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1.
J Nanobiotechnology ; 21(1): 149, 2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37149605

RESUMO

Surface-Enhanced Raman Scattering (SERS) technology, as a powerful tool to identify molecular species by collecting molecular spectral signals at the single-molecule level, has achieved substantial progresses in the fields of environmental science, medical diagnosis, food safety, and biological analysis. As deepening research is delved into SERS sensing, more and more high-performance or multifunctional SERS substrate materials emerge, which are expected to push Raman sensing into more application fields. Especially in the field of biological analysis, intrinsic and extrinsic SERS sensing schemes have been widely used and explored due to their fast, sensitive and reliable advantages. Herein, recent developments of SERS substrates and their applications in biomolecular detection (SARS-CoV-2 virus, tumor etc.), biological imaging and pesticide detection are summarized. The SERS concepts (including its basic theory and sensing mechanism) and the important strategies (extending from nanomaterials with tunable shapes and nanostructures to surface bio-functionalization by modifying affinity groups or specific biomolecules) for improving SERS biosensing performance are comprehensively discussed. For data analysis and identification, the applications of machine learning methods and software acquisition sources in SERS biosensing and diagnosing are discussed in detail. In conclusion, the challenges and perspectives of SERS biosensing in the future are presented.


Assuntos
Técnicas Biossensoriais , COVID-19 , Nanoestruturas , Humanos , Análise Espectral Raman/métodos , SARS-CoV-2 , Nanoestruturas/química , Nanotecnologia , Técnicas Biossensoriais/métodos
2.
Mol Cell Neurosci ; 123: 103771, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36064132

RESUMO

The precise control of proliferation and differentiation of neural progenitors is crucial for the development of the central nervous system. Fused in sarcoma (FUS) is an RNA-binding protein pathogenetically linked to Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Lobar Degeneration (FTLD) disease, yet the function of FUS on neurodevelopment is remained to be defined. Here we report a pivotal role of FUS in regulating the human cortical brain and spinal cord development via the human iPSCs-derived organoids. We found that depletion of FUS via CRISPR/CAS9 leads to an enhancement of neural proliferation and differentiation in cortical brain-organoids, but intriguingly an impairment of these phenotypes in spinal cord-organoids. In addition, FUS binds to the mRNA of a Trk tyrosine kinase receptor of neurotrophin-3 (Ntrk3) and regulates the expression of the different isoforms of Ntrk3 in a tissue-specific manner. Finally, alleviated Ntrk3 level via shRNA rescued the effects of FUS-knockout on the development of the brain- and spinal cord-organoids, suggesting that Ntrk3 is involved in FUS-regulated organoids developmental changes. Our findings uncovered the role of FUS in the neurodevelopment of the human CNS.


Assuntos
Esclerose Lateral Amiotrófica , Degeneração Lobar Frontotemporal , Humanos , Proteína FUS de Ligação a RNA/genética , Proteína FUS de Ligação a RNA/metabolismo , Organoides/metabolismo , Corpos de Inclusão/metabolismo , Degeneração Lobar Frontotemporal/genética , Esclerose Lateral Amiotrófica/metabolismo , Medula Espinal/metabolismo , Encéfalo/metabolismo
3.
Int J Environ Health Res ; : 1-9, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36473101

RESUMO

A case-control study was conducted to examine the association of particulate matter exposure during the pre-natal (the first, second, and third trimesters. and the whole pregnancy) and post-natal periods (the first year after birth) with childhood asthma in Beijing, China. Multivariable logistic regressions showed that childhood asthma was significantly associated with exposures to PM2.5 and PM10 during the entire pregnancy, with ORs of 1.28(95%CI:1.06-1.56) and 1.21(95%CI:1.02-1.42), respectively. The highest association with a 10 µg/m3 increase in PM2.5 and PM10 were both seen for the second trimester, with ORs of 1.17(95% CI: 1.05-1.30) and 1.14(95% CI: 1.04-1.24). Subgroup analyses suggested that significant and positive effects were subject to be observed in children with a family history of atopy. This study added evidence that exposures to PM2.5 and PM10 during pregnancy might increase the risk of childhood asthma in seriously polluted area, highlighting stronger associations in the second trimester.

