Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 261
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Pathog ; 20(4): e1011829, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38620036

RESUMO

Viruses target mitochondria to promote their replication, and infection-induced stress during the progression of infection leads to the regulation of antiviral defenses and mitochondrial metabolism which are opposed by counteracting viral factors. The precise structural and functional changes that underlie how mitochondria react to the infection remain largely unclear. Here we show extensive transcriptional remodeling of protein-encoding host genes involved in the respiratory chain, apoptosis, and structural organization of mitochondria as herpes simplex virus type 1 lytic infection proceeds from early to late stages of infection. High-resolution microscopy and interaction analyses unveiled infection-induced emergence of rough, thin, and elongated mitochondria relocalized to the perinuclear area, a significant increase in the number and clustering of endoplasmic reticulum-mitochondria contact sites, and thickening and shortening of mitochondrial cristae. Finally, metabolic analyses demonstrated that reactivation of ATP production is accompanied by increased mitochondrial Ca2+ content and proton leakage as the infection proceeds. Overall, the significant structural and functional changes in the mitochondria triggered by the viral invasion are tightly connected to the progression of the virus infection.


Assuntos
Herpes Simples , Herpesvirus Humano 1 , Mitocôndrias , Mitocôndrias/metabolismo , Herpesvirus Humano 1/fisiologia , Herpesvirus Humano 1/metabolismo , Humanos , Herpes Simples/metabolismo , Herpes Simples/virologia , Herpes Simples/patologia , Animais , Infecções por Herpesviridae/metabolismo , Infecções por Herpesviridae/virologia , Infecções por Herpesviridae/patologia , Progressão da Doença , Chlorocebus aethiops
2.
FASEB J ; 37(1): e22681, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36519968

RESUMO

Developing in silico models that accurately reflect a whole, functional cell is an ongoing challenge in biology. Current efforts bring together mathematical models, probabilistic models, visual representations, and data to create a multi-scale description of cellular processes. A realistic whole-cell model requires imaging data since it provides spatial constraints and other critical cellular characteristics that are still impossible to obtain by calculation alone. This review introduces Soft X-ray Tomography (SXT) as a powerful imaging technique to visualize and quantify the mesoscopic (~25 nm spatial scale) organelle landscape in whole cells. SXT generates three-dimensional reconstructions of cellular ultrastructure and provides a measured structural framework for whole-cell modeling. Combining SXT with data from disparate technologies at varying spatial resolutions provides further biochemical details and constraints for modeling cellular mechanisms. We conclude, based on the results discussed here, that SXT provides a foundational dataset for a broad spectrum of whole-cell modeling experiments.


Assuntos
Imageamento Tridimensional , Tomografia por Raios X , Raios X , Imageamento Tridimensional/métodos , Tomografia por Raios X/métodos , Organelas
3.
BMC Plant Biol ; 23(1): 595, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38017401

RESUMO

BACKGROUND: Stomatal variation, including guard cell (GC) density, size and chloroplast number, is often used to differentiate polyploids from diploids. However, few works have focused on stomatal variation with respect to polyploidization, especially for consecutively different ploidy levels within a plant species. For example, Allium tuberosum, which is mainly a tetraploid (2n = 4x = 32), is also found at other ploidy levels which have not been widely studied yet. RESULTS: We recently found cultivars with different ploidy levels, including those that are diploid (2n = 2x = 16), triploid (2n = 3x = 24), pseudopentaploid (2n = 34-42, mostly 40) and pseudohexaploid (2n = 44-50, mostly 48). GCs were evaluated for their density, size (length and width) and chloroplast number. There was no correspondence between ploidy level and stomatal density, in which anisopolyploids (approximately 57 and 53 stomata/mm2 in triploid and pseudopentaploid, respectively) had a higher stomatal density than isopolyploids (approximately 36, 43, and 44 stomata/mm2 in diploid, tetraploid and pseudohexaploid, respectively). There was a positive relationship between ploidy level and GC chloroplast number (approximately 44, 45, 51, 72 and 90 in diploid to pseudohexaploid, respectively). GC length and width also increased with ploidy level. However, the length increased approximately 1.22 times faster than the width during polyploidization. CONCLUSIONS: This study shows that GC size increased with increasing DNA content, but the rate of increase differed between length and width. In the process of polyploidization, plants evolved longer and narrower stomata with more chloroplasts in the GCs.


