the biosynthesis of extracellular polysaccharides and the regulation of floc formation. A large gene cluster for exopolysaccharide biosynthesis and a gene encoding the alternative sigma factor RpoN1, one of the four paralogues, have been identified in floc formation-deficient mutants generated by transposon mutagenesis, and the gene functions have been further confirmed by genetic complementation analyses. Interestingly, the biosynthesis of exopolysaccharides remained in the rpoN1-disrupted flocculation-defective mutants, but most of the exopolysaccharides were secreted and released rather than bound to the cells. Furthermore, the expression of exopolysaccharide biosynthesis genes seemed not to be regulated by RpoN1. Taken together, our results indicate that RpoN1 may play a role in regulating the expression of a certain gene(s) involved in the self-flocculation of bacterial cells but not in the biosynthesis and secretion of exopolysaccharides required for floc formation.IMPORTANCE Floc formation confers bacterial resistance to predation of protozoa and plays a central role in the widely used activated sludge process. In this study, we not only identified a large gene cluster for biosynthesis of extracellular polysaccharides but also identified four rpoN paralogues, one of which (rpoN1) is required for floc formation in A. tertiaricarbonis RN12. In addition, this RpoN sigma factor regulates the transcription of genes involved in biofilm formation and swarming motility, as previously shown in other bacteria. However, this RpoN paralogue is not required for the biosynthesis of exopolysaccharides, which are released and dissolved into culture broth by the rpoN1 mutant rather than remaining tightly bound to cells, as observed during the flocculation of the wild-type strain. These results indicate that floc formation is a regulated complex process, and other yet-to-be identified RpoN1-dependent factors are involved in self-flocculation of bacterial cells via exopolysaccharides and/or other biopolymers.


Assuntos
Proteínas de Bactérias/metabolismo , Betaproteobacteria/metabolismo , Polissacarídeos Bacterianos/biossíntese , Fator sigma/metabolismo , Proteínas de Bactérias/genética , Betaproteobacteria/química , Betaproteobacteria/genética , Floculação , Regulação Bacteriana da Expressão Gênica , Fator sigma/genética
15.
Mol Ecol ; 26(16): 4186-4196, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28570016

RESUMO

Aeolian soil erosion and deposition have worldwide impacts on agriculture, air quality and public health. However, ecosystem responses to soil erosion and deposition remain largely unclear in regard to microorganisms, which are the crucial drivers of biogeochemical cycles. Using integrated metagenomics technologies, we analysed microbial communities subjected to simulated soil erosion and deposition in a semiarid grassland of Inner Mongolia, China. As expected, soil total organic carbon and plant coverage were decreased by soil erosion, and soil dissolved organic carbon (DOC) was increased by soil deposition, demonstrating that field simulation was reliable. Soil microbial communities were altered (p < .039) by both soil erosion and deposition, with dramatic increase in Cyanobacteria related to increased stability in soil aggregates. amyA genes encoding α-amylases were specifically increased (p = .01) by soil deposition and positively correlated (p = .02) to DOC, which likely explained changes in DOC. Surprisingly, most of microbial functional genes associated with carbon, nitrogen, phosphorus and potassium cycling were decreased or unaltered by both erosion and deposition, probably arising from acceleration of organic matter mineralization. These divergent responses support the necessity to include microbial components in evaluating ecological consequences. Furthermore, Mantel tests showed strong, significant correlations between soil nutrients and functional structure but not taxonomic structure, demonstrating close relevance of microbial function traits to nutrient cycling.