4.
Small ; 17(14): e2006568, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33705596

RESUMO

Ensuring the stability of all-inorganic halide perovskite light-emitting diodes (LEDs) has become an obstacle that needs to be broken for commercial applications. Currently, lead halide perovskite CsPbX3 (X = Br, I, Cl) nanocrystals (NCs) are considered as alternative materials for future fluorescent lighting devices due to their combination of superior optical and electronic properties. However, the temperature of the surface of the LEDs will increase after long-term power-on work, which greatly affects the optical stability of CsPbX3 NCs. In order to overcome this bottleneck issue, a strategy of annealing perovskite materials in liquid is proposed, and the changes in photoluminescence and electroluminescence (EL) behaviors before and after annealing are studied. The results show that the luminescence stability of the annealed perovskite materials is significantly improved. Moreover, the EL stability of different perovskite LED devices under long-term operation is monitored, and the performance of the annealed materials is particularly outstanding. The results have proved that this convenient and low-cost liquid annealing strategy is suitable for large-scale postprocessing of perovskite materials, granting them stable fluorescence emission, which will bring a new dawn to the commercialization of next-generation optoelectronic devices.

5.
New Phytol ; 230(2): 698-709, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33458815

RESUMO

Rice (Oryza sativa) is the staple food for over half the world's population. Drought stress imposes major constraints on rice yields. Intriguingly, labdane-related diterpenoid (LRD) phytoalexins in maize (Zea mays) affect drought tolerance, as indicated by the increased susceptibility of an insertion mutant of the class II diterpene cyclase ZmCPS2/An2 that initiates such biosynthesis. Rice also produces LRD phytoalexins, utilizing OsCPS2 and OsCPS4 to initiate a complex metabolic network. For genetic studies of rice LRD biosynthesis the fast-growing Kitaake cultivar was selected for targeted mutagenesis via CRISPR/Cas9, with an initial focus on OsCPS2 and OsCPS4. The resulting cps2 and cps4 knockout lines were further crossed to create a cps2x4 double mutant. Both CPSs also were overexpressed. Strikingly, all of the cv Kitaake cps mutants exhibit significantly increased susceptibility to drought, which was associated with reduced stomatal closure that was evident even under well-watered conditions. However, CPS overexpression did not increase drought resistance, and cps mutants in other cultivars did not alter susceptibility to drought, although these also exhibited lesser effects on LRD production. The results suggest that LRDs may act as a regulatory switch that triggers stomatal closure in rice, which might reflect the role of these openings in microbial entry.


Assuntos
Produtos Biológicos , Diterpenos , Oryza , Secas , Oryza/genética , Proteínas de Plantas/genética , Zea mays
6.
New Phytol ; 231(1): 85-93, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33892515

RESUMO

Diterpenoids play important roles in rice microbial disease resistance as phytoalexins, as well as acting in allelopathy and abiotic stress responses. Recently, the casbane-type phytoalexin ent-10-oxodepressin was identified in rice, but its biosynthesis has not yet been elucidated. Here ent-10-oxodepressin biosynthesis was investigated via co-expression analysis and biochemical characterisation, with use of the CRISPR/Cas9 technology for genetic analysis. The results identified a biosynthetic gene cluster (BGC) on rice chromosome 7 (c7BGC), containing the relevant ent-casbene synthase (OsECBS), and four cytochrome P450 (CYP) genes from the CYP71Z subfamily. Three of these CYPs were shown to act on ent-casbene, with CYP71Z2 able to produce a keto group at carbon-5 (C5), while the closely related paralogues CYP71Z21 and CYP71Z22 both readily produce a keto group at C10. Together these C5 and C10 oxidases can elaborate ent-casbene to ent-10-oxodepressin (5,10-diketo-ent-casbene). OsECBS knockout lines no longer produce casbane-type diterpenoids and exhibit impaired resistance to the rice fungal blast pathogen Magnaporthe oryzae. Elucidation of ent-10-oxodepressin biosynthesis and the associated c7BGC provides not only a potential target for molecular breeding, but also, gives the intriguing parallels to the independently assembled BGCs for casbene-derived diterpenoids in the Euphorbiaceae, further insight into plant BGC evolution, as discussed here.