Assuntos
Cebolinha-Francesa , Estômatos de Plantas , Ploidias , Cebolinha-Francesa/genética , Tetraploidia , Triploidia
5.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(2): 186-192, 2023 Feb 15.
Artigo em Zh | MEDLINE | ID: mdl-36854696

RESUMO

OBJECTIVES: To investigate the association between maternal job burnout and adolescent depression and the mediating effect of maternal depression and parenting style. METHODS: A cross-sectional study was conducted. The cluster random sampling method was used to select 2 572 adolescents from 7 middle schools in Shanghai, China, from April to May, 2021. A survey was performed for these adolescents and their mothers. The research tools included a general information questionnaire, Maslach Burnout Inventory-General Survey, Center for Epidemiologic Studies Depression Scale, short-form of Egna Minnen av Barndoms Uppfostran, and Children's Depression Inventory. A structural equation model was established, and the Bootstrap method was used to investigate the mediating effect. RESULTS: The detection rate of depressive symptoms was 12.71% (327/2 572) among the adolescents. The scores of maternal job burnout, maternal depression, and negative parenting style were positively correlated with the score of adolescent depression (P<0.05), and the score of positive parenting style was negatively correlated with the score of adolescent depression (P<0.05). Maternal depression and parenting style played a mediating role between maternal job burnout and adolescent depression, including the individual mediating effect of maternal depression, the individual mediating effect of positive parenting style, and the chain mediating effect of maternal depression-negative/positive parenting style. CONCLUSIONS: Maternal job burnout may affect adolescent depression through the mediating effect of depression, parenting style, and depression-parenting style, suggesting that the symptoms of adolescent depression can be reduced by alleviating maternal job burnout, improving maternal depression, increasing positive parenting behaviors, and reducing negative parenting behaviors.


Assuntos
Depressão , Poder Familiar , Criança , Adolescente , Humanos , Estudos Transversais , Depressão/etiologia , China , Esgotamento Psicológico
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(1): 80-85, 2023 Jan 15.
Artigo em Zh | MEDLINE | ID: mdl-36655668

RESUMO

OBJECTIVES: To study the influence of family structure on depression and anxiety symptoms in adolescents and its mechanism. METHODS: The cluster sampling method was used to select the students from seven middle schools in Shanghai, China. An online questionnaire survey was conducted using a self-made general status questionnaire, Childhood Trauma Questionnaire, Children's Depression Inventory, and Screen for Child Anxiety Related Emotional Disorders. The methods including one-way analysis of variance, chi-square test, binary logistic regression analysis, and mediating effect analysis were used to evaluate depression and anxiety symptoms in adolescents and the difference in childhood trauma and its mediating effect. RESULTS: Compared with the adolescents from nuclear families, the adolescents from three-generation lineal families had a lower risk of depression symptoms (OR=0.794, 95%CI: 0.649-0.972, P<0.05), while those from host families had a higher risk of depression symptoms (OR=4.548, 95%CI: 1.113-18.580, P<0.05). The adolescents from inter-generational families and host families had a significantly higher score on the Childhood Trauma Questionnaire subscale of emotional neglect (P<0.05). Emotional neglect played a mediating role in the influence of inter-generational families and host families on depression symptoms in adolescents. CONCLUSIONS: Parents and grandparents have a certain positive effect in family structures. Separation from parents may make adolescents perceive more emotional neglect, which may increase the occurrence of depression symptoms.


