Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.974
Filter
Add more filters

Publication year range
1.
Immunity ; 52(2): 357-373.e9, 2020 02 18.
Article in English | MEDLINE | ID: mdl-32049051

ABSTRACT

Clearance of apoptotic cells by macrophages prevents excessive inflammation and supports immune tolerance. Here, we examined the effect of blocking apoptotic cell clearance on anti-tumor immune response. We generated an antibody that selectively inhibited efferocytosis by phagocytic receptor MerTK. Blockade of MerTK resulted in accumulation of apoptotic cells within tumors and triggered a type I interferon response. Treatment of tumor-bearing mice with anti-MerTK antibody stimulated T cell activation and synergized with anti-PD-1 or anti-PD-L1 therapy. The anti-tumor effect induced by anti-MerTK treatment was lost in Stinggt/gt mice, but not in Cgas-/- mice. Abolishing cGAMP production in Cgas-/- tumor cells, depletion of extracellular ATP, or inactivation of the ATP-gated P2X7R channel also compromised the effects of MerTK blockade. Mechanistically, extracellular ATP acted via P2X7R to enhance the transport of extracellular cGAMP into macrophages and subsequent STING activation. Thus, MerTK blockade increases tumor immunogenicity and potentiates anti-tumor immunity, which has implications for cancer immunotherapy.


Subject(s)
Macrophages/immunology , Membrane Proteins/metabolism , Neoplasms/immunology , Nucleotides, Cyclic/metabolism , Receptors, Purinergic P2X7/metabolism , c-Mer Tyrosine Kinase/immunology , Adenosine Triphosphate/metabolism , Animals , Apoptosis , B7-H1 Antigen/immunology , Cells, Cultured , Female , Immunity, Innate , Immunotherapy , Interferon Type I/metabolism , Macrophages/metabolism , Membrane Proteins/genetics , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/therapy , Nucleotidyltransferases/deficiency , Nucleotidyltransferases/metabolism , Phagocytosis , Programmed Cell Death 1 Receptor/immunology , Receptors, Purinergic P2X7/deficiency , Signal Transduction/immunology , Xenograft Model Antitumor Assays , c-Mer Tyrosine Kinase/genetics
2.
Plant Cell ; 35(1): 453-468, 2023 01 02.
Article in English | MEDLINE | ID: mdl-36190337

ABSTRACT

RAC/Rho of plant (ROP) GTPases are major molecular switches that control diverse signaling cascades for plant growth, development, and defense. Here, we discovered a signaling node that connects RAC/ROPs to cytokinins. Rice (Oryza sativa) plants develop a fibrous root system mainly composed of crown roots. Cytokinin signaling via a phosphorelay system is critical for crown root development. We show that OsRopGEF10, which activates RAC/ROPs, acts upstream of the cytoplasmic-nuclear shuttling phosphotransfer proteins AHPs of the cytokinin signaling pathway to promote crown root development. Mutations of OsRopGEF10 induced hypersensitivity to cytokinin, whereas overexpressing this gene reduced the cytokinin response. Loss of OsRopGEF10 function reduced the expression of the response regulator gene OsRR6, a repressor of cytokinin signaling, and impaired crown root development. Mutations in OsAHP1/2 led to increased crown root production and rescued the crown root defect of Osropgef10. Furthermore, auxin activates the ROP GTPase OsRAC3, which attenuates cytokinin signaling for crown root initiation. Molecular interactions between OsRopGEF10, OsRAC3, and OsAHP1/2 implicate a mechanism whereby OsRopGEF10-activated OsRAC3 recruits OsAHP1/2 to the cortical cytoplasm, sequestering them from their phosphorelay function in the nucleus. Together, our findings uncover the OsRopGEF10-OsRAC3-OsAHP1/2 signaling module, establish a link between RAC/ROPs and cytokinin, and reveal molecular crosstalk between auxin and cytokinin during crown root development.


