RESUMO
Early onset familial Alzheimer's disease (FAD) with APP, PS1/2 (presenilins) mutation accounts for only a small portion of AD cases, and most are late-onset sporadic. However, majority of AD mouse models are developed to mimic the genetic cause of human AD by overexpressing mutated forms of human APP, PS1/2, and/or Tau protein, though there is no Tau mutation in AD, and no single mouse model recapitulates all aspects of AD pathology. Here, we report Thy1-ApoE4/C/EBPß double transgenic mouse model that demonstrates key AD pathologies in an age-dependent manner in absence of any human APP or PS1/2 mutation. Using the clinical diagnosis criteria, we show that this mouse model exhibits tempo-spatial features in AD patient brains, including progressive cognitive decline associated with brain atrophy, which is accompanied with extensive neuronal degeneration. Remarkably, the mice display gradual Aß aggregation and neurofibrillary tangles formation in the brain validated by Aß PET and Tau PET. Moreover, the mice reveal widespread neuroinflammation as shown in AD brains. Hence, Thy1-ApoE4/C/EBPß mouse model acts as a sporadic AD mouse model, reconstituting the major AD pathologies.
RESUMO
Elimination of autoreactive developing B cells is an important mechanism to prevent autoantibody production. However, how B cell receptor (BCR) signaling triggers apoptosis of immature B cells remains poorly understood. We show that BCR stimulation up-regulates the expression of the lysosomal-associated transmembrane protein 5 (LAPTM5), which in turn triggers apoptosis of immature B cells through two pathways. LAPTM5 causes BCR internalization, resulting in decreased phosphorylation of SYK and ERK. In addition, LAPTM5 targets the E3 ubiquitin ligase WWP2 for lysosomal degradation, resulting in the accumulation of its substrate PTEN. Elevated PTEN levels suppress AKT phosphorylation, leading to increased FOXO1 expression and up-regulation of the cell cycle inhibitor p27Kip1 and the proapoptotic molecule BIM. In vivo, LAPTM5 is involved in the elimination of autoreactive B cells and its deficiency exacerbates autoantibody production. Our results reveal a previously unidentified mechanism that contributes to immature B cell apoptosis and B cell tolerance.
Assuntos
Apoptose , Tolerância Imunológica , Proteínas de Membrana , Células Precursoras de Linfócitos B , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Proteína Forkhead Box O1/metabolismo , Humanos , Lisossomos/metabolismo , Proteínas de Membrana/genética , PTEN Fosfo-Hidrolase/metabolismo , Células Precursoras de Linfócitos B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Risk prediction and disease prevention are the innovative care challenges of the 21st century. Apart from freeing the individual from the pain of disease, it will lead to low medical costs for society. Until very recently, risk assessments have ushered in a new era with the emergence of omics technologies, including genomics, transcriptomics, epigenomics, proteomics, and so on, which potentially advance the ability of biomarkers to aid prediction models. While risk prediction has achieved great success, there are still some challenges and limitations. We reviewed the general process of omics-based disease risk model construction and the applications in four typical diseases. Meanwhile, we highlighted the problems in current studies and explored the potential opportunities and challenges for future clinical practice.
RESUMO
Genetically encoded voltage indicators, particularly those based on microbial rhodopsins, are gaining traction in neuroscience as fluorescent sensors for imaging voltage dynamics with high-spatiotemporal precision. Here we establish a novel genetically encoded voltage indicator candidate based on the recently discovered subfamily of the microbial rhodopsin clade, termed heliorhodopsins. We discovered that upon excitation at 530 to 560 nm, wildtype heliorhodopsin exhibits near-infrared fluorescence, which is sensitive to membrane voltage. We characterized the fluorescence brightness, photostability, voltage sensitivity, and kinetics of wildtype heliorhodopsin in HEK293T cells and further examined the impact of mutating key residues near the retinal chromophore. The S237A mutation significantly improved the fluorescence response of heliorhodopsin by 76% providing a highly promising starting point for further protein evolution.