Assuntos
Maus-Tratos Infantis , Depressão , Criança , Humanos , Adolescente , Depressão/etiologia , Depressão/epidemiologia , Estrutura Familiar , Maus-Tratos Infantis/psicologia , China , Ansiedade/epidemiologia , Inquéritos e Questionários
7.
Ann Surg Oncol ; 29(8): 5022-5033, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35294651

RESUMO

BACKGROUND: The tumor immunosuppressive microenvironment can influence treatment response and outcomes. A previously validated immunosuppression scoring system (ISS) assesses multiple immune checkpoints in gastric cancer (GC) using tissue-based assays. We aimed to develop a radiological signature for non-invasive assessment of ISS and treatment outcomes. METHODS: A total of 642 patients with resectable GC from three centers were divided into four cohorts. Radiomic features were extracted from portal venous-phase CT images of GC. A radiomic signature for predicting ISS (RISS) was constructed using the least absolute shrinkage and selection operator (LASSO) regression method. Moreover, we investigated the value of the RISS in predicting survival and chemotherapy response. RESULTS: The RISS, which consisted of 10 selected features, showed good discrimination of immunosuppressive status in three independent cohorts (area under the curve = 0.840, 0.809, and 0.843, respectively). Multivariate analysis revealed that the RISS was an independent prognostic factor for both disease-free survival (DFS) and overall survival (OS) in all cohorts (all p < 0.05). Further analysis revealed that stage II and III GC patients with low RISS exhibited a favorable response to adjuvant chemotherapy (OS: hazard ratio [HR] 0.407, 95% confidence interval [CI] 0.284-0.584); DFS: HR 0.395, 95% CI 0.275-0.568). Furthermore, the RISS could predict prognosis and select stage II and III GC patients who could benefit from adjuvant chemotherapy independent of microsatellite instability status and Epstein-Barr virus status. CONCLUSION: The new, non-invasive radiomic signature could effectively predict the immunosuppressive status and prognosis of GC. Moreover, the RISS could help identify stage II and III GC patients most likely to benefit from adjuvant chemotherapy and avoid overtreatment.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Gástricas , Infecções por Vírus Epstein-Barr/patologia , Herpesvirus Humano 4 , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/tratamento farmacológico , Resultado do Tratamento , Microambiente Tumoral
8.
Plant Cell ; 31(3): 579-601, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30787178

RESUMO

Light and nutrients are critical regulators of photosynthesis and metabolism in plants and algae. Many algae have the metabolic flexibility to grow photoautotrophically, heterotrophically, or mixotrophically. Here, we describe reversible Glc-dependent repression/activation of oxygenic photosynthesis in the unicellular green alga Chromochloris zofingiensis. We observed rapid and reversible changes in photosynthesis, in the photosynthetic apparatus, in thylakoid ultrastructure, and in energy stores including lipids and starch. Following Glc addition in the light, C. zofingiensis shuts off photosynthesis within days and accumulates large amounts of commercially relevant bioproducts, including triacylglycerols and the high-value nutraceutical ketocarotenoid astaxanthin, while increasing culture biomass. RNA sequencing reveals reversible changes in the transcriptome that form the basis of this metabolic regulation. Functional enrichment analyses show that Glc represses photosynthetic pathways while ketocarotenoid biosynthesis and heterotrophic carbon metabolism are upregulated. Because sugars play fundamental regulatory roles in gene expression, physiology, metabolism, and growth in both plants and animals, we have developed a simple algal model system to investigate conserved eukaryotic sugar responses as well as mechanisms of thylakoid breakdown and biogenesis in chloroplasts. Understanding regulation of photosynthesis and metabolism in algae could enable bioengineering to reroute metabolism toward beneficial bioproducts for energy, food, pharmaceuticals, and human health.


Assuntos
Clorofíceas/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucose/farmacologia , Oxigênio/metabolismo , Fotossíntese/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Antioxidantes/metabolismo , Bioengenharia , Carbono/metabolismo , Clorofíceas/genética , Clorofíceas/efeitos da radiação , Clorofíceas/ultraestrutura , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fotossíntese/efeitos da radiação , Tilacoides/metabolismo , Tilacoides/ultraestrutura , Transcriptoma/efeitos da radiação , Xantofilas/metabolismo
9.
Neoplasma ; 69(4): 807-819, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35471977

