RESUMO
BACKGROUND: Dendrobium huoshanense, a traditional medicinal and food plant, has a rich history of use. Recently, its genome was decoded, offering valuable insights into gene function. However, there is no comprehensive gene functional analysis platform for D. huoshanense. RESULT: To address this, we created a platform for gene function analysis and comparison in D. huoshanense (DhuFAP). Using 69 RNA-seq samples, we constructed a gene co-expression network and annotated D. huoshanense genes by aligning sequences with public protein databases. Our platform contained tools like Blast, gene set enrichment analysis, heatmap analysis, sequence extraction, and JBrowse. Analysis revealed co-expression of transcription factors (C2H2, GRAS, NAC) with genes encoding key enzymes in alkaloid biosynthesis. We also showcased the reliability and applicability of our platform using Chalcone synthases (CHS). CONCLUSION: DhuFAP ( www.gzybioinformatics.cn/DhuFAP ) and its suite of tools represent an accessible and invaluable resource for researchers, enabling the exploration of functional information pertaining to D. huoshanense genes. This platform stands poised to facilitate significant biological discoveries in this domain.
Assuntos
Dendrobium , Dendrobium/genética , Dendrobium/metabolismo , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Angelica sinensis (Danggui), a renowned medicinal orchid, has gained significant recognition for its therapeutic effects in treating a wide range of ailments. Genome information serves as a valuable resource, enabling researchers to gain a deeper understanding of gene function. In recent times, the availability of chromosome-level genomes for A. sinensis has opened up vast opportunities for exploring gene functionality. Integrating multiomics data can allow researchers to unravel the intricate mechanisms underlying gene function in A. sinensis and further enhance our knowledge of its medicinal properties. RESULTS: In this study, we utilized genomic and transcriptomic data to construct a coexpression network for A. sinensis. To annotate genes, we aligned them with sequences from various databases, such as the NR, TAIR, trEMBL, UniProt, and SwissProt databases. For GO and KEGG annotations, we employed InterProScan and GhostKOALA software. Additionally, gene families were predicted using iTAK, HMMER, OrholoFinder, and KEGG annotation. To facilitate gene functional analysis in A. sinensis, we developed a comprehensive platform that integrates genomic and transcriptomic data with processed functional annotations. The platform includes several tools, such as BLAST, GSEA, Heatmap, JBrowse, and Sequence Extraction. This integrated resource and approach will enable researchers to explore the functional aspects of genes in A. sinensis more effectively. CONCLUSION: We developed a platform, named ASAP, to facilitate gene functional analysis in A. sinensis. ASAP ( www.gzybioinformatics.cn/ASAP ) offers a comprehensive collection of genome data, transcriptome resources, and analysis tools. This platform serves as a valuable resource for researchers conducting gene functional research in their projects, providing them with the necessary data and tools to enhance their studies.
Assuntos
Angelica sinensis , Genômica , Bases de Dados de Proteínas , Perfilação da Expressão Gênica , Pesquisa em GenéticaRESUMO
Renewable-energy-powered electrosynthesis has the potential to contribute to decarbonizing the production of propylene glycol, a chemical that is used currently in the manufacture of polyesters and antifreeze and has a high carbon intensity. Unfortunately, to date, the electrooxidation of propylene under ambient conditions has suffered from a wide product distribution, leading to a low faradic efficiency toward the desired propylene glycol. We undertook mechanistic investigations and found that the reconstruction of Pd to PdO occurs, followed by hydroxide formation under anodic bias. The formation of this metastable hydroxide layer arrests the progressive dissolution of Pd in a locally acidic environment, increases the activity, and steers the reaction pathway toward propylene glycol. Rh-doped Pd further improves propylene glycol selectivity. Density functional theory (DFT) suggests that the Rh dopant lowers the energy associated with the production of the final intermediate in propylene glycol formation and renders the desorption step spontaneous, a concept consistent with experimental studies. We report a 75% faradic efficiency toward propylene glycol maintained over 100 h of operation.
