ABSTRACT
The abundance of distractors in the world poses a major challenge to our brain's limited processing capacity, but little is known about how selective attention modulates stimulus representations in the brain to reduce interference and support durable target memory. Here, we collected functional magnetic resonance imaging (fMRI) data in a selective attention task in which target and distractor pictures of different visual categories were simultaneously presented. Participants were asked to selectively process the target according to the effective cue, either before the encoding period (i.e., perceptual attention) or the maintenance period (i.e., reflective attention). On the next day, participants were asked to perform a memory recognition task in the scanner in which the targets, distractors, and novel items were presented in a pseudorandom order. Behavioral results showed that perceptual attention was better at enhancing target memory and reducing distractor memory than reflective attention, although the overall memory capacity (memory for both target and distractor) was comparable. Using multiple-voxel pattern analysis of the neural data, we found more robust target representation and weaker distractor representation in working memory for perceptual attention than for reflective attention. Interestingly, perceptual attention partially shifted the regions involved in maintaining the target representation from the visual cortex to the parietal cortex. Furthermore, the targets and distractors simultaneously presented in the perceptual attention condition showed reduced pattern similarity in the parietal cortex during retrieval compared to items not presented together. This neural pattern repulsion positively correlated with individuals' recognition of both targets and distractors. These results emphasize the critical role of selective attention in transforming memory representations to reduce interference and improve long-term memory performance.
Subject(s)
Attention , Magnetic Resonance Imaging , Memory, Long-Term , Memory, Short-Term , Parietal Lobe , Humans , Attention/physiology , Parietal Lobe/physiology , Male , Memory, Short-Term/physiology , Female , Memory, Long-Term/physiology , Adult , Young Adult , Goals , Brain Mapping , Photic Stimulation/methods , Visual Perception/physiologyABSTRACT
The ability to present three-dimensional (3D) scenes with continuous depth sensation has a profound impact on virtual and augmented reality, human-computer interaction, education and training. Computer-generated holography (CGH) enables high-spatio-angular-resolution 3D projection via numerical simulation of diffraction and interference1. Yet, existing physically based methods fail to produce holograms with both per-pixel focal control and accurate occlusion2,3. The computationally taxing Fresnel diffraction simulation further places an explicit trade-off between image quality and runtime, making dynamic holography impractical4. Here we demonstrate a deep-learning-based CGH pipeline capable of synthesizing a photorealistic colour 3D hologram from a single RGB-depth image in real time. Our convolutional neural network (CNN) is extremely memory efficient (below 620 kilobytes) and runs at 60 hertz for a resolution of 1,920 × 1,080 pixels on a single consumer-grade graphics processing unit. Leveraging low-power on-device artificial intelligence acceleration chips, our CNN also runs interactively on mobile (iPhone 11 Pro at 1.1 hertz) and edge (Google Edge TPU at 2.0 hertz) devices, promising real-time performance in future-generation virtual and augmented-reality mobile headsets. We enable this pipeline by introducing a large-scale CGH dataset (MIT-CGH-4K) with 4,000 pairs of RGB-depth images and corresponding 3D holograms. Our CNN is trained with differentiable wave-based loss functions5 and physically approximates Fresnel diffraction. With an anti-aliasing phase-only encoding method, we experimentally demonstrate speckle-free, natural-looking, high-resolution 3D holograms. Our learning-based approach and the Fresnel hologram dataset will help to unlock the full potential of holography and enable applications in metasurface design6,7, optical and acoustic tweezer-based microscopic manipulation8-10, holographic microscopy11 and single-exposure volumetric 3D printing12,13.
Subject(s)
Computer Graphics , Computer Systems , Holography/methods , Holography/standards , Neural Networks, Computer , Animals , Augmented Reality , Color , Datasets as Topic , Deep Learning , Microscopy , Optical Tweezers , Printing, Three-Dimensional , Time Factors , Virtual RealityABSTRACT
Individuals generally form their unique memories from shared experiences, yet the neural representational mechanisms underlying this subjectiveness of memory are poorly understood. The current study addressed this important question from the cross-subject neural representational perspective, leveraging a large functional magnetic resonance imaging dataset (n = 415) of a face-name associative memory task. We found that individuals' memory abilities were predicted by their synchronization to the group-averaged, canonical trial-by-trial activation level and, to a lesser degree, by their similarity to the group-averaged representational patterns during encoding. More importantly, the memory content shared between pairs of participants could be predicted by their shared local neural activation pattern, particularly in the angular gyrus and ventromedial prefrontal cortex, even after controlling for differences in memory abilities. These results uncover neural representational mechanisms for individualized memory and underscore the constructive nature of episodic memory.