Subject(s)
Oryza , Oryza/metabolism , GTP Phosphohydrolase Activators/metabolism , rho GTP-Binding Proteins/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Roots/metabolism , Signal Transduction , Cytokinins/metabolism , Indoleacetic Acids/metabolism , Gene Expression Regulation, Plant
3.
J Immunol ; 212(12): 1877-1890, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38700398

ABSTRACT

Despite the advances in study on osmotic physiology in bony fish, the mechanism by which the immune system, especially T-cell immunity, adapts and responds to osmotic stress remains unknown. In the current study, we investigated the response of T cells to hyperosmotic stress in the bony fish Nile tilapia (Oreochromis niloticus). As a euryhaline fish, tilapia was able to adapt to a wide range of salinities; however, hypertonic stress caused inflammation and excessive T-cell activation. Furthermore, hypertonic stress increased the expression of IL-17A in T cells, upregulated the transcription factor RORα, and activated STAT3 signaling, along with IL-6- and TGF-ß1-mediated pathways, revealing an enhanced Th17 response in this early vertebrate. These hypertonic stress-induced events collectively resulted in an impaired antibacterial immune response in tilapia. Hypertonic stress elevated the intracellular ROS level, which in turn activated the p38-MK2 signaling pathway to promote IL-17A production by T cells. Both ROS elimination and the p38-MK2 axis blockade diminished the increased IL-17A production in T cells under hypertonic conditions. Moreover, the produced proinflammatory cytokines further amplified the hypertonic stress signaling via the MKK6-p38-MK2 axis-mediated positive feedback loop. To our knowledge, these findings represent the first description of the mechanism by which T-cell immunity responds to hypertonic stress in early vertebrates, thus providing a novel perspective for understanding the adaptive evolution of T cells under environmental stress.


Subject(s)
Inflammation , Osmotic Pressure , Th17 Cells , Tilapia , Animals , Th17 Cells/immunology , Inflammation/immunology , Tilapia/immunology , Signal Transduction/immunology , Lymphocyte Activation/immunology , Interleukin-17/metabolism , Interleukin-17/immunology
4.
Mol Cell ; 71(6): 1092-1104.e5, 2018 09 20.
Article in English | MEDLINE | ID: mdl-30174291

ABSTRACT

Activation of class I phosphatidylinositol 3-kinase (PI3K) leads to formation of phosphatidylinositol-3,4,5-trisphophate (PIP3) and phosphatidylinositol-3,4-bisphophate (PI34P2), which spatiotemporally coordinate and regulate a myriad of cellular processes. By simultaneous quantitative imaging of PIP3 and PI34P2 in live cells, we here show that they have a distinctively different spatiotemporal distribution and history in response to growth factor stimulation, which allows them to selectively induce the membrane recruitment and activation of Akt isoforms. PI34P2 selectively activates Akt2 at both the plasma membrane and early endosomes, whereas PIP3 selectively stimulates Akt1 and Akt3 exclusively at the plasma membrane. These spatiotemporally distinct activation patterns of Akt isoforms provide a mechanism for their differential regulation of downstream signaling molecules. Collectively, our studies show that different spatiotemporal dynamics of PIP3 and PI34P2 and their ability to selectively activate key signaling proteins allow them to mediate class I PI3K signaling pathways in a spatiotemporally specific manner.


Subject(s)
Optical Imaging/methods , Phosphatidylinositol Phosphates/physiology , Single Molecule Imaging/methods , Animals , Cell Line , Cell Membrane , Humans , Inositol Phosphates , Mice , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol 3-Kinases/physiology , Phosphatidylinositol Phosphates/metabolism , Phosphatidylinositols , Protein Isoforms , Protein Transport , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction
5.
Proc Natl Acad Sci U S A ; 120(4): e2212227120, 2023 01 24.
Article in English | MEDLINE | ID: mdl-36652475

ABSTRACT

Propagating spatiotemporal neural patterns are widely evident across sensory, motor, and association cortical areas. However, it remains unclear whether any characteristics of neural propagation carry information about specific behavioral details. Here, we provide the first evidence for a link between the direction of cortical propagation and specific behavioral features of an upcoming movement on a trial-by-trial basis. We recorded local field potentials (LFPs) from multielectrode arrays implanted in the primary motor cortex of two rhesus macaque monkeys while they performed a 2D reach task. Propagating patterns were extracted from the information-rich high-gamma band (200 to 400 Hz) envelopes in the LFP amplitude. We found that the exact direction of propagating patterns varied systematically according to initial movement direction, enabling kinematic predictions. Furthermore, characteristics of these propagation patterns provided additional predictive capability beyond the LFP amplitude themselves, which suggests the value of including mesoscopic spatiotemporal characteristics in refining brain-machine interfaces.