RESUMO

This article reported the mechanism of Anlotinib in gastric cancer treatment. Gastric cancer cells were treated with Anlotinib (8 µM) and transfected by STING shRNA and STING vectors. Cell counting kit-8 assay, wounding healing assay, and Transwell experiment were applied for proliferation, migration, and invasion detection. PD-L1 fluorescence intensity in gastric cancer cells was explored by flow cytometry. IFN-ß level was researched by enzyme-linked immunosorbent reaction. Xenograft tumor experiment was performed by administering mice with Anlotinib and anti-PD-L1 antibody. Immunohistochemistry and western blot were used for proteins expression detection. Quantitative real-time reverse transcription-polymerase chain reaction was applied for mRNA expression detection. Hematoxylin and eosin staining was conducted on lung, liver, kidney, and cerebral cortex of mice. Gastric cancer cells treated with Anlotinib exhibited reduced proliferation, migration, and invasion (p<0.01). Anlotinib treatment reduced PCNA, CDK1, and MMP2 protein expressions and increased E-cadherin protein expression in gastric cancer cells (p<0.01). Anlotinib treatment suppressed PD-L1 expression and activated the cGAS-STING/IFN-ß pathway in gastric cancer cells (p<0.01). STING knockdown partially reversed the inhibition of Anlotinib on gastric cancer cells proliferation, migration, invasion, and immune escape (p<0.05 or p<0.01). However, STING overexpression exhibited the opposite effect. Anlotinib synergistically improved anti-tumor efficacy of anti-PD-L1 in vivo. Anlotinib synergistic anti-PD-L1 increased CD3+, CD8+ T cells, and activated the cGAS-STING/IFN-ß pathway in xenograft tumor. Anlotinib was non-toxic to lung, liver, cortex, and kidney. Anlotinib suppressed gastric cancer cells proliferation, migration, and immune escape by activating the cGAS-STING/IFN-ß pathway.


Assuntos
Quinolinas , Neoplasias Gástricas , Animais , Proliferação de Células , Humanos , Indóis , Camundongos , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Quinolinas/farmacologia , Neoplasias Gástricas/tratamento farmacológico
10.
Zhongguo Zhong Yao Za Zhi ; 47(14): 3908-3914, 2022 Jul.
Artigo em Zh | MEDLINE | ID: mdl-35850849

RESUMO

Magnoflorine is an important aporphine alkaloid in Coptidis Rhizoma. As reported previously, coexisting components in Coptidis Rhizoma can change the pharmacokinetic characteristics of magnoflorine. To illustrate the interactional links of magnoflorine with its coexisting components in Coptidis Rhizoma, the present study investigated the influence of coexisting components in Coptidis Rhizoma on the excretion of magnoflorine in rat bile, urine, and feces. The rats were dosed with magnoflorine(30 mg·kg~(-1)) and water decoction of Coptidis Rhizoma(equivalent to 30 mg·kg~(-1) magnoflorine) via intragastric administration, and magnoflorine(10 mg·kg~(-1)) by intravenous administration, respectively, and the excretion of magnoflorine in rat bile, urine, and feces in 24 h was observed. The excretion rates of magnoflorine in bile and urine in 24 h were 0.90% and 37.11% respectively after intravenous administration of magnoflorine, which suggested that urination was the main excretive way of magnoflorine. The excretion rates of magnoflorine in feces were 8.77% and 6.18% respectively after intragastric administration of magnoflorine and water decoction of Coptidis Rhizoma, which indicated that defecation was the main excretion route of magnoflorine. The cumulative excretion rates of magnoflorine in the bile, urine, and feces in the Coptidis Rhizoma water decoction group were 77.78%, 79.44%, and 70.47% of those in the magnoflorine group. The results showed that the cumulative excretion rates of magnoflorine in rat bile, urine, and feces were not high, suggesting that magnoflorine was metabolized significantly in rats. The coexisting components of Coptidis Rhizoma could inhibit the excretion of magnoflorine in rat bile, urine, and feces, which was consistent with the decrease in the elimination rate of magnoflorine in the pharmacokinetics of Coptidis Rhizoma water decoction. It indicated interactions between drugs. This study is expected to provide references for the development of magnoflorine-containing new drugs and rational clinical medication of Coptidis Rhizoma.