Assuntos
Bactérias/classificação , Pradaria , Microbiologia do Solo , Solo/química , Carbono/análise , China , Nitrogênio/análise , Fósforo/análise , Potássio/análise
16.
Plant Physiol ; 170(3): 1524-34, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26739233

RESUMO

Flowering plant sperm cells transcribe a divergent and complex complement of genes. To examine promoter function, we chose an isopentenyltransferase gene known as PzIPT1. This gene is highly selectively transcribed in one sperm cell morphotype of Plumbago zeylanica, which preferentially fuses with the central cell during fertilization and is thus a founding cell of the primary endosperm. In transgenic Arabidopsis (Arabidopsis thaliana), PzIPT1 promoter displays activity in both sperm cells and upon progressive promoter truncation from the 5'-end results in a progressive decrease in reporter production, consistent with occurrence of multiple enhancer sites. Cytokinin-dependent protein binding motifs are identified in the promoter sequence, which respond with stimulation by cytokinin. Expression of PzIPT1 promoter in sperm cells confers specificity independently of previously reported Germline Restrictive Silencer Factor binding sequence. Instead, a cis-acting regulatory region consisting of two duplicated 6-bp Male Gamete Selective Activation (MGSA) motifs occurs near the site of transcription initiation. Disruption of this sequence-specific site inactivates expression of a GFP reporter gene in sperm cells. Multiple copies of the MGSA motif fused with the minimal CaMV35S promoter elements confer reporter gene expression in sperm cells. Similar duplicated MGSA motifs are also identified from promoter sequences of sperm cell-expressed genes in Arabidopsis, suggesting selective activation is possibly a common mechanism for regulation of gene expression in sperm cells of flowering plants.


Assuntos
Alquil e Aril Transferases/genética , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/genética , Pólen/genética , Sequências Reguladoras de Ácido Nucleico/genética , Arabidopsis/citologia , Arabidopsis/metabolismo , Citocininas/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Confocal , Mutação , Motivos de Nucleotídeos/genética , Reguladores de Crescimento de Plantas/farmacologia , Plantas Geneticamente Modificadas , Plumbaginaceae/genética , Pólen/citologia , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sítio de Iniciação de Transcrição
17.
Cell Immunol ; 310: 170-177, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27641635

RESUMO

Antigen-presenting dendritic cells interpret environmental signals to orchestrate local and systemic immune responses. In this study, the roles of Wnt proteins and their signaling pathway members in the maturation and function of monocyte-derived DCs were investigated. The present study showed higher expression of ß-catenin, as well as pGSK-3ß in DCs than those in monocytes. Wnt3a, Wnt5a and inhibition of GSK-3ß promoted differentiation of DCs, but inhibited maturation of DCs. GSK-3ß induced DCs maturation with unconventional phenotypes. Together with ß-catenin silence, these treatment lead to reduced secretion of cytokines and chemokines except for IL-10 in comparison with LPS treatment, and significantly promoted proliferation of T cells. Wnt3a and inhibition of GSK-3ß increased expression of MAPK signalings (p-ERK, p-p38, p-JNK). However, inhibition of MAPK signalings in turn differently regulated Wnt signaling proteins expression. These data suggest that Wnt pathway regulates DCs differentiation, maturation and function with interaction of MAPK signaling pathways.


Assuntos
Células Dendríticas/fisiologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Linfócitos T/imunologia , Proteína Wnt-5a/metabolismo , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Interleucina-10/metabolismo , Ativação Linfocitária , Monócitos/fisiologia , RNA Interferente Pequeno/genética , Transdução de Sinais , beta Catenina/genética
18.
Ecotoxicology ; 25(10): 1759-1770, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27637513