Subject(s)
Brain-Computer Interfaces , Motor Cortex , Animals , Macaca mulatta , Biomechanical Phenomena , Movement , Action Potentials
6.
J Immunol ; 210(8): 1166-1176, 2023 04 15.
Article in English | MEDLINE | ID: mdl-36881873

ABSTRACT

Efferocytosis is a phagocytic process by which apoptotic cells are cleared by professional and nonprofessional phagocytic cells. In tumors, efferocytosis of apoptotic cancer cells by tumor-associated macrophages prevents Ag presentation and suppresses the host immune response against the tumor. Therefore, reactivating the immune response by blockade of tumor-associated macrophage-mediated efferocytosis is an attractive strategy for cancer immunotherapy. Even though several methods have been developed to monitor efferocytosis, an automated and high-throughput quantitative assay should offer highly desirable advantages for drug discovery. In this study, we describe a real-time efferocytosis assay with an imaging system for live-cell analysis. Using this assay, we successfully discovered potent anti-MerTK Abs that block tumor-associated macrophage-mediated efferocytosis in mice. Furthermore, we used primary human and cynomolgus monkey macrophages to identify and characterize anti-MerTK Abs for potential clinical development. By studying the phagocytic activities of different types of macrophages, we demonstrated that our efferocytosis assay is robust for screening and characterization of drug candidates that inhibit unwanted efferocytosis. Moreover, our assay is also applicable to investigating the kinetics and molecular mechanisms of efferocytosis/phagocytosis.


Subject(s)
Apoptosis , Neoplasms , Mice , Humans , Animals , c-Mer Tyrosine Kinase , Macaca fascicularis , Phagocytosis , Macrophages , Neoplasms/pathology
7.
J Immunol ; 210(3): 229-244, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36548476

ABSTRACT

The braking mechanisms to protect the host from tissue damage and inflammatory disease caused by an overexuberant immune response are common in many T cell subsets. However, the negative regulation of T cell responses and detailed mechanisms are not well understood in early vertebrates. In the current study, using a Nile tilapia (Oreochromis niloticus) model, we investigated the suppression of T cell immunity by IL-10. Tilapia encodes an evolutionarily conserved IL-10, whose expression in lymphocytes is markedly induced during the primary adaptive immune response against Aeromonas hydrophila infection. Activated T cells of tilapia produce IL-10, which in turn inhibits proinflammatory cytokine expression and suppresses PHA-induced T cell activation. Moreover, administration of IL-10 impairs the proliferation of tilapia T cells, reduces their potential to differentiate into Th subsets, and cripples the cytotoxic function, rendering the animals more vulnerable to pathogen attack. After binding to its receptor IL-10Ra, IL-10 activates the JAK1/STAT3 axis by phosphorylation and enhances the expression of the suppressor of cytokine signaling 3 (SOCS3), which in turn attenuates the activation of the NF-κB and MAPK/ERK signaling pathways, thus suppressing the T cell response of tilapia. Our findings elucidate a negative regulatory mechanism of T cell immunity in a fish species and support the notion that the braking mechanism of T cells executed through IL-10 existed prior to the divergence of the tetrapod lineage from teleosts. Therefore, this study, to our knowledge, provides a novel perspective on the evolution of the adaptive immune system.


Subject(s)
Cichlids , Fish Diseases , Tilapia , Animals , NF-kappa B/metabolism , Tilapia/metabolism , Interleukin-10/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Fish Proteins/metabolism
8.
J Neurosci ; 43(21): 3807-3824, 2023 05 24.
Article in English | MEDLINE | ID: mdl-37185099

