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1.
Bioorg Chem ; 151: 107685, 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-39094509

ABSTRACT

Nonsmall-cell lung cancer (NSCLC) is the most frequent type of lung cancer, with early surgical treatment proving vital for prolonged patient survival. However, precise visualization of NSCLC remains a challenge due to limited molecular imaging probes, the unique anatomical structure of the lungs, and respiratory movement interference. In this study, we investigated the potential utility of CD36, which is highly expressed in NSCLC, as an imaging target. A selective and water-soluble fluorescent probe, MPA-ABT-510, was successfully constructed by coupling ABT-510 with MPA, a near-infrared (NIR) fluorescent dye. Molecular docking analysis shows that MPA-ABT-510 possesses strong binding affinity to the CD36 protein, with specific hydrogen bond interactions at defined amino acid residues. In vitro assays reveals that the fluorescein isothiocyanate-labeled peptide ABT-510 specifically binds to the CD36-high expressing NSCLC cell lines H1299 and A549. In vivo imaging verifies that the MPA-ABT-510 efficiently accumulates in the tumor site with a distinct fluorescent signal. Ex vivo imaging revealed that tumor-to-lung fluorescence ratios for subcutaneous and orthotopic H1299 mouse models were 7.19 ± 0.73 and 1.91 ± 0.42, respectively, while those for A549 mice were 5.53 ± 0.64 and 1.77 ± 0.41, respectively. Biodistribution analysis demonstrated efficient MPA-ABT-510 uptake in H1299 and A549 liver metastases models with tumor-to-liver fluorescence ratios of 2.47 ± 0.48 and 2.19 ± 0.22, respectively. High MPA-ABT-510 accumulation was evident in A549 intestinal metastases models, as evidenced by tumor-to-colorectal fluorescence ratios of 4.27 ± 0.11. MPA-ABT-510 exhibits superior imaging capabilities with minimal safety concerns, so it is a promising candidate for NSCLC surgical navigation.

3.
Cell Discov ; 10(1): 70, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38937452

ABSTRACT

KRAS mutations are highly prevalent in a wide range of lethal cancers, and these mutant forms of KRAS play a crucial role in driving cancer progression and conferring resistance to treatment. While there have been advancements in the development of small molecules to target specific KRAS mutants, the presence of undruggable mutants and the emergence of secondary mutations continue to pose challenges in the clinical treatment of KRAS-mutant cancers. In this study, we developed a novel molecular tool called tumor-targeting KRAS degrader (TKD) that effectively targets a wide range of KRAS mutants. TKD is composed of a KRAS-binding nanobody, a cell-penetrating peptide selectively targeting cancer cells, and a lysosome-binding motif. Our data revealed that TKD selectively binds to KRAS in cancer cells and effectively induces KRAS degradation via a lysosome-dependent process. Functionally, TKD suppresses tumor growth with no obvious side effects and enhances the antitumor effects of PD-1 antibody and cetuximab. This study not only provides a strategy for developing drugs targeting "undruggable" proteins but also reveals that TKD is a promising therapeutic for treating KRAS-mutant cancers.

4.
Sci Total Environ ; 945: 174026, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38885706

ABSTRACT

The rising global prevalence of microplastics (MPs) has highlighted their diverse toxicological effects. The oxytocin (OT) system in mammals, deeply intertwined with social behaviors, is recognized to be vulnerable to environmental stressors. We hypothesized that MP exposure might disrupt this system, a topic not extensively studied. We investigated the effects of MPs on behavioral neuroendocrinology via the gut-brain axis by exposing adolescent male C57BL/6 mice to varied sizes (5 µm and 50 µm) and concentrations (100 µg/L and 1000 µg/L) of polystyrene MPs over 10 weeks. The results demonstrated that exposure to 50 µm MPs significantly reduced colonic mucin production and induced substantial alterations in gut microbiota. Notably, the 50 µm-100 µg/L group showed a significant reduction in OT content within the medial prefrontal cortex and associated deficits in sociality, along with damage to the blood-brain barrier. Importantly, blocking the vagal pathway ameliorated these behavioral impairments, emphasizing the pivotal role of the gut-brain axis in mediating neurobehavioral outcomes. Our findings confirm the toxicity of MPs on sociality and the corresponding neuroendocrine systems, shedding light on the potential hazards and adverse effects of environmental MPs exposure on social behavior and neuroendocrine frameworks in social mammals, including humans.


