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1.
J Am Chem Soc ; 145(9): 5545-5552, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36827700

RESUMO

Controlling molecular chirality by external stimuli is of great significance in both fundamental research and technological applications. Herein, we report a high-temperature (384 K) molecular ferroelectric of a Cu(II) complex whose spontaneous polarization can be switched associated with flipping of molecular chirality. In this two-dimensional perovskite structure, the inorganic layer is separated by (NH3(CH2)2SS(CH2)2NH3)2+ organic cations skewed in a chiral conformation (P- or M-helicity in an individual crystal). As the stereodynamic disulfide bridge determines the molecular dipole moment along the polar axis, the chiral organic cation can be converted to its enantiomer as a consequence of an electric field-induced shift of the S-S moiety relative to its screw axis during the ferroelectric switching. The variation of the molecular chirality is examined with single-crystal X-ray diffraction and circular dichroism spectra. The simultaneous switching of molecular chirality and spontaneous polarization in this perovskite ferroelectric may lead to novel chiral electronic phenomena.

2.
Inorg Chem ; 62(23): 8778-8783, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37255342

RESUMO

In the past two decades, numerous molecular ferroelectrics have been reported. However, metal-free molecular ferroelectrics with high working temperatures and large spontaneous polarizations are still uncommon. Herein, we present two metal-free molecular ferroelectrics prepared from monoprotonated hexamethylenetetramine (HMTA), namely (HMTAH)Cl and (HMTAH)Br, which crystallize in a polar point group of 3m. In these crystals, the polar HMTAH+ organic cations can be reoriented 180° along the polar axis because of the quasispherical molecular geometry. As a result of the large shift of the positively charged protonated N atoms, these compounds demonstrate large spontaneous polarizations with values of 8.3 and 8.1 µC cm-2 and high working temperatures of 390 and 435 K, respectively. The ferroelectric property of these compounds is characterized with second-harmonic generation, ferroelectric hysteresis loop, and pyroelectric current measurements.

3.
J Environ Manage ; 344: 118326, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37329584

RESUMO

Accurately obtaining the pollution sources and their contribution rates is the basis for refining watershed management. Although many source analysis methods have been proposed, a systematic framework for watershed management is still lacking, including the complete process of pollution source identification to control. We proposed a framework for identification and abatement of pollutants and applied in the Huangshui River Basin. A newer contaminant flux variation method based on a one-dimensional river water quality model was used to calculate the contribution of pollutants. The contributions of various factors to the over-standard parameters of water quality sections at different spatial and temporal scales were calculated. Based on the calculation results, corresponding pollution abatement projects were developed, and the effectiveness of the projects was evaluated through scenario simulation. Our results showed that the large scale livestock and poultry farms and sewage treatment plants were the largest sources of total nitrogen (TP) in Xiaoxia bridge section, with contribution rates of 46.02% and 36.74%, respectively. Additionally, the largest contribution sources of ammonia nitrogen (NH3-N) were sewage treatment plants (36.17%) and industrial sewage (26.33%). Three towns that contributed the most to TP were Lejiawan Town (14.4%), Ganhetan Town (7.3%) and Handong Hui Nationality town (6.6%), while NH3-N mainly from the Lejiawan Town (15.9%), Xinghai Road Sub-district (12.4%) and Mafang Sub-district (9.5%). Further analysis found that point sources in these towns were the main contributor to TP and NH3-N. Accordingly, we developed abatement projects for point sources. Scenario simulation indicated that the TP and NH3-N could be significantly improved by closing down and upgrading relevant sewage treatment plants and building facilities for large scale livestock and poultry farms. The framework adopted in this study can accurately identify pollution sources and evaluate the effectiveness of pollution abatement projects, which is conducive to the refined water environment management.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Qualidade da Água , Rios , Monitoramento Ambiental/métodos , Esgotos , China , Nitrogênio/análise , Poluentes Químicos da Água/análise , Poluição da Água/prevenção & controle , Poluição da Água/análise , Fósforo/análise
4.
J Integr Plant Biol ; 65(3): 656-673, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36223073