Assuntos
Rodopsinas Microbianas , Humanos , Fluorescência , Células HEK293 , Rodopsinas Microbianas/químicaRESUMO
Ni-rich cathodes are some of the most promising candidates for advanced lithium-ion batteries, but their available capacities have been stagnant due to the intrinsic Li+ storage sites. Extending the voltage window down can induce the phase transition from O3 to 1T of LiNiO2-derived cathodes to accommodate excess Li+ and dramatically increase the capacity. By setting the discharge cutoff voltage of LiNi0.6Co0.2Mn0.2O2 to 1.4 V, we can reach an extremely high capacity of 393 mAh g-1 and an energy density of 1070 Wh kg-1 here. However, the phase transition causes fast capacity decay and related structural evolution is rarely understood, hindering the utilization of this feature. We find that the overlithiated phase transition is self-limiting, which will transform into solid-solution reaction with cycling and make the cathode degradation slow down. This is attributed to the migration of abundant transition metal ions into lithium layers induced by the overlithiation, allowing the intercalation of overstoichiometric Li+ into the crystal without the O3 framework change. Based on this, the wide-potential cycling stability is further improved via a facile charge-discharge protocol. This work provides deep insight into the overstoichiometric Li+ storage behaviors in conventional layered cathodes and opens a new avenue toward high-energy batteries.
RESUMO
Rapid construction of new fluorescence emitters is essential in advancing synthetic luminescent materials. This study illustrated a piperidine-promoted reaction of chiral dialdehyde with benzoylacetonitrile and malonitrile, leading to the formation of the 6/6/7 fused cyclic product in good yield. The proposed reaction mechanism involves a dual condensation/cyclization process, achieving the formation of up to six bonds for fused polycycles. The single crystal structure analysis revealed that the fused cyclic skeleton contains face-to-face naphthyl and cyanoalkenyl motifs, which act as the electronic donor and acceptor, respectively, potentially resulting in through-space charge transfer (TSCT) emission. While the TSCT emissions were weak in solution, a notable increase in luminescence intensity was observed upon aggregation, indicating bright fluorescent light. A series of theoretical analyses further supported the possibility of spatial electronic communication based on frontier molecular orbitals, the distance of charge transfer, and reduced density gradient analysis. This work not only provides guidance for the one-step synthesis of complex polycycles, but also offers valuable insights into the design of aggregation-enhanced TSCT emission materials.
RESUMO
The study on structure-property relationship has been a significant focus in the field of organic molecular luminescence. In the present work, three chiral binaphthyl-based triphenylethylene (HTPE) derivatives were prepared through condensation reactions. Despite their similar structures, these compounds exhibited distinct luminescent properties. Diphenylmethane-derived HTPE displayed dual-state emissions, characterized by dual-wavelength emissions which were insensitive to the polarity of solvents. The dual emissions in solution state could be attributed to the different locally excited (LE) excitons. However, upon aggregation, two stable conformers were generated, probably leading to different emission peaks. In contrast, dibenzocycloheptadiene-derived HTPE aggregates showed only a single emission peak. Surprisingly, fluorene-derived HTPE exhibited obvious luminescence in neither solution nor aggregate states due to inherent π-π interactions. These conclusions were substantiated by X-ray analysis, spectroscopic analysis, and theory calculations. Application studies demonstrated that fluorescence on/off switches could be achieved through exposure to acetone. More importantly, trace amounts of acetone could be detected using luminescent materials in both organic and aqueous phases with a detection limit of 0.08 %. Thus, this work not only presents a strategy for designing chiral triphenylethylene fluorophores but also provides valuable information for dual wavelength emissions resulting from two stable conformations.