Assuntos
Diterpenos , Oryza , Sesquiterpenos , Ascomicetos , Família Multigênica , Oryza/genética , Proteínas de Plantas/genética , Fitoalexinas
7.
Bioconjug Chem ; 32(6): 1094-1104, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34013721

RESUMO

Antibody-drug conjugates (ADCs) are complex pharmaceutical molecules that combine monoclonal antibodies with biologically active drugs through chemical linkers. ADCs are designed to specifically kill disease cells by utilizing the target specificity of antibodies and the cytotoxicity of chemical drugs. However, the traditional ADCs were only applied to a few disease targets because of some limitations such as the huge molecular weight, the uncontrollable coupling reactions, and a single mechanism of action. Here we report a simple, one-pot, successive reaction method to produce dual payload conjugates with the site-specifically engineered cysteine and p-acetyl-phenylalanine using Herceptin (trastuzumab), an anti-HER2 antibody drug widely used for breast cancer treatment, as a tool molecule. This strategy enables antibodies to conjugate with two mechanistically distinct cytotoxic drugs through different functional groups sequentially, therefore, rendering the newly designed ADCs with functional diversity and the potential to overcome drug resistance and enhance the therapeutic efficacy.


Assuntos
Cisteína/química , Imunoconjugados/química , Cinética , Trastuzumab/química
8.
Plant Cell ; 30(5): 1119-1131, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29691314

RESUMO

Among their responses to microbial infection, plants deploy an arsenal of natural antibiotic products. Historically these have been identified on the basis of their antibiotic activity in vitro, which leaves open the question of their relevance to defense in planta. The vast majority of such natural products from the important crop plant rice (Oryza sativa) are diterpenoids whose biosynthesis proceeds via either ent- or syn-copalyl diphosphate (CPP) intermediates, which were isolated on the basis of their antibiotic activity against the fungal blast pathogen Magnaporthe oryzae However, rice plants in which the gene for the syn-CPP synthase Os-CPS4 is knocked out do not exhibit increased susceptibility to M. oryzae Here, we show that knocking out or knocking down Os-CPS4 actually decreases susceptibility to the bacterial leaf blight pathogen Xanthomonas oryzae By contrast, genetic manipulation of the gene for the ent-CPP synthase Os-CPS2 alters susceptibility to both M. oryzae and X. oryzae Despite the secretion of diterpenoids dependent on Os-CPS2 or Os-CPS4 from roots, neither knockout exhibited significant changes in the composition of their rhizosphere bacterial communities. Nevertheless, rice plants allocate substantial metabolic resources toward syn- as well as ent-CPP derived diterpenoids upon infection/induction. Further investigation revealed that Os-CPS4 plays a role in fungal non-host disease resistance. Thus, examination of metabolic allocation provides important clues into physiological function.


Assuntos
Diterpenos/metabolismo , Oryza/metabolismo , Resistência à Doença/genética , Resistência à Doença/fisiologia , Regulação da Expressão Gênica de Plantas , Magnaporthe/patogenicidade , Oryza/microbiologia , Doenças das Plantas/microbiologia
9.
Plant J ; 97(5): 841-857, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30444296

RESUMO

Andrographis paniculata is a herbaceous dicot plant widely used for its anti-inflammatory and anti-viral properties across its distribution in China, India and other Southeast Asian countries. A. paniculata was used as a crucial therapeutic treatment during the influenza epidemic of 1919 in India, and is still used for the treatment of infectious disease in China. A. paniculata produces large quantities of the anti-inflammatory diterpenoid lactones andrographolide and neoandrographolide, and their analogs, which are touted to be the next generation of natural anti-inflammatory medicines for lung diseases, hepatitis, neurodegenerative disorders, autoimmune disorders and inflammatory skin diseases. Here, we report a chromosome-scale A. paniculata genome sequence of 269 Mb that was assembled by Illumina short reads, PacBio long reads and high-confidence (Hi-C) data. Gene annotation predicted 25 428 protein-coding genes. In order to decipher the genetic underpinning of diterpenoid biosynthesis, transcriptome data from seedlings elicited with methyl jasmonate were also obtained, which enabled the identification of genes encoding diterpenoid synthases, cytochrome P450 monooxygenases, 2-oxoglutarate-dependent dioxygenases and UDP-dependent glycosyltransferases potentially involved in diterpenoid lactone biosynthesis. We further carried out functional characterization of pairs of class-I and -II diterpene synthases, revealing the ability to produce diversified labdane-related diterpene scaffolds. In addition, a glycosyltransferase able to catalyze O-linked glucosylation of andrograpanin, yielding the major active product neoandrographolide, was also identified. Thus, our results demonstrate the utility of the combined genomic and transcriptomic data set generated here for the investigation of the production of the bioactive diterpenoid lactone constituents of the important medicinal herb A. paniculata.