RESUMO

Moderate stimuli in mitochondria improve wide-ranging stress adaptability in animals, but whether mitochondria play similar roles in plants is largely unknown. Here, we report the enhanced stress adaptability of S-type cytoplasmic male sterility (CMS-S) maize and its association with mild expression of sterilizing gene ORF355. A CMS-S maize line exhibited superior growth potential and higher yield than those of the near-isogenic N-type line in saline fields. Moderate expression of ORF355 induced the accumulation of reactive oxygen species and activated the cellular antioxidative defense system. This adaptive response was mediated by elevation of the nicotinamide adenine dinucleotide concentration and associated metabolic homeostasis. Metabolome analysis revealed broad metabolic changes in CMS-S lines, even in the absence of salinity stress. Metabolic products associated with amino acid metabolism and galactose metabolism were substantially changed, which underpinned the alteration of the antioxidative defense system in CMS-S plants. The results reveal the ORF355-mediated superior stress adaptability in CMS-S maize and might provide an important route to developing salt-tolerant maize varieties.


Assuntos
Infertilidade das Plantas , Zea mays , Zea mays/genética , Infertilidade das Plantas/genética , Mitocôndrias/metabolismo , Citoplasma/metabolismo , Homeostase
5.
J Environ Sci (China) ; 128: 107-116, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36801026

RESUMO

The degradation of metoprolol (MTP) by the UV/sulfite with oxygen as an advanced reduction process (ARP) and that without oxygen as an advanced oxidation process (AOP) was comparatively studied herein. The degradation of MTP by both processes followed the first-order rate law with comparable reaction rate constants of 1.50×10-3sec-1 and 1.20×10-3sec-1, respectively. Scavenging experiments demonstrated that both eaq- and H• played a crucial role in MTP degradation by the UV/sulfite as an ARP, while SO4•- was the dominant oxidant in the UV/sulfite AOP. The degradation kinetics of MTP by the UV/sulfite as an ARP and AOP shared a similar pH dependence with a minimum rate obtained around pH 8. The results could be well explained by the pH impacts on the MTP speciation and sulfite species. Totally six transformation products (TPs) were identified from MTP degradation by the UV/sulfite ARP, and two additional ones were detected in the UV/sulfite AOP. The benzene ring and ether groups of MTP were proposed as the major reactive sites for both processes based on molecular orbital calculations by density functional theory (DFT). The similar degradation products of MTP by the UV/sulfite process as an ARP and AOP indicated that eaq-/H• and SO4•- might share similar reaction mechanisms, primarily including hydroxylation, dealkylation, and H abstraction. The toxicity of MTP solution treated by the UV/sulfite AOP was calculated to be higher than that in the ARP by the Ecological Structure Activity Relationships (ECOSAR) software, due to the accumulation of TPs with higher toxicity.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Metoprolol/química , Oxigênio , Raios Ultravioleta , Poluentes Químicos da Água/química , Oxirredução , Sulfitos/química , Cinética , Purificação da Água/métodos
6.
BMC Plant Biol ; 22(1): 469, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36180833

RESUMO

BACKGROUND: Cytoplasmic male sterility (CMS) is a trait of economic importance in the production of hybrid seeds. In CMS-S maize, exerted anthers appear frequently in florets of field-grown female populations where only complete male-sterile plants were expected. It has been reported that these reversions are associated with the loss of sterility-conferring regions or other rearrangements in the mitochondrial genome. However, the relationship between mitochondrial function and sterility stability is largely unknown. RESULTS: In this study, we determined the ratio of plants carrying exerted anthers in the population of two CMS-S subtypes. The subtype with a high ratio of exerted anthers was designated as CMS-Sa, and the other with low ratio was designated as CMS-Sb. Through next-generation sequencing, we assembled and compared mitochondrial genomes of two CMS-S subtypes. Phylogenetic analyses revealed strong similarities between the two mitochondrial genomes. The sterility-associated regions, S plasmids, and terminal inverted repeats (TIRs) were intact in both genomes. The two subtypes maintained high transcript levels of the sterility gene orf355 in anther tissue. Most of the functional genes/proteins were identical at the nucleotide sequence and amino acid sequence levels in the two subtypes, except for NADH dehydrogenase subunit 1 (nad1). In the mitochondrial genome of CMS-Sb, a 3.3-kilobase sequence containing nad1-exon1 was absent from the second copy of the 17-kb repeat region. Consequently, we detected two copies of nad1-exon1 in CMS-Sa, but only one copy in CMS-Sb. During pollen development, nad1 transcription and mitochondrial biogenesis were induced in anthers of CMS-Sa, but not in those of CMS-Sb. We suggest that the impaired mitochondrial function in the anthers of CMS-Sb is associated with its more stable sterility. CONCLUSIONS: Comprehensive analyses revealed diversity in terms of the copy number of the mitochondrial gene nad1-exon1 between two subtypes of CMS-S maize. This difference in copy number affected the transcript levels of nad1 and mitochondrial biogenesis in anther tissue, and affected the reversion rate of CMS-S maize. The results of this study suggest the involvement of mitochondrial robustness in modulation of sterility stability in CMS-S maize.