Subject(s)
Memory, Episodic , Humans , Prefrontal Cortex/diagnostic imaging , Parietal LobeABSTRACT
Metastasis, especially intrahepatic, is a major challenge for hepatocellular carcinoma (HCC) treatment. Cytoskeleton remodeling has been identified as a vital process mediating intrahepatic spreading. Previously, we reported that HCC tumor adhesion and invasion were modulated by circular RNA (circRNA), which has emerged as an important regulator of various cellular processes and has been implicated in cancer progression. Here, we uncovered a nuclear circRNA, circASH2, which is preferentially lost in HCC tissues and inhibits HCC metastasis by altering tumor cytoskeleton structure. Tropomyosin 4 (TPM4), a critical binding protein of actin, turned out to be the major target of circASH2 and was posttranscriptionally suppressed. Such regulation is based on messenger RNA (mRNA)/precursormRNA splicing and degradation process. Furthermore, liquid-liquid phase separation of nuclear Y-box binding protein 1 (YBX1) enhanced by circASH2 augments TPM4 transcripts decay. Together, our data have revealed a tumor-suppressive circRNA and, more importantly, uncovered a fine regulation mechanism for HCC progression.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , MicroRNAs , Humans , Liver Neoplasms/pathology , Carcinoma, Hepatocellular/pathology , RNA, Circular/genetics , RNA, Circular/metabolism , RNA, Messenger , Cell Proliferation/genetics , Cytoskeletal Proteins/metabolism , Cytoskeleton/metabolism , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , Cell Line, Tumor , Y-Box-Binding Protein 1/geneticsABSTRACT
The long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is involved in a variety of human cancers. Two overlapping NEAT1 isoforms, NEAT1_1 and NEAT1_2, are produced through mutually exclusive alternative 3' end formation. Previous studies extensively investigated NEAT1 dysregulation in tumors, but often failed to achieve distinct quantification of the two NEAT1 isoforms. Moreover, molecular mechanisms governing the biogenesis of NEAT1 isoforms and the functional impacts of their dysregulation in tumorigenesis remain poorly understood. In this study, we employed an isoform-specific quantification assay and found differential dysregulation of NEAT1 isoforms in patient-derived glioblastoma multiforme cells. We further showed usage of the NEAT1 proximal polyadenylation site (PAS) is a critical mechanism that controls glioma NEAT1 isoform production. CRISPR-Cas9-mediated PAS deletion reduced NEAT1_1 and reciprocally increased NEAT1_2, which enhanced nuclear paraspeckle formation in human glioma cells. Moreover, the utilization of the NEAT1 PAS is facilitated by the RNA-binding protein quaking (QKI), which binds to the proximal QKI recognition elements. Functionally, we identified transcriptomic changes and altered biological pathways caused by NEAT1 isoform imbalance in glioma cells, including the pathway for the regulation of cell migration. Finally, we demonstrated the forced increase of NEAT1_2 upon NEAT1 PAS deletion is responsible for driving glioma cell migration and promoting the expression of genes implicated in the regulation of cell migration. Together, our studies uncovered a novel mechanism that regulates NEAT1 isoforms and their functional impacts on the glioma transcriptome, which affects pathological pathways of glioma, represented by migration.
ABSTRACT
In maize, two pyruvate orthophosphate dikinase (PPDK) regulatory proteins, ZmPDRP1 and ZmPDRP2, are respectively specific to the chloroplast of mesophyll cells (MCs) and bundle sheath cells (BSCs). Functionally, ZmPDRP1/2 catalyse both phosphorylation/inactivation and dephosphorylation/activation of ZmPPDK, which is implicated as a major rate-limiting enzyme in C4 photosynthesis of maize. Our study here showed that maize plants lacking ZmPDRP1 or silencing of ZmPDRP1/2 confer resistance to a prevalent potyvirus sugarcane mosaic virus (SCMV). We verified that the C-terminal domain (CTD) of ZmPDRP1 plays a key role in promoting viral infection while independent of enzyme activity. Intriguingly, ZmPDRP1 and ZmPDRP2 re-localize to cytoplasmic viral replication complexes (VRCs) following SCMV infection. We identified that SCMV-encoded cytoplasmic inclusions protein CI targets directly ZmPDRP1 or ZmPDRP2 or their CTDs, leading to their re-localization to cytoplasmic VRCs. Moreover, we found that CI could be degraded by the 26S proteasome system, while ZmPDRP1 and ZmPDRP2 could up-regulate the accumulation level of CI through their CTDs by a yet unknown mechanism. Most importantly, with genetic, cell biological and biochemical approaches, we provide evidence that BSCs-specific ZmPDRP2 could accumulate in MCs of Zmpdrp1 knockout (KO) lines, revealing a unique regulatory mechanism crossing different cell types to maintain balanced ZmPPDK phosphorylation, thereby to keep maize normal growth. Together, our findings uncover the genetic link of the two cell-specific maize PDRPs, both of which are co-opted to VRCs to promote viral protein accumulation for robust virus infection.