Assuntos
Aporfinas , Medicamentos de Ervas Chinesas , Animais , Bile , Coptis chinensis , Medicamentos de Ervas Chinesas/farmacologia , Fezes , Ratos , Água
11.
Fa Yi Xue Za Zhi ; 38(1): 20-30, 2022 Feb 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-35725700

RESUMO

Diatom detection is an important method for identifying drowning and throwing corpses after death and inferring the drowning sites in forensic examination of corpses in water. In recent years,high-throughput sequencing technology has achieved rapid development and has been widely used in research related to diatom taxonomic investigations. This paper reviews the research status and prospects of high-throughput sequencing technology and its application in forensic diatom detection.


Assuntos
Diatomáceas , Afogamento , Cadáver , Diatomáceas/genética , Afogamento/diagnóstico , Patologia Legal/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pulmão , Tecnologia
12.
Fa Yi Xue Za Zhi ; 38(1): 119-126, 2022 Feb 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-35725715

RESUMO

OBJECTIVES: To examine the effect of improving diatom DNA extraction by glass bead - vortex oscillation method. METHODS: The DNeasy PowerSoil Pro kit was used as control, two plant DNA extraction kits with different principles (New Plant genomic DNA extraction kit and Plant DNA Isolation kit) and one whole blood DNA extraction kit (whole blood genomic DNA extraction kit) were selected to extract diatom DNA from lung tissue and water sample of the same drowning case. The combination of mass ratio of glass beads with different sizes and vortex oscillation time was designed, and the optimal DNA extraction conditions were selected with the addition of glass beads oscillation. The extracted products of the conventional group and the modified group were directly electrophoretic and detected by diatom specific PCR. Finally, all the extracts were quantified by qPCR, and the Ct values of different groups were statistically analyzed. RESULTS: When the frequency of vortex oscillation was 3 000 r/min, the optimal combination of DNA extraction was vortex oscillation for 4 min, and the mass ratio of large glass beads to small glass beads was 1∶1. The DNeasy PowerSoil Pro kit was used as a reference, and the Ct value of 10 mL water sample was greater than that of 0.5 g tissue. The Ct values of the other three kits used for plant DNA extraction decreased after the glass beads-vortex oscillation method was used, and the Ct values of the tissues before and after the improvement were statistically significant (P<0.05). The whole blood genomic DNA extraction kit used in this study could successfully extract diatom DNA, the extraction of water samples was close to DNeasy PowerSoil Pro kit, after the modified method was applied to tissue samples, the difference in Ct value was statistically significant (P<0.05). However, when the three kits were used to extract diatom DNA from water samples, Ct values before and after the improvement were only statistically significant in New Plant genomic DNA extraction kit group (P<0.05). CONCLUSIONS: The improved glass bead-vortex oscillation method can improve the extraction efficiency of diatom DNA from forensic materials, especially from tissue samples, by plant and blood DNA extraction kits.


Assuntos
Diatomáceas , DNA de Plantas/genética , Diatomáceas/genética , Reação em Cadeia da Polimerase em Tempo Real , Água
13.
J Food Sci Technol ; 59(3): 990-1000, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35153324

RESUMO

This study evaluated high pressure processing (HPP) for achieving greater than 5-log reduction of Escherichia coli O157:H7 in shiikuwasha (Citrus depressa Hayata) juices and compare quality parameters, including microbiological safety, total phenolic content (TPC), total flavanones (TFC), and polymethoxylated flavones, browning, volatile aromatic, and physicochemical properties of HPP-treated juice with those of high-temperature short-time pasteurized juice. A HPP of 600 MPa for 150 s was identified capable of achieving greater than 5.15-log reductions of E. coli O157:H7 in shiikuwasha juice. The microbiological shelf life of the juices were at least 28 days when processed at HPP for 600 MPa/150 s or HTST for 90 °C/60 s. The color, aromatic, and antioxidant contents (TPC, TFC, Tangeletin, Nobiletin) were well preserved after HPP, however, HTST resulted in a significant (p < 0.05) loss of antioxidant content (TPC (8.8%), Tangeletin (6.8%)), and negatively impacted the juice color. By the end of storage, the amount of these aroma relevant volatiles appears to still be higher in HPP pasteurized juices compared to their conventional counterparts. This study demonstrated that under optimal conditions of HPP can attain the same level of microbiological safety as thermal pasteurization and preserved the acceptable quality of shiikuwasha juice.

14.
BMC Health Serv Res ; 21(1): 262, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33743674

RESUMO

BACKGROUND: The association of workplace factors on mental health of healthcare workers (HCWs) during the COVID-19 pandemic needs to be urgently established. This will enable governments and policy-makers to make evidence-based decisions. This international study reports the association between workplace factors and the mental health of HCWs during the pandemic. METHODS: An international, cross-sectional study was conducted in 41 countries. The primary outcome was depressive symptoms, derived from the validated Patient Health Questionnaire-2 (PHQ-2). Multivariable logistic regression identified factors associated with mental health outcomes. Inter-country differences were also evaluated. RESULTS: A total of 2527 responses were received, from 41 countries, including China (n = 1213; 48.0%), UK (n = 891; 35.3%), and USA (n = 252; 10.0%). Of all participants, 1343 (57.1%) were aged 26 to 40 years, and 2021 (80.0%) were female; 874 (34.6%) were doctors, and 1367 (54.1%) were nurses. Factors associated with an increased likelihood of depressive symptoms were: working in the UK (OR = 3.63; CI = [2.90-4.54]; p < 0.001) and USA (OR = 4.10; CI = [3.03-5.54]), p < 0.001); being female (OR = 1.74; CI = [1.42-2.13]; p < 0.001); being a nurse (OR = 1.64; CI = [1.34-2.01]; p < 0.001); and caring for a COVID-19 positive patient who subsequently died (OR = 1.20; CI = [1.01-1.43]; p = 0.040). Workplace factors associated with depressive symptoms were: redeployment to Intensive Care Unit (ICU) (OR = 1.67; CI = [1.14-2.46]; p = 0.009); redeployment with perceived unsatisfactory training (OR = 1.67; CI = [1.32-2.11]; p < 0.001); not being issued with appropriate personal protective equipment (PPE) (OR = 2.49; CI = [2.03-3.04]; p < 0.001); perceived poor workplace support within area/specialty (OR = 2.49; CI = [2.03-3.04]; p < 0.001); and perceived poor mental health support (OR = 1.63; CI = [1.38-1.92]; p < 0.001). CONCLUSION: This is the first international study, demonstrating that workplace factors, including PPE availability, staff training pre-redeployment, and provision of mental health support, are significantly associated with mental health during COVID-19. Governments, policy-makers and other stakeholders need to ensure provision of these to safeguard HCWs' mental health, for future waves and other pandemics.


Assuntos
COVID-19/psicologia , Pessoal de Saúde/psicologia , Saúde Mental , Pandemias/prevenção & controle , Local de Trabalho/psicologia , Adulto , COVID-19/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Equipamento de Proteção Individual , SARS-CoV-2
15.
Proc Natl Acad Sci U S A ; 115(46): 11796-11801, 2018 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-30373839

RESUMO

It has been hypothesized that mitochondria evolved from a bacterial ancestor that initially became established in an archaeal host cell as an endosymbiont. Here we model this first stage of mitochondrial evolution by engineering endosymbiosis between Escherichia coli and Saccharomyces cerevisiae An ADP/ATP translocase-expressing E. coli provided ATP to a respiration-deficient cox2 yeast mutant and enabled growth of a yeast-E. coli chimera on a nonfermentable carbon source. In a reciprocal fashion, yeast provided thiamin to an endosymbiotic E. coli thiamin auxotroph. Expression of several SNARE-like proteins in E. coli was also required, likely to block lysosomal degradation of intracellular bacteria. This chimeric system was stable for more than 40 doublings, and GFP-expressing E. coli endosymbionts could be observed in the yeast by fluorescence microscopy and X-ray tomography. This readily manipulated system should allow experimental delineation of host-endosymbiont adaptations that occurred during evolution of the current, highly reduced mitochondrial genome.


