RESUMO
Emerging evidence suggests that the gut microbiota is closely related to psychiatric disorders. However, little is known about the role of the gut microbiota in the development of obsessive-compulsive disorder (OCD). Here, to investigate the contribution of gut microbiota to the pathogenesis of OCD, we transplanted fecal microbiota from first-episode, drug-naive OCD patients or demographically matched healthy individuals into antibiotic-treated specific pathogen-free (SPF) mice and showed that colonization with OCD microbiota is sufficient to induce core behavioral deficits, including abnormal anxiety-like and compulsive-like behaviors. The fecal microbiota was analyzed using 16 S rRNA full-length sequencing, and the results demonstrated a clear separation of the fecal microbiota of mice colonized with OCD and control microbiota. Notably, microbiota from OCD-colonized mice resulted in injured neuronal morphology and function in the mPFC, with inflammation in the mPFC and colon. Unbiased metabolomic analyses of the serum and mPFC region revealed the accumulation of succinic acid (SA) in OCD-colonized mice. SA impeded neuronal activity and induced an inflammatory response in both the colon and mPFC, impacting intestinal permeability and brain function, which act as vital signal mediators in gut microbiota-brain-immune crosstalk. Manipulations of dimethyl malonate (DM) have been reported to exert neuroprotective effects by suppressing the oxidation of accumulated succinic acid, attenuating the downstream inflammatory response and neuronal damage, and can help to partly improve abnormal behavior and reduce neuroinflammation and intestinal inflammation in OCD-colonized mice. We propose that the gut microbiota likely regulates brain function and behaviors in mice via succinic acid signaling, which contributes to the pathophysiology of OCD through gut-brain crosstalk and may provide new insights into the treatment of this disorder.
Assuntos
Modelos Animais de Doenças , Transplante de Microbiota Fecal , Microbioma Gastrointestinal , Transtorno Obsessivo-Compulsivo , Ácido Succínico , Animais , Transtorno Obsessivo-Compulsivo/metabolismo , Transtorno Obsessivo-Compulsivo/microbiologia , Microbioma Gastrointestinal/fisiologia , Camundongos , Humanos , Masculino , Ácido Succínico/metabolismo , Transplante de Microbiota Fecal/métodos , Feminino , Doenças Neuroinflamatórias/metabolismo , Fezes/microbiologia , Adulto , Sintomas Comportamentais/metabolismo , Inflamação/metabolismo , Córtex Pré-Frontal/metabolismo , Ansiedade/metabolismo , Ansiedade/microbiologia , Camundongos Endogâmicos C57BL , Comportamento Animal , Encéfalo/metabolismo , Eixo Encéfalo-Intestino/fisiologiaRESUMO
The stability of covalent organic frameworks (COFs) is crucial for their applications in demanding environments. However, increasing the stability of COFs often comes with challenges such as higher synthesis difficulty, lower crystal quality, and reduced controllability during synthesis, making it difficult to regulate dimensions and morphology, thereby impacting the processing and shaping of stable COFs. Herein, the study presents a novel confined polymerization approach guided by hydrogen bonding preassembly to synthesize a soluble and stable COF featuring ß-ketoenamine linkage. The presence of relatively weaker hydrogen bonds accelerates the orderly arrangement of monomers, ensuring appropriate spacing, and orientations among functional groups. This facilitates efficient covalent polymerization, leading to the creation of the framework while minimizing the "self-correction" mechanism during crystal growth, thereby enhancing the efficiency of COF synthesis. Furthermore, this method offers precise control over the size of the synthesized COF. The resulting crystalline COF can be toggled between dissolution and precipitation states, facilitating the fabrication of mixed matrix membranes (MMMs) through leveraging the solubility properties of COF. Overall, this pioneering strategy yields valuable insights for advancing weak bond assembly-mediated confined polymerization approaches, the controlled synthesis of stable COFs, and the preparation and processing of soluble COFs in diverse applications.