Subject(s)
Plant Diseases , Plant Proteins , Potyvirus , Virus Replication , Zea mays , Potyvirus/physiology , Zea mays/virology , Zea mays/genetics , Zea mays/metabolism , Virus Replication/genetics , Plant Proteins/metabolism , Plant Proteins/genetics , Plant Diseases/virology , Photosynthesis/genetics , Pyruvate, Orthophosphate Dikinase/metabolism , Pyruvate, Orthophosphate Dikinase/genetics , Chloroplasts/metabolism , Chloroplasts/virologyABSTRACT
Viral communities exist in a variety of ecosystems and play significant roles in mediating biogeochemical processes, whereas viruses inhabiting strongly alkaline geochemical systems remain underexplored. In this study, the viral diversity, potential functionalities, and virus-host interactions in a strongly alkaline environment (pH = 10.4-12.4) exposed to the leachates derived from the serpentinization-like reactions of smelting slags were investigated. The viral populations (e.g., Herelleviridae, Queuovirinae, and Inoviridae) were closely associated with the dominating prokaryotic hosts (e.g., Meiothermus, Trueperaceae, and Serpentinomonas) in this ultrabasic environment. Auxiliary metabolic genes (AMGs) suggested that viruses may enhance hosts' fitness by facilitating cofactor biosynthesis, hydrogen metabolism, and carbon cycling. To evaluate the activity of synthesis of essential cofactor vitamin B9 by the viruses, a viral folA (vfolA) gene encoding dihydrofolate reductase (DHFR) was introduced into a thymidine-auxotrophic strain Escherichia coli MG1655 ΔfolA mutant, which restored the growth of the latter in the absence of thymidine. Notably, the homologs of the validated vDHFR were globally distributed in the viromes across various ecosystems. The present study sheds new light on the unique viral communities in hyperalkaline ecosystems and their potential beneficial impacts on the coexisting microbial consortia by supplying essential cofactors. IMPORTANCE: This study presents a comprehensive investigation into the diversity, potential functionalities, and virus-microbe interactions in an artificially induced strongly alkaline environment. Functional validation of the detected viral folA genes encoding dihydrofolate reductase substantiated the synthesis of essential cofactors by viruses, which may be ubiquitous, considering the broad distribution of the viral genes associated with folate cycling.
Subject(s)
Microbiota , Hydrogen-Ion Concentration , Virome/genetics , Viruses/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Tetrahydrofolate Dehydrogenase/genetics , Tetrahydrofolate Dehydrogenase/metabolism , Bacteria/genetics , Bacteria/metabolism , Bacteria/classificationABSTRACT
Ectomycorrhizal symbiosis, which involves mutually beneficial interactions between soil fungi and tree roots, is essential for promoting tree growth. To establish this symbiotic relationship, fungal symbionts must initiate and sustain mutualistic interactions with host plants while avoiding host defense responses. This study investigated the role of reactive oxygen species (ROS) generated by fungal NADPH oxidase (Nox) in the development of Laccaria bicolor/Populus tremula × alba symbiosis. Our findings revealed that L. bicolor LbNox expression was significantly higher in ectomycorrhizal roots than in free-living mycelia. RNAi was used to silence LbNox, which resulted in decreased ROS signaling, limited formation of the Hartig net, and a lower mycorrhizal formation rate. Using Y2H library screening, BiFC and Co-IP, we demonstrated an interaction between the mitogen-activated protein kinase LbSakA and LbNoxR. LbSakA-mediated phosphorylation of LbNoxR at T409, T477 and T480 positively modulates LbNox activity, ROS accumulation and upregulation of symbiosis-related genes involved in dampening host defense reactions. These results demonstrate that regulation of fungal ROS metabolism is critical for maintaining the mutualistic interaction between L. bicolor and P. tremula × alba. Our findings also highlight a novel and complex regulatory mechanism governing the development of symbiosis, involving both transcriptional and posttranslational regulation of gene networks.
Subject(s)
Fungal Proteins , Laccaria , Mycorrhizae , NADPH Oxidases , Reactive Oxygen Species , Symbiosis , Laccaria/physiology , Laccaria/genetics , Laccaria/metabolism , Mycorrhizae/physiology , NADPH Oxidases/metabolism , NADPH Oxidases/genetics , Reactive Oxygen Species/metabolism , Phosphorylation , Fungal Proteins/metabolism , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Mitogen-Activated Protein Kinases/metabolism , Mitogen-Activated Protein Kinases/geneticsABSTRACT
Systemic autoimmune diseases (SADs) are a growing spectrum of autoimmune disorders that commonly affect multiple organs. The role of Epstein-Barr virus (EBV) infection or reactivation as a trigger for the initiation and progression of SADs has been established, while the relationship between EBV envelope glycoproteins and SADs remains unclear. Here, we assessed the levels of IgG, IgA, and IgM against EBV glycoproteins (including gp350, gp42, gHgL, and gB) in serum samples obtained from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and found that RA and SLE patients exhibited a statistically significant increase in the levels of 8 and 11 glycoprotein antibodies, respectively, compared to healthy controls (p < 0.05). The LASSO model identified four factors as significant diagnostic markers for RA: gp350 IgG, gp350 IgA, gHgL IgM, and gp42 IgA; whereas for SLE it included gp350 IgG, gp350 IgA, gHgL IgA, and gp42 IgM. Combining these selected biomarkers yielded an area under the curve (AUC) of 0.749 for RA and 0.843 for SLE. We subsequently quantified the levels of autoantibodies associated with SADs in mouse sera following immunization with gp350. Remarkably, none of the tested autoantibody levels exhibited statistically significant alterations. Elevation of glycoprotein antibody concentration suggests that Epstein-Barr virus reactivation and replication occurred in SADs patients, potentially serving as a promising biomarker for diagnosing SADs. Moreover, the absence of cross-reactivity between gp350 antibodies and SADs-associated autoantigens indicates the safety profile of a vaccine based on gp350 antigen.
Subject(s)
Arthritis, Rheumatoid , Autoimmune Diseases , Epstein-Barr Virus Infections , Lupus Erythematosus, Systemic , Humans , Animals , Mice , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human , Antibodies, Viral , Arthritis, Rheumatoid/complications , Glycoproteins , Autoimmune Diseases/complications , Immunoglobulin G , Immunoglobulin A , Immunoglobulin MABSTRACT
Hepatitis B e antigen (HBeAg) seropositivity during the natural history of chronic hepatitis B (CHB) is known to coincide with significant increases in serum and intrahepatic HBV DNA levels. However, the precise underlying mechanism remains unclear. In this study, we found that PreC (HBeAg precursor) genetic ablation leads to reduced viral replication both in vitro and in vivo. Furthermore, PreC impedes the proteasomal degradation of HBV polymerase, promoting viral replication. We discovered that PreC interacts with SUV39H1, a histone methyltransferase, resulting in a reduction in the expression of Cdt2, an adaptor protein of CRL4 E3 ligase targeting HBV polymerase. SUV39H1 induces H3K9 trimethylation of the Cdt2 promoter in a PreC-induced manner. CRISPR-mediated knockout of endogenous SUV39H1 or pharmaceutical inhibition of SUV39H1 decreases HBV loads in the mouse liver. Additionally, genetic depletion of Cdt2 in the mouse liver abrogates PreC-related HBV replication. Interestingly, a negative correlation of intrahepatic Cdt2 with serum HBeAg and HBV DNA load was observed in CHB patient samples. Our study thus sheds light on the mechanistic role of PreC in inducing HBV replication and identifies potential therapeutic targets for HBV treatment.
Subject(s)
Hepatitis B virus , Hepatitis B, Chronic , Animals , Humans , Mice , DNA, Viral , Hepatitis B e Antigens , Hepatitis B virus/genetics , Methyltransferases , Repressor Proteins/genetics , Virus ReplicationABSTRACT
OBJECTIVES: We aimed to construct an artificial intelligence-enabled electrocardiogram (ECG) algorithm that can accurately predict the presence of left atrial low-voltage areas (LVAs) in patients with persistent atrial fibrillation. METHODS: The study included 587 patients with persistent atrial fibrillation who underwent catheter ablation procedures between March 2012 and December 2023 and 942 scanned images of 12-lead ECGs obtained before the ablation procedures were performed. Artificial intelligence-based algorithms were used to construct models for predicting the presence of LVAs. The DR-FLASH and APPLE clinical scores for LVA prediction were calculated. We used a receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis to evaluate model performance. RESULTS: The data obtained from the participants were split into training (n = 469), validation (n = 58), and test sets (n = 60). LVAs were detected in 53.7% of all participants. Using ECG alone, the deep learning algorithm achieved an area under the ROC curve (AUROC) of 0.752, outperforming both the DR-FLASH score (AUROC = 0.610) and the APPLE score (AUROC = 0.510). The random forest classification model, which integrated a probabilistic deep learning model and clinical features, showed a maximum AUROC of 0.759. Moreover, the ECG-based deep learning algorithm for predicting extensive LVAs achieved an AUROC of 0.775, with a sensitivity of 0.816 and a specificity of 0.896. The random forest classification model for predicting extensive LVAs achieved an AUROC of 0.897, with a sensitivity of 0.862, and a specificity of 0.935. CONCLUSION: The deep learning model based exclusively on ECG data and the machine learning model that combined a probabilistic deep learning model and clinical features both predicted the presence of LVAs with a higher degree of accuracy than the DR-FLASH and the APPLE risk scores.
ABSTRACT
Increasing expression of spindle and kinetochore-related complex subunit 3 (SKA3) is related to the progression of multiple malignancies. However, the role of SKA3 in osteosarcoma remains unexplored. The present study aimed to investigate the relevance of SKA3 in osteosarcoma. Preliminarily, SKA3 expression in osteosarcoma was assessed through The Cancer Genome Atlas (TCGA) analysis, which revealed high levels of SKA3 transcripts in osteosarcoma tissues. Subsequent examination of clinical tissues confirmed the abundant expression of SKA3 in osteosarcoma. Downregulation of SKA3 expression in osteosarcoma cell lines resulted in repressive effects on cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT), while upregulation of SKA3 expression had the opposite effect. Gene set enrichment analysis (GSEA) revealed that the Notch pathway is enriched in SKA3 high groups based on different expressed genes from the TCGA data. Further investigation showed that the levels of Notch1, Notch1 intracellular domain (NICD1), hairy and enhancer of split 1 (HES1), and hairy/enhancer-of-split related with YRPW motif protein 1 (HEY1) were downregulated in SKA3-silenced osteosarcoma cells, and upregulated in SKA3-overexpressed osteosarcoma cells. Activation of the Notch pathway by increasing NICD1 expression reversed the antitumour effects induced by SKA3 silencing, while deactivation of the Notch pathway diminished the protumour effects induced by SKA3 overexpression. Moreover, SKA3-silenced osteosarcoma cells exhibited a reduced capacity for xenograft formation in nude mice. In conclusion, SKA3 plays a cancer-enhancing role in osteosarcoma through its effect on the Notch pathway. Reducing the expression of SKA3 could be a potential therapeutic approach for treating osteosarcoma.
Subject(s)
Bone Neoplasms , Osteosarcoma , Animals , Humans , Mice , Bone Neoplasms/genetics , Bone Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/genetics , Kinetochores/metabolism , Kinetochores/pathology , Mice, Nude , Osteosarcoma/genetics , Osteosarcoma/pathology , Signal Transduction/geneticsABSTRACT
The Hamiltonian, which determines the evolution of a quantum system, is fundamental in quantum physics. Therefore, it is crucial to implement high-precision generation and measurement of the Hamiltonian in a practical quantum system. Here, we experimentally demonstrate ultrahigh-precision Hamiltonian parameter estimation with a significant quantum advantage in a superconducting circuit via sequential control. We first observe the commutation relation for noncommuting operations determined by the system Hamiltonian, both with and without adding quantum control, verifying the commuting property of controlled noncommuting operations. Based on this control-induced commuting property, we further demonstrate Hamiltonian parameter estimation for polar and azimuth angles in superconducting circuits, achieving ultrahigh metrological gains in measurement precision exceeding the standard quantum limit by up to 16.0 and 16.1 dB at N=100, respectively.
ABSTRACT
BACKGROUND: Diffuse large B-cell lymphomas (DLBCLs) display high molecular heterogeneity, but the International Prognostic Index (IPI) considers only clinical indicators and has not been updated to include molecular data. Therefore, we developed a widely applicable novel scoring system with molecular indicators screened by artificial intelligence (AI) that achieves accurate prognostic stratification and promotes individualized treatments. METHODS: We retrospectively enrolled a cohort of 401 patients with DLBCL from our hospital, covering the period from January 2015 to January 2019. We included 22 variables in our analysis and assigned them weights using the random survival forest method to establish a new predictive model combining bidirectional long-short term memory (Bi-LSTM) and logistic hazard techniques. We compared the predictive performance of our "molecular-contained prognostic model" (McPM) and the IPI. In addition, we developed a simplified version of the McPM (sMcPM) to enhance its practical applicability in clinical settings. We also demonstrated the improved risk stratification capabilities of the sMcPM. RESULTS: Our McPM showed superior predictive accuracy, as indicated by its high C-index and low integrated Brier score (IBS), for both overall survival (OS) and progression-free survival (PFS). The overall performance of the McPM was also better than that of the IPI based on receiver operating characteristic (ROC) curve fitting. We selected five key indicators, including extranodal involvement sites, lactate dehydrogenase (LDH), MYC gene status, absolute monocyte count (AMC), and platelet count (PLT) to establish the sMcPM, which is more suitable for clinical applications. The sMcPM showed similar OS results (P < 0.0001 for both) to the IPI and significantly better PFS stratification results (P < 0.0001 for sMcPM vs. P = 0.44 for IPI). CONCLUSIONS: Our new McPM, including both clinical and molecular variables, showed superior overall stratification performance to the IPI, rendering it more suitable for the molecular era. Moreover, our sMcPM may become a widely used and effective stratification tool to guide individual precision treatments and drive new drug development.
Subject(s)
Artificial Intelligence , Lymphoma, Large B-Cell, Diffuse , Humans , Lymphoma, Large B-Cell, Diffuse/mortality , Female , Male , Middle Aged , Prognosis , Retrospective Studies , China/epidemiology , Aged , Adult , Aged, 80 and over , Young Adult , AdolescentABSTRACT
Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei, an intracellular pathogen with a high mortality rate and significant antibiotic resistance. The high mortality rate and resistance to antibiotics have drawn considerable attention from researchers studying melioidosis. This study evaluated the effects of various concentrations (75, 50, and 25 µg/mL) of promethazine hydrochloride (PTZ), a potent antihistamine, on biofilm formation and lipase activity after 24 h of exposure to B. thailandensis E264. A concentration-dependent decrease in both biofilm biomass and lipase activity was observed. RT-PCR analysis revealed that PTZ treatment not only made the biofilm structure loose but also reduced the expression of btaR1, btaR2, btaR3, and scmR. Single gene knockouts of quorum sensing (QS) receptor proteins (∆btaR1, ∆btaR2, and ∆btaR3) were successfully constructed. Deletion of btaR1 affected biofilm formation in B. thailandensis, while deletion of btaR2 and btaR3 led to reduced lipase activity. Molecular docking and biological performance results demonstrated that PTZ inhibits biofilm formation and lipase activity by suppressing the expression of QS-regulated genes. This study found that repositioning PTZ reduced biofilm formation in B. thailandensis E264, suggesting a potential new approach for combating melioidosis.
Subject(s)
Biofilms , Burkholderia , Drug Repositioning , Promethazine , Biofilms/drug effects , Biofilms/growth & development , Burkholderia/drug effects , Burkholderia/physiology , Burkholderia/genetics , Promethazine/pharmacology , Molecular Docking Simulation , Anti-Bacterial Agents/pharmacology , Lipase/metabolism , Lipase/genetics , Gene Expression Regulation, Bacterial/drug effects , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Humans , Quorum Sensing/drug effectsABSTRACT
Mutations in the human kinesin family member 5A (KIF5A) gene were recently identified as a genetic cause of amyotrophic lateral sclerosis (ALS). Several KIF5A ALS variants cause exon 27 skipping and are predicted to produce motor proteins with an altered C-terminal tail (referred to as ΔExon27). However, the underlying pathogenic mechanism is still unknown. Here, we confirm the expression of KIF5A mutant proteins in patient iPSC-derived motor neurons. We perform a comprehensive analysis of ΔExon27 at the single-molecule, cellular, and organism levels. Our results show that ΔExon27 is prone to form cytoplasmic aggregates and is neurotoxic. The mutation relieves motor autoinhibition and increases motor self-association, leading to drastically enhanced processivity on microtubules. Finally, ectopic expression of ΔExon27 in Drosophila melanogaster causes wing defects, motor impairment, paralysis, and premature death. Our results suggest gain-of-function as an underlying disease mechanism in KIF5A-associated ALS.
Subject(s)
Amyotrophic Lateral Sclerosis , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Animals , DNA, Antisense/genetics , Drosophila melanogaster , Gain of Function Mutation , Humans , Kinesins/genetics , Motor Neurons/metabolism , Mutation , Transcription Factor 7-Like 2 Protein/metabolismABSTRACT
A novel chemoheterotrophic iron-reducing micro-organism, designated as strain LSZ-M11000T, was isolated from sediment of the Marianas Trench. Phylogenetic analysis based on the 16S rRNA gene revealed that strain LSZ-M11000T belonged to genus Tepidibacillus, with 97â% identity to that of Tepidibacillus fermentans STGHT, a mesophilic bacterium isolated from the Severo-Stavropolskoye underground gas storage facility in Russia. The polar lipid profile of strain LSZ-M11000T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, as well as other unidentified phospholipids and lipids. The major fatty acids were C16â:â0 (28.4â%), C18â:â0 (15.8â%), iso-C15â:â0 (12.9â%), and anteiso-C15â:â0 (12.0â%). Strain LSZ-M11000T had no menaquinone. Genome sequencing revealed that the genome size of strain LSZ-M11000T was 2.97 Mb and the DNA G+C content was 37.9âmol%. The average nucleotide identity values between strain LSZ-M11000T and its close phylogenetic relatives, Tepidibacillus fermentans STGHT and Tepidibacillus decaturensis Z9T, were 76.4 and 72.6â%, respectively. The corresponding DNA-DNA hybridization estimates were 20.9 and 23.4â%, respectively. Cells of strain LSZ-M11000T were rod-shaped (1.0-1.5×0.3-0.5 µm). Using pyruvate as an electron donor, it was capable of reducing KMnO4, MnO2, As(V), NaNO3, NaNO2, Na2SO4, Na2S2O3, and K2Cr2O7. Based on phenotypic, genotypic, and phylogenetic evidence, strain LSZ-M11000T is proposed to be a novel strain of the genus Tepidibacillus, for which the name Tepdibacillus marianensis is proposed. The type strain is LSZ-M11000T (=CCAM 1008T=JCM 39431T).
Subject(s)
Bacterial Typing Techniques , Base Composition , DNA, Bacterial , Fatty Acids , Geologic Sediments , Iron , Phospholipids , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , RNA, Ribosomal, 16S/genetics , Geologic Sediments/microbiology , DNA, Bacterial/genetics , Russia , Iron/metabolism , Heterotrophic Processes , Nucleic Acid Hybridization , Bacillaceae/classification , Bacillaceae/genetics , Bacillaceae/isolation & purification , Whole Genome Sequencing , Oxidation-ReductionABSTRACT
OBJECTIVES: To investigate whether a novel assessment of thrombus permeability obtained from perfusion computed tomography (CTP) can act as a more accurate predictor of clinical response to mechanical thrombectomy (MT) in acute ischemic stroke (AIS). MATERIALS AND METHODS: We performed a study including two cohorts of AIS patients who underwent MT admitted to a single-center between April 2018 and February 2022: a retrospective development cohort (n = 71) and a prospective independent validation cohort (n = 96). Thrombus permeability was determined in terms of entire thrombus time-attenuation curve (TAC) on CTP. Association between thrombus TAC distributions and histopathological results was analyzed in the development cohort. Logistic regression was used to assess the performance of the TAC for predicting 90-day modified Rankin Scale (mRS) score, and good outcome was defined as a mRS score of ≤ 2. Basic clinical characteristics was used to build a routine clinical model. A combined model gathered TAC and basic clinical characteristics was also developed. The performance of the three models is compared on the independent validation set. RESULTS: Two TAC distributions were observed-unimodal (uTAC) and linear (lTAC). TAC distributions achieved strong correlations (|r|= 0.627, p < 0.001) with histopathological results, in which uTAC associated with fibrin- and platelet-rich clot while lTAC associated with red blood cell-rich clot. The uTAC was independently associated with poor outcome (odds ratio, 0.08 [95% confidence interval (CI), 0.02-0.31]; p < 0.001). TAC distributions yielded an AUC of 0.78 (95% CI, 0.70-0.87) for predicting clinical outcome. When combined clinical characteristics, the performance was significantly improved (AUC, 0.85 [95% CI, 0.76-0.93]; p < 0.001) and higher than routine clinical model (AUC, 0.69 [95% CI, 0.59-0.83]; p < 0.001). CONCLUSIONS: Thrombus TAC on CTP were found to be a promising new imaging biomarker to predict the outcomes of MT in AIS. CLINICAL RELEVANCE STATEMENT: This study revealed that clot-based time attenuation curve based on admission perfusion CT could reflect the permeability and composition of thrombus and, also, provide valuable information to predict the clinical outcomes of mechanical thrombectomy in patients with acute ischemia stroke. KEY POINTS: ⢠Two time-attenuation curves distributions achieved strong correlations (|r|= 0.627, p < 0.001) with histopathological results. ⢠The unimodal time-attenuation curve was independently associated with poor outcome (odds ratio, 0.08 [0.02-0.31]; p < 0.001). ⢠The time-attenuation curve distributions yielded a higher performance for detecting clinical outcome than routine clinical model (AUC, 0.78 [0.70-0.87] vs 0.69 [0.59-0.83]; p < 0.001).
Subject(s)
Brain Ischemia , Ischemic Stroke , Stroke , Thrombosis , Humans , Stroke/diagnostic imaging , Stroke/therapy , Ischemic Stroke/diagnostic imaging , Ischemic Stroke/surgery , Treatment Outcome , Retrospective Studies , Prospective Studies , Thrombectomy , Cerebral Angiography/methods , Ischemia , Brain Ischemia/diagnostic imaging , Brain Ischemia/surgeryABSTRACT
OBJECTIVES: Colitis is a global disease usually accompanied by intestinal epithelial damage and intestinal inflammation, and an increasing number of studies have found natural products to be highly effective in treating colitis. Anemoside B4 (AB4), an abundant saponin isolated from Pulsatilla chinensis (Bunge), which was found to have strong anti-inflammatory activity. However, the exact molecular mechanisms and direct targets of AB4 in the treatment of colitis remain to be discovered. METHODS: The anti-inflammatory activities of AB4 were verified in LPS-induced cell models and 2, 4, 6-trinitrobenzene sulfonic (TNBS) or dextran sulfate sodium (DSS)-induced colitis mice and rat models. The molecular target of AB4 was identified by affinity chromatography analysis using chemical probes derived from AB4. Experiments including proteomics, molecular docking, biotin pull-down, surface plasmon resonance (SPR), and cellular thermal shift assay (CETSA) were used to confirm the binding of AB4 to its molecular target. Overexpression of pyruvate carboxylase (PC) and PC agonist were used to study the effects of PC on the anti-inflammatory and metabolic regulation of AB4 in vitro and in vivo. RESULTS: AB4 not only significantly inhibited LPS-induced NF-κB activation and increased ROS levels in THP-1 cells, but also suppressed TNBS/DSS-induced colonic inflammation in mice and rats. The molecular target of AB4 was identified as PC, a key enzyme related to fatty acid, amino acid and tricarboxylic acid (TCA) cycle. We next demonstrated that AB4 specifically bound to the His879 site of PC and altered the protein's spatial conformation, thereby affecting the enzymatic activity of PC. LPS activated NF-κB pathway and increased PC activity, which caused metabolic reprogramming, while AB4 reversed this phenomenon by inhibiting the PC activity. In vivo studies showed that diisopropylamine dichloroacetate (DADA), a PC agonist, eliminated the therapeutic effects of AB4 by changing the metabolic rearrangement of intestinal tissues in colitis mice. CONCLUSION: We identified PC as a direct cellular target of AB4 in the modulation of inflammation, especially colitis. Moreover, PC/pyruvate metabolism/NF-κB is crucial for LPS-driven inflammation and oxidative stress. These findings shed more light on the possibilities of PC as a potential new target for treating colitis.
Subject(s)
Colitis , Saponins , Rats , Mice , Animals , Pyruvate Carboxylase/metabolism , NF-kappa B/metabolism , Lipopolysaccharides/pharmacology , Molecular Docking Simulation , Colitis/chemically induced , Colitis/drug therapy , Colitis/metabolism , Inflammation/metabolism , Saponins/pharmacology , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Macrophages/metabolism , Dextran Sulfate/adverse effects , Dextran Sulfate/metabolism , Mice, Inbred C57BL , Disease Models, AnimalABSTRACT
A water mediated three-component reaction of isatin, 4-aminocoumarin, and 1,3-cyclodicarbonyl compounds is reported for the synthesis of spiro[chromeno[4,3-b]cyclopenta[e]pyridine-7,3'-indoline]trione and the spiro[chromeno[4,3-b]quinoline 7,3'-indoline]trione. Up to 27 different spirooxindole derivatives were synthesized by this method. The bioactivity of these spirooxindole derivatives was evaluated and they were found to show antifungal activity against Cercospora arachidicola, Physalospora piricola, Rhizoctonia cerealis, and Fusarium moniliforme.