Assuntos
Genoma Mitocondrial , Infertilidade Masculina , Genoma Mitocondrial/genética , Humanos , Infertilidade Masculina/genética , Masculino , NADH Desidrogenase/genética , Filogenia , Infertilidade das Plantas/genética , Zea mays/genética
7.
Theor Appl Genet ; 135(9): 3039-3055, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35788748

RESUMO

KEY MESSAGE: The novel ZmR1CQ01 allele for maize anthocyanin synthesis was identified, and the biological function and regulatory molecular mechanisms of three ZmR1 alleles were unveiled. Anthocyanins in maize are valuable to human health. The R1 gene family is one of the important regulatory genes for the tissue-specific distribution of anthocyanins. R1 gene allelic variations are abundant and its biological function and regulatory molecular mechanisms are not fully understood. By exploiting genetic mapping and transgenic verification, we found that anthocyanin pigmentation in maize leaf midrib was controlled by ZmR1 on chromosome 10. Allelism test of maize zmr1 EMS mutants confirmed that anthocyanin pigmentation in leaf sheath was also controlled by ZmR1. ZmR1CQ01 was a novel ZmR1 allelic variation obtained from purple maize. Its overexpression caused the whole maize plant to turn purple. ZmR1B73 allele confers anthocyanin accumulation in near ground leaf sheath rather than in leaf midribs. The mRNA expression level of ZmR1B73 was low in leaf midribs, resulting in no anthocyanin accumulation. ZmR1B73 overexpression promoted anthocyanin accumulation in leaf midribs. Loss of exon 5 resulted in ZmR1ZN3 allele function destruction and no anthocyanin accumulation in leaf midrib and leaf sheath. DNA affinity purification sequencing revealed 1010 genes targeted by ZmR1CQ01, including the bz2 in anthocyanin synthesis pathway. RNA-seq analysis showed 55 genes targeted by ZmR1CQ01 changed the expression level significantly, and the expression of genes encoding key enzymes in flavonoid and phenylpropanoid biosynthesis pathways were significantly up-regulated. ZmR1 functional molecular marker was developed. These results revealed the effects of transcriptional regulation and sequence variation on ZmR1 function and identified the genes targeted by ZmR1CQ01 at the genome-wide level.


Assuntos
Antocianinas , Zea mays , Alelos , DNA , Regulação da Expressão Gênica de Plantas , Pigmentação/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro , Zea mays/genética , Zea mays/metabolismo
8.
Genomics ; 113(4): 1940-1951, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33895282

RESUMO

Na+, K+ and pH homeostasis are important for plant life and they are controlled by the monovalent cation proton antiporter (CPA) superfamily. The roles of ZmCPAs in salt tolerance are not fully elucidated. In this study, we identified 35 ZmCPAs comprising 13 Na+/H+ exchangers (ZmNHXs), 16 cation/H+ exchanger (ZmCHXs), and 6 K+ efflux antiporters (ZmKEAs). All ZmCPAs have transmembrane domains and most of them were localized to plasma membrane or tonoplast. ZmCHXs were specifically highly expressed in anthers, while ZmNHXs and ZmKEAs showed high expression in various tissues. ZmNHX5 and ZmKEA2 were up-regulated in maize seedlings under both NaCl and KCl stresses. Yeast complementation experiments revealed the roles of ZmNHX5, ZmKEA2 in NaCl tolerance. Analysis of the maize mutants further validated the salt tolerance functions of ZmNHX5 and ZmKEA2. Our study highlights comprehensive information of ZmCPAs and provides new gene targets for salt tolerance maize breeding.