Subject(s)
Brain-Gut Axis , Brain , Mice, Inbred C57BL , Microplastics , Oxytocin , Polystyrenes , Social Behavior , Animals , Oxytocin/metabolism , Mice , Male , Polystyrenes/toxicity , Microplastics/toxicity , Brain/drug effects , Brain/metabolism , Brain-Gut Axis/physiology , Brain-Gut Axis/drug effects , Gastrointestinal Microbiome/drug effects
5.
Talanta ; 278: 126452, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38943766

ABSTRACT

Septic cardiomyopathy (SCM) is the main cause of death in critically ill patients with sepsis. However, its definitive pathogenic mechanisms remain to be elucidated. Lipid droplets (LDs) are important sub-organelles that store lipids and participate in intracellular lipid metabolism. Abnormal aggregation and altered polarity of LDs are associated with the development of several cardiac diseases. To date, visualization of abnormal polarity in models of SCM has not been achieved. Herein, we designed and synthesized the probe BDP-551, a polarity-sensitive probe possessing a donor-π-acceptor (D-π-A) structure. BDP-551 exhibits excellent photostability, high LDs targeting, near-infrared (NIR) emission (up to 678 nm) and strong polarity sensitivity. With the help of confocal imaging microscopy, the BDP-551 was able to detect the polarity changes induced in the SCM model cells and visualize the yolk sac region in hypoxic as well as inflamed living zebrafish. In addition, the BDP-551 has been successfully applied to visualize the polarity changes of mice hearts with SCM, proving a decrease of microenvironmental polarity in the development of SCM. Therefore, BDP-551 in this study can be used as a reliable tool to investigate polarity fluctuations and provide new insights into the associated pathogenic and therapeutic mechanisms on SCM.

6.
FASEB J ; 38(10): e23705, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38805171

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a notoriously dismal prognosis. As a competitive inhibitor of DNA synthesis, gemcitabine is the cornerstone drug for treating PDAC at all stages. The therapeutic effect of gemcitabine, however, is often hindered by drug resistance, and the underlying mechanisms remain largely unknown. It is unclear whether their response to chemotherapeutics is regulated by endocrine regulators, despite the association between PDAC risk and endocrine deregulation. Here, we show that prolactin receptor (PRLR) synergizes with gemcitabine in both in vitro and in vivo treatment of PDAC. Interestingly, PRLR promotes the expression of miR-4763-3p and miR-3663-5p, two novel miRNAs whose functions are unknown. Furthermore, the analysis of transcriptome sequencing data of tumors from lactating mouse models enriches the PPP pathway, a multifunctional metabolic pathway. In addition to providing energy, the PPP pathway mainly provides a variety of raw materials for anabolism. We demonstrate that two key enzymes of the pentose phosphate pathway (PPP), G6PD and TKT, are directly targeted by miR-4763-3p and miR-3663-5p. Notably, miR-4763-3p and miR-3663-5p diminish the nucleotide synthesis of the PPP pathway, thereby increasing gemcitabine sensitivity. As a result, PRLR harnesses these two miRNAs to suppress PPP and nucleotide synthesis, subsequently elevating the gemcitabine sensitivity of PDAC cells. Also, PDAC tissues and tumors from LSL-KrasG12D/+, LSL-Trp53R172H/+, and PDX1-cre (KPC) mice exhibit downregulation of PRLR. Bisulfite sequencing of PDAC tissues revealed that PRLR downregulation is due to epigenetic methylation. In this study, we show for the first time that the endocrine receptor PRLR improves the effects of gemcitabine by boosting two new miRNAs that block the PPP pathway and nucleotide synthesis by inhibiting two essential enzymes concurrently. The PRLR-miRNAs-PPP axis may serve as a possible therapeutic target to supplement chemotherapy advantages in PDAC.


