Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 926
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 627(8003): 313-320, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38480964

RESUMO

Intrinsically stretchable electronics with skin-like mechanical properties have been identified as a promising platform for emerging applications ranging from continuous physiological monitoring to real-time analysis of health conditions, to closed-loop delivery of autonomous medical treatment1-7. However, current technologies could only reach electrical performance at amorphous-silicon level (that is, charge-carrier mobility of about 1 cm2 V-1 s-1), low integration scale (for example, 54 transistors per circuit) and limited functionalities8-11. Here we report high-density, intrinsically stretchable transistors and integrated circuits with high driving ability, high operation speed and large-scale integration. They were enabled by a combination of innovations in materials, fabrication process design, device engineering and circuit design. Our intrinsically stretchable transistors exhibit an average field-effect mobility of more than 20 cm2 V-1 s-1 under 100% strain, a device density of 100,000 transistors per cm2, including interconnects and a high drive current of around 2 µA µm-1 at a supply voltage of 5 V. Notably, these achieved parameters are on par with state-of-the-art flexible transistors based on metal-oxide, carbon nanotube and polycrystalline silicon materials on plastic substrates12-14. Furthermore, we realize a large-scale integrated circuit with more than 1,000 transistors and a stage-switching frequency greater than 1 MHz, for the first time, to our knowledge, in intrinsically stretchable electronics. Moreover, we demonstrate a high-throughput braille recognition system that surpasses human skin sensing ability, enabled by an active-matrix tactile sensor array with a record-high density of 2,500 units per cm2, and a light-emitting diode display with a high refreshing speed of 60 Hz and excellent mechanical robustness. The above advancements in device performance have substantially enhanced the abilities of skin-like electronics.


Assuntos
Desenho de Equipamento , Pele , Transistores Eletrônicos , Dispositivos Eletrônicos Vestíveis , Humanos , Silício , Nanotubos de Carbono , Tato
2.
Nature ; 603(7902): 624-630, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35322250

RESUMO

Next-generation light-emitting displays on skin should be soft, stretchable and bright1-7. Previously reported stretchable light-emitting devices were mostly based on inorganic nanomaterials, such as light-emitting capacitors, quantum dots or perovskites6-11. They either require high operating voltage or have limited stretchability and brightness, resolution or robustness under strain. On the other hand, intrinsically stretchable polymer materials hold the promise of good strain tolerance12,13. However, realizing high brightness remains a grand challenge for intrinsically stretchable light-emitting diodes. Here we report a material design strategy and fabrication processes to achieve stretchable all-polymer-based light-emitting diodes with high brightness (about 7,450 candela per square metre), current efficiency (about 5.3 candela per ampere) and stretchability (about 100 per cent strain). We fabricate stretchable all-polymer light-emitting diodes coloured red, green and blue, achieving both on-skin wireless powering and real-time displaying of pulse signals. This work signifies a considerable advancement towards high-performance stretchable displays.

3.
Proc Natl Acad Sci U S A ; 121(42): e2406936121, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39388269

RESUMO

Kirsten rat sarcoma virus (KRAS) mutation is associated with malignant tumor transformation and drug resistance. However, the development of clinically effective targeted therapies for KRAS-mutant cancer has proven to be a formidable challenge. Here, we report that tripartite motif-containing protein 21 (TRIM21) functions as a target of extracellular signal-regulated kinase 2 (ERK2) in KRAS-mutant colorectal cancer (CRC), contributing to regorafenib therapy resistance. Mechanistically, TRIM21 directly interacts with and ubiquitinates v-myc avian myelocytomatosis viral oncogene homolog (c-Myc) at lysine 148 (K148) via K63-linkage, enabling c-Myc to be targeted to the autophagy machinery for degradation, ultimately resulting in the downregulation of enolase 2 expression and inhibition of glycolysis. However, mutant KRAS (KRAS/MT)-driven mitogen-activated protein kinase (MAPK) signaling leads to the phosphorylation of TRIM21 (p-TRIM21) at Threonine 396 (T396) by ERK2, disrupting the interaction between TRIM21 and c-Myc and thereby preventing c-Myc from targeting autophagy for degradation. This enhances glycolysis and contributes to regorafenib resistance. Clinically, high p-TRIM21 (T396) is associated with an unfavorable prognosis. Targeting TRIM21 to disrupt KRAS/MT-driven phosphorylation using the antidepressant vilazodone shows potential for enhancing the efficacy of regorafenib in treating KRAS-mutant CRC in preclinical models. These findings are instrumental for KRAS-mutant CRC treatment aiming at activating TRIM21-mediated selective autophagic degradation of c-Myc.