Assuntos
Andrographis/genética , Diterpenos/metabolismo , Genoma de Planta/genética , Glucosídeos/biossíntese , Compostos Fitoquímicos/biossíntese , Proteínas de Plantas/metabolismo , Andrographis/química , Andrographis/enzimologia , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Proteínas de Plantas/genética , Plantas Medicinais/química , Plantas Medicinais/enzimologia , Plantas Medicinais/genética , Tetra-Hidronaftalenos
10.
New Phytol ; 227(3): 930-943, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32187685

RESUMO

Lonicera japonica is a widespread member of the Caprifoliaceae (honeysuckle) family utilized in traditional medical practices. This twining vine honeysuckle also is a much-sought ornamental, in part due to its dynamic flower coloration, which changes from white to gold during development. The molecular mechanism underlying dynamic flower coloration in L. japonica was elucidated by integrating whole genome sequencing, transcriptomic analysis and biochemical assays. Here, we report a chromosome-level genome assembly of L. japonica, comprising nine pseudochromosomes with a total size of 843.2 Mb. We also provide evidence for a whole-genome duplication event in the lineage leading to L. japonica, which occurred after its divergence from Dipsacales and Asterales. Moreover, gene expression analysis not only revealed correlated expression of the relevant biosynthetic genes with carotenoid accumulation, but also suggested a role for carotenoid degradation in L. japonica's dynamic flower coloration. The variation of flower color is consistent with not only the observed carotenoid accumulation pattern, but also with the release of volatile apocarotenoids that presumably serve as pollinator attractants. Beyond novel insights into the evolution and dynamics of flower coloration, the high-quality L. japonica genome sequence also provides a foundation for molecular breeding to improve desired characteristics.


Assuntos
Lonicera , Carotenoides , Flores/genética , Perfilação da Expressão Gênica , Lonicera/genética
11.
Environ Res ; 183: 109066, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32058147

RESUMO

INTRODUCTION: Epidemiologic studies have reported associations between short-term exposure to particulate matter <2.5 µm in aerodynamic diameter (PM2.5) and mortality, but the role of modifiers remains unclear with studies reporting inconsistent results. We evaluated the impact of individual (age, gender and education) and township (geographic area, socioeconomic status, background air pollution and road density) level factors on the relationship between short-term variation in PM2.5 with cause-specific mortality in Beijing (population: 21.7 million in 2016), China. METHODS: Daily PM2.5 concentrations in each township (n = 327; township population: 2000-359,400; township area: 1-392 km2) within Beijing were estimated by kriging with external drift using measurements from 35 air quality monitoring stations and geographic variables. Time-stratified case-crossover analysis with township-level mortality data from Oct. 1st, 2012 to Dec. 31st, 2013 was then used to examine associations between PM2.5 exposure estimates and cause-specific mortality, stratified by the potential effect modifiers. RESULTS: A 10-µg/m3 increase in PM2.5 concentration was associated with a 0.17% [95% confidence interval (CI): 0.05%-0.29%] and 0.27% (95%CI:0.01%-0.52%) increase in non-accidental and stroke mortality with no lag, a 0.81% (95%CI:0.39%-1.23%) and 0.96% (95%CI:0.35%-1.57%) increase in respiratory disease (RD) and chronic obstructive pulmonary disease (COPD) mortality at a lag of two-day moving average. For individual-level effect modifiers, the elderly showed higher effects for all the specific causes of mortality; those with lower education level showed higher effects for non-accidental, cardiovascular disease and stroke mortality; females showed higher effects for non-accidental and cause-specific cardiovascular diseases. For township-level effect modifiers, effect estimates tended to be larger for suburban areas, areas of lower road density, lower PM2.5 and lower socioeconomic status. CONCLUSIONS: Short-term exposure to township-level ambient PM2.5 was associated with increased mortality in Beijing, with indications of effect modification by both individual and township-level factors.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Mortalidade , Material Particulado , Pequim , China , Exposição Ambiental , Feminino , Humanos , Masculino , Mortalidade/tendências , Material Particulado/toxicidade , Doença Pulmonar Obstrutiva Crônica/mortalidade , Acidente Vascular Cerebral/mortalidade
12.
Plant J ; 93(1): 50-65, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29086455