RESUMO

The Lanzhou reach of the Yellow River, located at the upstream of Lanzhou, has been contaminated by heavy metals and polycyclic aromatic hydrocarbons over a long-time. We hypothesized that indigenous microbial communities would remediate those contaminants and some unique populations could play an important role in this process. In this study, we investigated the sediment microbial community structure and function from the Lanzhou reach. Sediment samples were collected from two nearby sites (site A and site B) in the Lanzhou reach along the Yellow River. Sediment geochemical property data showed that site A sediment samples contained significantly (p < 0.05) higher heavy metals than site B, such as chromium (Cr), manganese (Mn), and copper (Cu). Both site A and B samples were incubated with or without hexavalent chromium (Cr (VI)) for 30 days in the laboratory, and Cr (VI) reduction was only observed in site A sediment samples. After incubation, MiSeq sequencing of 16S rRNA gene amplicons revealed that the phylogenetic composition and structure of microbial communities changed in both samples, and especially Proteobacteria, as the most abundant phylum increased from 45.1 % to 68.2 % in site A, and 50.1 % to 71.3 % in site B, respectively. Some unique OTUs and populations affiliated with Geobacter, Clostridium, Desulfosporosinus and Desulfosporosinus might be involved in Cr (VI) reduction in site A. Furthermore, GeoChip 4.0 (a comprehensive functional gene array) data showed that genes involved in carbon and nitrogen cycling and metal resistance significantly (p < 0.05) increased in site A sediment samples. All the results indicated that indigenous sediment microbial communities might be able to remediate contaminants like Cr (VI), and this information provides possible strategies for future bioremediation of the Lanzhou reach.


Assuntos
Bactérias/efeitos dos fármacos , Cromo/toxicidade , Monitoramento Ambiental , Sedimentos Geológicos/microbiologia , Microbiologia da Água , Poluentes Químicos da Água/toxicidade , Bactérias/classificação , Biodegradação Ambiental , Filogenia , RNA Ribossômico 16S , Rios
19.
Zhongguo Zhong Yao Za Zhi ; 41(16): 2987-2992, 2016 Aug.
Artigo em Zh | MEDLINE | ID: mdl-28920336

RESUMO

Study on 5 effective components and 6 soil enzyme activities of 2 different growth patterns, analyse the dates with the canonical correlation analysis, In order to reveal the relations between the effective components and soil enzyme activities. The result showed that they had a great relation between the effective components and soil enzyme activities, the activity of the same enzyme in humus soil was higher than that in farmland soil. Growth pattern of farmland soil, if the invertase and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside, water-miscible total proteins and total amino acid; Growth pattern of humus soil, if the invertase, urease and phosphatase activity were too high, which would inhibit the accumulation of total ginsenoside and the total essential oils. Integral soil enzyme activity can be used as a index of soil quality, which, together with other growth factors. The appropriate enzyme activity can accelerate the circulation and transformation of all kinds of material in the soil, improve effectively components accumulation.


Assuntos
Panax/crescimento & desenvolvimento , Monoéster Fosfórico Hidrolases/metabolismo , Solo/química , Urease/metabolismo , beta-Frutofuranosidase/metabolismo , Ginsenosídeos
20.
BMC Microbiol ; 15: 125, 2015 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-26084274

RESUMO

BACKGROUND: Although high-throughput sequencing, such as Illumina-based technologies (e.g. MiSeq), has revolutionized microbial ecology, adaptation of amplicon sequencing for environmental microbial community analysis is challenging due to the problem of low base diversity. RESULTS: A new phasing amplicon sequencing approach (PAS) was developed by shifting sequencing phases among different community samples from both directions via adding various numbers of bases (0-7) as spacers to both forward and reverse primers. Our results first indicated that the PAS method substantially ameliorated the problem of unbalanced base composition. Second, the PAS method substantially improved the sequence read base quality (an average of 10 % higher of bases above Q30). Third, the PAS method effectively increased raw sequence throughput (~15 % more raw reads). In addition, the PAS method significantly increased effective reads (9-47 %) and the effective read sequence length (16-96 more bases) after quality trim at Q30 with window 5. In addition, the PAS method reduced half of the sequencing errors (0.54-1.1 % less). Finally, two-step PCR amplification of the PAS method effectively ameliorated the amplification biases introduced by the long barcoded PCR primers. CONCLUSION: The developed strategy is robust for 16S rRNA gene amplicon sequencing. In addition, a similar strategy could also be used for sequencing other genes important to ecosystem functional processes.


Assuntos
Archaea/classificação , Bactérias/classificação , DNA Ribossômico/análise , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Archaea/genética , Bactérias/genética , Primers do DNA , DNA Arqueal/análise , DNA Bacteriano/análise , Microbiologia Ambiental , Humanos , Saliva/microbiologia
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