Assuntos
Autofagia , Neoplasias Colorretais , Compostos de Fenilureia , Proteínas Proto-Oncogênicas c-myc , Proteínas Proto-Oncogênicas p21(ras) , Piridinas , Ribonucleoproteínas , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Humanos , Autofagia/efeitos dos fármacos , Compostos de Fenilureia/farmacologia , Animais , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Piridinas/farmacologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Camundongos , Ribonucleoproteínas/metabolismo , Ribonucleoproteínas/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteólise/efeitos dos fármacos , Mutação , Camundongos Nus
4.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38436563

RESUMO

The proliferation of single-cell RNA-seq data has greatly enhanced our ability to comprehend the intricate nature of diverse tissues. However, accurately annotating cell types in such data, especially when handling multiple reference datasets and identifying novel cell types, remains a significant challenge. To address these issues, we introduce Single Cell annotation based on Distance metric learning and Optimal Transport (scDOT), an innovative cell-type annotation method adept at integrating multiple reference datasets and uncovering previously unseen cell types. scDOT introduces two key innovations. First, by incorporating distance metric learning and optimal transport, it presents a novel optimization framework. This framework effectively learns the predictive power of each reference dataset for new query data and simultaneously establishes a probabilistic mapping between cells in the query data and reference-defined cell types. Secondly, scDOT develops an interpretable scoring system based on the acquired probabilistic mapping, enabling the precise identification of previously unseen cell types within the data. To rigorously assess scDOT's capabilities, we systematically evaluate its performance using two diverse collections of benchmark datasets encompassing various tissues, sequencing technologies and diverse cell types. Our experimental results consistently affirm the superior performance of scDOT in cell-type annotation and the identification of previously unseen cell types. These advancements provide researchers with a potent tool for precise cell-type annotation, ultimately enriching our understanding of complex biological tissues.


Assuntos
Curadoria de Dados , Análise da Expressão Gênica de Célula Única , Humanos , Benchmarking , Aprendizagem , Pesquisadores
5.
J Biol Chem ; 300(6): 107379, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38762184

RESUMO

Bacterial RecJ exhibits 5'→3' exonuclease activity that is specific to ssDNA; however, archaeal RecJs show 5' or 3' exonuclease activity. The hyperthermophilic archaea Methanocaldococcus jannaschii encodes the 5'-exonuclease MjRecJ1 and the 3'-exonuclease MjRecJ2. In addition to nuclease activity, archaeal RecJ interacts with GINS, a structural subcomplex of the replicative DNA helicase complex. However, MjRecJ1 and MjRecJ2 do not interact with MjGINS. Here, we report the structural basis for the inability of the MjRecJ2 homologous dimer to interact with MjGINS and its efficient 3' hydrolysis polarity for short dinucleotides. Based on the crystal structure of MjRecJ2, we propose that the interaction surface of the MjRecJ2 dimer overlaps the potential interaction surface for MjGINS and blocks the formation of the MjRecJ2-GINS complex. Exposing the interaction surface of the MjRecJ2 dimer restores its interaction with MjGINS. The cocrystal structures of MjRecJ2 with substrate dideoxynucleotides or product dCMP/CMP show that MjRecJ2 has a short substrate binding patch, which is perpendicular to the longer patch of bacterial RecJ. Our results provide new insights into the function and diversification of archaeal RecJ/Cdc45 proteins.