Subject(s)
Carcinoma, Pancreatic Ductal , Deoxycytidine , Gemcitabine , Glucosephosphate Dehydrogenase , MicroRNAs , Pancreatic Neoplasms , Receptors, Prolactin , Animals , Female , Humans , Mice , Antimetabolites, Antineoplastic/pharmacology , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Deoxycytidine/analogs & derivatives , Deoxycytidine/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Glucosephosphate Dehydrogenase/metabolism , Glucosephosphate Dehydrogenase/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Receptors, Prolactin/metabolism , Receptors, Prolactin/genetics , Mice, Nude
7.
PLoS One ; 19(5): e0304098, 2024.
Article in English | MEDLINE | ID: mdl-38809895

ABSTRACT

BACKGROUND: Obesity, characterized by excessive body fat accumulation, is associated with various chronic health conditions. Body fat plays a crucial role in health outcomes, and nutrient intake is a contributing factor. Menopause further influences body fat, but the precise relationships between nutrients and fat mass distribution in pre- and post-menopausal women are unclear. METHODS: Data from 4751 adult women aged ≥18 years old (3855 pre-menopausal, 896 post-menopausal) with completed information were obtained from the National Health and Examination Survey (NHANES) from 2011 to 2018. Multivariate linear regression models were used to examine the associations between protein, carbohydrate, fat intake and total percent fat (TPF), android percent fat (APF), gynoid percent fat (GPF), android to gynoid ratio (A/G), subcutaneous adipose tissue mass (SAT), visceral adipose tissue mass (VAT). Subgroup analyses, stratified by menopausal status, were also conducted. Additionally, we employed smoothing curve fitting techniques to investigate potential non-linear relationships between fat mass distribution and nutrient intake. RESULTS: Compared with pre-menopausal women, post-menopausal women had higher body fat, BMI, and metabolic indicators but lower nutrient intake (All p<0.05). In the overall analysis, we found significant correlations between nutrient intake and fat mass. Specifically, protein intake was negatively correlated with TPF (ß = -0.017, 95% CI: -0.030, -0.005), APF (ß = -0.028, 95% CI: -0.044, -0.012), GPF (ß = -0.019, 95% CI: -0.030, -0.008), while fat intake showed positive correlations with these measures (SAT: ß = 2.769, 95% CI: 0.860, 4.678). Carbohydrate intake exhibited mixed associations. Notably, body fat mass-nutrient intake correlations differed by menopausal status. Generally speaking, protein intake showed negative correlations with body fat distribution in pre-menopausal women but positive correlations in post-menopausal women. Carbohydrate intake revealed significant negative associations with abdominal and visceral fat in post-menopausal women, while fat intake was consistently positive across all fat distribution indices, especially impacting visceral fat in post-menopausal women. CONCLUSION: Dietary intake plays a crucial role in body fat distribution, with menopausal status significantly influencing the impact of nutrients on specific fat distribution metrics. The study emphasizes the need for dietary guidelines to consider the nutritional needs and health challenges unique to women at different life stages, particularly concerning menopausal status, to effectively manage obesity.


Subject(s)
Postmenopause , Premenopause , Humans , Female , Postmenopause/physiology , Middle Aged , Adult , Nutrients , Body Fat Distribution , Body Mass Index , Dietary Proteins/administration & dosage , Nutrition Surveys , Aged , Obesity/metabolism , Adipose Tissue/metabolism , Dietary Fats/administration & dosage
8.
Exp Neurol ; 378: 114816, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38789023

ABSTRACT

High spinal cord injury (SCI) leads to persistent and debilitating compromise in respiratory function. Cervical SCI not only causes the death of phrenic motor neurons (PhMNs) that innervate the diaphragm, but also damages descending respiratory pathways originating in the rostral ventral respiratory group (rVRG) located in the brainstem, resulting in denervation and consequent silencing of spared PhMNs located caudal to injury. It is imperative to determine whether interventions targeting rVRG axon growth and respiratory neural circuit reconnection are efficacious in chronic cervical contusion SCI, given that the vast majority of individuals are chronically-injured and most cases of SCI involve contusion-type damage to the cervical region. We therefore employed a rat model of chronic cervical hemicontusion to test therapeutic manipulations aimed at reconstructing damaged rVRG-PhMN-diaphragm circuitry to achieve recovery of respiratory function. At a chronic time point post-injury, we systemically administered: an antagonist peptide directed against phosphatase and tensin homolog (PTEN), a central inhibitor of neuron-intrinsic axon growth potential; an antagonist peptide directed against receptor-type protein tyrosine phosphatase sigma (PTPσ), another important negative regulator of axon growth capacity; or a combination of these two peptides. PTEN antagonist peptide (PAP4) promoted partial recovery of diaphragm motor activity out to nine months post-injury (though this effect depended on the anesthetic regimen used during recording), while PTPσ peptide did not impact diaphragm function after cervical SCI. Furthermore, PAP4 promoted robust growth of descending bulbospinal rVRG axons caudal to the injury within the denervated portion of the PhMN pool, while PTPσ peptide did not affect rVRG axon growth at this location that is critical to control of diaphragmatic respiratory function. In conclusion, we find that, when PTEN inhibition is targeted at a chronic time point following cervical contusion, our non-invasive PAP4 strategy can successfully promote significant regrowth of damaged respiratory neural circuitry and also partial recovery of diaphragm motor function.


Subject(s)
Axons , Diaphragm , PTEN Phosphohydrolase , Recovery of Function , Spinal Cord Injuries , Animals , Female , Rats , Axons/drug effects , Cervical Cord/injuries , Chronic Disease , Diaphragm/innervation , Disease Models, Animal , PTEN Phosphohydrolase/antagonists & inhibitors , PTEN Phosphohydrolase/metabolism , Rats, Sprague-Dawley , Receptor-Like Protein Tyrosine Phosphatases, Class 2/antagonists & inhibitors , Receptor-Like Protein Tyrosine Phosphatases, Class 2/metabolism , Recovery of Function/physiology , Recovery of Function/drug effects , Spinal Cord Injuries/physiopathology , Spinal Cord Injuries/pathology
9.
Cell Rep Med ; 5(5): 101573, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38776874

ABSTRACT

Epstein-Barr virus (EBV) is linked to various malignancies and autoimmune diseases, posing a significant global health challenge due to the lack of specific treatments or vaccines. Despite its crucial role in EBV infection in B cells, the mechanisms of the glycoprotein gp42 remain elusive. In this study, we construct an antibody phage library from 100 EBV-positive individuals, leading to the identification of two human monoclonal antibodies, 2B7 and 2C1. These antibodies effectively neutralize EBV infection in vitro and in vivo while preserving gp42's interaction with the human leukocyte antigen class II (HLA-II) receptor. Structural analysis unveils their distinct binding epitopes on gp42, different from the HLA-II binding site. Furthermore, both 2B7 and 2C1 demonstrate potent neutralization of EBV infection in HLA-II-positive epithelial cells, expanding our understanding of gp42's role. Overall, this study introduces two human anti-gp42 antibodies with potential implications for developing EBV vaccines targeting gp42 epitopes, addressing a critical gap in EBV research.


Subject(s)
Antibodies, Monoclonal , Epitopes , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Humans , Herpesvirus 4, Human/immunology , Epstein-Barr Virus Infections/immunology , Epstein-Barr Virus Infections/virology , Antibodies, Monoclonal/immunology , Epitopes/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Mice , Histocompatibility Antigens Class II/immunology , Histocompatibility Antigens Class II/metabolism , Viral Proteins/immunology , B-Lymphocytes/immunology
10.
Biomed Pharmacother ; 175: 116670, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38692065

ABSTRACT

Neutrophils are heterogeneous and plastic, with the ability to polarize from antitumour to protumour phenotype and modulate tumour microenvironment components. While some advances have been made, the neutrophil-targeting therapy remains underexplored. Activation of formyl peptide receptors (FPRs) by formylated peptides is needed for local control of infection through the recruitment of activated neutrophils while the potential contribution of antitumour activity remains underexplored. Here, we demonstrate that neutrophils can be harnessed to suppress tumour growth through the action of the formyl peptide (FP) on the formyl peptide receptor (FPR). Mechanistically, FP efficiently recruits neutrophils to produce reactive oxygen species production (ROS), resulting in the direct killing of tumours. Antitumour functions disappeared when neutrophils were depleted by anti-Ly6G antibodies. Interestingly, extensive T-cell activation was observed in mouse tumours treated with FP, showing the potential to alter the immune suppressed tumour microenvironment (TME) and further sensitize mice to anti-PD1 therapy. Transcriptomic and flow cytometry analyses revealed the mechanisms of FP-sensitized anti-PD1 therapy, mainly including stimulated neutrophils and an altered immune-suppressed tumour microenvironment. Collectively, these data establish FP as an effective combination partner for sensitizing anti-PD1 therapy by stimulating tumour-infiltrated neutrophils.


Subject(s)
Immunotherapy , Mice, Inbred C57BL , Neutrophils , Receptors, Formyl Peptide , T-Lymphocytes , Tumor Microenvironment , Animals , Neutrophils/drug effects , Neutrophils/immunology , Neutrophils/metabolism , Tumor Microenvironment/drug effects , Tumor Microenvironment/immunology , Mice , Immunotherapy/methods , Receptors, Formyl Peptide/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/drug effects , Cell Line, Tumor , Reactive Oxygen Species/metabolism , Humans , Female , Neutrophil Activation/drug effects , Neoplasms/immunology , Neoplasms/drug therapy , Neoplasms/pathology , Lymphocyte Activation/drug effects , Programmed Cell Death 1 Receptor/metabolism , Programmed Cell Death 1 Receptor/immunology
11.
Virology ; 595: 110069, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38640788

ABSTRACT

Soybean mosaic virus (SMV) is a potyvirus found worldwide in soybean (Glycine max). GmCYB5-4 is a strong candidate interactor of P3. In this study, we comprehensively analyzed the GmCYB5 family in soybeans, including its distribution on chromosomes, promoter analysis, conserved motifs, phylogenetic analysis, and expression patterns. We cloned the full-length GmCYB5-4 and examined its interaction with P3 in yeast, which was later confirmed using bimolecular fluorescence complementation (BiFc). We silenced GmCYB5-4 using a bean pottle mosaic viris (BPMV) based system to generate SilCYB5-4 tissues, which surprisingly knocked down four isoforms of GmCYB5s for functional characterization. SilCYB5-4 plants were challenged with the SC3 strain to determine its involvement in SMV infection. Silencing GmCYB5-4 increased SMV accumulation, indicating that GmCYB5-4 inhibited SMV proliferation. However, further experiments are needed to elucidate the mechanism underlying the involvement of GmCYB5-4 in SMV infection.


Subject(s)
Glycine max , Plant Diseases , Potyvirus , Potyvirus/genetics , Potyvirus/physiology , Glycine max/virology , Glycine max/metabolism , Plant Diseases/virology , Viral Proteins/genetics , Viral Proteins/metabolism , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Virus Replication , Host-Pathogen Interactions
12.
Sci Total Environ ; 929: 172626, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38657823

ABSTRACT

Despite the wide acknowledgment that plastic pollution and global warming have become serious agricultural concerns, their combined impact on crop growth remains poorly understood. Given the unabated megatrend, a simulated soil warming (SWT, +4 °C) microcosm experiment was carried out to provide a better understanding of the effects of temperature fluctuations on wheat seedlings exposed to nanoplastics (NPs, 1 g L-1 61.71 ± 0.31 nm polystyrene). It was documented that SWT induced oxidative stress in wheat seedlings grown in NPs-contaminated soil, with an 85.56 % increase in root activity, while decreasing plant height, fresh weight, and leaf area by 8.72 %, 47.68 %, and 15.04 % respectively. The SWT also resulted in reduced photosynthetic electron-transfer reaction and Calvin-Benson cycle in NPs-treated plants. Under NPs, SWT stimulated the tricarboxylic acid (TCA) metabolism and bio-oxidation process. The decrease in photosynthesis and the increase in respiration resulted in an 11.94 % decrease in net photosynthetic rate (Pn). These results indicated the complicated interplay between climate change and nanoplastic pollution in crop growth and underscored the potential risk of nanoplastic pollution on crop production in the future climate.


Subject(s)
Photosynthesis , Soil Pollutants , Soil , Temperature , Triticum , Triticum/physiology , Triticum/drug effects , Soil/chemistry , Soil Pollutants/toxicity , Photosynthesis/drug effects , Global Warming , Climate Change , Seedlings/drug effects , Seedlings/physiology , Plastics/toxicity
13.
Plant Physiol Biochem ; 210: 108643, 2024 May.
Article in English | MEDLINE | ID: mdl-38653097

ABSTRACT

Drought priming is known to enhance plant low temperature tolerance, whereas polystyrene nanoplastic contamination exerts detrimental effects on plant growth. This study investigates the less-explored influence of nanoplastic contamination on cold stress tolerance in drought-primed plants. We compared the photosynthetic carbon assimilation, carbohydrate metabolism, reactive oxygen species metabolism, and grain yield between the non-primed and drought-primed wheat grown in both nanoplastic-contaminated and healthy soils. Our results reveal that the beneficial effects of drought priming on photosynthetic carbon assimilation and the efficiency of the "water-water" cycle were compromised in the presence of nanoplastics (nPS). Additionally, nPS exposure disturbed carbohydrate metabolism, which impeded source-to-sink transport of sugar and resulted in reduced grain yield in drought-primed plants under low temperature conditions. These findings unveil the suppression of nPS on drought-primed low-temperature tolerance (DPLT) in wheat plants, suggesting an intricate interplay between the induction of stress tolerance and responses to nPS contamination. The study raises awareness about a potential challenge for future crop production.


Subject(s)
Cold Temperature , Droughts , Polystyrenes , Triticum , Triticum/drug effects , Triticum/metabolism , Triticum/physiology , Triticum/growth & development , Soil/chemistry , Photosynthesis/drug effects , Reactive Oxygen Species/metabolism , Soil Pollutants/toxicity , Nanoparticles
14.
IEEE J Biomed Health Inform ; 28(6): 3660-3671, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38502612

ABSTRACT

The wide prevalence of staining variations in digital pathology presents a significant obstacle, often undermining the effectiveness of diagnosis and analysis. The current strategies to counteract this issue primarily revolve around Stain Normalization (SN) and Stain Augmentation (SA). Nonetheless, these methodologies come with inherent limitations. They struggle to adapt to the vast array of staining styles, tend to presuppose linear associations between color spaces, and often lead to unrealistic color transformations. In response to these challenges, we introduce RandStainNA++, a novel method seamlessly integrating SN and SA. This method exploits the versatility of random SN and SA within randomly selected color spaces, effectively managing variations for the foreground and background independently. By refining the transformations of staining styles for the foreground and background within a realistic scope, this strategy promotes the generation of more practical staining transformations during the training phase. Further enhancing our approach, we propose a unique self-distillation method. This technique incorporates prior knowledge of stain variation, substantially augmenting the generalization capability of the network. The striking results yield that, compared to conventional classification models, our method boosts performance by a significant margin of 16-25%. Furthermore, when juxtaposed with baseline segmentation models, the Dice score registers an increase of 0.06.


Subject(s)
Staining and Labeling , Humans , Staining and Labeling/methods , Image Interpretation, Computer-Assisted/methods , Algorithms , Image Processing, Computer-Assisted/methods
15.
Polymers (Basel) ; 16(5)2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38475391

ABSTRACT

The post-heat mechanical property is one of the important indices for the fire-resistance evaluation of fiber-reinforced polymers. At present, the primary approach to improving the post-heat mechanical property of a material involves incorporating inorganic fillers; yet, the enhancement is limited, and is accompanied by a reduction in room-temperature performance and processability. This study prepares glass-fiber-reinforced composites with elevated mechanical properties after heat through utilizing two variants of epoxy resins modified with polysiloxane, phenolic resin, kaolin, and graphite. In comparison to the phenolic samples, the phenylpropylsiloxane-modified epoxy resulted in a 115% rise in post-heat flexural strength and a 70% increase in the room-temperature flexural strength of phenolic composites. On the other hand, dimethylsiloxane-modified epoxy leads to a 117% improvement in post-heat flexural strength but a 44% decrease in the room-temperature flexural strength of phenolic composites. Macroscopic/microscopic morphologies and a residual structure model of the composites after heat reveal that, during high temperature exposure, the pyrolysis products of polysiloxane promote interactions between carbon elements and fillers, thus preserving more residues and improving the dimensional stability as well as the density of materials. Consequently, a notable enhancement is observed in both the post-heat flexural strength and the mass of carbon residue after the incorporation of polysiloxane and fillers into the materials. The pyrolysis products of polysiloxane-modified epoxy play a vital role in enhancing the post-heat flexural strength by promoting carbon retention, carbon fixation, and interactions with fillers, offering novel pathways for the development of advanced composites with superior fire-resistance properties.

16.
Front Psychol ; 15: 1323710, 2024.
Article in English | MEDLINE | ID: mdl-38505361

ABSTRACT

Introduction: The effect of intergroup contact on cooperation is well documented, but little is known about the cultural moderators of this relationship. Contributing to the literature, we examined whether cultural orientation moderates the effect of positive intergroup contact on cooperation and places emphasis on individualism. Methods: By creating a gamecooperation situation by the trust game paradigm, 322 Taiwanese youth were involved in the study and completed the positive intergroup contact scale, individual-collectivism scale, and social distance scale. Results: (1) positive intergroup contact effectively promotes cooperative behavior; (2) Taiwanese youth who have closer social distance with mainland youth demonstrate higher levels of cooperative behavior after group interactions than larger social distance; and (3) individualism has a significant moderating role in the relationship between positive inter-group contact and cooperation. The effect of positive inter-group contact on cooperation became stronger in the less individualistic group. The effect of social distance on cooperation became stronger in the less individualistic group.Cultural orientation represented by individualism is proved to be one moderato of the intergroup contact-cooperation relationship.

17.
Nat Commun ; 15(1): 2249, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38480695

ABSTRACT

Icing of seawater droplets is capable of causing catastrophic damage to vessels, buildings, and human life, yet it also holds great potential for enhancing applications such as droplet-based freeze desalination and anti-icing of sea sprays. While large-scale sea ice growth has been investigated for decades, the icing features of small salty droplets remain poorly understood. Here, we demonstrate that salty droplet icing is governed by salt rejection-accompanied ice crystal growth, resulting in freezing dynamics different from pure water. Aided by the observation of brine films emerging on top of frozen salty droplets, we propose a universal definition of freezing duration to quantify the icing rate of droplets having varying salt concentrations. Furthermore, we show that the morphology of frozen salty droplets is governed by ice crystals that sprout from the bottom of the brine film. These crystals grow until they pierce the free interface, which we term ice sprouting. We reveal that ice sprouting is controlled by condensation at the brine film free interface, a mechanism validated through molecular dynamics simulations. Our findings shed light on the distinct physics that govern salty droplet icing, knowledge that is essential for the development of related technologies.

18.
Plant Physiol ; 195(3): 2176-2194, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38423969

ABSTRACT

Leaf senescence is a combined response of plant cells stimulated by internal and external signals. Sugars acting as signaling molecules or energy metabolites can influence the progression of leaf senescence. Both sugar starvation and accumulation can promote leaf senescence with diverse mechanisms that are reported in different species. Sugars Will Eventually be Exported Transporters (SWEETs) are proposed to play essential roles in sugar transport, but whether they have roles in senescence and the corresponding mechanism are unclear. Here, we functionally characterized a sugar transporter, OsSWEET1b, which transports sugar and promotes senescence in rice (Oryza sativa L.). OsSWEET1b could import glucose and galactose when heterologously expressed in Xenopus oocytes and translocate glucose and galactose from the extracellular apoplast into the intracellular cytosol in rice. Loss of function of OsSWEET1b decreased glucose and galactose accumulation in leaves. ossweet1b mutants showed accelerated leaf senescence under natural and dark-induced conditions. Exogenous application of glucose and galactose complemented the defect of OsSWEET1b deletion-promoted senescence. Moreover, the senescence-activated transcription factor OsWRKY53, acting as a transcriptional repressor, genetically functions upstream of OsSWEET1b to suppress its expression. OsWRKY53-overexpressing plants had attenuated sugar accumulation, exhibiting a similar phenotype as the ossweet1b mutants. Our findings demonstrate that OsWRKY53 downregulates OsSWEET1b to impair its influx transport activity, leading to compromised sugar accumulation in the cytosol of rice leaves where sugar starvation promotes leaf senescence.


Subject(s)
Gene Expression Regulation, Plant , Oryza , Plant Leaves , Plant Proteins , Oryza/genetics , Oryza/physiology , Oryza/growth & development , Oryza/metabolism , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Leaves/physiology , Plant Proteins/genetics , Plant Proteins/metabolism , Glucose/metabolism , Plant Senescence/genetics , Galactose/metabolism , Sugars/metabolism , Gene Deletion , Biological Transport
19.
Oncogenesis ; 13(1): 10, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38424455

ABSTRACT

Endocrine receptors play an essential role in tumor metabolic reprogramming and represent a promising therapeutic avenue in pancreatic ductal adenocarcinoma (PDAC). PDAC is characterized by a nutrient-deprived microenvironment. To meet their ascendant energy demands, cancer cells can internalize extracellular proteins via macropinocytosis. However, the roles of endocrine receptors in macropinocytosis are not clear. In this study, we found that progesterone receptor (PGR), a steroid-responsive nuclear receptor, is highly expressed in PDAC tissues obtained from both patients and transgenic LSL-KrasG12D/+; LSL-Trp53R172H/+; PDX1-cre (KPC) mice. Moreover, PGR knockdown restrained PDAC cell survival and tumor growth both in vitro and in vivo. Genetic and pharmacological PGR inhibition resulted in a marked attenuation of macropinocytosis in PDAC cells and subcutaneous tumor models, indicating the involvement of this receptor in macropinocytosis regulation. Mechanistically, PGR upregulated CDC42, a critical regulator in macropinocytosis, through PGR-mediated transcriptional activation. These data deepen the understanding of how the endocrine system influences tumor progression via a non-classical pathway and provide a novel therapeutic option for patients with PDAC.

20.
Dev Comp Immunol ; 155: 105139, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38325499

ABSTRACT

Gasdermin (GSDM) proteins, as the direct executors of pyroptosis, are structurally and functionally conserved among vertebrates and play crucial roles in host defense against infection, inflammation, and cancer. However, the origin of functional GSDMs remains elusive in the animal kingdom. Here, we found that functional GSDME homologs first appeared in the cnidarian. Moreover, these animal GSDME homologs share evolutionarily conserved apoptotic caspase cleavage sites. Thus, we verified the functional conservation of apoptotic caspase-GSDME cascade in Hydra, a representative species of cnidarian. Unlike vertebrate GSDME homologs, HyGSDME could be cleaved by four Hydra caspase homologs with caspase-3 activity at two sites. Furthermore, in vivo activation of Hydra caspases resulted in HyGSDME cleavage to induce pyroptosis, exacerbating injury and restricting bacterial burden, which protects Hydra from pathogen invasion. In conclusion, these results suggest that GSDME-dependent pyroptosis may be an ancient and conserved host defense mechanism, which may contribute to better understanding on the origin and evolution of GSDMs.


Subject(s)
Hydra , Pyroptosis , Animals , Caspases/genetics , Caspases/metabolism , Hydra/metabolism , Gasdermins , Caspase 3/metabolism
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