ABSTRACT

Sphingosine-1-phosphate (S1P), a bioactive sphingolipid concentrated in the brain, is essential for normal brain functions, such as learning and memory and feeding behaviors. Sphingosine kinase 1 (SphK1), the primary kinase responsible for S1P production in the brain, is abundant within presynaptic terminals, indicating a potential role of the SphK1/S1P axis in presynaptic physiology. Altered S1P levels have been highlighted in many neurologic diseases with endocytic malfunctions. However, it remains unknown whether the SphK1/S1P axis may regulate synaptic vesicle endocytosis in neurons. The present study evaluates potential functions of the SphK1/S1P axis in synaptic vesicle endocytosis by determining effects of a dominant negative catalytically inactive SphK1. Our data for the first time identify a critical role of the SphK1/S1P axis in endocytosis in both neuroendocrine chromaffin cells and neurons from mice of both sexes. Furthermore, our Ca2+ imaging data indicate that the SphK1/S1P axis may be important for presynaptic Ca2+ increases during prolonged stimulations by regulating the Ca2+ permeable TRPC5 channels, which per se regulate synaptic vesicle endocytosis. Collectively, our data point out a critical role of the regulation of TRPC5 by the SphK1/S1P axis in synaptic vesicle endocytosis.SIGNIFICANCE STATEMENT Sphingosine kinase 1 (SphK1), the primary kinase responsible for brain sphingosine-1-phosphate (S1P) production, is abundant within presynaptic terminals. Altered SphK1/S1P metabolisms has been highlighted in many neurologic disorders with defective synaptic vesicle endocytosis. However, whether the SphK1/S1P axis may regulate synaptic vesicle endocytosis is unknown. Here, we identify that the SphK1/S1P axis regulates the kinetics of synaptic vesicle endocytosis in neurons, in addition to controlling fission-pore duration during single vesicle endocytosis in neuroendocrine chromaffin cells. The regulation of the SphK1/S1P axis in synaptic vesicle endocytosis is specific since it has a distinguished signaling pathway, which involves regulation of Ca2+ influx via TRPC5 channels. This discovery may provide novel mechanistic implications for the SphK1/S1P axis in brain functions under physiological and pathologic conditions.


Subject(s)
Phosphotransferases (Alcohol Group Acceptor) , Synaptic Vesicles , Male , Female , Mice , Animals , Synaptic Vesicles/metabolism , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Sphingosine/metabolism , Endocytosis , Lysophospholipids/metabolism , TRPC Cation Channels
9.
J Proteome Res ; 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38686625

ABSTRACT

NPC intracellular cholesterol transporter 1 (NPC1) is a multipass, transmembrane glycoprotein mostly recognized for its key role in facilitating cholesterol efflux. Mutations in the NPC1 gene result in Niemann-Pick disease, type C (NPC), a fatal, lysosomal storage disease. Due to the progressively expanding implications of NPC1-related disorders, we investigated endogenous NPC1 protein-protein interactions in the mouse cortex and human-derived iPSCs neuronal models of the disease through coimmunoprecipitation-coupled with LC-MS based proteomics. The current study investigated protein-protein interactions specific to the wild-type and the most prevalent NPC1 mutation (NPC1I1061T) while filtering out any protein interactor identified in the Npc1-/- mouse model. Additionally, the results were matched across the two species to map the parallel interactome of wild-type and mutant NPC1I1061T. Most of the identified wild-type NPC1 interactors were related to cytoskeleton organization, synaptic vesicle activity, and translation. We found many putative NPC1 interactors not previously reported, including two SCAR/WAVE complex proteins that regulate ARP 2/3 complex actin nucleation and multiple membrane proteins important for neuronal activity at synapse. Moreover, we identified proteins important in trafficking specific to wild-type and mutant NPC1I1061T. Together, the findings are essential for a comprehensive understanding of NPC1 biological functions in addition to its classical role in sterol efflux.

10.
J Cell Mol Med ; 28(3): e18073, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38063077

ABSTRACT

Diabetic kidney disease (DKD) can lead to accumulation of glucose upstream metabolites due to dysfunctional glycolysis. But the effects of accumulated glycolysis metabolites on podocytes in DKD remain unknown. The present study examined the effect of dihydroxyacetone phosphate (DHAP) on high glucose induced podocyte pyroptosis. By metabolomics, levels of DHAP, GAP, glucose-6-phosphate and fructose 1, 6-bisphosphate were significantly increased in glomeruli of db/db mice. Furthermore, the expression of LDHA and PKM2 were decreased. mRNA sequencing showed upregulation of pyroptosis-related genes (Nlrp3, Casp1, etc.). Targeted metabolomics demonstrated higher level of DHAP in HG-treated podocytes. In vitro, ALDOB expression in HG-treated podocytes was significantly increased. siALDOB-transfected podocytes showed less DHAP level, mTORC1 activation, reactive oxygen species (ROS) production, and pyroptosis, while overexpression of ALDOB had opposite effects. Furthermore, GAP had no effect on mTORC1 activation, and mTORC1 inhibitor rapamycin alleviated ROS production and pyroptosis in HG-stimulated podocytes. Our findings demonstrate that DHAP represents a critical metabolic product for pyroptosis in HG-stimulated podocytes through regulation of mTORC1 pathway. In addition, the results provide evidence that podocyte injury in DKD may be treated by reducing DHAP.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Podocytes , Mice , Animals , Diabetic Nephropathies/metabolism , Podocytes/metabolism , Dihydroxyacetone Phosphate/metabolism , Dihydroxyacetone Phosphate/pharmacology , Reactive Oxygen Species/metabolism , Pyroptosis , Glucose/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Diabetes Mellitus/metabolism
11.
Cancer Sci ; 115(4): 1141-1153, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38287724