RESUMO
Thaumatin-like proteins (TLPs) in plants play a crucial role in combating stress, and they have been proven to possess antifungal properties. However, the role of TLPs in pathogens has not been reported. We identified a effector protein, Pt9029, which contained a Thaumatin domain in Puccinia triticina (Pt), possessing a chloroplast transit peptide and localized in the chloroplasts. Silencing Pt9029 in the Pt physiological race THTT resulted in a notable reduction in virulence and stunted growth and development of Pt hypha in near-isogenic wheat line TcLr2b. Overexpression of Pt9029 in wheat exerted a suppressive effect on H2O2 production, consequently impeding the wheat's disease resistance mechanisms. The TLP domain of Pt9029 targets the Rubisco activase (TaRCA) in chloroplasts. This interaction effectively inhibited the function of TaRCA, subsequently leading to a decrease in Rubisco enzyme activity. Therefore, this indicates that TLPs in Pt can inhibit host defense mechanisms during the pathogenic process of Pt. Moreover, TaRCA silencing resulted in reduced resistance of TcLr2b against Pt race THTT. This clearly demonstrated that TaRCA positively regulates wheat resistance to leaf rust. These findings reveal a novel strategy exploited by Pt to manipulate wheat rust resistance and promote pathogenicity.
RESUMO
Pyroptosis is a form of regulated cell death mediated by the gasdermin protein family. During virus infection, cell pyroptosis restricts viral replication. The mechanisms of the tripartite motif (TRIM) protein family and IFN-stimulated genes (ISGs) against viruses have been studied. The role of TRIMs and ISGs in pyroptosis remains unclear. In this study, we show that TRIM21 interacts with ISG12a in viral infection and facilitates its translocation into the mitochondria by promoting its ubiquitination, thereby causing caspase 3 activation. Gasdermin E (GSDME) is specifically cleaved by caspase 3 upon viral infection, releasing the GSDME N-terminal domain, perforating the cell membrane, and causing cell pyroptosis. Our study uncovers a new mechanism of TRIM21 and ISG12a in regulating virus-induced cell pyroptosis.
Assuntos
Piroptose , Vírus , Piroptose/fisiologia , Caspase 3/metabolismo , Ubiquitinação , Morte Celular , Proteínas com Motivo Tripartido/metabolismoRESUMO
OBJECTIVES: Neuroinflammation has been suggested that affects the processing of depression. There is renewed interest in berberine owing to its anti-inflammatory effects. Herein, we investigated whether berberine attenuate depressive-like behaviors via inhibiting NLRP3 inflammasome activation in mice model of depression. METHODS: Adult male C57BL/6N mice were administrated corticosterone (CORT, 20 mg/kg/day) for 35 days. Two doses (100 mg/kg/day and 200 mg/kg/day) of berberine were orally administrated from day 7 until day 35. Behavioral tests were performed to measure the depression-like behaviors alterations. Differentially expressed gene analysis was performed for RNA-sequencing data in the prefrontal cortex. NLRP3 inflammasome was measured by quantitative reverse transcription polymerase chain reaction, western blotting, and immunofluorescence labeling. The neuroplasticity and synaptic function were measured by immunofluorescence labeling, Golgi-Cox staining, transmission electron microscope, and whole-cell patch-clamp recordings. RESULTS: The results of behavioral tests demonstrated that berberine attenuated the depression-like behaviors induced by CORT. RNA-sequencing identified that NLRP3 was markedly upregulated after long-term CORT exposure. Berberine reversed the concentrations of peripheral and brain cytokines, NLRP3 inflammasome elicited by CORT in the prefrontal cortex and hippocampus were decreased by berberine. In addition, the lower frequency of neuronal excitation as well as the dendritic spine reduction were reversed by berberine treatment. Together, berberine increases hippocampal adult neurogenesis and synaptic plasticity induced by CORT. CONCLUSION: The anti-depressants effects of berberine were accompanied by reduced the neuroinflammatory response via inhibiting the activation of NLRP3 inflammasome and rescued the neuronal deterioration via suppression of impairments in synaptic plasticity and neurogenesis.
Assuntos
Berberina , Doenças Neuroinflamatórias , Masculino , Camundongos , Animais , Camundongos Endogâmicos C57BL , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Depressão , Plasticidade NeuronalRESUMO
The compatibility of crystallinity, stability, and functionality in covalent organic frameworks (COFs) is challenging but significant in reticular chemistry and materials science. Herein, it is presented for the first time a strategy to synthesize directly amino-functionalized COF with stable benzodiimidazole linkage by regioselective one-step cyclization and aromatization. Bandrowski's base with two types of amino groups is used as a unique monomer, providing not only construction sites for the material framework through specific region-selective reaction, but also amino active sites for functionality, which is usually difficult to achieve directly in COF synthesis because amino groups are the participants in COF bonding. In addition, the aromatic benzodiimidazole rings and the large conjugated system of the product effectively improve the crystallinity and stability, so that the as-prepared BBCOF remains unchanged in both acid and base solutions, which is obviously better than the conventional imine-linked COF. Impressively, the significantly enhanced conjugation degree by the benzodiimidazole structure also endows BBCOF with an efficient photocatalytic reduction of uranyl ion, with removal rate as high as 96.6% in single-ion system and 95% in multi-ion system. This study is of great importance to the design and synthesis of functional COFs with a commendable trade-off among crystallinity, stability, and functionality.