Assuntos
Bioengenharia/métodos , Mitocôndrias/genética , Simbiose/genética , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Evolução Biológica , Escherichia coli/genética , Escherichia coli/metabolismo , Mitocôndrias/metabolismo , Modelos Biológicos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Tiamina/metabolismo
16.
FASEB J ; 33(1): 239-253, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29975569

RESUMO

Reduced fetal nutrition and rapid postnatal growth accelerates the aging phenotype in many organ systems; however, effects on the immune system are unclear. We addressed this by studying the thymus from a rat model of developmental programming. The recuperated group was generated by in utero protein restriction, followed by cross-fostering to control-fed mothers, and were then compared with controls. Fat infiltration and adipocyte size increased with age ( P < 0.001) and in recuperated thymi ( P < 0.05). Cortex/medulla ratio decreased with age ( P < 0.001) and decreased ( P < 0.05) in 12-mo recuperated thymi. Age-associated decreases in thymic-epithelial cell ( P < 0.01) and thymocyte markers ( P < 0.01) were observed in both groups and was decreased ( P < 0.05) in recuperated thymi. These data demonstrate effects of developmental programming upon thymic involution. The recuperated group had longer thymic telomeres than controls ( P < 0.001) at 22 d and at 3 mo, which was associated with increased expression of telomere-length maintenance molecules [telomerase RNA component ( Terc; P < 0.01), P23 ( P = 0.02), and Ku70 and Ku80 ( P < 0.01)]. By 12 mo, recuperated offspring had shorter thymic telomeres than controls had ( P < 0.001) and reduced DNA damage-response markers [( DNA-PKcs, Mre11 ( P < 0.01), Xrcc4 ( P = 0.02), and γ-H2ax ( P < 0.001], suggesting failure of earlier compensatory responses. Our results suggest that low birth weight with rapid postnatal growth results in premature thymic maturation, resulting in accelerated thymic aging. This could lead to increased age-associated vulnerability to infection.-Tarry-Adkins, J. L., Aiken, C. E., Ashmore, T. J., Fernandez-Twinn, D. S., Chen, J.-H., Ozanne, S. E. A suboptimal maternal diet combined with accelerated postnatal growth results in an altered aging profile in the thymus of male rats.


Assuntos
Envelhecimento/patologia , Senescência Celular , Dieta , Desnutrição/fisiopatologia , Fenômenos Fisiológicos da Nutrição Materna , Encurtamento do Telômero , Timo/patologia , Envelhecimento/metabolismo , Animais , Biomarcadores , Dano ao DNA , Feminino , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Timo/metabolismo
17.
Molecules ; 25(17)2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32824884

RESUMO

The use of antagonistic microorganisms and their volatile organic compounds (VOCs) to control plant fungal pathogens is an eco-friendly and promising substitute for chemical fungicides. In this work, endophytic bacterium ETR-B22, isolated from the root of Sophora tonkinensis Gagnep., was found to exhibit strong antagonistic activity against 12 fungal pathogens found in agriculture. Strain ETR-B22 was identified as Burkholderia cenocepacia based on 16S rRNA and recA sequences. We evaluated the antifungal activity of VOCs emitted by ETR-B22. The VOCs from strain ETR-B22 also showed broad-spectrum antifungal activity against 12 fungal pathogens. The composition of the volatile profiles was analyzed based on headspace solid phase microextraction (HS-SPME) gas chromatography coupled to mass spectrometry (GC-MS). Different extraction strategies for the SPME process significantly affected the extraction efficiency of the VOCs. Thirty-two different VOCs were identified. Among the VOC of ETR-B22, dimethyl trisulfide, indole, methyl anthranilate, methyl salicylate, methyl benzoate, benzyl propionate, benzyl acetate, 3,5-di-tert-butylphenol, allyl benzyl ether and nonanoic acid showed broad-spectrum antifungal activity, and are key inhibitory compounds produced by strain ETR-B22 against various fungal pathogens. Our results suggest that the endophytic strain ETR-B22 and its VOCs have high potential for use as biological controls of plant fungal pathogens.