Assuntos
Antiporters , Tolerância ao Sal , Antiporters/genética , Antiporters/metabolismo , Cátions Monovalentes/metabolismo , Melhoramento Vegetal , Prótons , Tolerância ao Sal/genética , Zea mays/genética , Zea mays/metabolismo
9.
J Cell Mol Med ; 25(16): 7783-7795, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34160889

RESUMO

Cognitive dysfunction is one of the complications of diabetes. Unfortunately, there is no effective methods to block its progression currently. One of the pathophysiological mechanisms is synaptic protein damage and neuronal signal disruption because of glucose metabolism disorder. Dystroglycan protein, located in the post-synaptic membrane of neurons, links the intracellular cytoskeleton with extracellular matrix. Abnormal expression of dystroglycan protein affects neuronal biological functions and leads to cognitive impairment. However, there are no relevant studies to observe the changes of ß-dystroglycan protein in diabetes rat brain and in primary neurons under high glucose exposure. Our data demonstrated the alterations of cognitive abilities in the diabetic rats; ß-dystroglycan protein degradation occurred in hippocampal and cortical tissues in diabetic rat brain. We further explored the mechanisms underlying of this phenomenon. When neurons are exposed to high glucose environment in long-term period, microRNA-132 (miR-132) would be down-regulated in neurons. Matrix Metalloproteinases-9 (MMP-9) mRNA, as a target of miR-132, could be up-regulated; higher expression and overlay activity of MMP-9 protein could increase ß-DG protein degradation. In this way, ß-DG degradation may affect structure and functions among the synapses, which related to cognition decline. It may provide some theoretical basis for elucidating the molecular mechanism of diabetes-induced cognitive dysfunction.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Distroglicanas/metabolismo , Glucose/toxicidade , Hipocampo/patologia , Metaloproteinase 9 da Matriz/metabolismo , MicroRNAs/genética , Neurônios/patologia , Animais , Células Cultivadas , Dieta Hiperlipídica , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Metaloproteinase 9 da Matriz/genética , MicroRNAs/administração & dosagem , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Proteólise , Ratos , Ratos Sprague-Dawley , Edulcorantes/toxicidade
10.
Lab Invest ; 101(7): 808-823, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33574439

RESUMO

Dimethylarginine dimethylamino hydrolase-1 (DDAH-1) is an important regulator of nitric oxide (NO) metabolism that has been implicated in the pathogenesis of cardiovascular diseases. Nevertheless, its role in cerebral ischemia still needs to be elucidated. Herein, we examined the expression of DDAH-1 in the brain of rat by double-label immunofluorescence staining. DDAH-1 knock-out (DDAH-1-/-) and wild-type rats underwent middle cerebral artery occlusion/reperfusion (MCAO/R). After 24 h, neurological scores, TTC staining and TUNEL assay were used to evaluate neurological damages. 3 and 7-days infarct outcomes were also shown. Blood-brain-barrier (BBB) permeability was examined via Evans blue extravasation and tight junction (TJ) proteins expression and mRNA levels by western blot and RT-qPCR. The levels of plasma asymmetric dimethylarginine (ADMA), NO and ADMA in brain tissue were also assessed. In addition, supplementation of L-arginine to DDAH-1-/- rats was used to explore its role in regulating NO. DDAH-1 was abundantly distributed in cerebral cortex and basal nuclei, and mainly expressed in neurons and endothelial cells. DDAH-1-/- rats showed aggravated neurological damage and BBB disruption, including decrease of TJ proteins expression but indistinguishable mRNA levels after MCAO/R. DDAH-1 depletion and neurological damages were accompanied with increased ADMA levels and decreased NO concentrations. The supplementation with L-arginine partly restored the neurological damages and BBB disruption. To sum up, DDAH-1 revealed to have a protective role in ischemia stroke (IS) and IS-induced leakage of BBB via decreasing ADMA level and possibly via preventing TJ proteins degradation.