RESUMO
BACKGROUND: Converging evidence suggests that stress alters behavioural responses in a sex-specific manner; however, the underlying molecular mechanisms of stress remain largely unknown. METHODS: We adapted unpredictable maternal separation (UMS) and adult restraint stress (RS) paradigms to mimic stress in rats in early life or adulthood, respectively. The sexual dimorphism of the prefrontal cortex was noted, and we performed RNA sequencing (RNA-Seq) to identify specific genes or pathways responsible for sexually dimorphic responses to stress. We then performed quantitative reverse transcription polymerase chain reaction (qRT-PCR) to verify the results of RNA-Seq. RESULTS: Female rats exposed to either UMS or RS showed no negative effects on anxiety-like behaviours, whereas the emotional functions of the PFC were impaired markedly in stressed male rats. Leveraging differentially expressed genes (DEG) analyses, we identified sex-specific transcriptional profiles associated with stress. There were many overlapping DEGs between UMS and RS transcriptional data sets, where 1406 DEGs were associated with both biological sex and stress, while only 117 DEGs were related to stress. Notably, Uba52 and Rpl34-ps1 were the first-ranked hub gene in 1406 and 117 DEGs respectively, and Uba52 was higher than Rp134-ps1, suggesting that stress may have led to a more pronounced effect on the set of 1406 DEGs. Pathway analysis revealed that 1406 DEGs were primarily enriched in ribosomal pathway. These results were confirmed by qRT-PCR. LIMITATIONS: Sex-specific transcriptional profiles associated with stress were identified in this study, but more in-depth experiments, such as single-cell sequencing and manipulation of male and female gene networks in vivo, are needed to verify our findings. CONCLUSION: Our findings show sex-specific behavioural responses to stress and highlight sexual dimorphism at the transcriptional level, shedding light on developing sex-specific therapeutic strategies for stress-related psychiatric disorders.
Assuntos
Privação Materna , Córtex Pré-Frontal , Animais , Feminino , Masculino , Ratos , Ansiedade/genética , Transtornos de Ansiedade , Perfilação da Expressão Gênica , Córtex Pré-Frontal/metabolismo , Caracteres Sexuais , Transcrição GênicaRESUMO
Early-life stress is normally thought of as a major risk for psychiatric disorders, but many researchers have revealed that adversity early in life may enhance stress resilience later in life. Few studies have been performed in rodents to address the possibility that exposure to early-life stress may enhance stress resilience, and the underlying neural mechanisms are far from being understood. Here, we established a "two-hit" stress model in rats by applying two different early-life stress paradigms: predictable and unpredictable maternal separation (MS). Predictable MS during the postnatal period promotes resilience to adult restraint stress, while unpredictable MS increases stress susceptibility. We demonstrate that structural and functional impairments occur in glutamatergic synapses in pyramidal neurons of the medial prefrontal cortex (mPFC) in rats with unpredictable MS but not in rats with predictable MS. Then, we used differentially expressed gene (DEG) analysis of RNA sequencing data from the adult male PFC to identify a hub gene that is responsible for stress resilience. Oxytocin, a peptide hormone, was the highest ranked differentially expressed gene of these altered genes. Predictable MS increases the expression of oxytocin in the mPFC compared to normal raised and unpredictable MS rats. Conditional knockout of the oxytocin receptor in the mPFC was sufficient to generate excitatory synaptic dysfunction and anxiety behavior in rats with predictable MS, whereas restoration of oxytocin receptor expression in the mPFC modified excitatory synaptic function and anxiety behavior in rats subjected to unpredictable MS. These findings were further supported by the demonstration that blocking oxytocinergic projections from the paraventricular nucleus of the hypothalamus (PVN) to the mPFC was sufficient to exacerbate anxiety behavior in rats exposed to predictable MS. Our findings provide direct evidence for the notion that predictable MS promotes stress resilience, while unpredictable MS increases stress susceptibility via mPFC oxytocin signaling in rats.