RESUMO
Mutation of phenylalanine at position 508 in the cystic fibrosis transmembrane conductance regulator (F508del CFTR) yields a protein unstable at physiological temperatures that is rapidly degraded in the cell. This mutation is present in about 90% of cystic fibrosis patients, hence there is great interest in compounds reversing its instability. We have previously reported the expression of the mutated protein at low temperature and its purification in detergent. Here we describe the use of the protein to screen compounds present in a library of Federal Drug Administration (FDA) - approved drugs and also in a small natural product library. The kinetics of unfolding of F508del CFTR at 37 °C were probed by the increase in solvent-exposed cysteine residues accessible to a fluorescent reporter molecule. This occurred in a bi-exponential manner with a major (≈60%) component of half-life around 5 min and a minor component of around 60 min. The faster kinetics match those observed for loss of channel activity of F508del CFTR in cells at 37 °C. Most compounds tested had no effect on the fluorescence increase, but some were identified that significantly slowed the kinetics. The general properties of these compounds, and any likely mechanisms for inducing stability in purified CFTR are discussed. These experimental data may be useful for artificial intelligence - aided design of CFTR-specific drugs and in the identification of stabilizing additives for membrane proteins (in general).
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Bibliotecas de Moléculas Pequenas , Regulador de Condutância Transmembrana em Fibrose Cística/química , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Humanos , Cinética , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Desdobramento de Proteína , Estabilidade Proteica , Fibrose Cística/metabolismo , Fibrose Cística/genética , Fibrose Cística/tratamento farmacológico , MutaçãoRESUMO
Both epidemiological investigation and animal experiments demonstrated that pre-/postnatal exposure to perfluorooctane sulfonic acid (PFOS) could induce neurodevelopmental disorders. Previous studies showed that astrocyte was involved in PFOS-induced neurotoxicity, while little information is available. In the present study, the role of astrocyte-derived calmodulin-dependent protein kinase II (CaMKII)-phosphorylated discs large homolog 1 (DLG1) signaling in PFOS eliciting cytotoxicity in neuron was explored with primary cultured hippocampal astrocyte and neuron. The application of PFOS showed a decreased cell viability, synapse length and glutamate transporter 1 (GLT-1) expression, but an increased CaMKII, DLG1 and cyclic AMP response element binding protein (CREB) expression in primary cultured astrocyte. With 2-(2-hydroxyethylamino)-6-aminohexylcarbamic acid tert-butyl ester-9-isopropylpurine (CK59), the CaMKII inhibitor, the disturbed cell viability and molecules induced by PFOS could be alleviated (CREB expression was excluded) in astrocytes. The cytotoxic effect of neuron exposed to astrocyte conditional medium collected from PFOS (PFOS-ACM) pretreated with CK59 was also decreased. These results indicated that PFOS mediated GLT-1 expression through astrocyte-derived CaMKII-DLG signaling, which might be associated with injuries on neurons. The present study gave an insight in further exploration of mechanism in PFOS-induced neurotoxicity.
Assuntos
Ácidos Alcanossulfônicos , Astrócitos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Fluorocarbonos , Ratos , Animais , Astrócitos/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo , Células CultivadasRESUMO
The Ir-catalyzed asymmetric hydrogenation of ß-keto esters with Cinchona-alkaloid-derived NNP ligands has been developed. ß-Hydroxy esters of opposite configuration were afforded smoothly with 91.5-99.1 and 81.6-99.3% ee, respectively, using NNP L2 and L7 derived from quinidine and quinine separately even on the gram scale. The protocol for the preparation of ß-hydroxy esters of opposite configuration by the simple conversion of ligand configurations offered further opportunities for the synthesis of biologically active molecules and drugs.
RESUMO
Mature HIV-1 particles contain conical-shaped capsids that enclose the viral RNA genome and perform essential functions in the virus life cycle. Previous structural analysis of two- and three-dimensional arrays of the capsid protein (CA) hexamer revealed three interfaces. Here, we present a cryoEM study of a tubular assembly of CA and a high-resolution NMR structure of the CA C-terminal domain (CTD) dimer. In the solution dimer structure, the monomers exhibit different relative orientations compared to previous X-ray structures. The solution structure fits well into the EM density map, suggesting that the dimer interface is retained in the assembled CA. We also identified a CTD-CTD interface at the local three-fold axis in the cryoEM map and confirmed its functional importance by mutagenesis. In the tubular assembly, CA intermolecular interfaces vary slightly, accommodating the asymmetry present in tubes. This provides the necessary plasticity to allow for controlled virus capsid dis/assembly.
Assuntos
Proteínas do Capsídeo/química , HIV-1/química , Proteínas do Capsídeo/metabolismo , Microscopia Crioeletrônica , HIV-1/metabolismo , Ressonância Magnética Nuclear Biomolecular , RNA Viral/metabolismo , Montagem de VírusRESUMO
BACKGROUND: Endoscopic resection has been reported for vascular anomalies (VA) previously. However, there is no study comparing endoscopic resection surgery (ERS) with open resection surgery (ORS) in children. We aimed to compare clinical and cosmetic outcomes between two approaches in pediatric VA. METHODS: Between June 2018 and June 2023, 138 pediatric VA patients undergoing ERS or ORS were retrospectively reviewed. Propensity score matching (PSM) was performed to minimize selection bias. The Scar Cosmesis Assessment and Rating (SCAR) Scale and numerical rating scale (NRS) based on patient satisfaction were used for cosmetic assessment. RESULTS: After PSM for age, depth of lesion, size of lesion, and site of surgery, 72 patients (ERS = 24, ORS = 48) were analyzed. Patients undergoing ERS had longer operative time (164.25 ± 18.46 vs. 112.85 ± 14.26 min; P < 0.001), less estimated blood loss (5.42 ± 2.15 vs. 18.04 ± 1.62 ml; P < 0.001), and shorter median hospital stay (4.50 [3.00-5.00] vs. 6.00 [5.00-6.00] days; P < 0.001). The follow-up time was 8.04 ± 1.23 month for ERS group and 8.56 ± 1.57 month for ORS group. For aesthetic results, the median overall SCAR score in ERS was lower than that in ORS (2 [1-3] vs. 5 [4-5]; P < 0.001), and the subscales of "scar spread," "dyspigmentation," "track marks or suture marks," and "overall impression" were better. The median NRS score was higher (8 [7-8] vs. 6 [5-6]; P < 0.001) and length of scars was shorter (2.18 ± 0.30 vs. 8.75 ± 1.98 cm; P < 0.001) in ERS group than those in ORS group. The incidences of total complications and recurrence showed no significant difference between two groups. CONCLUSIONS: Endoscopic surgery can be a safe and effective option for pediatric VA in the limbs and trunk. It offers the advantages of improving aesthetic outcomes and reducing postoperative wound healing time.
RESUMO
Kinetic measurement plays a crucial role in understanding aptamer binding mechanisms and identifying appropriate aptamers for clinical and research applications. Current techniques, while well established, generally require large sample volumes, bulky and expensive instruments operated by trained personnel, and are hence not readily accessible to resource-limited research laboratories. This paper presents a fluorescence microscopy-based microfluidic assay for measuring aptamer-analyte binding kinetics in a simple and cost-effective manner. Kinetic measurements are achieved by monitoring time-course fluorescence of fluorescently labeled aptamers as they bind to the targets trapped in a microfluidic chip. Fluorescence measurements are performed on a standard fluorescence microscope and are accessible to laboratories with only modest resources. Moreover, microfluidic technology allows efficient and cost-effective immobilization of small amounts of target molecules or live cells as well as flow-based manipulation of aptamers for the measurements. Kinetic measurements of aptamer binding to immunoglobulin E protein and CCRF-CEM cells have yielded results consistent with those obtained from established methods, demonstrating the potential utility of our method for exploring aptamer-target interactions and identifying aptamers that best suit specific given biomedical applications.
RESUMO
With the development of autonomous driving, there has been considerable attention on 3D object detection using LiDAR. Pillar-based LiDAR point cloud detection algorithms are extensively employed in the industry due to their simple structure and high real-time performance. Nevertheless, the pillar-based detection network suffers from significant loss of 3D coordinate information during the feature degradation and extraction process. In the paper, we introduce a novel framework with high performance, termed EFNet. The EFNet uses the Enhancing Pillar Feature Module (EPFM) to provide more accurate representations of features from two directions: pillar internal space and pillar external space. Additionally, the Head Up Module (HUM) is utilized in the detection head to integrate multi-scale information and enhance the network's information perception ability. The EFNet achieves impressive results on the nuScenes datasets, namely, 53.3% NDS and 42.4% mAP. Compared to the baseline PointPillars, EFNet improves 8% NDS and 11.9% mAP. The results demonstrate that the proposed framework can effectively improve the network's accuracy while ensuring deployability.
RESUMO
The birefringence in a dual-hole microstructured optical fiber is numerically calculated and characterized with an optical frequency domain reflectometry (OFDR) method. Due to the asymmetric dual air holes in the cross-section, the polarized L P01x and L P01y modes propagate with different group velocities and time delays. Through a polarized coherent OFDR system in experiment, the Fresnel reflection peaks for each mode are separated in the frequency domain with their corresponding beat frequency. Thus, the group birefringence -9.68×10-4 is calculated with a beat frequency difference of 50.03 Hz between the L P01x and L P01y modes at a 6.2 m fiber end, which is in good agreement with that of -9.54×10-4 from the theoretical simulation. Our demonstration provides an accurate and flexible method for group birefringence characterization in microstructured optical fibers with complex cross-sectional structures.
RESUMO
Estrogens and estrogenic chemicals are endocrine-disrupting chemicals (EDCs). The potential toxicity of EDCs to humans and aquatic organisms has become increasingly concerning. However, at present, the potential toxic mechanisms of EDCs on neural and vascular development are still being fully investigated. During the study, we utilized zebrafish to assess the developmental neural and vascular toxicity of different estrogens. The results indicated that zebrafish treated with different estrogens, especially E2, exhibit developmental malformations, including increased mortality, decreased body length, decreased heart rate, aberrant swimming behavior, and increased developmental malformations, including spinal curvature (SC), yolk edema (YE) and pericaidial edema (PE), in a dose-dependent manner with 72â¯h-treated. Further morphological evaluation revealed that E2 exposure significantly induced motor neural abnormalities in zebrafish embryos. In addition, treated with these three estrogens also impaired the vascular development in the early stage of zebrafish embryos. Mechanistically, the identification of downstream factors revealed that several key neural and vascular development-related genes, including syn2a, gfap, gap43, shha, kdr, flt1 and flt4, were transcriptionally downregulated after estrogen exposure in zebrafish, suggesting that estrogen exposure might cause neural and vascular toxicity by interfering the mRNA levels of genes relevant to neural and vascular development.
RESUMO
The accumulation of the active pharmaceutical chemical in the environment usually results in environmental pollution to increase the risk to human health. Indomethacin is a non-steroidal anti-inflammatory drug that potentially causes systemic and developmental toxicity in various tissues. However, there have been few studies for its potential effects on cardiac development. In this study, we systematically determined the cardiotoxicity of acute indomethacin exposure in zebrafish at different concentrations with morphological, histological, and molecular levels. Specifically, the malformation and dysfunction of cardiac development, including pericardial oedema, abnormal heart rate, the larger distance between the venous sinus and bulbus arteriosus (SV-BA), enlargement of the pericardial area, and aberrant motor capability, were determined after indomethacin exposure. In addition, further investigation indicated that indomethacin exposure results in myocardial apoptosis in a dose-dependent manner in zebrafish at early developmental stage. Mechanistically, our results revealed that indomethacin exposure mainly regulates key cardiac development-related genes, especially genes related to the cardiac muscle contraction-related signaling pathway, in zebrafish embryos. Thus, our findings suggested that acute indomethacin exposure might cause cardiotoxicity by disturbing the cardiac muscle contraction-related signaling pathway and inducing myocardial apoptosis in zebrafish embryos.
RESUMO
The biogenic synthesis of silver nanoparticles (AgNPs) by microorganisms has been a subject of increasing attention. Despite extensive studies on this biosynthetic pathway, the mechanisms underlying the involvement of proteins and enzymes in AgNPs production have not been fully explored. Herein, we reported that Burkholderia contaminans ZCC was able to reduce Ag+ to AgNPs with a diameter of (10±5) nm inside the cell. Exposure of B. contaminans ZCC to Ag+ ions led to significant changes in the functional groups of cellular proteins, with approximately 5.72% of the (C-OH) bonds being converted to (C-C/C-H) (3.61%) and CO (2.11%) bonds, and 4.52% of the CO (carbonyl) bonds being converted to (C-OH) bonds. Furthermore, the presence of Ag+ and AgNPs induced the ability of extracellular electron transfer for ZCC cells via specific membrane proteins, but this did not occur in the absence of Ag+ ions. Proteomic analysis of the proteins and enzymes involved in heavy metal efflux systems, protein secretion system, oxidative phosphorylation, intracellular electron transfer chain, and glutathione metabolism suggests that glutathione S-transferase and ubiquinol-cytochrome c reductase iron-sulfur subunit play importance roles in the biosynthesis of AgNPs. These findings contribute to a deeper understanding of the functions exerted by glutathione S-transferase and ferredoxin-thioredoxin reductase iron-sulfur subunits in the biogenesis of AgNPs, thereby hold immense potential for optimizing biotechnological techniques aimed at enhancing the yield and purity of biosynthetic AgNPs.
Assuntos
Burkholderia , Nanopartículas Metálicas , Proteoma , Prata , Prata/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Proteoma/metabolismo , Burkholderia/metabolismo , Proteômica , Proteínas de Bactérias/metabolismoRESUMO
Two rare 5/5/5/6 four-ring system iridoids, allamancinsâ A and B (1 and 2) together with one known biogenetically related iridoid derivative, 3-O-methyallamancin (3) were isolated from the flowers of Plumeria alba L. The structures of these iridoid derivatives were determined by comprehensive spectroscopic analyses. The absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of compoundsâ 1-3 against nitric oxide (NO) production induced and three cancer cell lines were evaluated inâ vitro. Compoundsâ 1 and 3 showed inhibitory activities on NO production with IC50 values of 18.3±0.12 and 22.1±0.14â µM, respectively. Compoundsâ 1-3 showed moderate inhibitory activities against cancer cell lines of A549, Hela and MCF-7.
Assuntos
Apocynaceae , Iridoides , Humanos , Iridoides/farmacologia , Iridoides/química , Células HeLa , Apocynaceae/química , Óxido Nítrico/metabolismo , Cristalografia por Raios X , Estrutura MolecularRESUMO
Loop-closure detection plays a pivotal role in simultaneous localization and mapping (SLAM). It serves to minimize cumulative errors and ensure the overall consistency of the generated map. This paper introduces a multi-sensor fusion-based loop-closure detection scheme (TS-LCD) to address the challenges of low robustness and inaccurate loop-closure detection encountered in single-sensor systems under varying lighting conditions and structurally similar environments. Our method comprises two innovative components: a timestamp synchronization method based on data processing and interpolation, and a two-order loop-closure detection scheme based on the fusion validation of visual and laser loops. Experimental results on the publicly available KITTI dataset reveal that the proposed method outperforms baseline algorithms, achieving a significant average reduction of 2.76% in the trajectory error (TE) and a notable decrease of 1.381 m per 100 m in the relative error (RE). Furthermore, it boosts loop-closure detection efficiency by an average of 15.5%, thereby effectively enhancing the positioning accuracy of odometry.