RESUMO
Studies from rodents to primates and humans indicate that individuals vary in how resilient they are to stress, and understanding the basis of these variations may help improve treatments for depression. Here we explored the potential contribution of the gut microbiome to such variation. Mice were exposed to chronic unpredictable mild stress (CUMS) for 4 weeks then allowed to recover for 3 weeks, after which they were subjected to behavioral tests and categorized as showing low or high stress resilience. The two types of mouse were compared in terms of hippocampal gene expression using RNA sequencing, fecal microbiomes using 16S RNA sequencing, and extent of neurogenesis in the hippocampus using immunostaining of brain sections. Fecal microbiota were transplanted from either type of mouse into previously stress-exposed and stress-naïve animals, and the effects of the transplantation on stress-induced behaviors and neurogenesis in the hippocampus were examined. Finally, we blocked neurogenesis using temozolomide to explore the role of neurogenesis promoted by fecal microbiota transplantation in enhancing resilience to stress. Results showed that highly stress-resilient mice, but not those with low resilience, improved significantly on measures of anhedonia, behavioral despair, and anxiety after 3-week recovery from CUMS. Their feces showed greater abundance of Lactobacillus, Bifidobacterium and Romboutsia than feces from mice with low stress resilience, as well as lower abundance of Staphylococcus, Psychrobacter and Corynebacterium. Similarly, highly stress-resilient mice showed greater neurogenesis in hippocampus than animals with low stress resilience. Transplanting fecal microbiota from mice with high stress resilience into previously CUMS-exposed recipients rescued neurogenesis in hippocampus, facilitating recovery from stress-induced depression and cognitive decline. Blockade of neurogenesis with temozolomide abolished recovery of recipients from CUMS-induced depression and cognitive decline in mice transplanted with fecal microbiota from mice with high stress resilience. In conclusion, our results suggested that remodeling of the gut microbiome after stress may reverse stress-induced impairment of hippocampal neurogenesis and thereby promote recovery from stress-induced depression.
Assuntos
Depressão , Microbioma Gastrointestinal , Humanos , Camundongos , Animais , Depressão/metabolismo , Microbioma Gastrointestinal/genética , Temozolomida/metabolismo , Temozolomida/farmacologia , Hipocampo/metabolismo , Neurogênese , Estresse Psicológico/psicologiaRESUMO
BACKGROUND: Mental disorders may be involved in neuroinflammatory processes that are triggered by gut microbiota. How gut microbiota influence microglia-mediated sensitivity to stress remains unclear. Here we explored in an animal model of depression whether disruption of the gut microbiome primes hippocampal microglia, thereby impairing neurogenesis and sensitizing to stress. METHODS: Male C57BL/6J mice were exposed to chronic unpredictable mild stress (CUMS) for 4 weeks, and effects on gut microbiota were assessed using 16S rRNA sequencing. Fecal microbiota was transplanted from control or CUMS mice into naïve animals. The depression-like behaviors of recipients were evaluated in a forced swimming test and sucrose preference test. The morphology and phenotype of microglia in the hippocampus of recipients were examined using immunohistochemistry, quantitative PCR, and enzyme-linked immunosorbent assays. The recipients were treated with lipopolysaccharide or chronic stress exposure, and effects were evaluated on behavior, microglial responses and hippocampal neurogenesis. Finally, we explored the ability of minocycline to reverse the effects of CUMS on hippocampal neurogenesis and stress sensitivity in recipients. RESULTS: CUMS altered the gut microbiome, leading to higher relative abundance of some bacteria (Helicobacter, Bacteroides, and Desulfovibrio) and lower relative abundance of some bacteria (Lactobacillus, Bifidobacterium, and Akkermansia). Fecal microbiota transplantation from CUMS mice to naïve animals induced microglial priming in the dentate gyrus of recipients. This microglia showed hyper-ramified morphology, and became more sensitive to LPS challenge or chronic stress, which characterized by more significant morphological changes and inflammatory responses, as well as impaired hippocampal neurogenesis and increased depressive-like behaviors. Giving minocycline to recipients reversed these effects of fecal transplantation. CONCLUSIONS: These findings suggest that gut microbiota from stressed animals can induce microglial priming in the dentate gyrus, which is associated with a hyper-immune response to stress and impaired hippocampal neurogenesis. Remodeling the gut microbiome or inhibiting microglial priming may be strategies to reduce sensitivity to stress.
Assuntos
Depressão , Microbioma Gastrointestinal , Humanos , Camundongos , Masculino , Animais , Depressão/microbiologia , Microglia , Minociclina/farmacologia , RNA Ribossômico 16S , Camundongos Endogâmicos C57BL , Hipocampo , Neurogênese/fisiologia , Estresse PsicológicoRESUMO
Surface ozone is a severe air pollution problem in the North China Plain, which is home to 300 million people. Ozone concentrations are highest in summer, driven by fast photochemical production of hydrogen oxide radicals (HOx) that can overcome the radical titration caused by high emissions of nitrogen oxides (NOx) from fuel combustion. Ozone has been very low during winter haze (particulate) pollution episodes. However, the abrupt decrease of NOx emissions following the COVID-19 lockdown in January 2020 reveals a switch to fast ozone production during winter haze episodes with maximum daily 8-h average (MDA8) ozone concentrations of 60 to 70 parts per billion. We reproduce this switch with the GEOS-Chem model, where the fast production of ozone is driven by HOx radicals from photolysis of formaldehyde, overcoming radical titration from the decreased NOx emissions. Formaldehyde is produced by oxidation of reactive volatile organic compounds (VOCs), which have very high emissions in the North China Plain. This remarkable switch to an ozone-producing regime in January-February following the lockdown illustrates a more general tendency from 2013 to 2019 of increasing winter-spring ozone in the North China Plain and increasing association of high ozone with winter haze events, as pollution control efforts have targeted NOx emissions (30% decrease) while VOC emissions have remained constant. Decreasing VOC emissions would avoid further spreading of severe ozone pollution events into the winter-spring season.
Assuntos
Poluição do Ar/análise , Ozônio/análise , Material Particulado/análise , Estações do Ano , Compostos Orgânicos Voláteis , COVID-19 , China , Produtos Agrícolas , Monitoramento Ambiental , Poluição Ambiental , Humanos , Óxidos de Nitrogênio/química , Pandemias , Saúde PúblicaRESUMO
BACKGROUND: Aflatoxin B1, which can penetrate the blood-brain barrier and kill neural cells, can contaminate traditional herbal medicines, posing a significant risk to human health. The present study examined cellular, cognitive and behavioral consequences of aflatoxin B1 contamination of the anti-osteoporotic medicine Radix Dipsaci. METHODS: A mouse model of osteoporosis was created by treating the animals with all-trans-retinoic acid. Then the animals were treated intragastically with water decoctions of Radix Dipsaci that contained detectable aflatoxin B1 or not. The animals were compared in terms of mineral density and mineral salt content of bone, production of pro-inflammatory factors, neurogenesis and microglial activation in hippocampus, as well as behavior and cognitive function. RESULTS: Contamination of Radix Dipsaci with aflatoxin B1 significantly reduced the medicine's content of bioactive saponins. It destroyed the ability of the herbal decoction to improve mineral density and mineral salt content in the bones of diseased mice, and it induced the production of the oxidative stress marker malondialdehyde as well as the pro-inflammatory cytokines interleukin-1ß and tumor necrosis factor-α. Aflatoxin B1 contamination inhibited formation of new neurons and increased the proportion of activated microglia in the hippocampus. These neurological changes were associated with anhedonia, behavioral despair, and deficits in short-term memory and social memory. CONCLUSION: Contamination of Radix Dipsaci with aflatoxin B1 not only eliminates the herbal decoction's anti-osteoporotic effects, but it also induces neurotoxicity that can lead to cognitive decline and behavioral abnormalities. Such contamination should be avoided through tightly regulated production and quality control of medicinal herbs.
RESUMO
MXenes have been extensively studied due to their high metallic conductivity, hydrophilic properties, tunable layer structure and attractive surface chemistry, making them highly desirable for energy-related applications. However, slow catalytic reaction kinetics and limited active sites have severely impeded their further practical applications. Surface engineering of MXenes has been rationally designed and investigated to regulate their electronic structure, increase the density of active sites, optimize the binding energy, and thus boost the electrocatalytic performance. In this review, we comprehensively summarized the surface engineering strategies for MXene nanostructures, including surface termination engineering, defect engineering, heteroatom doping engineering (metals or non-metals), secondary material engineering, and extension to MXene analogues. By identifying the roles of each component in the engineered MXenes at the atomic level, their intrinsic active sites have been discussed to establish the relationships between the atomic structures and catalytic activities. We highlighted the state-of-the-art progress of MXenes in electrochemical conversion reactions including hydrogen, oxygen, carbon dioxide, nitrogen and sulfur conversion reactions. The challenges and perspectives of MXene-based catalysts for electrochemical conversion reactions are presented to inspire more efforts toward the understanding and development of MXene-based materials to meet the ever-growing demand for a sustainable future.
RESUMO
Cholangiocarcinoma (CCA) is a highly malignant cancer of the biliary tree. Although studies have implicated enhancer of Zeste homolog 2 (EZH2) in CCA growth, the role of EZH2 in CCA development has not been investigated, and the mechanism for EZH2-regulated gene expression in CCA remains to be further defined. The current study used a mouse model of CCA induced by hydrodynamic tail vein injection of Notch1 intracellular domain and myristoylated-AKT plasmids. Mice with liver-specific EZH2 knockout displayed reduced CCA development. In a xenograft model, EZH2 knockdown significantly decreased CCA progression. Administration of the EZH2 inhibitor GSK126 decreased CCA tumor burden in mice. Accordingly, EZH2 depletion or inhibition reduced the growth and colony formation capability of CCA cells. Analysis of high-throughput data identified a set of 12 tumor-inhibiting genes as targets of EZH2 in CCA. The experimental results suggest that EZH2 may down-regulate these tumor-inhibiting genes through methylation of lysine 27 on histone H3 (H3K27) in the gene louses and through regulation of specific miRNAs. High mobility group box 1 was shown to facilitate the methyltransferase activity of EZH2, which is implicated in the regulation of CCA cell growth. The study shows that EZH2 promotes CCA development and progression through a complicated regulatory network involving tumor-inhibiting genes, miRNAs, and high mobility group box 1, which support targeting EZH2 as a potentially effective strategy for CCA treatment.
Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , MicroRNAs , Animais , Humanos , Camundongos , Neoplasias dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/genética , Modelos Animais de Doenças , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Genes Supressores de Tumor , Histonas , Metilação , MicroRNAs/genéticaRESUMO
PASylation, which was recently reported as the conjugation of pharmacologically active compounds with polypeptide sequences mainly made of proline, alanine and serine, has been proposed as an alternative to PEGylation. In this study, we designed PAS-modified liposomes (PASylated liposomes) and studied the effect of the incorporation of PAS-lipid on the stability and pharmacokinetic properties of liposomes, and compared them both in vitro and in vivo to PEGylated liposomes. Results showed that PASylated liposomes modified with single-chained PAS-lipid C16-(PA3)7 (SC-PAS-Lip) showed comparable storage and serum stability to PEGylated liposomes (PEG-Lip), and a significantly decreased macrophage uptake compared with unmodified liposomes. SC-PAS-Lip displayed long circulating pharmacokinetic profile which was not impacted by the repeated administration of liposomes, and they were less likely to induce the production of anti-PEG IgM compared with PEGylated liposomes, presenting PASylation as an alternative liposome modification strategy to PEGylation.
Assuntos
Lipídeos , LipossomosRESUMO
BACKGROUND: Chronic aflatoxin B1 (AFB1) exposure may increase the risk of multiple neuropsychiatric disorders. Stress is considered one of the main contributors to major depressive disorder. Whether and how chronic AFB1 exposure affects vulnerability to stress is unclear. METHODS: Mice were exposed for three weeks to AFB1 (100 µg/kg/d) and/or chronic mild stress (CMS). The vulnerability behaviors in response to stress were assessed in the forced swimming test (FST), sucrose preference test (SPT), and tail suspension test (TST). Microglial pyroptosis was investigated using immunofluorescence, enzyme-linked immunosorbent assays, and western blot assay in the hippocampus of mice. Hippocampal neurogenesis and the effects of AFB1-treated microglia on proliferation and differentiation of neural stem/precursor cells (NSPCs) were assessed via immunofluorescence in the hippocampus of mice. RESULTS: Mice exposed to CMS in the presence of AFB1 exhibited markedly greater vulnerability to stress than mice treated with CMS or AFB1 alone, as indicated by reduced sucrose preference and longer immobility time in the forced swimming test. Chronic aflatoxin B1 exposure resulted in changes in the microglial morphology and increase in TUNEL+ microglia and GSDMD+ microglia in the hippocampal dentate gyrus. When mice were exposed to both CMS and AFB1, pyroptosis-related molecules (such as NLRP3, caspase-1, GSDMD-N, and interleukin-1ß) were significantly upregulated in the hippocampus. These molecules were also significantly enhanced by AFB1 in primary microglial cultures. AFB1-treated mice showed decrease in the numbers of BrdU+, BrdU-DCX+, and BrdU-NeuN+ cells in the hippocampal dentate gyrus, as well as the percentages of BrdU+ cells that were NeuN+ in the presence or absence of CMS when compared with vehicle-treated mice. The combination of AFB1 and CMS exacerbated these effects to an even greater extent. The number of DCX+ cells correlated negatively with the percentage of ameboid microglia, TUNEL+ microglia and GSDMD+ microglia in the hippocampal dentate gyrus. AFB1-treated microglia suppressed the proliferation and neuronal differentiation of NSPCs in vitro. CONCLUSION: Chronic AFB1 exposure induces microglial pyroptosis, promoting an adverse neurogenic microenvironment that impairs hippocampal neurogenesis, which may render mice more vulnerable to stress.
Assuntos
Transtorno Depressivo Maior , Microglia , Camundongos , Animais , Aflatoxina B1/toxicidade , Piroptose , Bromodesoxiuridina , Hipocampo , SacaroseRESUMO
Rationally electronic structure engineering of nanocomposite electrodes shows great promise for enhancing the electrochemical performance of rechargeable batteries. Herein, we report antimony single atoms and quantum dots (â¼5 nm) codecorated Ti3C2Tx MXene-based aerogels (Sb SQ@MA) for high-performance potassium-ion batteries (PIBs). We found that the atomically dispersed Sb could modify the electronic structure of the Sb/Ti3C2Tx composite, improve the charge transfer kinetics, and enhance the potassium storage capability at the heterointerfaces. Additionally, the MXene-based aerogel with rich surface functional groups and defects provides abundant anchoring sites and endows the composite reinforced structural stability and highly efficient electron transfer. The high loading of Sb (â¼60.3 wt %) with short ionic transport pathways is desired potassium reservoirs. These features synergistically enhance the rate and cycling performance of the Sb SQ@MA electrodes in PIBs. This work has demonstrated an enlightening technique to tailor the interface activity of heterostructured electrodes for electrochemical applications.
RESUMO
By investigating the contamination status and predicting the exposure risk of mycotoxin in Coicis Semen, we aim to provide guidance for the safety supervision of Chinese medicinal materials and the formulation(revision) of mycotoxin limit standards. The content of 14 mycotoxins in the 100 Coicis Semen samples collected from five major markets of Chinese medicinal materials in China was determined by UPLC-MS/MS. The probability evaluation model based on Monte Carlo simulation method was established after Chi-square test and One-way ANOVA of the sample contamination data. Health risk assessment was performed on the basis of margin of exposure(MOE) and margin of safety(MOS). The results showed that zearalenone(ZEN), aflatoxin B_1(AFB_1), deoxynivalenol(DON), sterigmatocystin(ST), and aflatoxin B_2(AFB_2) in the Coicis Semen samples had the detection rates of 84%, 75%, 36%, 19%, and 18%, and the mean contamination levels of 117.42, 4.78, 61.16, 6.61, and 2.13 µg·kg~(-1), respectively. According to the limit standards in the Chinese Pharmacopoeia(2020 edition), AFB_1, AFs and ZEN exceeded the standards to certain extents, with the over-standard rates of 12.0%, 9.0%, and 6.0%, respectively. The exposure risks of Coicis Semen to AFB_1, AFB2, ST, DON, and ZEN were low, while 86% of the samples were contaminated with two or more toxins, which needs more attention. It is suggested that the research on the combined toxicity of different mycotoxins should be strengthened to accelerate the cumulative exposure assessment of mixed contaminations and the formulation(revision) of toxin limit standards.
Assuntos
Coix , Micotoxinas , Humanos , Micotoxinas/análise , Aflatoxina B1/análise , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem/métodosRESUMO
The oxygen reduction reaction (ORR) on transition single-atom catalysts (SACs) is sustainable in energy-conversion devices. However, the atomically controllable fabrication of single-atom sites and the sluggish kinetics of ORR have remained challenging. Here, we accelerate the kinetics of acid ORR through a direct O-O cleavage pathway through using a bi-functional ligand-assisted strategy to pre-control the distance of hetero-metal atoms. Concretely, the as-synthesized Fe-Zn diatomic pairs on carbon substrates exhibited an outstanding ORR performance with the ultrahigh half-wave potential of 0.86â V vs. RHE in acid electrolyte. Experimental evidence and density functional theory calculations confirmed that the Fe-Zn diatomic pairs with a specific distance range of around 3â Å, which is the key to their ultrahigh activity, average the interaction between hetero-diatomic active sites and oxygen molecules. This work offers new insight into atomically controllable SACs synthesis and addresses the limitations of the ORR dissociative mechanism.
RESUMO
Electrocatalysts for highly efficient oxygen reduction reaction (ORR) are crucial for energy conversion and storage devices. Single-atom catalysts with maximized metal utilization and altered electronic structure are the most promising alternatives to replace current benchmark precious metals. However, the atomic level understanding of the functional role for each species at the anchoring sites is still unclear and poorly elucidated. Herein, we report Fe single atom catalysts with the sulfur and oxygen functional groups near the atomically dispersed metal centers (Fe1/NSOC) for highly efficient ORR. The Fe1/NSOC delivers a half-wave potential of 0.92â V vs. RHE, which is much better than those of commercial Pt/C (0.88â V), Fe single atoms on N-doped carbon (Fe1/NC, 0.89â V) and most reported nonprecious metal catalysts. The spectroscopic measurements reveal that the presence of sulfur group induces the formation of epoxy groups near the FeN4S2 centers, which not only modulate the electronic structure of Fe single atoms but also participate the catalytic process to improve the kinetics. The density functional theory calculations demonstrate the existence of sulfur and epoxy group engineer the charges of Fe reactive center and facilitate the reductive release of OH* (rate-limiting step), thus boosting the overall oxygen reduction efficiency.
RESUMO
The conversion of CO2 into ethanol with renewable H2 has attracted tremendous attention due to its integrated functions of carbon elimination and chemical synthesis, but remains challenging. The electronic properties of a catalyst are essential to determine the adsorption strength and configuration of the key intermediates, therefore altering the reaction network for targeted synthesis. Herein, we describe a catalytic system in which a carbon buffer layer is employed to tailor the electronic properties of the ternary ZnOx -Fe5 C2 -Fe3 O4 , in which the electron-transfer pathway (ZnOx âFe species or carbon layer) ensures the appropriate adsorption strength of -CO* on the catalytic interface, facilitating C-C coupling between -CHx * and -CO* for ethanol synthesis. Benefiting from this unique electron-transfer buffering effect, an extremely high ethanol yield of 366.6â gEtOH kgcat -1 h-1 (with CO of 10â vol % co-feeding) is achieved from CO2 hydrogenation. This work provides a powerful electronic modulation strategy for catalyst design in terms of highly oriented synthesis.
RESUMO
BACKGROUND: The natural compound asperosaponin VI has shown potential as an antidepressant, but how it works is unclear. Here, we explored its effects on mice exposed to chronic mild stress (CMS) and the underlying molecular pathways. METHODS: Mice were exposed to CMS for 3 weeks followed by asperosaponin VI (40 mg/kg) or imipramine (20 mg/kg) for another 3 weeks. Depression-like behaviors were assessed in the forced swimming test (FST), sucrose preference test (SPT), tail suspension test (TST). Microglial phenotypes were evaluated using immunofluorescence staining, real-time quantitative PCR and enzyme-linked immunosorbent assays in hippocampus of mice. In some experiments, stressed animals were treated with the PPAR-γ antagonist GW9662 to examine its involvement in the effects of asperosaponin VI. Blockade of PPAR-γ in asperosaponin VI-treated primary microglia in the presence of lipopolysaccharide (LPS) was executed synchronously. The nuclear transfer of PPAR-γ in microglia was detected by immunofluorescence staining in vitro and in vivo. A co-cultured model of neuron and microglia was used for evaluating the regulation of ASA VI on the microglia-neuron crosstalk molecules. RESULTS: Asperosaponin VI ameliorated depression-like behaviors of CMS mice based on SPT, TST and FST, and this was associated with a switch of hippocampal microglia from a pro-inflammatory (iNOS+-Iba1+) to neuroprotective (Arg-1+-Iba1+) phenotype. CMS reduced the expression levels of PPAR-γ and phosphorylated PPAR-γ in hippocampus, which asperosaponin VI partially reversed. GW9662 treatment prevented the nuclear transfer of PPAR-γ in asperosaponin VI-treated microglia and inhibited the induction of Arg-1+ microglia. Blockade of PPAR-γ signaling also abolished the ability of asperosaponin VI to suppress pro-inflammatory cytokines while elevating anti-inflammatory cytokines in the hippocampus of CMS mice. The asperosaponin VI also promoted interactions between hippocampal microglia and neurons by enhancing CX3CL1/CX3CR1 and CD200/CD200R, and preserved synaptic function based on PSD95, CamKII ß and GluA levels, but not in the presence of GW9662. Blockade of PPAR-γ signaling also abolished the antidepressant effects of asperosaponin VI in the SPT, TST and FST. CONCLUSION: CMS in mice induces a pro-inflammatory microglial phenotype that causes reduced crosstalk between microglia and neuron, inflammation and synaptic dysfunction in the hippocampus, ultimately leading to depression-like behaviors. Asperosaponin VI may ameliorate the effects of CMS by inducing microglia to adopt a PPAR-γ-dependent neuroprotective phenotype.
Assuntos
Depressão , Microglia , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Citocinas/metabolismo , Depressão/tratamento farmacológico , Depressão/etiologia , Depressão/metabolismo , Hipocampo/metabolismo , Camundongos , Microglia/metabolismo , PPAR gama/metabolismo , Fenótipo , Saponinas , Estresse Psicológico/metabolismoRESUMO
Graphitic carbon nitride (g-C3N4) has attracted extensive research attention because of its virtues of a metal-free nature, feasible synthesis, and excellent properties. However, the low specific surface area and mediocre charge separation dramatically limit the practical applications of g-C3N4. Herein, porous nitrogen defective g-C3N4 (PDCN) was successfully fabricated by the integration of urea-assisted supramolecular assembly with the polymerization process. Advanced characterization results suggested that PDCN exhibited a much larger specific surface area and dramatically improved charge separation compared to bulk g-C3N4, leading to the formation of more active sites and the improvement in mass transfer. The synthesized PDCN rendered a 16-fold increase in photocatalytic tetracycline degradation efficiency compared to g-C3N4. Additionally, the hydrogen evolution rate of PDCN was 10.2 times higher than that of g-C3N4. Meanwhile, the quenching experiments and electron spin resonance (ESR) spectra suggested that the superoxide radicals and holes are the predominant reactive species for the photocatalytic degradation process. This study may inspire the new construction design of efficient g-C3N4-based visible-light photocatalysts.
RESUMO
Novel all-hydrocarbon cross-linked aza-stapled peptides were designed and synthesized for the first time by ring-closing metathesis between two aza-alkenylglycine residues. Three aza-stapled peptidic analogues based on the peptide dual inhibitor of p53-MDM2/MDMX interactions were synthesized and screened for biological activities. Among the three aza-stapled peptides, aSPDI-411 displayed increased anti-tumor activity, binding affinities to both MDM2 and MDMX, and cell membrane permeability compared to its linear peptide counterpart.
Assuntos
Proteínas Proto-Oncogênicas c-mdm2 , Proteína Supressora de Tumor p53 , Proteína Supressora de Tumor p53/química , Sequência de Aminoácidos , Peptídeos/química , Ligação Proteica , HidrocarbonetosRESUMO
Antimicrobial peptides (AMPs) have great potentials for developing novel antibiotics against multi-drug resistant (MDR) bacteria. However, the clinical application of AMPs is limited due to their poor protease stability and high hemolytic toxicity. Various strategies have been widely explored to improve the pharmacological properties of natural or artificial antimicrobial peptides, including D- or non-natural amino acid residue replacement, backbone modification, cyclization, PEGlytion, and lipidation. Among others, peptide cyclization, which has been widely applied to enhance the biostability and target selectivity of bioactive peptide, is a very appealing and promising strategy for developing novel antibiotics based on AMPs. Herein, we summarize the current strategies for synthesizing cyclic antimicrobial peptides and the resulting influence of peptide cyclization on the biological activities.