ABSTRACT

The indigenous microbial milieu within tumorous tissues exerts a pivotal influence on the genesis and advancement of gastric cancer (GC). This investigation scrutinizes the functions and molecular mechanisms attributed to Prevotella intermedia in the malignant evolution of GC. Isolation of P. intermedia from paired GC tissues was undertaken. Quantification of P. intermedia abundance in 102 tissues was accomplished using quantitative real-time PCR (qRT-PCR). Assessment of the biological effects of P. intermedia on GC cells was observed using culture medium supernatant. Furthermore, the protein profile of GC cells treated with tumor-derived P. intermedia was examined through label-free protein analysis. The functionality of perilipin 3 (PLIN3) was subsequently confirmed using shRNA. Our investigation revealed that the relative abundance of P. intermedia in tumor tissues significantly surpassed that of corresponding healthy tissues. The abundance of P. intermedia exhibited correlations with tumor differentiation (p = 0.006), perineural invasion (p = 0.004), omentum majus invasion (p = 0.040), and the survival duration of GC patients (p = 0.042). The supernatant derived from tumor-associated P. intermedia bolstered the proliferation, clone formation, migration, and invasion of GC cells. After indirect co-cultivation with tumor-derived P. intermedia, dysregulation of 34 proteins, including PLIN3, was discerned in GC cells. Knockdown of PLIN3 mitigated the malignancy instigated by P. intermedia in GC cells. Our findings posit that P. intermedia from the tumor microenvironment plays a substantial role in the malignant progression of GC via the modulation of PLIN3 expression. Moreover, the relative abundance of P. intermedia might serve as a potential biomarker for the diagnosis and prognosis of GC.


Subject(s)
Stomach Neoplasms , Humans , Cell Differentiation , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Perilipin-3 , Prevotella intermedia , Prognosis , Stomach Neoplasms/pathology , Tumor Microenvironment
12.
Opt Express ; 32(2): 2321-2332, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38297765

ABSTRACT

Deep learning-based computer-generated holography (DeepCGH) has the ability to generate three-dimensional multiphoton stimulation nearly 1,000 times faster than conventional CGH approaches such as the Gerchberg-Saxton (GS) iterative algorithm. However, existing DeepCGH methods cannot achieve axial confinement at the several-micron scale. Moreover, they suffer from an extended inference time as the number of stimulation locations at different depths (i.e., the number of input layers in the neural network) increases. Accordingly, this study proposes an unsupervised U-Net DeepCGH model enhanced with temporal focusing (TF), which currently achieves an axial resolution of around 5 µm. The proposed model employs a digital propagation matrix (DPM) in the data preprocessing stage, which enables stimulation at arbitrary depth locations and reduces the computation time by more than 35%. Through physical constraint learning using an improved loss function related to the TF excitation efficiency, the axial resolution and excitation intensity of the proposed TF-DeepCGH with DPM rival that of the optimal GS with TF method but with a greatly increased computational efficiency.

13.
Liver Int ; 44(4): 920-930, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38291865

ABSTRACT

BACKGROUND & AIMS: Our retrospective study has suggested encouraging outcomes of lenvatinib combined with PD-1 inhibitor and transarterial chemoembolization (TACE) on advanced hepatocellular carcinoma (HCC). This phase II trial was conducted to prospectively investigate the efficacy and safety of lenvatinib, sintilimab (a PD-1 inhibitor) plus TACE (Len-Sin-TACE) in patients with advanced stage HCC. METHODS: This was a single-arm phase II trial. Patients with BCLC stage C HCC were recruited. They received lenvatinib (bodyweight ≥60 kg, 12 mg; bodyweight <60 kg, 8 mg) orally once daily, sintilimab (200 mg) intravenously once every 3 weeks, and on demand TACE. The primary endpoint was progression-free survival (PFS) per mRECIST. RESULTS: Thirty patients were enrolled. The primary endpoint was met with a median PFS of 8.0 (95% confidence interval [CI]: 6.1-9.8) months per mRECIST, which was the same as that per RECIST 1.1. The objective response rate was 60.0% per mRECIST and 30.0% per RECIST 1.1. The disease control rate was 86.7% per mRECIST/RECIST 1.1. The median duration of response was 7.4 (95% CI: 6.6-8.2) months per mRECIST (n = 18) and 4.3 (95% CI: 4.0-4.6) months per RECIST 1.1 (n = 9). The median overall survival was 18.4 (95% CI: 14.5-22.3) months. Treatment-related adverse events (TRAEs) occurred in 28 patients (93.3%) and grade 3 TRAEs were observed in 12 patients (40.0%). There were no grade 4/5 TRAEs. CONCLUSIONS: Len-Sin-TACE showed promising antitumour activities with a manageable safety profile in patients with advanced stage HCC. The preliminary results need to be further evaluated with phase III randomized trials.


Subject(s)
Antibodies, Monoclonal, Humanized , Carcinoma, Hepatocellular , Chemoembolization, Therapeutic , Liver Neoplasms , Phenylurea Compounds , Quinolines , Humans , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Carcinoma, Hepatocellular/therapy , Immune Checkpoint Inhibitors , Liver Neoplasms/therapy , Phenylurea Compounds/adverse effects , Phenylurea Compounds/therapeutic use , Quinolines/adverse effects , Quinolines/therapeutic use , Retrospective Studies
14.
Vet Res ; 55(1): 37, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38532498

ABSTRACT

In the last decade, prophages that possess the ability of lysogenic transformation have become increasingly significant. Their transfer and subsequent activity in the host have a significant impact on the evolution of bacteria. Here, we investigate the role of prophage phi456 with high spontaneous induction in the bacterial genome of Avian pathogenic Escherichia coli (APEC) DE456. The phage particles, phi456, that were released from DE456 were isolated, purified, and sequenced. Additionally, phage particles were no longer observed either during normal growth or induced by nalidixic acid in DE456Δphi456. This indicated that the released phage particles from DE456 were only phi456. We demonstrated that phi456 contributed to biofilm formation through spontaneous induction of the accompanying increase in the eDNA content. The survival ability of DE456Δphi456 was decreased in avian macrophage HD11 under oxidative stress and acidic conditions. This is likely due to a decrease in the transcription levels of three crucial genes-rpoS, katE, and oxyR-which are needed to help the bacteria adapt to and survive in adverse environments. It has been observed through animal experiments that the presence of phi456 in the DE456 genome enhances colonization ability in vivo. Additionally, the number of type I fimbriae in DE456Δphi456 was observed to be reduced under transmission electron microscopy when compared to the wild-type strain. The qRT-PCR results indicated that the expression levels of the subunit of I fimbriae (fimA) and its apical adhesin (fimH) were significantly lower in DE456Δphi456. Therefore, it can be concluded that phi456 plays a crucial role in helping bacterial hosts survive in unfavorable conditions and enhancing the colonization ability in DE456.


Subject(s)
Bacteriophages , Escherichia coli Infections , Animals , Escherichia coli/genetics , Prophages/genetics , Chickens/microbiology , Adhesins, Bacterial/genetics , Escherichia coli Infections/microbiology , Escherichia coli Infections/veterinary
15.
J Org Chem ; 89(1): 644-655, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-38088130

ABSTRACT

A photoredox-catalyzed intermolecular tandem sulfonamination/cyclization of enaminones was realized by using N-aminopyridinium salts as the sulfonaminated reagents without transition-metal catalysts or bases. The reaction exhibits a broad scope and good functional group tolerance, good yields, and regioselectivity. Preliminary mechanistic studies support the radical property of the reaction and the involvement of N-centered radical intermediates.