Assuntos
Privação Materna , Ocitocina , Animais , Ansiedade/metabolismo , Masculino , Ocitocina/metabolismo , Córtex Pré-Frontal/metabolismo , Ratos , Transdução de Sinais , Estresse PsicológicoRESUMO
Nitric oxide (NO), the highly reactive radical gas, provides an attractive strategy in the control of microbial infections. NO not only exhibits bactericidal effect at high concentrations but also prevents bacterial attachment and disperses biofilms at low, nontoxic concentrations, rendering bacteria less tolerant to antibiotic treatment. The endogenously generated NO by airway epithelium in healthy populations significantly contributes to the eradication of invading pathogens. However, this pathway is often compromised in patients suffering from chronic lung infections where biofilms dominate. Thus, exogenous supplementation of NO is suggested to improve the therapeutic outcomes of these infectious diseases. Compared to previous reviews focusing on the mechanism of NO-mediated biofilm inhibition, this review explores the applications of NO for inhibiting biofilms in chronic lung infections. It discusses how abnormal levels of NO in the airways contribute to chronic infections in cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), and primary ciliary dyskinesia (PCD) patients and why exogenous NO can be a promising antibiofilm strategy in clinical settings, as well as current and potential in vivo NO delivery methods. KEY POINTS : ⢠The relationship between abnormal NO levels and biofilm development in lungs ⢠The antibiofilm property of NO and current applications in lungs ⢠Potential NO delivery methods and research directions in the future.
Assuntos
Óxido Nítrico , Infecções por Pseudomonas , Antibacterianos/uso terapêutico , Biofilmes , Humanos , Pulmão , Doadores de Óxido Nítrico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosaRESUMO
Humans are exposed to many xenobiotics simultaneously, but little is known about the toxic effects based on chemical-chemical interactions. This study aims at evaluating the binary interactions between 13 common environmental organic compounds (resulting in 78 pairs) by observing their cytotoxicity on HepG2 cells. Among all of the tested pairs, the combination of flame-retardant triphenyl phosphate (TPP) and tris(1,3-dichloro-2-propyl)phosphate (TDCPP) exhibited one of the most significant synergistic effects. We further characterized the transcriptome and metabolome after combined exposure to TPP and TDCPP and individual exposure. The results suggested that the coexposure caused many more changes in gene expressions and cellular activities. The transcriptome data showed that the coexposure triggered significant pathway changes including "cholesterol biosynthesis" and "ATF6-Alpha activated chaperone genes", together with distinct gene ontology (GO) terms such as the "negative regulation of the ERK1 and ERK2 cascade". Additionally, coexposure enhanced the biological activity of liver X receptors and nuclear factor erythroid 2-related factor 2 (Nrf2). The metabolome data showed that coexposure significantly elevated oxidative stress and affected the purine and pyrimidine metabolism. Overall, this study showed that interactions, which may enhance or suppress the biological processes, are common among environmental chemicals, although their environmental relevance should be studied in the future.
Assuntos
Produtos Biológicos , Retardadores de Chama , Humanos , Organofosfatos/toxicidade , Compostos Organofosforados , FosfatosRESUMO
Understanding the dynamics of biofilm development in response to chemical cues and signals is required toward the development of controllable biofilm-mediated bioprocesses. In this study, we report a new biofilm growth system that integrates a microfluidic gradient mixer with a biofilm growth chamber. The biofilm growth system allows biofilms to grow under defined solute gradients and enables nondestructive monitoring of the biofilm development dynamics in response to the defined gradients. The solute gradients generated in the system were simulated and then validated experimentally. We then demonstrated the applicability of the biofilm growth system in studying biofilm development under defined solute gradients. Specifically, we examined biofilm development of Shewanella oneidensis and Comamonas testosteroni under a defined calcium and nitrate gradient, respectively. Using two C. testosteroni strains (WDL7 and I2), we further demonstrated the applicability of our biofilm growth system to study the development of coculture biofilms under a defined solute gradient. Our results show that the biofilm growth system we have developed here can be a promising tool to reveal the dynamics of biofilm development in response to chemical cues and signals as well as the interorganism interactions in coculture biofilms.
Assuntos
Biofilmes/crescimento & desenvolvimento , Comamonas testosteroni/efeitos dos fármacos , Meios de Cultura/química , Dispositivos Lab-On-A-Chip , Microfluídica/instrumentação , Microfluídica/métodos , Shewanella/efeitos dos fármacos , Cálcio/metabolismo , Comamonas testosteroni/crescimento & desenvolvimento , Nitratos/metabolismo , Shewanella/crescimento & desenvolvimentoRESUMO
Humans spend most of their time indoors and thus have long-term exposure to chemicals. Dust is a sink for most indoor chemicals, and its ingestion is an important pathway for chemical uptake. Therefore, the chemical atlas from dust is an ideal environmental sample to investigate the indoor exposome and associated risk. In this study, we aimed to establish an indoor exposome database through comprehensive data mining on the occurrence of identified compounds in dust, and we prioritize chemicals of health concern. Through an extensive literature review (2849 articles), 355 chemicals and their concentrations were documented and analyzed for human exposure. Together with 81 compounds without concentration and 75 volatile organic compounds, we have established an indoor exposome database with 511 chemicals. Sixteen toxicological end points were selected for toxicity prioritization. Toxic equivalency factor (TEF)-based toxicity, calculated from EPA's ToxCast database, revealed a comprehensive atlas of the chemicals that had a primary contribution. Many of the prioritized compounds are currently neglected or are not actively studied. Overall, this investigation provides one of the most comprehensive analyses on chemical occurrence in indoor dust and prioritizes their chemical toxicity. Our findings can be used as a database for future exposome studies of the indoor environment and provide guidance for indoor risk assessments.
Assuntos
Poluição do Ar em Ambientes Fechados , Compostos Orgânicos Voláteis , Bases de Dados Factuais , Poeira , HumanosRESUMO
The human gut microbiome experiences long-term exposure to numerous organic contaminants (e.g., xenobiotics) in the digestive tract, and the possible consequences have rarely been characterized. To date, very few studies have investigated the metabolic variation from different species of gut bacteria in response to xenobiotic mixtures. In this study, we applied liquid chromatography mass spectrometry-based global metabolomics, coupled with targeted metabolomics, to characterize the model gut bacterial responses toward the xenobiotic mixture, covering diverse classes of compounds at human relevant concentrations. The xenobiotic "cocktail" will not likely affect the growth or morphological properties of model bacteria at human relevant concentrations. However, the metabolic results were distinct between four model bacteria and dose levels, showing species-specific and dose-dependent responsive patterns among different commensal gut bacteria. The key metabolites responsive to xenobiotic exposure are mainly involved in amino acid metabolism and central carbon metabolism, including sulfur-containing amino acids, aromatic amino acids, amino sugars, neurotransmitters, and energy-related metabolic pathways. Many of those metabolites also play an important role in the host's health. In summary, our results show that the gut microbiome can be significantly perturbed by exposure to xenobiotic mixtures at human relevant levels, providing key information on susceptibilities of individuals with diverse gut microbial structures.
Assuntos
Microbioma Gastrointestinal , Trato Gastrointestinal , Animais , Bactérias , Humanos , Metaboloma , Camundongos , Camundongos Endogâmicos C57BL , XenobióticosRESUMO
This article describes molecular design, synthesis and characterization of colloidal nanoparticles containing polycaprolactone-grafted conjugated polymers that exhibit strong far red/near-infrared (FR/NIR) fluorescence for bioimaging. Specifically, we synthesized two kinds of conjugated polymer bottle brushes (PFTB(out)-g-PCL and PFTB(in)-g-PCL) with different positions of the hexyl groups on the thiophene rings. A synthetic amphiphilic block copolymer PCL-b-POEGMA was employed as surfactants to encapsulate PFTB-g-PCL polymers into colloidal nanoparticles (denoted as "nanoREDs") in aqueous media. The chain length of the PCL side chains in PFTB-g-PCL played a critical role in determining the fluorescence properties in both bulk solid states and the colloidal nanoparticles. Compared to semiconducting polymer dots (Pdots) composed of PFTB(out) without grafted PCL, nanoRED(out) showed at least four times higher fluorescence quantum yield (â¼20%) and a broader emission band centered at 635 nm. We further demonstrated the application of this new class of nanoREDs for effective labeling of L929 cells and HeLa cancer cells with good biocompatibility. This strategy of hydrophobic-sheath segregated macromolecular fluorophores is expected to be applicable to a broad range of conjugated polymers with tunable optical properties for applications such as bioimaging.
Assuntos
Fibroblastos/citologia , Corantes Fluorescentes/química , Imagem Molecular/métodos , Nanopartículas/química , Poliésteres/química , Polímeros/química , Células Cultivadas , Fibroblastos/metabolismo , Fluorescência , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Pontos Quânticos , Espectrofotometria InfravermelhoRESUMO
Biofilms are the most ubiquitous and resilient form of microbial life on earth. One most important feature of a biofilm is the presence of a self-produced matrix, which creates highly heterogeneous and dynamic microenvironments within biofilms. Redox status in biofilm microenvironments plays a critical role in biofilm development and function. However, there is a lack of non-intrusive tools to quantify extracellular redox status of microenvironments within a biofilm matrix. In this study, using Shewanella oneidensis as a model organism, we demonstrated a novel approach to monitor extracellular redox status in biofilm microenvironments. Specifically, we displayed a redox sensitive fluorescence protein roGFP onto the cell surface of S. oneidensis by fusing it to the C-terminus of BpfA, a large surface protein, and used the surface displayed roGFP as a sensor to quantify the extracellular redox status in the matrix of S. oneidensis biofilms. The fusion of roGFP into BpfA has no negative impacts on cell growth and biofilm formation. Upon exposure to oxidizing agents such as H2 O2 , Ag(+) , and SeO3 (2-) , S. oneidensis BpfA-roGFP cells exhibited a characteristic fluorescence of roGFP. Proteinase treatment assay and super-resolution structured illumination microscopy confirmed the surface localization of BpfA-roGFP. We further used the surface displayed roGFP monitored the extracellular redox status in the matrix at different depths of a biofilm exposed to H2 O2 . This study provides a novel approach to non-invasively monitor extracellular redox status in microenvironments within biofilms, which can be used to understand redox responses of biofilms to environmental perturbations.
Assuntos
Biofilmes , Técnicas Biossensoriais/métodos , Técnicas de Visualização da Superfície Celular/métodos , Proteínas de Fluorescência Verde/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Shewanella/metabolismo , Espaço Extracelular/química , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Oxirredução , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Shewanella/química , Espectrometria de FluorescênciaRESUMO
Obsessive-compulsive disorder (OCD) is a chronic, severe psychiatric disorder that has been ranked by the World Health Organization as one of the leading causes of illness-related disability, and first-line interventions are limited in efficacy and have side-effect issues. However, the exact pathophysiology underlying this complex, heterogeneous disorder remains unknown. This scenario is now rapidly changing due to the advancement of powerful technologies that can be used to verify the function of the specific gene and dissect the neural circuits underlying the neurobiology of OCD in rodents. Genetic and circuit-specific manipulation in rodents has provided important insights into the neurobiology of OCD by identifying the molecular, cellular, and circuit events that induce OCD-like behaviors. This review will highlight recent progress specifically toward classic genetic animal models and advanced neural circuit findings, which provide theoretical evidence for targeted intervention on specific molecular, cellular, and neural circuit events.
RESUMO
Wheat leaf rust fungus is an obligate parasitic fungus that can absorb nutrients from its host plant through haustoria and secrete effector proteins into host cells. The effector proteins are crucial factors for pathogenesis as well as targets for host disease resistance protein recognition. Exploring the role of effector proteins in the pathogenic process of Puccinia triticina Eriks. (Pt) is of great significance for unraveling its pathogenic mechanisms. We previously found that a cysteine-rich effector protein, Pt1641, is highly expressed during the interaction between wheat and Pt, but its specific role in pathogenesis remains unclear. Therefore, this study employed techniques such as heterologous expression, qRT-PCR analysis, and host-induced gene silencing (HIGS) to investigate the role of Pt1641 in the pathogenic process of Pt. The results indicate that Pt1641 is an effector protein with a secretory function and can inhibit BAX-induced programmed cell death in Nicotiana benthamiana. qRT-PCR analyses showed that expression levels of Pt1641 were different during the interaction between the high-virulence strain THTT and low-virulence strains FGD and Thatcher, respectively. The highest expression level in the low-virulence strain FGD was four times that of the high-virulence strain THTT. The overexpression of Pt1641 in wheat near-isogenic line TcLr1 induced callose deposition and H2O2 production on TcLr1. After silencing Pt1641 in the Pt low-virulence strain FGD on wheat near-isogenic line TcLr1, the pathogenic phenotype of Pt physiological race FGD on TcLr1 changed from ";" to "3", indicating that Pt1641 plays a non-toxic function in the pathogenicity of FGD to TcLr1. This study helps to reveal the pathogenic mechanism of wheat leaf rust and provides important guidance for the mining and application of Pt avirulent genes.
RESUMO
Superstructures with complex hierarchical spatial configurations exhibit broader structural depth than single hierarchical structures and the associated broader application prospects. However, current preparation methods are greatly constrained by cumbersome steps and harsh conditions. Here, for the first time, a concise and efficient thermally responsive dynamic synthesis strategy for the preparation of multidimensional complex superstructures within soluble covalent organic networks (SCONs) with tunable morphology from 0D hollow supraparticles to 2D films is presented. Mechanism study reveals the thermally responsive dynamic "cleavage-remodeling" characteristics of SCONs, synthesized based on the unique bilayer structure of (2.2)paracyclophane, and the temperature control facilitates the process from reversible solubility to reorganization and construction of superstructures. Specifically, during the process, the oil-water-emulsion two-phase interface can be generated through droplet jetting, leading to the preparation of 0D hollow supraparticles and other bowl-like complex superstructures with high yield. Additionally, by modulating the volatility and solubility of exogenous solvents, defect-free 2D films are prepared relying on an air-liquid interface. Expanded experiments further confirm the generalizability and scalability of the proposed dynamic "cleavage-remodeling" strategy. Research on the enrichment mechanism of guest iodine highlights the superior kinetic mass transfer performance of superstructural products compared to single-hierarchical materials.
RESUMO
BACKGROUND: The limited regenerative capacity of damaged neurons in adult mammals severely restricts neural repair. Although stem cell transplantation is promising, its clinical application remains challenging. Direct reprogramming, which utilizes cell plasticity to regenerate neurons, is an emerging alternative approach. METHODS: We utilized primary postnatal cortical astrocytes for reprogramming induced neurons (iNs) through the viral-mediated overexpression of the transcription factors Ngn2 and Pax6 (NP). Fluorescence-activated cell sorting (FACS) was used to enrich successfully transfected cells, followed by single-cell RNA sequencing (scRNA-seq) using the 10 × Genomics platform for comprehensive transcriptomic analysis. RESULTS: The scRNA-seq revealed that NP overexpression led to the differentiation of astrocytes into iNs, with percentages of 36% and 39.3% on days 4 and 7 posttransduction, respectively. CytoTRACE predicted the developmental sequence, identifying astrocytes as the reprogramming starting point. Trajectory analysis depicted the dynamic changes in gene expression during the astrocyte-to-iN transition. CONCLUSIONS: This study elucidates the molecular dynamics underlying astrocyte reprogramming into iNs, revealing key genes and pathways involved in this process. Our research contributes novel insights into the molecular mechanisms of NP-mediated reprogramming, suggesting avenues for optimizing the efficiency of the reprogramming process.
Assuntos
Astrócitos , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Reprogramação Celular , Proteínas do Tecido Nervoso , Fator de Transcrição PAX6 , Análise de Célula Única , Astrócitos/metabolismo , Animais , Reprogramação Celular/genética , Fator de Transcrição PAX6/genética , Fator de Transcrição PAX6/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Análise de Célula Única/métodos , Camundongos , Diferenciação Celular/genética , Linhagem da Célula/genética , Neurônios/metabolismo , Células CultivadasRESUMO
Pseudomonas aeruginosa is a widespread nosocomial pathogen with a significant to cause both severe planktonic acute and biofilm-related chronic infections. Small RNAs (sRNAs) are noncoding regulatory molecules that are stabilized by the RNA chaperone Hfq to trigger various virulence-related signaling pathways. Here, we identified an Hfq-binding sRNA in P. aeruginosa PAO1, PqsS, which promotes bacterial pathogenicity and pseudomonas quinolone signal quorum sensing (pqs QS) system. Specifically, PqsS enhanced acute bacterial infections by inducing host cell death and promoting rhamnolipid-regulated swarming motility. Meanwhile, PqsS reduced chronic infection traits including biofilm formation and antibiotic resistance. Moreover, PqsS repressed pqsL transcript, increasing PQS levels for pqs QS. A PQS-rich environment promoted PqsS expression, thus forming a positive feedback loop. Furthermore, we demonstrated that the PqsS interacts and destabilizes the pqsL mRNA by recruiting RNase E to drive degradation. These findings provide insights for future research on P. aeruginosa pathogenesis and targeted treatment.