ABSTRACT
BACKGROUND: As a significant biomarker of melanocytic lesions, tyrosinase (TYR) plays an essential role in the clinical diagnosis and treatment of melanin-related diseases. Thus, it is important to develop robust methods for assessing TYR activity. Covalent organic frameworks (COFs) have garnered considerable attention owing to their unique properties, including high chemical stability, good biocompatibility, and large surface area compared with organic dyes, noble metal nanoclusters, and semiconductor quantum dots. However, most COFs are insoluble in water and exhibit weak or no fluorescence emission. Therefore, the development of a water-soluble fluorescent COF for detecting TYR activity in biological samples remains highly desired. RESULTS: In this work, a sensitive and facile fluorometric method based on fluorescent COF was constructed for the detection of TYR activity in human serum samples. The water-soluble COF was fabricated through the condensation polymerization of 4',4â´,4''''',4'''''''-(1,2-ethene-diylidene) tetrakis [1,1'-biphenyl]-4-carboxaldehyde and 2,4,6-tris-(4-aminophenyl)-triazine. The resulting COF displayed yellow-green fluorescence with a maximum emission peak at 560 nm. Tyrosine was catalyzed by TYR to produce melanin-like polymers which formed a coating on the surface of COF and effectively quenched its fluorescence due to fluorescence resonance energy transfer. The proposed approach demonstrated a strong linear correlation in the range of 0.5-80 U/L with a low detection limit of 0.09 U/L. Additionally, the limit of detection for kojic acid, serving as a representative TYR inhibitor, was determined to be 0.0004 µg/mL. SIGNIFICANCE: Our proposed fluorometric sensing platform exhibited exceptional selectivity, sensitivity, and satisfactory recoveries in human serum samples, which is of paramount importance for the clinical diagnostics of melanin-related diseases. Furthermore, the proposed approach was further employed for the screening of TYR inhibitors, suggesting the potential applications in clinical treatment and pharmaceutical research.
Subject(s)
Enzyme Inhibitors , Fluorescent Dyes , Metal-Organic Frameworks , Monophenol Monooxygenase , Monophenol Monooxygenase/antagonists & inhibitors , Monophenol Monooxygenase/metabolism , Metal-Organic Frameworks/chemistry , Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Humans , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemistry , Spectrometry, Fluorescence , Limit of Detection , Enzyme Assays/methods , PyronesABSTRACT
An increasing evidence supports that cell competition, a vital selection and quality control mechanism in multicellular organisms, is involved in tumorigenesis and development; however, the mechanistic contributions to the association between cell competition and tumor drug resistance remain ill-defined. In our study, based on a contructed lenvitinib-resistant hepatocellular carcinoma (HCC) cells display obvious competitive growth dominance over sensitive cells through reprogramming energy metabolism. Mechanistically, the hyperactivation of BCL2 interacting protein3 (BNIP3) -mediated mitophagy in lenvatinib-resistant HCC cells promotes glycolytic flux via shifting energy production from mitochondrial oxidative phosphorylation to glycolysis, by regulating AMP-activated protein kinase (AMPK) -enolase 2 (ENO2) signaling, which perpetually maintaining lenvatinib-resistant HCC cells' competitive advantage over sensitive HCC cells. Of note, BNIP3 inhibition significantly sensitized the anti-tumor efficacy of lenvatinib in HCC. Our findings emphasize a vital role for BNIP3-AMPK-ENO2 signaling in maintaining the competitive outcome of lenvitinib-resistant HCC cells via regulating energy metabolism reprogramming; meanwhile, this work recognizes BNIP3 as a promising target to overcome HCC drug resistance.
Subject(s)
Carcinoma, Hepatocellular , Drug Resistance, Neoplasm , Energy Metabolism , Liver Neoplasms , Membrane Proteins , Mitophagy , Phenylurea Compounds , Quinolines , Humans , Quinolines/pharmacology , Mitophagy/drug effects , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Membrane Proteins/metabolism , Energy Metabolism/drug effects , Phenylurea Compounds/pharmacology , Drug Resistance, Neoplasm/drug effects , Animals , Cell Line, Tumor , Proto-Oncogene Proteins/metabolism , Mice , Mice, Nude , Cell Proliferation/drug effects , Signal Transduction/drug effects , AMP-Activated Protein Kinases/metabolism , Mice, Inbred BALB C , Metabolic ReprogrammingABSTRACT
Introduction: In this study, the seasonal differences in the intestinal microbiota of Chinese mitten crab (Eriocheir sinensis) larvae were investigated at different sites in the intertidal zone of the Yangtze River Estuary. Methods: 16S rRNA high-throughput sequencing technology was used to compare and analyze the microbial community structure in the intestines of juvenile crab from different seasons. Results: The results showed that the main microbial phyla in all seasons and sites were Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, which accounted for 97.1% of the total microbiota. Composition analysis revealed that the relative abundance of Proteobacteria decreased from summer to winter at each station, whereas Bacteroidetes showed the opposite trend. Alpha diversity analysis showed that species richness increased from summer to winter at the upstream site (P < 0.05), but decreased at the downstream site (P < 0.05), with no significant differences observed in other comparisons. Biomarker species analysis showed that juvenile crab exhibited a more specialized microbial community in summer compared with autumn and winter. Co-occurrence network analysis revealed that microbial interaction network complexity was lower in autumn compared with summer and autumn. Functional prediction analysis showed that the microbial community only exhibited seasonal differences in amino acid biosynthesis, cofactor, prosthetic group, electron carrier, and vitamin biosynthesis, aromatic compound degradation, nucleotide and nucleoside degradation, and tricarboxylic acid cycle pathways. Discussion: The results indicated that the microbiota did not significantly differ among sites, and seasonal variation was a main factor influencing the differences in intestinal microbiota of Chinese mitten juvenile crab. Moreover, the microbial community was more complex in summer compared with autumn and winter.
Subject(s)
Brachyura , Estuaries , Gastrointestinal Microbiome , RNA, Ribosomal, 16S , Seasons , Animals , Brachyura/microbiology , RNA, Ribosomal, 16S/genetics , China , High-Throughput Nucleotide Sequencing , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Phylogeny , Biodiversity , Larva/microbiology , Bacteroidetes/classification , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Proteobacteria/genetics , Proteobacteria/classification , Proteobacteria/isolation & purification , Firmicutes/genetics , Firmicutes/classification , Firmicutes/isolation & purification , DNA, Bacterial/genetics , Rivers/microbiologyABSTRACT
In this study, a ligand fishing method for the screening of α-glucosidase inhibitors from Ginkgo biloba leaf was established for the first time using α-glucosidase immobilized on the magnetic metal-organic framework. The immobilized α-glucosidase exhibited enhanced resistance to temperature and pH, as well as good thermal stability and reusability. Two ligands, namely quercitrin and quercetin, were screened from Ginkgo biloba leaf and identified by ultra-high performance liquid chromatography-tandem mass spectrometry. The half-maximal inhibitory concentration values for quercitrin and quercetin were determined to be 105.69 ± 0.39 and 83.49 ± 0.79 µM, respectively. Molecular docking further confirmed the strong inhibitory effect of these two ligands. The proposed approach in this study demonstrates exceptional efficiency in the screening of α-glucosidase inhibitors from complex natural medicinal plants, thus exhibiting significant potential for the discovery of antidiabetic compounds.
Subject(s)
Enzymes, Immobilized , Ginkgo biloba , Glycoside Hydrolase Inhibitors , Metal-Organic Frameworks , Plant Leaves , alpha-Glucosidases , Ginkgo biloba/chemistry , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Metal-Organic Frameworks/chemistry , Plant Leaves/chemistry , alpha-Glucosidases/metabolism , alpha-Glucosidases/chemistry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/antagonists & inhibitors , Enzymes, Immobilized/metabolism , Molecular Docking Simulation , Drug Evaluation, Preclinical , Plant Extracts/chemistry , Plant Extracts/pharmacology , Quercetin/chemistry , Quercetin/analysis , Quercetin/pharmacology , Quercetin/analogs & derivatives , Chromatography, High Pressure LiquidABSTRACT
BACKGROUND: As promising biomarkers of diabetes, α-glucosidase (α-Glu) and ß-glucosidase (ß-Glu) play a crucial role in the diagnosis and management of diseases. However, there is a scarcity of techniques available for simultaneously and sensitively detecting both enzymes. What's more, most of the approaches for detecting α-Glu and ß-Glu rely on a single-mode readout, which can be affected by multiple factors leading to inaccurate results. Hence, the simultaneous detection of the activity levels of both enzymes in a single sample utilizing multiple-readout sensing approaches is highly attractive. RESULTS: In this work, we constructed a facile sensing platform for the simultaneous determination of α-Glu and ß-Glu by utilizing a luminescent covalent organic framework (COF) as a fluorescent indicator. The enzymatic hydrolysis product common to both enzymes, p-nitrophenol (PNP), was found to affect the fluorometric signal through an inner filter effect on COF, enhance the colorimetric response by intensifying the absorption peak at 400 nm, and induce changes in RGB values when analyzed using a smartphone-based color recognition application. By combining fluorometric/colorimetric measurements with smartphone-assisted RGB mode, we achieved sensitive and accurate quantification of α-Glu and ß-Glu. The limits of detection for α-Glu were determined to be 0.8, 1.22, and 1.85 U/L, respectively. Similarly, the limits of detection for ß-Glu were 0.16, 0.42, and 0.53 U/L, respectively. SIGNIFICANCE: Application of the proposed sensing platform to clinical serum samples revealed significant differences in the two enzymes between healthy people and diabetic patients. Additionally, the proposed sensing method was successfully applied for the screening of α-Glu inhibitors and ß-Glu inhibitors, demonstrating its viability and prospective applications in the clinical management of diabetes as well as the discovery of antidiabetic medications.
Subject(s)
Glycoside Hydrolase Inhibitors , Metal-Organic Frameworks , alpha-Glucosidases , beta-Glucosidase , Metal-Organic Frameworks/chemistry , Humans , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , beta-Glucosidase/antagonists & inhibitors , beta-Glucosidase/metabolism , alpha-Glucosidases/metabolism , alpha-Glucosidases/blood , Colorimetry/methods , Limit of Detection , Nitrophenols/metabolism , Nitrophenols/chemistry , Nitrophenols/analysis , Drug Evaluation, Preclinical , Fluorescent Dyes/chemistryABSTRACT
Novel metal-organic framework MIL-101(Cr)-NH2 functionalised hydrophilic polydopamine-modified Fe3O4 magnetic nanoparticles (Fe3O4@PDA@MIL-101(Cr)-NH2) were synthesised and used as magnetic solid-phase extraction (MSPE) adsorbents for extracting tetracyclines (TCs) from milk samples. The integrated Fe3O4@PDA@MIL-101(Cr)-NH2 exhibited convenient magnetic separation and exceptional multi-target binding capabilities. Furthermore, the PDA coating significantly enhanced the hydrophilicity and extraction efficiency of the material, thereby facilitating the extraction of trace TCs. Various factors affecting MSPE, such as adsorbent dosage, extraction time, pH value, and desorption conditions, were optimised. The developed MSPE method coupled with high-performance liquid chromatography demonstrated good linearity (R2 ≥ 0.9989), acceptable accuracy (82.2%-106.1%), good repeatability (intra-day precision of 0.8%-4.7% and inter-day precision of 1.1%-4.5%), low limits of detection (2.18-6.25 µg L-1), and low limits of quantification (6.54-18.75 µg L-1) in TCs detection. The approach was successfully used for the quantification of trace TCs in real milk samples.
Subject(s)
Magnetite Nanoparticles , Metal-Organic Frameworks , Milk , Solid Phase Extraction , Tetracyclines , Milk/chemistry , Solid Phase Extraction/methods , Solid Phase Extraction/instrumentation , Metal-Organic Frameworks/chemistry , Tetracyclines/isolation & purification , Tetracyclines/chemistry , Tetracyclines/analysis , Animals , Magnetite Nanoparticles/chemistry , Hydrophobic and Hydrophilic Interactions , Chromatography, High Pressure Liquid , Adsorption , Food Contamination/analysisABSTRACT
BACKGROUND: ß-Glucuronidase (GUS) is considered as a promising biomarker for primary cancer. Thus, the reliable detection of GUS has great practical significance in the discovery and diagnosis of cancer. Compared with traditional organic probes, silicon nanoparticles (Si NPs) have emerged as robust optical nanomaterials due to their facile preparation, superior photobleaching resistance and excellent biocompatibility. However, most nanomaterials-based methods only output a single signal which is easily influenced by external factors in complex systems. Hence, developing nanomaterial-based multi-signal optical assays for highly sensitive GUS determination is still urgently desired. RESULTS: In this study, we developed a simple and efficient one-step method for the in situ preparation of yellow color and yellow-green fluorescent Si NPs. This was achieved by combining 3-[2-(2-aminoethylamino) ethylamino] propyl-trimethoxysilane with p-aminophenol (AP) in an aqueous solution. The obtained Si NPs showed yellow-green fluorescence at 535 nm when excited at 380 nm, while also exhibiting an absorption peak at a wavelength of 490 nm. Taking inspiration from the easy synthesis step regulated by AP, which is generated through the hydrolysis of 4-aminophenyl ß-D-glucuronide catalyzed by GUS, we constructed a direct fluorometric and colorimetric dual-mode method to measure GUS activity. The developed fluorometric and colorimetric sensing platform showed high sensitivity and accuracy with detection limits for GUS determination as low as 0.0093 and 0.081 U/L, respectively. SIGNIFICANCE: This study provides a facile dual-mode fluorometric and colorimetric approach for determination of GUS activity based on novel Si NPs for the first time. This designed sensing approach was successfully employed for the quantification of GUS in human serum samples and screening of GUS inhibitors, indicating the feasibility and potential applications in clinical cancer diagnosis and anti-cancer drug discovery.
Subject(s)
Nanoparticles , Silicon , Humans , Glucuronidase , Colorimetry/methods , FluorometryABSTRACT
Knee replacement surgery confronts challenges including patient dissatisfaction and the necessity for secondary procedures. A key requirement lies in dual-modal measurement of force and temperature of artificial joints during postoperative monitoring. Here, a novel non-toxic near-infrared (NIR) phosphor Sr3Sn2O7:Nd, Yb, is designed to realize the dual-modal measurement. The strategy is to entail phonon-assisted upconversion luminescence (UCL) and trap-controlled mechanoluminescence (ML) in a single phosphor well within the NIR biological transmission window. The phosphor is embedded in medical bone cement forming a smart joint in total knee replacements illustrated as a proof-of-concept. The sensing device can be charged in vitro by a commercial X-ray source with a safe dose rate for ML, and excited by a low power 980 nm laser for UCL. It attains impressive force and temperature sensing capabilities, exhibiting a force resolution of 0.5% per 10 N, force detection threshold of 15 N, and a relative temperature sensitive of up to 1.3% K-1 at 309 K. The stability against humidity and thermal shock together with the robustness of the device are attested. This work introduces a novel methodological paradigm, paving the way for innovative research to enhance the functionality of artificial tissues and joints in living organisms.
Subject(s)
Arthroplasty, Replacement, Knee , Temperature , Humans , Strontium/chemistry , Ytterbium/chemistry , Luminescence , Neodymium/chemistry , Luminescent Measurements/methods , Infrared RaysABSTRACT
Lenvatinib is a frontline tyrosine kinase inhibitor for patients with advanced hepatocellular carcinoma (HCC). However, just 25% of patients benefit from the treatment, and acquired resistance always develops. To date, there are neither effective medications to combat lenvatinib resistance nor accurate markers that might predict how well a patient would respond to the lenvatinib treatment. Thus, novel strategies to recognize and deal with lenvatinib resistance are desperately needed. In the current study, a robust Lenvatinib Resistance index (LRi) model to predict lenvatinib response status in HCC was first established. Subsequently, five candidate drugs (Mercaptopurine, AACOCF3, NU1025, Fasudil, and Exisulind) that were capable of reversing lenvatinib resistance signature were initially selected by performing the connectivity map (CMap) analysis, and fasudil finally stood out by conducting a series of cellular functional assays in vitro and xenograft mouse model. Transcriptomics revealed that the co-administration of lenvatinib and fasudil overcame lenvatinib resistance by remodeling the hedgehog signaling pathway. Mechanistically, the feedback activation of EGFR by lenvatinib led to the activation of the GLI2-ABCC1 pathway, which supported the HCC cell's survival and proliferation. Notably, co-administration of lenvatinib and fasudil significantly inhibited IHH, the upstream switch of the hedgehog pathway, to counteract GLI2 activation and finally enhance the effectiveness of lenvatinib. These findings elucidated a novel EGFR-mediated mechanism of lenvatinib resistance and provided a practical approach to overcoming drug resistance in HCC through meaningful drug repurposing strategies.
Subject(s)
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , Antineoplastic Agents , Carcinoma, Hepatocellular , Liver Neoplasms , Phenylurea Compounds , Quinolines , Humans , Animals , Mice , Carcinoma, Hepatocellular/metabolism , Hedgehog Proteins , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Liver Neoplasms/drug therapy , Liver Neoplasms/metabolism , Cell Line, Tumor , ErbB Receptors , Zinc Finger Protein Gli2 , Nuclear ProteinsABSTRACT
Though burgeoning research manifests that cell competition, an essential selection and quality control mechanism for maintaining tissue or organ growth and homeostasis in multicellular organisms, is closely related to tumorigenesis and development, the mechanism of cell competition associated with tumor drug resistance remains elusive. In the study, we uncovered that oxaliplatin-resistant hepatocellular carcinoma (HCC) cells exhibit a pronounced competitive advantage against their sensitive counterparts, which is related to lipid takeover of resistant cells from sensitive cells. Of note, such lipid takeover is dependent on the existence of isocitrate dehydrogenase 1 (IDH1) in resistant HCC cells. Mechanistically, IDH1 activity is regulated by heat shock protein 90 alpha (HSP90α) through binding with each other, which orchestrates the expressions of lipid metabolic enzymes and lipid accumulation in resistant HCC cells. Our results suggest that HCC cell competition-driven chemoresistance can be regulated by HSP90α/IDH1-mediated lipid metabolism, which may serve as a promising target for overcoming drug resistance in HCC.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Oxaliplatin/pharmacology , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Cell Competition , Lipids , Isocitrate Dehydrogenase/geneticsABSTRACT
The balance among different CD4+ T cell subsets is crucial for repairing the injured spinal cord. Dendritic cell (DC)-derived small extracellular vesicles (DsEVs) effectively activate T-cell immunity. Altered peptide ligands (APLs), derived from myelin basic protein (MBP), have been shown to affect CD4+ T cell subsets and reduce neuroinflammation levels. However, the application of APLs is challenging because of their poor stability and associated side effects. Herein, it is demonstrate that DsEVs can act as carriers for APL MBP87-99 A91 (A91-DsEVs) to induce the activation of 2 helper T (Th2) and regulatory T (Treg) cells for spinal cord injury (SCI) in mice. These stimulated CD4+ T cells can efficiently "home" to the lesion area and establish a beneficial microenvironment through inducing the activation of M2 macrophages/microglia, inhibiting the expression of inflammatory cytokines, and increasing the release of neurotrophic factors. The microenvironment mediated by A91-DsEVs may enhance axon regrowth, protect neurons, and promote remyelination, which may support the recovery of motor function in the SCI model mice. In conclusion, using A91-DsEVs as a therapeutic vaccine may help induce neuroprotective immunity in the treatment of SCI.
Subject(s)
Extracellular Vesicles , Spinal Cord Injuries , Vaccines , Rats , Mice , Animals , Rats, Sprague-Dawley , Ligands , Spinal Cord Injuries/therapy , Spinal Cord Injuries/metabolism , Vaccines/pharmacology , Vaccines/therapeutic use , Peptides , T-Lymphocytes, Regulatory , Extracellular Vesicles/metabolism , Dendritic CellsABSTRACT
BACKGROUND: The Armed Forces Institute of Pathology (AFIP) had higher accuracy and reliability in prognostic assessment and treatment strategies for patients with gastric stromal tumors (GSTs). The AFIP classification is frequently used in clinical applications. But the risk classification is only available for patients who are previously untreated and received complete resection. We aimed to investigate the feasibility of multi-slice MSCT features of GSTs in predicting AFIP risk classification preoperatively. METHODS: The clinical data and MSCT features of 424 patients with solitary GSTs were retrospectively reviewed. According to pathological AFIP risk criteria, 424 GSTs were divided into a low-risk group (n = 282), a moderate-risk group (n = 72), and a high-risk group (n = 70). The clinical data and MSCT features of GSTs were compared among the three groups. Those variables (p < 0.05) in the univariate analysis were included in the multivariate analysis. The nomogram was created using the rms package. RESULTS: We found significant differences in the tumor location, morphology, necrosis, ulceration, growth pattern, feeding artery, vascular-like enhancement, fat-positive signs around GSTs, CT value in the venous phase, CT value increment in the venous phase, longest diameter, and maximum short diameter (all p < 0.05). Two nomogram models were successfully constructed to predict the risk of GSTs. Low- vs. high-risk group: the independent risk factors of high-risk GSTs included the location, ulceration, and longest diameter. The area under the receiver operating characteristic curve (AUC) of the prediction model was 0.911 (95% CI: 0.872-0.951), and the sensitivity and specificity were 80.0% and 89.0%, respectively. Moderate- vs. high-risk group: the morphology, necrosis, and feeding artery were independent risk factors of a high risk of GSTs, with an AUC value of 0.826 (95% CI: 0.759-0.893), and the sensitivity and specificity were 85.7% and 70.8%, respectively. CONCLUSIONS: The MSCT features of GSTs and the nomogram model have great practical value in predicting pathological AFIP risk classification between high-risk and non-high-risk groups before surgery.
ABSTRACT
The contribution of lateral carbon (C) to hydrological processes is well known for its ecological functions in the estuarine C budget across the terrestrial-aquatic interfaces. However, sampling of individual daily tides during multiple months or seasons in heterogeneous patches of landscape makes extrapolation from days to months or seasons challenging. In this paper, we examine the terrestrial-aquatic lateral hydrological C flux for an estuarine marsh where monthly tides, including consecutive daily spring tides, were measured over the course of an entire year. We found a significant correlation between imported and exported hydrological dissolved C, both dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC), although a similar correlation was not found for particulate organic carbon (POC). Based on a total of 44 sampling trips over a year, this saltmarsh appeared to be a net exporter of DOC and DIC but a net sink of POC. Furthermore, the lateral hydrological C budget functioned as a limited lateral C sink in terms of organic C (i.e., ΔPOC and ΔDOC), while the marsh functioned as a small lateral C source. Our findings highlight the importance of lateral hydrologic inflows/outflows in wetland C budgets of land-water interfaces, especially in those characterized by the meta-ecosystem framework. Surprisingly, different C species responded unequally to the lateral hydrological C budget, suggesting that a conceptual realization of meta-ecosystem is a powerful theoretical framework to extend the outwelling hypothesis.
ABSTRACT
The aim of this paper is to propose laws of trephine operation based on a robot-assisted cutting cornea in order to obtain better microsurgical effects for keratoplasty. Using a trephine robot integrated with a microforce sensor and a handheld trephine manipulator, robotic and manual experiments were performed, with porcine corneas as the test subjects. The effect of trephine operational parameters on the results reflected by the biomechanical response is discussed, and the parameters include linear velocity, rotating angle, and angular velocity. Using probability density functions, the distributions of the manual operational parameters show some randomness, and there is a large fluctuation in the trephine force during the experiments. The biomechanical response shows regular trends in the robotic experiments even under different parameters, and compared to manual trephination, the robot may perform the operation of trephine cornea cutting more stably. Under different operational parameters, the cutting force shows different trends, and the optimal initial parameters that result in better trephine effects can be obtained based on the trends. Based on this derived law, the operational parameters can be set in robotic trephination, and surgeons can also be specially trained to achieve a better microsurgical result.
ABSTRACT
Spinal cord injury (SCI) is a traumatic condition that causes myelin destruction and neuronal death, making it challenging to reverse. In spinal cord tissue, oligodendrocyte progenitor cells and oligodendrocytes are essential for maintaining myelin morphology and axon regeneration. The decrease in oligodendrocyte lineage cells after SCI is a major factor contributing to the difficulty in restoring spinal cord function. However, there is still a lack of research on the status and intercellular communication between oligodendrocyte lineage cells after injury. The development of single-cell sequencing technology has enabled researchers to obtain highly accurate cellular transcriptional information, facilitating detailed studies of cellular subpopulations. This study delved into the cellular heterogeneity of oligodendrocyte lineage cells using a single-cell transcriptomic approach to uncover functional changes and cellular interactions during different time points after SCI. Our findings highlighted the critical roles of Psap (Prosaposin)/Gpr37l1 and Psap/Gpr37 ligand-receptor pairs among oligodendrocyte lineage cells. Furthermore, we predicted the transcription factors that may play a key regulatory role. We demonstrated for the first time that Junb acts almost exclusively in mature oligodendrocytes, which provides a potential target for the study of oligodendrocyte transcriptional mechanisms.
Subject(s)
Axons , Spinal Cord Injuries , Humans , Cell Lineage , Nerve Regeneration/physiology , Oligodendroglia/physiology , Spinal Cord Injuries/genetics , Spinal Cord , Single-Cell AnalysisABSTRACT
ConspectusSingle-atom catalysts (SACs) offer unique advantages such as high (noble) metal utilization through maximum possible dispersion, large metal-support contact areas, and oxidation states usually unattainable in classic nanoparticle catalysis. In addition, SACs can serve as models for determining active sites, a simultaneously desired as well as elusive target in the field of heterogeneous catalysis. Due to the complexity of heterogeneous catalysts bearing a variety of different sites on metal particles and the respective support as well as at their interface, studies of intrinsic activities and selectivities remain largely inconclusive. While SACs could close this gap, many supported SACs remain intrinsically ill-defined due to complexities arising from the variety of different adsorption sites for atomically dispersed metals, hampering the establishment of meaningful structure-activity correlations. In addition to overcoming this limitation, well-defined SACs could even be utilized to shed light on fundamental phenomena in catalysis that remain ambiguous when studies are obscured by the complexity of heterogeneous catalysts.In this Account, we describe approaches to break down the complexity of supported single-atom catalysts through the careful choice of oxide supports with specific binding motives as well as the adsorption of well-defined ligands such as ionic liquids on single metal sites. An example of molecularly defined oxide supports is polyoxometalates (POMs), which are metal oxo clusters with precisely known composition and structure. POMs exhibit a limited number of sites to anchor atomically dispersed metals such as Pt, Pd, and Rh. Polyoxometalate-supported single-atom catalysts (POM-SACs) thus represent ideal systems for the in situ spectroscopic study of single atom sites during reactions as, in principle, all sites are identical and thus equally active in catalytic reactions. We have utilized this benefit in studies of the mechanism of CO and alcohol oxidation reactions as well as the hydro(deoxy)genation of various biomass-derived compounds. More so, the redox properties of polyoxometalates can be finely tuned by changing the composition of the support while keeping the geometry of the single-atom active site largely constant. We further developed soluble analogues of heterogeneous POM-SACs, opening the door to advanced liquid-phase nuclear magnetic resonance (NMR) and UV-vis techniques but, in particular, to electrospray ionization mass spectrometry (ESI-MS) which proves powerful in determining catalytic intermediates as well as their gas-phase reactivity. Employing this technique, we were able to resolve some of the long-standing questions about hydrogen spillover, demonstrating the broad utility of studies on defined model catalysts.
ABSTRACT
The water-gas shift (WGS) reaction is often conducted at elevated temperature and requires energy-intensive separation of hydrogen (H2 ) from methane (CH4 ), carbon dioxide (CO2 ), and residual carbon monoxide (CO). Designing processes to decouple CO oxidation and H2 production provides an alternative strategy to obtain high-purity H2 streams. We report an electrothermal WGS process combining thermal oxidation of CO on a silicomolybdic acid (SMA)-supported Pd single-atom catalyst (Pd1 /CsSMA) and electrocatalytic H2 evolution. The two half-reactions are coupled through phosphomolybdic acid (PMA) as a redox mediator at a moderate anodic potential of 0.6â V (versus Ag/AgCl). Under optimized conditions, our catalyst exhibited a TOF of 1.2â s-1 with turnover numbers above 40 000â mol CO 2 ${{_{{\rm CO}{_{2}}}}}$ molPd -1 achieving stable H2 production with a purity consistently exceeding 99.99 %.
ABSTRACT
PURPOSE: Recently, aberrant glycosylation has been recognized to be relate to malignant behaviors of cancer and outcomes of patients with various cancers. SLC35A2 plays an indispensable role on glycosylation as a nucleotide sugar transporter. However, effects of SLC35A2 on malignant behaviors of cancer cells and alteration of cancer cells surface glycosylation profiles are still not fully understood, particularly in hepatocellular carcinoma (HCC). Hence, from a glycosylation perspective, we investigated the effects of SLC35A2 on metastatic behaviors of HCC cells. METHODS: SLC35A2 expression in clinical samples and HCC cells was examined by immunohistochemical staining or Western blot/quantitative PCR and was regulated by RNA interference or vectors-mediated transfection. Effects of SLC35A2 expression alteration on metastatic behaviors and membrane glycan profile of HCC cells were observed by using respectively invasion, migration, cell adhesion assay, in vivo lung metastatic nude mouse model and lectins microarray. Co-location among proteins in HCC cells was observed by fluorescence microscope and detected by an in vitro co-immunoprecipitation assay. RESULTS: SLC35A2 was upregulated in HCC tissues, and is associated with poor prognosis of HCC patients. SLC35A2 expression alteration significantly affected the invasion, adhesion, metastasis and membrane glycan profile and led to the dysregulated expressions or glycosylation of cell adhesion-related molecules in HCC cells. Mechanistically, the maintenance of SLC35A2 activity is critical for the recruitment of the key galactosyltransferase B4GalT1, which is responsible for complex glycoconjugate and lactose biosynthesis, to Golgi apparatus in HCC cells. CONCLUSION: SLC35A2 plays important roles in promoting HCC metastasis by regulating cellular glycosylation modification and inducing the cell adhesive ability of HCC cells.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Monosaccharide Transport Proteins , Nucleotide Transport Proteins , Animals , Humans , Mice , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Cell Movement/genetics , Gene Expression Regulation, Neoplastic , Glycosylation , Liver Neoplasms/metabolism , Monosaccharide Transport Proteins/metabolism , Neoplasm Invasiveness , Neoplasm Metastasis , Nucleotide Transport Proteins/metabolism , Nucleotides/metabolism , Polysaccharides , Sugars/metabolismABSTRACT
Hepatocellular cancer (HCC) is a serious illness with high prevalence and mortality throughout the whole world. For advanced HCC, immunotherapy is somewhat impactful and encouraging. Nevertheless, a substantial proportion of patients with advanced HCC are still unable to achieve a durable response, owing to heterogeneity from clonal variability and differential expression of the PD-1/PD-L1 axis. Recently, heat shock factor 1 (HSF1) is recognized as an important component of tumor immunotherapeutic response as well as related to PD-L1 expression in cancer. However, the mechanism of HSF1 regulating PD-L1 in cancer, especially in HCC, is still not fully clear. In this study, we observed the significantly positive correlation between HSF1 expression and PD-L1 expression in HCC samples; meanwhile combination expressions of HSF1 and PD-L1 served as the signature for predicting prognosis of patients with HCC. Mechanistically, HSF1 upregulated PD-L1 expression by inducing APOJ expression and activating STAT3 signaling pathway in HCC. In addition, we explored further the potential values of targeting the HSF1-APOJ-STAT3 axis against CD8+ T cells-mediated cancer cells cytotoxicity. These findings unveiled the important involvement of HSF1 in regulating PD-L1 expression in HCC as well as provided a novel invention component for improving the clinical response rate and efficacy of PD-1/PD-L1 blockade.
Subject(s)
Carcinoma, Hepatocellular , Heat Shock Transcription Factors , Immunotherapy , Liver Neoplasms , Humans , B7-H1 Antigen/genetics , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/therapy , CD8-Positive T-Lymphocytes , Liver Neoplasms/genetics , Liver Neoplasms/therapy , Programmed Cell Death 1 Receptor/genetics , STAT3 Transcription Factor/genetics , Heat Shock Transcription Factors/geneticsABSTRACT
Laser soldering has been gradually applied to the soldering of electronic components due to the rapid development of microelectronics. However, it is inefficient to use a mechanical shaft to move a laser beam. Here, a laser soldering system is constructed using galvanometer scanning, and an intelligent algorithm is also introduced to optimize the soldering path. Firstly, a laser soldering system for scanning of galvanometers is established, and the functions of visual monitoring, motion planning and parameter integration are presented. Secondly, the position of the laser beam and the corresponding soldering spot are determined, and the coordinate information is provided to plan a route by camera calibration and coordinate system transformation. Finally, the problem of path planning in this system is decomposed into the generation of the soldering point full coverage processing frame, and the route optimization of processing platform and laser beam motion. Furthermore, an improved clustering algorithm, based on the characteristics of system structure, and a hybrid optimization algorithm are designed to deal with the generation of the soldering point full coverage processing frame, the route optimization of processing platform and laser beam motion. In addition, the simulations and experiments are verified by test board. These findings shown that the established system and designed optimization algorithm can promote the efficiency of laser soldering.