Assuntos
Amidoidrolases , Arginina/análogos & derivados , Barreira Hematoencefálica/fisiopatologia , Isquemia Encefálica/fisiopatologia , Amidoidrolases/genética , Amidoidrolases/metabolismo , Animais , Arginina/sangue , Arginina/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Encéfalo/patologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Masculino , Óxido Nítrico/sangue , Óxido Nítrico/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos
11.
Plant Biotechnol J ; 19(10): 1937-1951, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33934485

RESUMO

Salt stress is a major devastating abiotic factor that affects the yield and quality of maize. However, knowledge of the molecular mechanisms of the responses to salt stress in maize is limited. To elucidate the genetic basis of salt tolerance traits, a genome-wide association study was performed on 348 maize inbred lines under normal and salt stress conditions using 557 894 single nucleotide polymorphisms (SNPs). The phenotypic data for 27 traits revealed coefficients of variation of >25%. In total, 149 significant SNPs explaining 6.6%-11.2% of the phenotypic variation for each SNP were identified. Of the 104 identified quantitative trait loci (QTLs), 83 were related to salt tolerance and 21 to normal traits. Additionally, 13 QTLs were associated with two to five traits. Eleven and six QTLs controlling salt tolerance traits and normal root growth, respectively, co-localized with QTL intervals reported previously. Based on functional annotations, 13 candidate genes were predicted. Expression levels analysis of 12 candidate genes revealed that they were all responsive to salt stress. The CRISPR/Cas9 technology targeting three sites was applied in maize, and its editing efficiency reached 70%. By comparing the biomass of three CRISPR/Cas9 mutants of ZmCLCg and one zmpmp3 EMS mutant with their wild-type plants under salt stress, the salt tolerance function of candidate genes ZmCLCg and ZmPMP3 were confirmed. Chloride content analysis revealed that ZmCLCg regulated chloride transport under sodium chloride stress. These results help to explain genetic variations in salt tolerance and provide novel loci for generating salt-tolerant maize lines.


Assuntos
Estudo de Associação Genômica Ampla , Zea mays , Dissecação , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Tolerância ao Sal/genética , Plântula/genética , Zea mays/genética
12.
Plant Biotechnol J ; 19(1): 35-50, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32569428

RESUMO

High-throughput phenotyping is increasingly becoming an important tool for rapid advancement of genetic gain in breeding programmes. Manual phenotyping of vascular bundles is tedious and time-consuming, which lags behind the rapid development of functional genomics in maize. More robust and automated techniques of phenotyping vascular bundles traits at high-throughput are urgently needed for large crop populations. In this study, we developed a standard process for stem micro-CT data acquisition and an automatic CT image process pipeline to obtain vascular bundle traits of stems including geometry-related, morphology-related and distribution-related traits. Next, we analysed the phenotypic variation of stem vascular bundles between natural population subgroup (480 inbred lines) based on 48 comprehensively phenotypic information. Also, the first database for stem micro-phenotypes, MaizeSPD, was established, storing 554 pieces of basic information of maize inbred lines, 523 pieces of experimental information, 1008 pieces of CT scanning images and processed images, and 24 192 pieces of phenotypic data. Combined with genome-wide association studies (GWASs), a total of 1562 significant single nucleotide polymorphism (SNPs) were identified for 30 stem micro-phenotypic traits, and 84 unique genes of 20 traits such as VBNum, VBAvArea and PZVBDensity were detected. Candidate genes identified by GWAS mainly encode enzymes involved in cell wall metabolism, transcription factors, protein kinase and protein related to plant signal transduction and stress response. The results presented here will advance our knowledge about phenotypic trait components of stem vascular bundles and provide useful information for understanding the genetic controls of vascular bundle formation and development.


Assuntos
Feixe Vascular de Plantas , Zea mays , Estudos de Associação Genética , Fenótipo , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Zea mays/genética
13.
J Exp Bot ; 72(18): 6230-6246, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34235535

RESUMO

Cadmium (Cd) accumulation in maize grains is detrimental to human health. Developing maize varieties with low Cd content is important for safe consumption of maize grains. However, the key genes controlling maize grain Cd accumulation have not been cloned. Here, we identified one major locus for maize grain Cd accumulation (qCd1) using a genome-wide association study (GWAS) and bulked segregant RNA-seq analysis with a biparental segregating population of Jing724 (low-Cd line) and Mo17 (high-Cd line). The candidate gene ZmHMA3 was identified by fine mapping and encodes a tonoplast-localized heavy metal P-type ATPase transporter. An ethyl methane sulfonate mutant analysis and an allelism test confirmed that ZmHMA3 influences maize grain Cd accumulation. A transposon in intron 1 of ZmHMA3 is responsible for the abnormal amino acid sequence in Mo17. Based on the natural sequence variations in the ZmHMA3 gene of diverse maize lines, four PCR-based molecular markers were developed, and these were successfully used to distinguish five haplotypes with different grain Cd contents in the GWAS panel and to predict grain Cd contents of widely used maize inbred lines and hybrids. These molecular markers can be used to breed elite maize varieties with low grain Cd contents.


Assuntos
ATPases do Tipo-P , Poluentes do Solo , Cádmio/metabolismo , Grão Comestível/metabolismo , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Zea mays/genética , Zea mays/metabolismo
14.
Inorg Chem ; 60(10): 7337-7344, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33945276

RESUMO

Materials that demonstrate a multichannel controllable color change in response to external stimuli are fascinating for their potential applications in sensoring and displaying devices. Herein we report a FeII spin-crossover (SCO) compound that exhibits both solvatochromism and thermochromism under an ambient environment. This Hofmann-type compound possesses two different pores where the solvent guests can be removed in a two-step process. Because the loss of solvent guests modifies the spin state of magnetic centers, an unusual yellow-red-yellow two-step color change of crystals was detected. Moreover, because of the strong cooperativity of the spin centers, a dramatic red-to-yellow color change of crystals in response to a minute thermal perturbation around 303 K is triggered by an abrupt spin transition of the metal centers. The multichannel controllable dramatic color change demonstrated in the present compound highlights the sensoring and displaying roles of SCO materials.

15.
Brain ; 143(5): 1476-1497, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32355963

RESUMO

Accumulation of neuronal α-synuclein is a prominent feature in Parkinson's disease. More recently, such abnormal protein aggregation has been reported to spread from cell to cell and exosomes are considered as important mediators. The focus of such research, however, has been primarily in neurons. Given the increasing recognition of the importance of non-cell autonomous-mediated neurotoxicity, it is critical to investigate the contribution of glia to α-synuclein aggregation and spread. Microglia are the primary phagocytes in the brain and have been well-documented as inducers of neuroinflammation. How and to what extent microglia and their exosomes impact α-synuclein pathology has not been well delineated. We report here that when treated with human α-synuclein preformed fibrils, exosomes containing α-synuclein released by microglia are fully capable of inducing protein aggregation in the recipient neurons. Additionally, when combined with microglial proinflammatory cytokines, these exosomes further increased protein aggregation in neurons. Inhibition of exosome synthesis in microglia reduced α-synuclein transmission. The in vivo significance of these exosomes was demonstrated by stereotaxic injection of exosomes isolated from α-synuclein preformed fibrils treated microglia into the mouse striatum. Phosphorylated α-synuclein was observed in multiple brain regions consistent with their neuronal connectivity. These animals also exhibited neurodegeneration in the nigrostriatal pathway in a time-dependent manner. Depleting microglia in vivo dramatically suppressed the transmission of α-synuclein after stereotaxic injection of preformed fibrils. Mechanistically, we report here that α-synuclein preformed fibrils impaired autophagy flux by upregulating PELI1, which in turn, resulted in degradation of LAMP2 in activated microglia. More importantly, by purifying microglia/macrophage derived exosomes in the CSF of Parkinson's disease patients, we confirmed the presence of α-synuclein oligomer in CD11b+ exosomes, which were able to induce α-synuclein aggregation in neurons, further supporting the translational aspect of this study. Taken together, our study supports the view that microglial exosomes contribute to the progression of α-synuclein pathology and therefore, they may serve as a promising therapeutic target for Parkinson's disease.


Assuntos
Exossomos/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Doença de Parkinson/patologia
16.
Biol Pharm Bull ; 44(3): 396-403, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33642547

RESUMO

Ferulic acid (FA) has potential therapeutic effects in multiple diseases including cardiovascular diseases. However, the effect and molecular basis of FA in heart failure (HF) has not been thoroughly elucidated. Herein, we investigated the roles and mechanisms of FA in HF in isoproterenol (ISO)-induced HF rat model. Results found that FA ameliorated cardiac dysfunction, alleviated oxidative stress, reduced cell/myocardium injury-related enzyme plasma level, inhibited cardiocyte apoptosis in ISO-induced HF rat models. Moreover, FA reduced the co-localization of Keap1 and nuclear factor-E2-related factor 2 (Nrf2) in heart tissues of ISO-induced HF rats, and FA alleviated the inhibitory effects of ISO on expressions of p-Nrf2, heme oxygenase-1 (HO-1) and reduced nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1). Additionally, Nrf2 signaling pathway inhibitor ML385 showed adverse effects. FA weakened the effects of ML385 in ISO-induced HF rat models. Collectively, FA ameliorated HF by decreasing oxidative stress and inhibiting cardiocyte apoptosis via activating Nrf2 pathway in ISO-induced HF rats. Our data elucidated the underling molecular mechanism and provided a novel insight into the cardioprotective function of FA, thus suggested the therapeutic potential of FA in HF treatment.


Assuntos
Cardiotônicos/uso terapêutico , Ácidos Cumáricos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Cardiotônicos/farmacologia , Ácidos Cumáricos/farmacologia , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Isoproterenol , Masculino , Miocárdio/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
17.
J Nanobiotechnology ; 19(1): 324, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654438

RESUMO

The ratio of excitatory to inhibitory neurotransmitters is essential for maintaining the firing patterns of neural networks, and is strictly regulated within individual neurons and brain regions. Excitatory to inhibitory (E/I) imbalance has been shown to participate in the progression of neurodegenerative diseases, including Alzheimer's disease (AD). Glutamate excitotoxicity and GABAergic neuron dysfunction appear to be key components of the neuronal cell death that takes place in AD. Since extracellular vesicles (EVs) are now explored as an important vehicle in transmitting signals between cells, we hypothesized that the function of neuron-derived small EVs (sEVs) might be regulated by the status of neurotransmitter balance and that sEVs might affect amyloid ß (Aß) toxicity on neurons. This study aimed to reveal the effects of sEVs from unbalanced neurotransmitter-stimulated neurons on Aß-induced toxicity. We demonstrated the opposite effects of the two groups of sEVs isolated from neurons stimulated by glutamate or GABA on Aß toxicity in vivo and in vitro. The sEVs released from GABA-treated neurons alleviated Aß-induced damage, while those released from glutamate-treated neurons aggravated Aß toxicity. Furthermore, we compared the microRNA (miRNA) composition of sEVs isolated from glutamate/GABA/PBS-treated neurons. Our results showed that glutamate and GABA oppositely regulated miR-132 levels in sEVs, resulting in the opposite destiny of recipient cells challenged with Aß. Our results indicated that manipulating the function of sEVs by different neurotransmitters may reveal the mechanisms underlying the pathogenesis of AD and provide a promising strategy for AD treatment.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Vesículas Extracelulares/metabolismo , Neurônios/citologia , Neurotransmissores/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/genética , Animais , Modelos Animais de Doenças , Ácido Glutâmico/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Neurônios/química , Neurônios/metabolismo , Ácido gama-Aminobutírico/metabolismo
18.
J Stroke Cerebrovasc Dis ; 30(5): 105686, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33735668

RESUMO

OBJECTIVES: End-stage renal disease (ESRD) is one of the most critical risk factors of intracerebral hemorrhage (ICH). We aimed to investigate the effects of maintenance hemodialysis on hematoma volume, edema volume, and prognosis in patients with comorbid ESRD and ICH. MATERIALS AND METHODS: Patients with comorbid ESRD and ICH were divided into two groups based on whether receiving maintenance hemodialysis. Hematoma and perihemorrhagic edema (PHE) volumes and relative edema ratio after admission were assessed on head computed tomography scans. RESULTS: During the initial diagnosis, the dialysis group had lower PHE volume (16.41 vs 35.90 mL, P = 0.010), total volume of hematoma and edema (31.58 vs 54.58 mL, P = 0.013), and relative edema ratio (0.57 vs 0.92, P = 0.033) than the non-dialysis group. In addition, the peak PHE volume (36.68 vs 84.30 mL, P < 0.001), peak total volume of hematoma and edema (53.45 vs 127.69 mL, P = 0.011), and peak relative edema ratio (1.12 vs 1.92, P = 0.001) within one week after onset were lower in the dialysis group than in the non-dialysis group. The dialysis group had a higher in-hospital mortality rate than the non-dialysis group (40% vs 10%, P = 0.007). At 1-year follow-up, the two groups had similar 1-year-mortality rates and modified Rankin Scale. CONCLUSIONS: Hemodialysis can prevent the enlargement of edema and reduce PHE volume shortly after onset. Although dialyzed patients had a higher in-hospital mortality rate, hemodialysis did not affect 1-year survival rate and functional neurologic scales.


Assuntos
Edema Encefálico/prevenção & controle , Hemorragia Cerebral/terapia , Falência Renal Crônica/terapia , Diálise Renal , Idoso , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Edema Encefálico/mortalidade , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/mortalidade , China , Comorbidade , Feminino , Mortalidade Hospitalar , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Diálise Renal/efeitos adversos , Diálise Renal/mortalidade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
19.
BMC Plant Biol ; 20(1): 515, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176702

RESUMO

BACKGROUND: Stalk fracture caused by strong wind can severely reduce yields in maize. Stalks with higher stiffness and flexibility will exhibit stronger lodging resistance. However, stalk flexibility is rarely studied in maize. Stalk fracture of the internode above the ear before tasseling will result in the lack of tassel and pollen, which is devastating for pollination in seed production. In this study, we focused on stalk lodging before tasseling in two maize inbred lines, JING724 and its improved line JING724A1 and their F2:3 population. RESULTS: JING724A1 showed a larger stalk fracture angle than JING724, indicating higher flexibility. In addition, compared to JING724, JING724A1 also had longer and thicker stalks, with a conical, frustum-shaped internode above the ear. Microscopy and X-ray microcomputed tomography of the internal stalk architecture revealed that JING724A1 had more vascular bundles and thicker sclerenchyma tissue. Furthermore, total soluble sugar content of JING724A1, especially the glucose component, was substantially higher than in JING724. Using an F2:3 population derived from a JING724 and JING724A1 cross, we performed bulk segregant analysis for stalk fracture angle and detected one QTL located on Chr3: 14.00-19.28 Mb. Through transcriptome data analysis and ∆ (SNP-index), we identified two candidate genes significantly associated with high stalk fracture angle, which encode a RING/U-box superfamily protein (Zm00001d039769) and a MADS-box transcription factor 54 (Zm00001d039913), respectively. Two KASP markers designed from these two candidate genes also showed significant correlations with stalk fracture angle. CONCLUSIONS: The internode shape and glucose content are possibly correlated with stalk flexibility in maize. Two genes in the detected QTL are potentially associated with stalk fracture angle. These novel phenotypes and associated loci will provide a theoretical foundation for understanding the genetic mechanisms of lodging, and facilitate the selection of maize varieties with improved flexibility and robust lodging resistance.


Assuntos
Parede Celular/química , Caules de Planta/anatomia & histologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/genética , Zea mays/anatomia & histologia , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Cruzamentos Genéticos , Genes de Plantas , Variação Genética , Genótipo , Fenótipo , Locos de Características Quantitativas
20.
Chemistry ; 26(30): 6778-6783, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32129523

RESUMO

Manipulating the collective molecular movements to implement macroscopic mechanical response of bulk material is attractive and challenging. Here, an organic-inorganic hybrid single crystal is synthesized, which exhibits a giant macroscopic shape transformation with a remarkable thermal hysteretic feature. The colossal anisotropic shape change, which manifests as an abrupt elongation of ca. 9 % along the crystallographic c-axis and a concomitant contraction of ca. 9 % in a perpendicular direction, is induced by a significant reorientation of imidazolium, accompanied with a substantial configurational variation in CuBr4 2- complex anions. The synergistic motions of both the molecular cations and anions engender a remarkable large thermal hysteresis (>30 K) in the shape transformation of the single crystal, implying that this material may play a role in alternating memory media. Furthermore, due to the stable crystal lattice, a single crystal that demonstrates naked-eye detectable large shape transformation was used as a thermal actuator to spontaneously control an electric circuit by temperature variation.

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