Assuntos
Antifúngicos/farmacologia , Burkholderia cenocepacia/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Raízes de Plantas/microbiologia , Microextração em Fase Sólida/métodos , Sophora/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Antifúngicos/análise , Antifúngicos/isolamento & purificação , Burkholderia cenocepacia/crescimento & desenvolvimento , RNA Ribossômico 16S/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação
18.
Biochem Soc Trans ; 47(2): 489-508, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30952801

RESUMO

Morphometric measurements, such as quantifying cell shape, characterizing sub-cellular organization, and probing cell-cell interactions, are fundamental in cell biology and clinical medicine. Until quite recently, the main source of morphometric data on cells has been light- and electron-based microscope images. However, many technological advances have propelled X-ray microscopy into becoming another source of high-quality morphometric information. Here, we review the status of X-ray microscopy as a quantitative biological imaging modality. We also describe the combination of X-ray microscopy data with information from other modalities to generate polychromatic views of biological systems. For example, the amalgamation of molecular localization data, from fluorescence microscopy or spectromicroscopy, with structural information from X-ray tomography. This combination of data from the same specimen generates a more complete picture of the system than that can be obtained by a single microscopy method. Such multimodal combinations greatly enhance our understanding of biology by combining physiological and morphological data to create models that more accurately reflect the complexities of life.


Assuntos
Tomografia por Raios X/métodos , Humanos , Microscopia Eletrônica , Microscopia de Fluorescência/métodos , Imagem Multimodal/métodos
19.
J Struct Biol ; 204(1): 9-18, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29908247

RESUMO

In this article, we introduce a linear approximation of the forward model of soft X-ray tomography, such that the reconstruction is solvable by standard iterative schemes. This linear model takes into account the three-dimensional point spread function (PSF) of the optical system, which consequently enhances the reconstruction of data. The feasibility of the model is demonstrated on both simulated and experimental data, based on theoretically estimated and experimentally measured PSFs.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Algoritmos , Tomografia por Raios X/métodos
20.
Int J Syst Evol Microbiol ; 68(8): 2574-2579, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29944093

RESUMO

A Gram-staining-negative, aerobic, motile and rod-shaped bacterium, designated strain X1-8T, was isolated from rhizosphere soil of Nicotiana tabacum L. collected from the tobacco produce base located in Kunming, south-west PR China. Cells showed oxidase-negative and catalase-positive reactions and were motile by means of peritrichous flagella. Growth occurred at 25-40 °C and pH 6.0-8.0 with optimal growth at 30-35 °C, pH 7.0. The major respiratory lipoquinone was Q-10. C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) were identified as major cellular fatty acids. The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, sphingoglycolipid, phosphatidylcholine and one unidentified glycolipid. The major polyamine was sym-homospermidine. The genomic DNA G+C content was 66.5 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that X1-8T should be affiliated to the genus Sphingomonasand formed a clade with most closely related species Sphingomonas changbaiensisNBRC 104936T. The results of 16S rRNA gene sequences similarity analysis indicated that X1-8T had the highest similarity with S. changbaiensisNBRC 104936T (98.4 %) and lower than 96.0 % with other species of the genus Sphingomonas. DNA-DNA hybridization data indicated that X1-8T represented a novel genomic species of the genus Sphingomonas. The characteristics determined in the polyphasic taxonomic study indicated that X1-8T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas tabacisoli sp. nov. (type strain X1-8T=KCTC 62032T=CGMCC 1.16275T) is proposed.


Assuntos
Nicotiana/microbiologia , Filogenia , Rizosfera , Microbiologia do Solo , Sphingomonas/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/análogos & derivados , Espermidina/química , Sphingomonas/genética , Sphingomonas/isolamento & purificação , Ubiquinona/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA