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N6-methyladenosine (m 6 A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m 6 A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m 6 A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m 6 A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m 6 A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m 6 A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m 6 A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m 6 A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m 6 A's role in neurodegenerative processes. The roles of m 6 A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be attributed to the time-specific nature of m 6 A and its varying effects on distinct brain regions and in different environments.
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An electrochemical gem-difluorination of indeno[1,2-c]furans using commercially available and easy-to-use triethylamine trihydrofluoride as both the electrolyte and fluorinating agent was developed. Remarkably, different reaction pathways of indeno[1,2-c]furans, i.e., paired electrolysis and net oxidation, are operative in a batch reactor and a continuous-flow microreactor to afford the corresponding gem-difluorinated indanones and indenones, respectively.
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INTRODUCTION: Glioblastoma multiforme (GBM) poses a significant challenge in terms of treatment due to its high malignancy, necessitating the identification of additional molecular targets. VSIG4, an oncogenic gene participates in tumor growth and migration in various cancer types. Nevertheless, the precise process through which VSIG4 facilitates the malignant progression of glioma remains to be elucidated. OBJECTIVES: This research aims to explore the function and molecular mechanism involving VSIG4 in the malignant progression of glioma. METHODS: The amount of VSIG4 was measured using qPCR, western blotting, and immunohistochemistry. Lentivirus infections were applied for upregulating or downregulating molecules within glioma cells. The incorporation of 5-ethynyl-20-deoxyuridine, Transwell, cell counting kit-8, and clone formation experiments, were applied to assess the biological functions of molecules on glioma cells. Dual luciferase reporter gene, RNA immunoprecipitation, and chromatin immunoprecipitation assays were used to explore the functional relationship among relevant molecules. RESULTS: The upregulation of VSIG4 was observed in GBM tissues, indicating an adverse prognosis. Silencing VSIG4 in glioma cells resulted in a decrease in cell viability, invasion, proliferation, and tumorigenesis, an increase in cell apoptosis, and a stagnation in the cell cycle progression at the G0/G1 phase. Mechanistically, SPI1-mediated upregulation of VSIG4 expression led to binding between VSIG4 and THBS1 protein, ultimately facilitating the malignant progression of glioma cells through the activation of the PI3K/AKT pathway. The inhibited proliferative and invasive capabilities of glioma cells were reversed by overexpressing THBS1 following the knockdown of VSIG4. CONCLUSION: Our findings provide evidence for the role of VSIG4 as an oncogene and reveal the previously unidentified contribution of the SPI1/VSIG4/THBS1 axis in the malignant progression of glioma. This signaling cascade enhances tumor growth and invasion by modulating the PI3K/AKT pathway. VSIG4 as a potential biomarker may be a viable strategy in the development of tailored molecular therapies for GBM.
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Gamma knife radiosurgery (GKRS) is recommended as the first-line treatment for brain metastases of lung adenocarcinoma (LUAD) in many guidelines, but its specific mechanism is unclear. We aimed to study the changes in the proteome of brain metastases of LUAD in response to the hyperacute phase of GKRS and further explore the mechanism of differentially expressed proteins (DEPs). Cancer tissues were collected from a clinical trial for neoadjuvant stereotactic radiosurgery before surgical resection of large brain metastases (ChiCTR2000038995). Five brain metastasis tissues of LUAD were collected within 24 h after GKRS. Five brain metastasis tissues without radiotherapy were collected as control samples. Proteomics analysis showed that 163 proteins were upregulated and 25 proteins were downregulated. GO and KEGG enrichment analyses showed that the DEPs were closely related to ribosomes. Fifty-three of 70 ribosomal proteins were significantly overexpressed, while none of them were underexpressed. The risk score constructed from 7 upregulated ribosomal proteins (RPL4, RPS19, RPS16, RPLP0, RPS2, RPS26 and RPS25) was an independent risk factor for the survival time of LUAD patients. Overexpression of ribosomal proteins may represent a desperate response to lethal radiotherapy. We propose that targeted inhibition of these ribosomal proteins may enhance the efficacy of GKRS.
Subject(s)
Adenocarcinoma of Lung , Brain Neoplasms , Lung Neoplasms , Proteomics , Radiosurgery , Ribosomal Proteins , Humans , Ribosomal Proteins/metabolism , Radiosurgery/methods , Brain Neoplasms/secondary , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Male , Female , Proteomics/methods , Adenocarcinoma of Lung/metabolism , Adenocarcinoma of Lung/pathology , Adenocarcinoma of Lung/mortality , Adenocarcinoma of Lung/surgery , Adenocarcinoma of Lung/radiotherapy , Lung Neoplasms/pathology , Lung Neoplasms/metabolism , Lung Neoplasms/radiotherapy , Middle Aged , Aged , Gene Expression Regulation, Neoplastic , Proteome/metabolismABSTRACT
Precise electrochemical synthesis of commodity chemicals and fuels from CO2 building blocks provides a promising route to close the anthropogenic carbon cycle, in which renewable but intermittent electricity could be stored within the greenhouse gas molecules. Here, we report state-of-the-art CO2-to-HCOOH valorization performance over a multiscale optimized Cu-Bi cathodic architecture, delivering a formate Faradaic efficiency exceeding 95% within an aqueous electrolyzer, a C-basis HCOOH purity above 99.8% within a solid-state electrolyzer operated at 100 mA cm-2 for 200 h and an energy efficiency of 39.2%, as well as a tunable aqueous HCOOH concentration ranging from 2.7 to 92.1 wt%. Via a combined two-dimensional reaction phase diagram and finite element analysis, we highlight the role of local geometries of Cu and Bi in branching the adsorption strength for key intermediates like *COOH and *OCHO for CO2 reduction, while the crystal orbital Hamiltonian population analysis rationalizes the vital contribution from moderate binding strength of η2(O,O)-OCHO on Cu-doped Bi surface in promoting HCOOH electrosynthesis. The findings of this study not only shed light on the tuning knobs for precise CO2 valorization, but also provide a different research paradigm for advancing the activity and selectivity optimization in a broad range of electrosynthetic systems.
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Reconfigurable variable stiffness actuator (RVSA) has attracted increasing attention in robotics due to its safety, compliance, and robustness. However, the control of the RVSA is challenging due to nonlinear factors such as high-order nonlinear dynamic, model uncertainties, time-varying model parameters, and disturbances. In this paper, firstly, a lightweight RVSA structure with both passive and active nonlinear variable stiffness characteristic is developed. Secondly, a dynamic surface backstepping control method based on a radial basis neural network and disturbance observer (DSBC-RBFNN-DOB) is proposed to achieve position control of the lightweight RVSA with matched and unmatched uncertainties. To address solve the "complexity explosion" and noise problems in traditional backstepping control, the dynamic surface backstepping control (DSBC) method is used to design the controller. Then, a method based on radial basis neural network (RBFNN) and disturbance observer (DOB) are used to compensate for the matched and unmatched uncertainties in the link and motor. In this method, the matched uncertainties are compensated using RBFNN, and the DOB is integrated to compensate RBFNN approximation errors and unmatched uncertainties. Through Lyapunov stability analysis, the semi-global boundedness of the controller is proven. Finally, the proposed method is simulated and actually implemented, verifying the effectiveness of the method. Simulation and experimental results show that the root mean square error (RMSE) of the proposed method is only 0.97277° and 0.6418°, respectively. Compared with PID, DSBC, and DSBC-RBFNN, the error reduction percentages in simulation (experiment) are 85.6 % (88.9 %), 49.4 % (88.4 %) and 36.1 % (80.0 %) respectively.
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BACKGROUND: Pathological changes, such as microglia activation in the hippocampus frequently occur in individuals with animal models of depression; however, they may share a common cellular mechanism, such as endoplasmic reticulum (ER) stress and mitochondrial dysfunction. Mitochondria associated membranes (MAMs) are communication platforms between ER and mitochondria. This study aimed to investigate the role of intracellular stress responses, especially structural and functional changes of MAMs in depression. METHODS: We used chronic social defeat stress (CSDS) to mimic depression in C57 mice to investigate the pathophysiological changes in the hippocampus associated with depression and assess the antidepressant effect of electroacupuncture (EA). Molecular, histological, and electron microscopic techniques were utilized to study intracellular stress responses, including the ER stress pathway reaction, mitochondrial damage, and structural and functional changes in MAMs in the hippocampus after CSDS. Proteomics technology was employed to explore protein-level changes in MAMs caused by CSDS. RESULTS: CSDS caused mitochondrial dysfunction, ER stress, closer contact between ER and mitochondria, and enrichment of functional protein clusters at MAMs in hippocampus along with depressive-like behaviors. Also, EA showed beneficial effects on intracellular stress responses and depressive-like behaviors in CSDS mice. LIMITATION: The cellular specificity of MAMs related protein changes in CSDS mice was not explored. CONCLUSIONS: In the hippocampus, ER stress and mitochondrial damage occur, along with enriched mitochondria-ER interactions and MAM-related protein enrichment, which may contribute to depression's pathophysiology. EA may improve depression by regulating intracellular stress responses.
Subject(s)
Depression , Disease Models, Animal , Endoplasmic Reticulum Stress , Hippocampus , Mice, Inbred C57BL , Stress, Psychological , Animals , Hippocampus/pathology , Hippocampus/physiopathology , Mice , Endoplasmic Reticulum Stress/physiology , Male , Stress, Psychological/complications , Stress, Psychological/metabolism , Stress, Psychological/physiopathology , Mitochondria , Electroacupuncture , Mitochondrial Membranes/metabolism , Social Defeat , Behavior, Animal/physiology , Mitochondria Associated MembranesABSTRACT
Focused microwave breast hyperthermia (FMBH) employs a phased antenna array to perform beamforming that can focus microwave energy at targeted breast tumors. Selective heating of the tumor endows the hyperthermia treatment with high accuracy and low side effects. The effect of FMBH is highly dependent on the applied phased antenna array. This work investigates the effect of polarizations of antenna elements on the microwave-focusing results by simulations. We explore two kinds of antenna arrays with the same number of elements using different digital realistic human breast phantoms. The first array has all the elements' polarization in the vertical plane of the breast, while the second array has half of the elements' polarization in the vertical plane and the other half in the transverse plane, i.e., cross polarization. In total, 96 sets of different simulations are performed, and the results show that the second array leads to a better focusing effect in dense breasts than the first array. This work is very meaningful for the potential improvement of the antenna array for FMBH, which is of great significance for the future clinical applications of FMBH. The antenna array with cross polarization can also be applied in microwave imaging and sensing for biomedical applications.
Subject(s)
Breast Neoplasms , Hyperthermia, Induced , Microwaves , Phantoms, Imaging , Humans , Microwaves/therapeutic use , Breast Neoplasms/therapy , Hyperthermia, Induced/methods , Female , Breast/pathology , Computer SimulationABSTRACT
Aqueous Zn-ion batteries (ZIBs) are promising next-generation energy storage devices, yet suffer from the issues of hydrogen evolution reaction (HER) and intricate side reactions on the Zn anode surface. The hydrogen (H)-bond networks play a critical role in interfacial proton transport that may closely relate to HER but are rarely investigated. Herein, we report a self-assembled monolayer (SAM) strategy which is constructed by anchoring ionic liquid cations on Ti3C2Tx substrate for HER-free Zn anode. Molecule dynamics simulations reveal that the rationally designed SAM with a high coordination number of water molecules (25-27, 4-6 for Zn2+) largely reduces the interfacial densities of H2O molecules, therefore breaking the connectivity of H-bond networks and blocking proton transport on the interface, by which the HER is suppressed. Then, a series of in situ characterizations demonstrate that negligible amounts of H2 gas are collected from the Zn@SAM-MXene anode. Consequently, the symmetric cell enables a long-cycling life of 3000â h at 1â mA cm-2 and 1000â h at 5â mA cm-2. More significantly, the stable Zn@SAM-MXene films are successfully used for coin full cells showing high-capacity retention of over 94 % after 1000 cycles and large-area (10×5â cm2) pouch cells with desired performance.
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Four undescribed compounds including three harzianic acids (1, 3 and 4) and one oxazolidinone (2), along with three known ones (5-7) were isolated from the solid fermented product of endophytic fungus Ilyonectria sp., their structures were elucidated as 1-amino-harzianic acid (1), ilyonectria-oxazolidinone (2),10'-nor- isoharzianic acid (3), isohomoharzianic acid (4), harzianic acid (5), isoharzianic acid (6), homoharzianic acid (7) by means of detailed chemical evidences and spectroscopic data analysis. All the compounds were evaluated for cytotoxicity against SMMC-7721 human cancer cell lines by MTS assay. Among the seven tested compounds, 1-amino-harzianic acid (1) demonstrated well cytotoxic activity against SMMC-7721 with IC50 value of 26.84 µM. The results of molecular docking indicated that compound exhibited moderate anti-tumor activity may through binding to apoptosis related proteins.
Subject(s)
Antineoplastic Agents , Molecular Docking Simulation , Oxazolidinones , Humans , Cell Line, Tumor , Molecular Structure , Antineoplastic Agents/pharmacology , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/chemistry , Oxazolidinones/pharmacology , Oxazolidinones/isolation & purification , Endophytes/chemistry , China , Hypocreales/chemistryABSTRACT
Diamines play important roles in synthetic organic chemistry and thus facilitate life and materials sciences. Herein we report a cobalt-catalyzed ring opening, nucleophilic amination of aziridines and azetidines with N-fluorosulfonamides toward a wide range of 1,2- and 1,3-diamine derivatives in moderate to good yields under mild conditions.
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The preparation of polycyclic aromatic hydrocarbons (PAHs) by the Scholl reaction is typically performed by using superstoichiometric oxidants. Herein, we develop an electrochemical continuous-flow Scholl reaction to access PAHs that features a reduction in the use of supporting electrolytes and easy scale-up without changing the reaction conditions and setups. This reaction allows the synthesis of distorted PAHs containing three [5]helicene units that possess intriguing electronic and optical properties.
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Reasonable design of cost-effective counter electrode (CE) catalysts for triiodide (I3-) reduction reaction (IRR) by simultaneously combining heteroatom doping and facet engineering is highly desired in iodine-based dye-sensitized solar cells (DSSCs), but really challenging. Herein, the density function theory (DFT) calculations were first conducted to demonstrate that the Fe-doped NiSe (111) showed an appropriate adsorption energy for I3-, increased number of metal active sites, reinforced charge-transfer ability, and strong interaction between 3d states of metal sites and 5p state of I1 atoms in I3-, compared to NiSe (111). Based on this finding, the well-defined Fe-NiSe octahedron with exposed (111) plane (marked as Fe-NiSe (111)) and NiSe octahedron with the same exposed plane (named as NiSe (111)) are controllably synthesized. When the as-prepared Fe-NiSe (111) and NiSe (111) worked as CE catalysts, Fe-NiSe (111) exhibits improved electrochemical performance with higher power conversion efficiency (PCE) than NiSe (111), providing new opportunity to replace precious Pt for DSSCs.
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BACKGROUND: Definitive concurrent chemoradiotherapy (dCCRT) is the gold standard for the treatment of locally advanced esophageal squamous cell carcinoma (ESCC). However, the potential benefits of consolidation chemotherapy after dCCRT in patients with esophageal cancer remain debatable. Prospective randomized controlled trials comparing the outcomes of dCCRT with or without consolidation chemotherapy in patients with ESCC are lacking. In this study, we aim to generate evidence regarding consolidation chemotherapy efficacy in patients with locally advanced, inoperable ESCC. METHODS: This is a multicenter, prospective, open-label, phase-III randomized controlled trial comparing non-inferiority of dCCRT alone to consolidation chemotherapy following dCCRT. In total, 600 patients will be enrolled and randomly assigned in a 1:1 ratio to receive either consolidation chemotherapy after dCCRT (Arm A) or dCCRT alone (Arm B). Overall survival will be the primary endpoint, whereas progression-free survival, locoregional progression-free survival, distant metastasis-free survival, and treatment-related toxicity will be the secondary endpoints. DISCUSSION: This study aid in further understanding the effects of consolidation chemotherapy after dCCRT in patients with locally advanced, inoperable ESCC. TRIAL REGISTRATION: ChiCTR1800017646.
Subject(s)
Esophageal Neoplasms , Esophageal Squamous Cell Carcinoma , Humans , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Chemoradiotherapy , Consolidation Chemotherapy , Esophageal Neoplasms/drug therapy , Esophageal Neoplasms/radiotherapy , Esophageal Squamous Cell Carcinoma/therapy , Esophageal Squamous Cell Carcinoma/pathology , Prospective Studies , Randomized Controlled Trials as Topic , Multicenter Studies as Topic , Clinical Trials, Phase III as Topic , Equivalence Trials as TopicABSTRACT
Efficient control over several possible reaction pathways of free radicals is the chemical basis of their highly selective transformations. Among various competing reaction pathways, sulfonimidyl radicals generated from the electrolysis of 2-alkynylbenzenesulfonamides undergo cascade migratory or ortho-cyclization cyclization selectively. It is found that the incorporation of an extra 2-methyl substituent biases the selective migration of the acyl- over vinyl-linker of the key spirocyclic cation intermediate and thus serves as an enabling handle to achieve the synthetically interesting yet under-investigated cascade migratory cyclization of spirocyclic cations.
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An electrochemical intramolecular 5-exo-dig aza-cyclization of 2-alkynylbenzamides and subsequent nucleophilic fluorination have been developed to afford the highly selective synthesis of mono- and trifluorinated isoindolin-1-one derivatives. This work demonstrates the unique capability of synthetic electrochemistry in controlling reaction selectivity through the applied electrolytic parameters. In addition, the obtained monofluorinated 3-methyleneisoindolin-1-one (19) displays interesting photophysical properties that are not observed in its nonfluorinated analog.
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The study of molecular adsorption is crucial for understanding various chemical processes. Spectroscopy offers a convenient and non-invasive way of probing structures of adsorbed states and can be used for real-time observation of molecular binding profiles, including both structural and energetic information. However, deciphering atomic structures from spectral information using the first-principles approach is computationally expensive and time-consuming because of the sophistication of recording spectra, chemical structures, and their relationship. Here, we demonstrate the feasibility of a data-driven machine learning approach for predicting binding energy and structural information directly from vibrational spectra of the adsorbate by using CO adsorption on iron porphyrin as an example. Our trained machine learning model is not only interpretable but also readily transferred to similar metal-nitrogen-carbon systems with comparable accuracy. This work shows the potential of using structure-encoded spectroscopic descriptors in machine learning models for the study of adsorbed states of molecules on transition metal complexes.
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5-Hydroxymethfurural (5-HMF) is naturally found in a variety of foods and beverages and represents a main inhibitor in the lignocellulosic hydrolysates used for fermentation. This study investigated the impact of 5-HMF on the genomic stability and phenotypic plasticity of the yeast Saccharomyces cerevisiae. Using next-generation sequencing technology, we examined the genomic alterations of diploid S. cerevisiae isolates that were subcultured on a medium containing 1.2 g/L 5-HMF. We found that in 5-HMF-treated cells, the rates of chromosome aneuploidy, large deletions/duplications, and loss of heterozygosity were elevated compared with that in untreated cells. 5-HMF exposure had a mild impact on the rate of point mutations but altered the mutation spectrum. Contrary to what was observed in untreated cells, more monosomy than trisomy occurred in 5-HMF-treated cells. The aneuploidy mutant with monosomic chromosome IX was more resistant to 5-HMF than the diploid parent strain because of the enhanced activity of alcohol dehydrogenase. Finally, we found that overexpression of ADH6 and ZWF1 effectively stabilized the yeast genome under 5-HMF stress. Our findings not only elucidated the global effect of 5-HMF on the genomic integrity of yeast but also provided novel insights into how chromosomal instability drives the environmental adaptability of eukaryotic cells.IMPORTANCESingle-cell microorganisms are exposed to a range of stressors in both natural and industrial settings. This study investigated the effects of 5-hydroxymethfurural (5-HMF), a major inhibitor found in baked foods and lignocellulosic hydrolysates, on the chromosomal instability of yeast. We examined the mechanisms leading to the distinct patterns of 5-HMF-induced genomic alterations and discovered that chromosomal loss, typically viewed as detrimental to cell growth under most conditions, can contribute to yeast tolerance to 5-HMF. Our results increased the understanding of how specific stressors stimulate genomic plasticity and environmental adaptation in yeast.
Subject(s)
Genomic Instability , Saccharomyces cerevisiae , Humans , Saccharomyces cerevisiae/genetics , Adaptation, Physiological , Aneuploidy , Chromosomal InstabilityABSTRACT
Tumor cells can evade immune surveillance through overexpressing programmed cell death-ligand 1 (PD-L1) to interact with programmed cell death-1 (PD-1). Besides, tumor-intrinsic PD-L1 is involved in tumor progression without interaction with PD-1, which provides more challenges for the discovery of PD-L1 inhibitors. Herein, we report the discovery of novel PD-L1 inhibitors using the fragment coupling strategy. Among them, B9 was found to inhibit the PD-1/PD-L1 interaction with the best IC50 value of 1.8 ± 0.7 nM. Beyond the blockade of the PD-1/PD-L1 axis, B9 promotes the dimerization, internalization, and degradation of PD-L1. Furthermore, B9 displayed high in vivo antitumor efficacy in the CT26 mouse model and activated the immune microenvironment and induced PD-L1 degradation of PD-L1 in the tumor. These results show that B9 is a promising lead PD-L1 inhibitor through the blockade of PD-1/PD-L1 interaction and functional inhibition of the PD-L1 signal pathway.