RESUMO

Tripterygium wilfordii, which has long been used as a medicinal plant, exhibits impressive and effective anti-inflammatory, immunosuppressive and anti-tumor activities. The main active ingredients are diterpenoids and triterpenoids, such as triptolide and celastrol, respectively. A major challenge to harnessing these natural products is that they are found in very low amounts in planta. Access has been further limited by the lack of knowledge regarding their underlying biosynthetic pathways, particularly for the abeo-abietane tri-epoxide lactone triptolide. Here suspension cell cultures of T. wilfordii were found to produce triptolide in an inducible fashion, with feeding studies indicating that miltiradiene is the relevant abietane olefin precursor. Subsequently, transcriptome data were used to identify eight putative (di)terpene synthases that were then characterized for their potential involvement in triptolide biosynthesis. This included not only biochemical studies which revealed the expected presence of class II diterpene cyclases that produce the intermediate copalyl diphosphate (CPP), along with the more surprising finding of an atypical class I (di)terpene synthase that acts on CPP to produce the abietane olefin miltiradiene, but also their subcellular localization and, critically, genetic analysis. In particular, RNA interference targeting either both of the CPP synthases, TwTPS7v2 and TwTPS9v2, or the subsequently acting miltiradiene synthase, TwTPS27v2, led to decreased production of triptolide. Importantly, these results then both confirm that miltiradiene is the relevant precursor and the relevance of the identified diterpene synthases, enabling future studies of the biosynthesis of this important bioactive natural product.


Assuntos
Alquil e Aril Transferases/metabolismo , Diterpenos/metabolismo , Fenantrenos/metabolismo , Tripterygium/enzimologia , Alquil e Aril Transferases/genética , Vias Biossintéticas , Compostos de Epóxi/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Medicinais , Interferência de RNA , Tripterygium/genética
13.
Proc Natl Acad Sci U S A ; 113(9): 2526-31, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26884192

RESUMO

The substrate specificity of enzymes from natural products' metabolism is a topic of considerable interest, with potential biotechnological use implicit in the discovery of promiscuous enzymes. However, such studies are often limited by the availability of substrates and authentic standards for identification of the resulting products. Here, a modular metabolic engineering system is used in a combinatorial biosynthetic approach toward alleviating this restriction. In particular, for studies of the multiply reactive cytochrome P450, ent-kaurene oxidase (KO), which is involved in production of the diterpenoid plant hormone gibberellin. Many, but not all, plants make a variety of related diterpenes, whose structural similarity to ent-kaurene makes them potential substrates for KO. Use of combinatorial biosynthesis enabled analysis of more than 20 such potential substrates, as well as structural characterization of 12 resulting unknown products, providing some insight into the underlying structure-function relationships. These results highlight the utility of this approach for investigating the substrate specificity of enzymes from complex natural products' biosynthesis.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Giberelinas/biossíntese , Sondas Moleculares , Filogenia , Plantas/enzimologia , Plantas/metabolismo , Especificidade por Substrato
14.
Plant Physiol ; 175(1): 92-103, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28751314