Assuntos
Proteínas Arqueais , Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Proteínas Arqueais/genética , Cristalografia por Raios X , Methanocaldococcus/enzimologia , Methanocaldococcus/metabolismo , Ligação Proteica , Multimerização Proteica , DNA Helicases/metabolismo , DNA Helicases/química , DNA Helicases/genética , Modelos Moleculares , Exodesoxirribonucleases/metabolismo , Exodesoxirribonucleases/química , Exodesoxirribonucleases/genética
6.
Plant J ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115017

RESUMO

Demographic history and mutational load are of paramount importance for the adaptation of the endangered species. However, the effects of population evolutionary history and genetic load on the adaptive potential in endangered conifers remain unclear. Here, using population transcriptome sequencing, whole chloroplast genomes and mitochondrial DNA markers, combined with niche analysis, we determined the demographic history and mutational load for three threatened whitebark pines having different endangered statuses, Pinus bungeana, P. gerardiana and P. squamata. Demographic inference indicated that severe bottlenecks occurred in all three pines at different times, coinciding with periods of major climate and geological changes; in contrast, while P. bungeana experienced a recent population expansion, P. gerardiana and P. squamata maintained small population sizes after bottlenecking. Abundant homozygous-derived variants accumulated in the three pines, particularly in P. squamata, while the species with most heterozygous variants was P. gerardiana. Abundant moderately and few highly deleterious variants accumulated in the pine species that have experienced the most severe demographic bottlenecks (P. gerardiana and P. squamata), most likely because of purging effects. Finally, niche modeling showed that the distribution of P. bungeana might experience a significant expansion in the future, and the species' identified genetic clusters are also supported by differences in the ecological niche. The integration of genomic, demographic and niche data has allowed us to prove that the three threatened pines have contrasting patterns of demographic history and mutational load, which may have important implications in their adaptive potential and thus are also key for informing conservation planning.

7.
Brief Bioinform ; 24(4)2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37232385

RESUMO

The volume of ribonucleic acid (RNA)-seq data has increased exponentially, providing numerous new insights into various biological processes. However, due to significant practical challenges, such as data heterogeneity, it is still difficult to ensure the quality of these data when integrated. Although some quality control methods have been developed, sample consistency is rarely considered and these methods are susceptible to artificial factors. Here, we developed MassiveQC, an unsupervised machine learning-based approach, to automatically download and filter large-scale high-throughput data. In addition to the read quality used in other tools, MassiveQC also uses the alignment and expression quality as model features. Meanwhile, it is user-friendly since the cutoff is generated from self-reporting and is applicable to multimodal data. To explore its value, we applied MassiveQC to Drosophila RNA-seq data and generated a comprehensive transcriptome atlas across 28 tissues from embryogenesis to adulthood. We systematically characterized fly gene expression dynamics and found that genes with high expression dynamics were likely to be evolutionarily young and expressed at late developmental stages, exhibiting high nonsynonymous substitution rates and low phenotypic severity, and they were involved in simple regulatory programs. We also discovered that human and Drosophila had strong positive correlations in gene expression in orthologous organs, revealing the great potential of the Drosophila system for studying human development and disease.


Assuntos
Drosophila melanogaster , Transcriptoma , Humanos , Animais , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Perfilação da Expressão Gênica/métodos , RNA/genética , RNA-Seq , Análise de Sequência de RNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Drosophila
8.
Syst Biol ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39283716

RESUMO

Despite significant advances in phylogenetics over the past decades, the deep relationships within Bivalvia (phylum Mollusca) remain inconclusive. Previous efforts based on morphology or several genes have failed to resolve many key nodes in the phylogeny of Bivalvia. Advances have been made recently using transcriptome data, but the phylogenetic relationships within Bivalvia historically lacked consensus, especially within Pteriomorphia and Imparidentia. Here, we inferred the relationships of key lineages within Bivalvia using matrices generated from specifically designed ultraconserved elements (UCEs) with 16 available genomic resources and 85 newly sequenced specimens from 55 families. Our new probes (Bivalve UCE 2k v.1) for target sequencing captured an average of 849 UCEs with 1085-bp in mean length from in vitro experiments. Our results introduced novel schemes from six major clades (Protobranchina, Pteriomorphia, Palaeoheterodonta, Archiheterodonta, Anomalodesmata and Imparidentia), though some inner nodes were poorly resolved, such as paraphyletic Heterodonta in some topologies potentially due to insufficient taxon sampling. The resolution increased when analyzing specific matrices for Pteriomorphia and Imparidentia. We recovered three Pteriomorphia topologies different from previously published trees, with the strongest support for ((Ostreida + (Arcida + Mytilida)) + (Pectinida + (Limida + Pectinida))). Limida were nested within Pectinida, warranting further studies. For Imparidentia, our results strongly supported the new hypothesis of (Galeommatida + (Adapedonta + Cardiida)), while the possible non-monophyly of Lucinida was inferred but poorly supported. Overall, our results provide important insights into the phylogeny of Bivalvia and show that target enrichment sequencing of UCEs can be broadly applied to study both deep and shallow phylogenetic relationships.

10.
Chem Soc Rev ; 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39254255

RESUMO

The rapid development of wearable and implantable electronics has enabled the real-time transmission of electrophysiological signals in situ, thus allowing the precise monitoring and regulation of biological functions. Devices based on organic materials tend to have low moduli and intrinsic stretchability, making them ideal choices for the construction of seamless bioelectronic interfaces. In this case, as an organic ionic-electronic conductor, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has low impedance to offer a high signal-to-noise ratio for monitoring bioelectrical signals, which has become one of the most promising conductive polymers. However, the initial conductivity and stretchability of pristine PEDOT:PSS are insufficient to meet the application requirements, and there is a trade-off between their improvement. In addition, PEDOT:PSS has poor stability in aqueous environments due to the hygroscopicity of the PSS chains, which severely limits its long-term applications in water-rich bioelectronic interfaces. Considering the growing demands of multi-function integration, the high-resolution fabrication of electronic devices is urgent. It is a great challenge to maintain both electrical and mechanical performance after miniaturization, particularly at feature sizes below 100 µm. In this review, we focus on the combined improvement in the conductivity and stretchability of PEDOT:PSS, as well as the corresponding mechanisms in detail. Also, we summarize the effective strategies to improve the stability of PEDOT:PSS in aqueous environments, which plays a vital role in long-term applications. Finally, we introduce the reliable micropatterning technologies and PEDOT:PSS-based stretchable optoelectronic devices applied at bio-interfaces.

11.
J Cell Mol Med ; 28(17): e70065, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39233332

RESUMO

Glioblastoma multiforme (GBM) is a malignant tumour with a poor prognosis. Therefore, potential treatment strategies and novel therapeutic targets have gained increased attention. Our data showed that the ethanol extract of Vanilla planifolia stem (VAS) significantly decreased the viability and the colony formation of GBM cells. Moreover, VAS induced the cleavage of MAP1LC3, a marker of autophagy. Further RNA-seq and bioinformatic analysis revealed 4248 differentially expressed genes (DEGs) between VAS-treated GBM cells and the control cells. Protein-protein interactions between DEGs with fold changes less than -3 and more than 5 were further analysed, and we found that 16 and 9 hub DEGs, respectively, were correlated with other DEGs. Further qPCR experiments confirmed that 14 hub DEGs was significantly downregulated and 9 hub DEGs was significantly upregulated. In addition, another significantly downregulated DEG, p21-activated kinase 6 (PAK6), was correlated with the overall survival of GBM patients. Further validation experiments confirmed that VAS significantly reduced the mRNA and protein expression of PAK6, which led to the abolition of cell viability and colony formation. These findings demonstrated that VAS reduced cell viability, suppressed colony formation and induced autophagy and revealed PAK6 and other DEGs as potential therapeutic targets for GBM treatment.


Assuntos
Autofagia , Regulação Neoplásica da Expressão Gênica , Glioblastoma , Extratos Vegetais , Quinases Ativadas por p21 , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Quinases Ativadas por p21/metabolismo , Quinases Ativadas por p21/genética , Extratos Vegetais/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Linhagem Celular Tumoral , Autofagia/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Caules de Planta/química , Etanol , Proliferação de Células/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Morte Celular/efeitos dos fármacos
12.
Anal Chem ; 96(16): 6476-6482, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38606798

RESUMO

Modulating mass transfer is crucial for optimizing the catalytic and separation performances of porous materials. Here, we systematically developed a series of continuously tunable MOFs (CTMOFs) that exhibit incessantly increased mass transfer. This was achieved through the strategic blending of ligands with different lengths and ratios in MOFs featuring the fcu topology. By employing a proportional mixture of two ligands in the synthesis of UiO-66, the micropores expanded, facilitating faster mass transfer. The mass transfer rate was evaluated by dye adsorption, dark-field microscopy, and gas chromatography (GC). The GC performance proved that both too-fast and too-slow mass transfer led to low separation performance. The optimized mass transfer in CTMOFs resulted in an exceptionally high separation resolution (5.96) in separating p-xylene and o-xylene. Moreover, this study represents the first successful use of MOFs for high-performance separation of propylene and propane by GC. This strategy provides new inspiration in regulating mass transfer in porous materials.

13.
Anal Chem ; 96(21): 8458-8466, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38710075

RESUMO

G-triplexes are G-rich oligonucleotides composed of three G-tracts and have absorbed much attention due to their potential biological functions and attractive performance in biosensing. Through the optimization of loop compositions, DNA lengths, and 5'-flanking bases of G-rich sequences, a new stable G-triplex sequence with 14 bases (G3-F15) was discovered to dramatically activate the fluorescence of Thioflavin T (ThT), a water-soluble fluorogenic dye. The fluorescence enhancement of ThT after binding with G3-F15 reached 3200 times, which was the strongest one by far among all of the G-rich sequences. The conformations of G3-F15 and G3-F15/ThT were studied by circular dichroism. The thermal stability measurements indicated that G3-F15 was a highly stable G-triplex structure. The conformations of G3-F15 and G3-F15/ThT in the presence of different metal cations were studied thoroughly by fluorescent spectroscopy, circular dichroism, and nuclear magnetic resonance. Furthermore, using the G3-F15/ThT complex as a fluorescent probe, a robust and simple turn-on fluorescent sensor for uracil-DNA glycosylase activity was developed. This study proposes a new systematic strategy to explore new functional G-rich sequences and their ligands, which will promote their applications in diagnosis, therapy, and biosensing.


Assuntos
Benzotiazóis , DNA , Fluorescência , Uracila-DNA Glicosidase , Humanos , Benzotiazóis/química , Benzotiazóis/metabolismo , Técnicas Biossensoriais/métodos , Dicroísmo Circular , DNA/química , DNA/metabolismo , Corantes Fluorescentes/química , Espectrometria de Fluorescência , Uracila-DNA Glicosidase/metabolismo , Uracila-DNA Glicosidase/química
14.
BMC Med ; 22(1): 454, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39394137

RESUMO

BACKGROUND: Adverse pregnancy outcomes have reached epidemic proportions in recent years with serious health ramifications, especially for diverse cancers risk. Therefore, we carried out an umbrella review to systematically evaluate the validity and strength of the data and the extent of potential biases of the established association between adverse pregnancy outcomes and cancers risk in both mother and offspring. METHODS: PubMed, Embase, and Web of Science databases were searched from inception until 18 January 2024. Meta-analyses of observational studies investigating the relationship between adverse pregnancy outcomes and multiple cancers risk in both mother and offspring were included. Evidence certainty was assessed using Grading of Recommendations, Assessment, Development, and Evaluation. The protocol for this umbrella review was prospectively registered in PROSPERO (CRD42023470544). RESULTS: The search identified 129 meta-analyses of observational studies and 42 types of cancer. Moderate certainty of evidence, exhibiting statistical significance, has been observed linking per kilogram increase in birth weight to a heightened risk of breast cancer (OR = 1.07, 95% CI = 1.02-1.12), prostate cancer (OR = 1.02, 95% CI = 1.00-1.05), leukemia (OR = 1.18, 95% CI = 1.13-1.23), and acute lymphoblastic leukemia in offspring (OR = 1.18, 95% CI = 1.12-1.23); rubella infection during pregnancy to an increased risk of leukemia in offspring (OR = 2.79, 95% CI = 1.16-6.71); and a linear dose-response association between an increase in the proportion of optimal birth weight and an elevated risk of acute lymphoblastic leukemia in offspring (OR = 1.16, 95% CI = 1.09-1.24), respectively. CONCLUSIONS: Although some adverse pregnancy outcomes have clinically promising associations with risk of several cancers in both mother and offspring, it is essential to conduct additional research to solidify the evidence, evaluate causality, and ascertain clinical utility.