16.
Psychophysiology ; 61(4): e14479, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37920144

ABSTRACT

The locus coeruleus-norepinephrine (LC-NE) system, which regulates arousal levels, is important for cognitive control, including emotional conflict resolution. Additionally, the LC-NE system is implicated in P300 generation. If the P300 is mediated by the LC-NE system, and considering the established correlations between LC activity and pupil dilation, P300 amplitude should correlate with task-evoked (phasic) pupil dilation on a trial-by-trial basis. However, prior studies, predominantly utilizing oddball-type paradigms, have not demonstrated correlations between concurrently recorded task-evoked pupil dilation and P300 responses. Using a recently developed emotional face-word Stroop task that links pupil dilation to the LC-NE system, here, we examined both intra- and inter-individual correlations between task-evoked pupil dilation and P300 amplitude. We found that lower accuracy, slower reaction times, and larger task-evoked pupil dilation were obtained in the incongruent compared to the congruent condition. Furthermore, we observed intra-individual correlations between task-evoked pupil dilation and P300 amplitude, with larger pupil dilation correlating with a greater P300 amplitude. In contrast, pupil dilation did not exhibit consistent correlations with N450 and N170 amplitudes. Baseline (tonic) pupil size also showed correlations with P300 and N170 amplitudes, with smaller pupil size corresponding to larger amplitude. Moreover, inter-individual differences in task-evoked pupil dilation between the congruent and incongruent conditions correlated with differences in reaction time and P300 amplitude, though these effects only approached significance. To summarize, our study provides evidence for a connection between task-evoked pupil dilation and P300 amplitude at the single-trial level, suggesting the involvement of the LC-NE system in P300 generation.


Subject(s)
Arousal , Pupil , Humans , Stroop Test , Pupil/physiology , Reaction Time/physiology , Arousal/physiology , Locus Coeruleus/physiology , Norepinephrine/physiology
17.
Nanotechnology ; 35(38)2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38958589

ABSTRACT

Green energy technology is generally becoming one of hot issues that need to be solved due to the adverse effects on the environment of fossil fuels. One of the strategies being studied and developed by theorists and experimentalists is the use of photoelectrochemical (PEC) cells, which are emerging as a candidate to produce hydrogen from water splitting. However, creating photoelectrodes that meet the requirements for PEC water splitting has emerged as the primary obstacle in bringing this technology to commercial fruition. Here, we construct a heterostructure, which consists of MoS2/TiO2/Au nanoparticles (NPs) to overcome the drawbacks of the photoanode. Owing to the dependence on charge transfer, the bandgap of MoS2/TiO2and the utilization the Au NPs as a stimulant for charges separation of TiO2by localized surface plasmon resonances effect as well as the increase of hot electron injection to cathode, leading to photocatalytic activities are improved. The results have recorded a significant increase in the photocurrent density from 2.3µAcm-2of TiO2to approximately 16.3µAcm-2of MoS2/TiO2/Au NPs. This work unveils a promising route to enhance the visible light adsorption and charge transfer in photo-electrode of the PEC cells by combining two-dimensional materials with metal NPs.

18.
BMC Infect Dis ; 24(1): 427, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38649864

ABSTRACT

BACKGROUND: COVID-19 has been shown to increase the risk of extracorporeal coagulation during hemodialysis in patients, but the underlying mechanism remains unclear. This study aimed to investigate the effect and mechanism of COVID-19 on the risk of extracorporeal coagulation in patients with chronic kidney disease undergoing hemodialysis. METHODS: A retrospective analysis of the extracorporeal coagulation status of 339 hemodialysis patients at our center before and after COVID-19 infection was performed, including subgroup analyses. Post-infection blood composition was analyzed by protein spectrometry and ELISA. RESULTS: Compared to the pre-COVID-19 infection period, COVID-19-induced extracorporeal coagulation predominantly occurred in patients with severe/critical symptoms. Further proteomic analysis demonstrated that in patients with severe/critical symptoms, the coagulation cascade reaction, platelet activation, inflammation, and oxidative stress-related pathways were significantly amplified compared to those in patients with no/mild symptoms. Notably, the vWF/FBLN5 pathway, which is associated with inflammation, vascular injury, and coagulation, was significantly upregulated. CONCLUSIONS: Patients with severe/critical COVID-19 symptoms are at a higher risk of extracorporeal coagulation during hemodialysis, which is associated with the upregulation of the vWF/FBLN5 signaling pathway. These findings highlight the importance of early anticoagulant therapy initiation in COVID-19 patients with severe/critical symptoms, particularly those undergoing hemodialysis. Additionally, vWF/FBLN5 upregulation may be a novel mechanism for virus-associated thrombosis/coagulation.


Subject(s)
COVID-19 , Renal Dialysis , SARS-CoV-2 , Signal Transduction , Up-Regulation , von Willebrand Factor , Humans , COVID-19/blood , COVID-19/metabolism , Renal Dialysis/adverse effects , Male , Female , Middle Aged , Retrospective Studies , von Willebrand Factor/metabolism , von Willebrand Factor/analysis , Aged , Blood Coagulation , Renal Insufficiency, Chronic/therapy , Renal Insufficiency, Chronic/metabolism , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/blood , Adult
19.
Crit Care ; 28(1): 118, 2024 04 09.
Article in English | MEDLINE | ID: mdl-38594772

ABSTRACT

BACKGROUND: This study aimed to develop an automated method to measure the gray-white matter ratio (GWR) from brain computed tomography (CT) scans of patients with out-of-hospital cardiac arrest (OHCA) and assess its significance in predicting early-stage neurological outcomes. METHODS: Patients with OHCA who underwent brain CT imaging within 12 h of return of spontaneous circulation were enrolled in this retrospective study. The primary outcome endpoint measure was a favorable neurological outcome, defined as cerebral performance category 1 or 2 at hospital discharge. We proposed an automated method comprising image registration, K-means segmentation, segmentation refinement, and GWR calculation to measure the GWR for each CT scan. The K-means segmentation and segmentation refinement was employed to refine the segmentations within regions of interest (ROIs), consequently enhancing GWR calculation accuracy through more precise segmentations. RESULTS: Overall, 443 patients were divided into derivation N=265, 60% and validation N=178, 40% sets, based on age and sex. The ROI Hounsfield unit values derived from the automated method showed a strong correlation with those obtained from the manual method. Regarding outcome prediction, the automated method significantly outperformed the manual method in GWR calculation (AUC 0.79 vs. 0.70) across the entire dataset. The automated method also demonstrated superior performance across sensitivity, specificity, and positive and negative predictive values using the cutoff value determined from the derivation set. Moreover, GWR was an independent predictor of outcomes in logistic regression analysis. Incorporating the GWR with other clinical and resuscitation variables significantly enhanced the performance of prediction models compared to those without the GWR. CONCLUSIONS: Automated measurement of the GWR from non-contrast brain CT images offers valuable insights for predicting neurological outcomes during the early post-cardiac arrest period.


Subject(s)
Out-of-Hospital Cardiac Arrest , White Matter , Humans , Retrospective Studies , Gray Matter/diagnostic imaging , Out-of-Hospital Cardiac Arrest/diagnostic imaging , Tomography, X-Ray Computed/methods , Prognosis
20.
BMC Public Health ; 24(1): 208, 2024 01 17.
Article in English | MEDLINE | ID: mdl-38233777

ABSTRACT

OBJECTIVE: This cross-sectional study examined the socio-ecological factors influencing fundamental motor skills (FMS) in Chinese school-aged children. METHODS: A total of 1012 parent-child pairs were randomly sampled between March-1st and April-15th, 2022. Based on the socio-ecological model of Children's FMS, three levels of factors: individual-level (e.g., demographic, physical, psychological, and behavioral characteristics of children), family-level (e.g., caregiver demographics, parental support, and socioeconomic status), and environmental factors (e.g., availability of physical activity equipment) were assessed using self-reported scales (e.g., the Self-perception Profile for Children, the Physical Activity Enjoyment Scale, and the 12-item Psychological Well-Being Scale for Children) and objective measures (e.g., ActiGraph GT3X, the Chinese National Student Physical Fitness Standard, and the Test of Gross Motor Development-Third Edition). Multi-level regression models were employed using SPSS. RESULTS: The results demonstrated that children's age, sex, physical fitness, parental support, and the quality of home and community physical activity environments consistently influenced all three types of FMS, including locomotor, ball, and composite skills. Additionally, seven individual-level factors (children's age, sex, body mass index, light physical activity, sleep duration, perceived motor competence, and physical fitness) were associated with different types of FMS. CONCLUSIONS: The findings underscore the multidimensional and complex nature of FMS development, with individual-level factors playing a particularly significant role. Future research should adopt rigorous longitudinal designs, comprehensive assessment tools covering various FMS skills, and objective measurement of parents' movement behaviors to better understand the strength and direction of the relationship between socio-ecological factors and children's FMS.


Subject(s)
Exercise , Motor Skills , Humans , Child , Cross-Sectional Studies , Physical Fitness , China
SELECTION OF CITATIONS
SEARCH DETAIL