RESUMO

Adventitious root cultures were developed from Tripterygium regelii, and growth conditions were optimized for the abundant production of diterpenoids, which can be collected directly from the medium. An analysis of publicly available transcriptome data sets collected with T. regelii roots and root cultures indicated the presence of a large gene family (with 20 members) for terpene synthases (TPSs). Nine candidate diterpene synthase genes were selected for follow-up functional evaluation, of which two belonged to the TPS-c, three to the TPS-e/f, and four to the TPS-b subfamilies. These genes were characterized by heterologous expression in a modular metabolic engineering system in Escherichia coli Members of the TPS-c subfamily were characterized as copalyl diphosphate (diterpene) synthases, and those belonging to the TPS-e/f subfamily catalyzed the formation of precursors of kaurane diterpenoids. The TPS-b subfamily encompassed genes coding for enzymes involved in abietane diterpenoid biosynthesis and others with activities as monoterpene synthases. The structural characterization of diterpenoids accumulating in the medium of T. regelii adventitious root cultures, facilitated by searching the Spektraris online spectral database, enabled us to formulate a biosynthetic pathway for the biosynthesis of triptolide, a diterpenoid with pharmaceutical potential. Considering the significant enrichment of diterpenoids in the culture medium, fast-growing adventitious root cultures may hold promise as a sustainable resource for the large-scale production of triptolide.


Assuntos
Técnicas de Cultura , Diterpenos/metabolismo , Fenantrenos/metabolismo , Raízes de Plantas/metabolismo , Tripterygium/metabolismo , Compostos de Epóxi/metabolismo
15.
BMC Infect Dis ; 18(1): 158, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29614964

RESUMO

BACKGROUND: Hand-foot-mouth disease (HFMD) is a common infectious disease in China and occurs mostly in infants and children. Beijing is a densely populated megacity, in which HFMD has been increasing in the last decade. The aim of this study was to quantify spatio-temporal characteristics of HFMD and the relationship between meteorological factors and HFMD incidence in Beijing, China. METHODS: Daily counts of HFMD cases from January 2010 to December 2012 were obtained from the Beijing Center for Disease Prevention and Control (CDC). Seasonal trend decomposition with Loess smoothing was used to explore seasonal patterns and temporal trends of HFMD. Bayesian spatiotemporal Poisson regression models were used to quantify spatiotemporal patterns of HFMD incidence and associations with meteorological factors. RESULTS: There were 114,777 HFMD cases reported to Beijing CDC from 1 January 2010 to 31 December 2012 and the raw incidence was 568.6 per 100,000 people. May to July was the peak period of HFMD incidence each year. Low-incidence townships were clustered in central, northeast and southwest regions of Beijing. Mean temperature, relative humidity, wind velocity and sunshine hours were all positively associated with HFMD. The effect of wind velocity was significant with a RR of 3.30 (95%CI: 2.37, 4.60) per meter per second increase, as was sunshine hours with a RR of 1.20 (95%CI: 1.02, 1.40) per 1 hour increase. CONCLUSIONS: The distribution of HFMD in Beijing was spatiotemporally heterogeneous, and was associated with meteorological factors. Meteorological monitoring could be incorporated into prediction and surveillance of HFMD in Beijing.


Assuntos
Doença de Mão, Pé e Boca/diagnóstico , Análise Espaço-Temporal , Adolescente , Teorema de Bayes , Criança , Pré-Escolar , China/epidemiologia , Feminino , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/etiologia , Humanos , Umidade , Incidência , Lactente , Recém-Nascido , Masculino , Risco , Estações do Ano , Temperatura , Vento
16.
Plant Physiol ; 170(2): 742-51, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26620527

RESUMO

While most commonly associated with its role in gibberellin phytohormone biosynthesis, ent-kaurene also serves as an intermediate in more specialized diterpenoid metabolism, as exemplified by the more than 800 known derived natural products. Among these are the maize kauralexins. However, no ent-kaurene synthases (KSs) have been identified from maize. The maize gibberellin-deficient dwarf-5 (d5) mutant has been associated with a loss of KS activity. The relevant genetic lesion has been previously mapped, and was found here to correlate with the location of the KS-like gene ZmKSL3. Intriguingly, this forms part of a tandem array with two other terpene synthases (TPSs). Although one of these, ZmTPS1, has been previously reported to encode a sesquiterpene synthase, and both ZmTPS1 and that encoded by the third gene, ZmKSL5, have lost the N-terminal γ-domain prototypically associated with KS(L)s, all three genes fall within the KS(L) or TPS-e subfamily. Here it is reported that all three genes encode enzymes that are targeted to the plastid in planta, where diterpenoid biosynthesis is initiated, and which all readily catalyze the production of ent-kaurene. Consistent with the closer phylogenetic relationship of ZmKSL3 with previously identified KSs from cereals, only transcription of this gene is affected in d5 plants. On the other hand, the expression of all three of these genes is inducible, suggesting a role in more specialized metabolism, such as that of the kauralexins. Thus, these results clarify not only gibberellin phytohormone, but also diterpenoid phytoalexin biosynthesis in this important cereal crop plant.


Assuntos
Alquil e Aril Transferases/genética , Giberelinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Zea mays/enzimologia , Alquil e Aril Transferases/metabolismo , Sequência de Bases , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Alinhamento de Sequência , Sesquiterpenos/metabolismo , Zea mays/genética , Fitoalexinas
17.
Metabolomics ; 14(1): 5, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30830317

RESUMO

INTRODUCTION: The absolute quantitation of lipids at the lipidome-wide scale is a challenge but plays an important role in the comprehensive study of lipid metabolism. OBJECTIVES: We aim to develop a high-throughput quantitative lipidomics approach to enable the simultaneous identification and absolute quantification of hundreds of lipids in a single experiment. Then, we will systematically characterize lipidome-wide changes in the aging mouse brain and provide a link between aging and disordered lipid homeostasis. METHODS: We created an in-house lipid spectral library, containing 76,361 lipids and 181,300 MS/MS spectra in total, to support accurate lipid identification. Then, we developed a response factor-based approach for the large-scale absolute quantifications of lipids. RESULTS: Using the lipidomics approach, we absolutely quantified 1212 and 864 lipids in human cells and mouse brains, respectively. The quantification accuracy was validated using the traditional approach with a median relative error of 12.6%. We further characterized the lipidome-wide changes in aging mouse brains, and dramatic changes were observed in both glycerophospholipids and sphingolipids. Sphingolipids with longer acyl chains tend to accumulate in aging brains. Membrane-esterified fatty acids demonstrated diverse changes with aging, while most polyunsaturated fatty acids consistently decreased. CONCLUSION: We developed a high-throughput quantitative lipidomics approach and systematically characterized the lipidome-wide changes in aging mouse brains. The results proved a link between aging and disordered lipid homeostasis.


Assuntos
Encéfalo/metabolismo , Ácidos Graxos/metabolismo , Glicerofosfolipídeos/metabolismo , Metabolismo dos Lipídeos/fisiologia , Esfingolipídeos/metabolismo , Fatores Etários , Animais , Cromatografia Líquida de Alta Pressão/métodos , Ensaios de Triagem em Larga Escala/métodos , Homeostase/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Bibliotecas de Moléculas Pequenas/metabolismo , Espectrometria de Massas em Tandem/métodos
18.
J Nat Prod ; 80(2): 328-333, 2017 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-28140586

RESUMO

While terpenoid production is generally associated with plants, a variety of fungi contain operons predicted to lead to such biosynthesis. Notably, fungi contain a number of cyclases characteristic of labdane-related diterpenoid metabolism, which have not been much explored. These also are often found near cytochrome P450 (CYP) mono-oxygenases that presumably further decorate the ensuing diterpene, suggesting that these fungi might produce more elaborate diterpenoids. To probe the functional diversity of such biosynthetic capacity, an investigation of the phylogenetically diverse cyclases and associated CYPs from the fungal genus Aspergillus was undertaken, revealing their ability to produce isopimaradiene-derived diterpenoids. Intriguingly, labdane-related diterpenoid biosynthetic genes are largely found in plant-associated fungi, hinting that these natural products may play a role in such interactions. Accordingly, it is hypothesized here that isopimarane production may assist the plant-saprophytic lifestyle of Aspergillus fungi.


Assuntos
Aspergillus/química , Sistema Enzimático do Citocromo P-450/metabolismo , Diterpenos/química , Aspergillus/fisiologia , Diterpenos/metabolismo , Estrutura Molecular
19.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 37(2): 179-183, 2017 Feb.
Artigo em Zh | MEDLINE | ID: mdl-30650270

RESUMO

Objective To evaluate the efficacy and safety of Liujin Runzao Concentrated Decoction (LRCD) for the treatment of primary Sjögren's syndrome (pSS). Methods Forty pSS patients with fluid depletion and distribution obstacles syndrome (FDDOS) were randomly assigned to the experimen- tal group and the control group according to 1:1 proportion. All patients received standard therapy: Radix Paeoniae alba total glycosides 600 mg, twice per day. Patients in the experimental group additionally took LRCD, 30 mL each time, twice per day. The therapeutic course for all was 4 weeks, and two courses for all. The improvement of dry mouth and dry eyes were comprehensively evaluated. Each outcome of composite index constitutions (integrals of dry eyes and dry mouth, salivary flow rate, Schirmer test) was respectively reported. Schirmer test and salivary flow rate were determined as well. Score of TCM syndrome, blood sedimentation,'immunoglobulin, and adverse drug reactions were observed. Results The effective rate of comprehensive effect for dry eyes and dry mouth improvement at the end of 8 weeks was 80% in the experimental group and 35% in the control group, with statistical difference (X² =8. 286, P <0. 05). As for the composition of comprehensive effect for dry eyes and dry mouth improvement: The score for dry eyes and dry mouth decreased in the two groups more after treatment than before treatment. The difference in pre-post treatment score for dry eyes and dry mouth at week 8 was higher in the experimental group than in the control group. The difference in pre-post treatment score at week 8 was 1. 71 (95% Cl: -0. 37 -3. 78) between the two groups (P <0. 05). The difference in pre-post treatment Schirmer test and salivary flow rate at week 8 was higher in the experimental group than in the control group, but with on statistical difference (P >0. 05). The difference in pre-post treatment Schirmer test and salivary flow rate at week 8 was 2. 74 mL/15 min (95% Cl: 0. 49 -4.98) and 0. 13 mm/5 min (95% Cl: 0. 92 -1. 23) between the two groups (P <0. 05). The score of TCM syndrome decreased more in the two groups, as compared with before treatment. The difference in pre-post treatment score of TCM syn- drome at week 8 was 1. 71 (95% CI: -1. 40 -4. 81) between the two groups (P >0. 05). One case of uri- nary tract infections occurred in the control group, while no obvious adverse event occurred in the exper- imental group. Conclusion Standard treatment combined LRCD showed better comprehensive effect for dry eyes and dry mouth in pSS patients with FDDOS, and was more safe.


Assuntos
Medicamentos de Ervas Chinesas , Síndrome de Sjogren , Sedimentação Sanguínea , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Síndrome de Sjogren/terapia
20.
Appl Microbiol Biotechnol ; 99(18): 7549-58, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25758958

RESUMO

The oxygenation reactions catalyzed by cytochromes P450 (CYPs) play critical roles in plant natural products biosynthesis. At the same time, CYPs are one of most challenging enzymes to functionally characterize due to the difficulty of recombinantly expressing these membrane-associated monooxygenases. In the course of investigating rice diterpenoid biosynthesis, we have developed a synthetic biology approach for functional expression of relevant CYPs in Escherichia coli. In certain cases, activity was observed for only one of two closely related paralogs although it seems clear that related reactions are required for production of the known diterpenoids. Here, we report that optimization of the recombinant expression system enabled characterization of not only these previously recalcitrant CYPs, but also discovery of additional activity relevant to rice diterpenoid biosynthesis. Of particular interest, CYP701A8 was found to catalyze 3ß-hydroxylation of syn-pimaradiene, which is presumably relevant to momilactone biosynthesis, while CYP71Z6 & 7 were found to catalyze multiple reactions, with CYP71Z6 catalyzing the production of 2α,3α-dihydroxy-ent-isokaurene via 2α-hydroxy-ent-isokaurene, and CYP71Z7 catalyzing the production of 3α-hydroxy-ent-cassadien-2-one via 2α-hydroxy-ent-cassadiene and ent-cassadien-2-one, which may be relevant to oryzadione and phytocassane biosynthesis, respectively.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Diterpenos/metabolismo , Oryza/enzimologia , Escherichia coli/genética , Escherichia coli/metabolismo , Oryza/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
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