Assuntos
Neoplasias , Estudos Observacionais como Assunto , Resultado da Gravidez , Revisões Sistemáticas como Assunto , Humanos , Gravidez , Feminino , Neoplasias/epidemiologia , Metanálise como Assunto , Complicações na Gravidez/epidemiologia , Fatores de Risco
15.
Small ; : e2404432, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38973075

RESUMO

Long-term epidermal recording of bioelectricity is of paramount importance for personal health monitoring. It requires stretchable and dry film electrodes that can be seamlessly integrated with skin. The simultaneous achievement of high conductivity and skin-like ductility of conducting materials is a prerequisite for reliable signal transduction at the dynamic interface, which is also the bottleneck of epidermal electrophysiology. Here, carbon nanotubes (CNTs) are introduced as "conjugation linkers" into a topologically plasticized conducting polymer (PEDOT:PSS). A thin-film electrode with high conductivity (≈3250 S cm-1) and high stretchability (crack-onset strain>100%) is obtained. In particular, the conjugation linker enables the high volumetric capacitance and the low film resistance, both of which synergically reduce the interfacial impedance. The capabilities of this electrode is further demonstrated in the precise recording of various electrophysiological signals.

16.
Small ; 20(24): e2307963, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38183362

RESUMO

pH-dependent peptide biomaterials hold tremendous potential for cell delivery and tissue engineering. However, identification of responsive self-assembling sequences with specified secondary structure remains a challenge. In this work, An experimental procedure based on the one-bead one-compound (OBOC) combinatorial library is developed to rapidly screen self-assembling ß-sheet peptides at neutral aqueous solution (pH 7.5) and disassemble at weak acidic condition (pH 6.5). Using the hydrophobic fluorescent molecule thioflavin T (ThT) as a probe, resin beads displaying self-assembling peptides show fluorescence under pH 7.5 due to the insertion of ThT into the hydrophobic domain, and are further cultured in pH 6.5 solution. The beads with extinguished fluorescence are selected. Three heptapeptides are identified that can self-assemble into nanofibers or nanoparticles at pH 7.5 and disassemble at pH 6.5. P1 (LVEFRHY) shows a rapid acid response and morphology transformation with pH modulation. Changes in the charges of histidine and hydrophobic phenyl motif of phenylalanine may play important roles in the formation of pH-responsive ß-sheet nanofiber. This high-throughput screening method provides an efficient way to identify pH-dependent ß-sheet self-assembling peptide and gain insights into structural design of such nanomaterials.


Assuntos
Peptídeos , Concentração de Íons de Hidrogênio , Peptídeos/química , Conformação Proteica em Folha beta , Ensaios de Triagem em Larga Escala/métodos , Nanofibras/química , Interações Hidrofóbicas e Hidrofílicas , Benzotiazóis/química
17.
Small ; : e2406870, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39390849

RESUMO

The development of tumors relies on lactate metabolic reprogramming to facilitate their unchecked growth and evade immune surveillance. This poses a significant challenge to the efficacy of antitumor immunity. To address this, a tumor-selective nano-dispatcher, PIMDQ/Syro-RNP, to enforce the immunotherapeutic effect through regulation of lactate metabolism and activation of toll-like receptors is developed. By using the tumor-targeting properties of c-RGD, the system can effectively deliver monocarboxylate transporters 4 (MCT4) inhibitor (Syro) to inhibit lactate efflux in tumor cells, leading to decreased lactate levels in the tumor microenvironment (TME) and increased accumulation within tumor cells. The reduction of lactate in TME will reduce the nutritional support for regulatory T cells (Tregs) and promote the effector function of T cells. The accumulation of lactate in tumor cells will lead to tumor death due to cellular acidosis. In addition, it will also reduce the uptake of glucose by tumor cells, reduce nutrient plunder, and further weaken the inhibition of T cell function. Furthermore, the pH-responsive release of Toll-like receptors (TLR) 7/8 agonist IMDQ within the TME activates dendritic cells (DCs) and promotes the infiltration of T cells. These findings offer a promising approach for enhancing tumor immune response through targeted metabolic interventions.

18.
Chembiochem ; : e202400596, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39215136

RESUMO

Nucleus is the central regulator of cells that controls cell proliferation, metabolism, and cell cycle, and is considered the most important organelle in cells. The precision medicine that can achieve nuclear targeting has achieved good therapeutic effects in anti-tumor therapy. However, the presence of biological barriers such as cell membranes and nuclear membranes in cells limit the delivery of therapeutic agents to the nucleus. Therefore, developing effective nuclear-targeting drug delivery strategies is particularly important. Nuclear-targeting peptides are a class of functional peptides that can penetrate cell membranes and target the nucleus. They mainly recognize and bind to the nuclear transport molecules (such as Importin-α/ß) and transport the therapeutic agents to the nucleus through nuclear pore complexes (NPC). This review summarizes the most recent developments of strategies for anti-tumor therapy utilizing nuclear-targeting peptides, which will ultimately contribute to the development of more effective nuclear-targeting strategies to achieve better anti-tumor outcomes.

19.
Planta ; 259(2): 45, 2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38281265

RESUMO

MAIN CONCLUSION: The divergence of subsect. Gerardianae was likely triggered by the uplift of the Qinghai-Tibetan Plateau and adjacent mountains. Pinus bungeana might have probably experienced expansion since Last Interglacial period. Historical geological and climatic oscillations have profoundly affected patterns of nucleotide variability, evolutionary history, and species divergence in numerous plants of the Northern Hemisphere. However, how long-lived conifers responded to geological and climatic fluctuations in East Asia remain poorly understood. Here, based on paternally inherited chloroplast genomes and maternally inherited mitochondrial DNA markers, we investigated the population demographic history and molecular evolution of subsect. Gerardianae (only including three species, Pinus bungeana, P. gerardiana, and P. squamata) of Pinus. A low level of nucleotide diversity was found in P. bungeana (π was 0.00016 in chloroplast DNA sequences, and 0.00304 in mitochondrial DNAs). The haplotype-based phylogenetic topology and unimodal distributions of demographic analysis suggested that P. bungeana probably originated in the southern Qinling Mountains and experienced rapid population expansion since Last Interglacial period. Phylogenetic analysis revealed that P. gerardiana and P. squamata had closer genetic relationship. The species divergence of subsect. Gerardianae occurred about 27.18 million years ago (Mya) during the middle to late Oligocene, which was significantly associated with the uplift of the Qinghai-Tibetan Plateau and adjacent mountains from the Eocene to the mid-Pliocene. The molecular evolutionary analysis showed that two chloroplast genes (psaI and ycf1) were under positive selection, the genetic lineages of P. bungeana exhibited higher transition and nonsynonymous mutations, which were involved with the strongly environmental adaptation. These findings shed light on the population evolutionary history of white pine species and provide striking insights for comprehension of their species divergence and molecular evolution.


Assuntos
Genoma de Cloroplastos , Pinus , Filogenia , Pinus/genética , Genoma de Cloroplastos/genética , Evolução Molecular , DNA de Cloroplastos/genética , DNA Mitocondrial/genética , Nucleotídeos , Demografia , Variação Genética
20.
J Antimicrob Chemother ; 79(8): 1951-1961, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38863365

RESUMO

OBJECTIVES: Pseudomonas aeruginosa and Acinetobacter baumannii are ranked as top-priority organisms by WHO. Antimicrobial peptides (AMPs) are promising antimicrobial agents that are highly effective against serious bacterial infections. METHODS: In our previous study, a series of α-helical AMPs were screened using a novel multiple-descriptor strategy. The current research suggested that S24 exhibited strong antimicrobial activity against major pathogenic bacteria, and displayed minimal haemolysis, good serum stability and maintained salt resistance. RESULTS: We found that S24 exerted an antimicrobial effect by destroying outer membrane permeability and producing a strong binding effect on bacterial genomic DNA that inhibits genomic DNA migration. Furthermore, S24 exerted a strong ability to promote healing in wound infected by P. aeruginosa, A. baumannii and mixed strains in a mouse model. CONCLUSIONS: Overall, S24 showed good stability under physiological conditions and excellent antimicrobial activity, suggesting it may be a potential candidate for the development of serious bacterial infection treatment.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas , Pseudomonas aeruginosa , Infecção dos Ferimentos , Acinetobacter baumannii/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Camundongos , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Antibacterianos/farmacologia , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Modelos Animais de Doenças , Permeabilidade da Membrana Celular/efeitos dos fármacos , Humanos , DNA Bacteriano/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA