Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 722
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nature ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898282

RESUMO

Graphene-based, high-quality, two-dimensional electronic systems have emerged as a highly tunable platform for studying superconductivity1-21. Specifically, superconductivity has been observed in both electron- and hole-doped twisted graphene moiré systems1-17, whereas in crystalline graphene systems, superconductivity has so far been observed only in hole-doped rhombohedral trilayer graphene (RTG)18 and hole-doped Bernal bilayer graphene (BBG)19-21. Recently, enhanced superconductivity has been demonstrated20,21 in BBG because of the proximity to a monolayer WSe2. Here we report the observation of superconductivity and a series of flavour-symmetry-breaking phases in electron- and hole-doped BBG/WSe2 devices by electrostatic doping. The strength of the observed superconductivity is tunable by applied vertical electric fields. The maximum Berezinskii-Kosterlitz-Thouless transition temperature for the electron- and hole-doped superconductivity is about 210 mK and 400 mK, respectively. Superconductivities emerge only when the applied electric fields drive the BBG electron or hole wavefunctions towards the WSe2 layer, underscoring the importance of the WSe2 layer in the observed superconductivity. The hole-doped superconductivity violates the Pauli paramagnetic limit, consistent with an Ising-like superconductor. By contrast, the electron-doped superconductivity obeys the Pauli limit, although the proximity-induced Ising spin-orbit coupling is also notable in the conduction band. Our findings highlight the rich physics associated with the conduction band in BBG, paving the way for further studies into the superconducting mechanisms of crystalline graphene and the development of superconductor devices based on BBG.

2.
EMBO J ; 41(6): e109102, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35146778

RESUMO

The microbiome plays an important role in shaping plant growth and immunity, but few plant genes and pathways impacting plant microbiome composition have been reported. In Arabidopsis thaliana, the phosphate starvation response (PSR) was recently found to modulate the root microbiome upon phosphate (Pi) starvation through the transcriptional regulator PHR1. Here, we report that A. thaliana PHR1 directly binds to the promoters of rapid alkalinization factor (RALF) genes, and activates their expression under phosphate-starvation conditions. RALFs in turn suppress complex formation of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) receptor through FERONIA, a previously-identified PTI modulator that increases resistance to certain detrimental microorganisms. Suppression of immunity via the PHR1-RALF-FERONIA axis allows colonization by specialized root microbiota that help to alleviate phosphate starvation by upregulating the expression of PSR genes. These findings provide a new paradigm for coordination of host-microbe homeostasis through modulating plant innate immunity after environmental perturbations.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Microbiota , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Fosfatos/metabolismo , Imunidade Vegetal/genética , Plantas/metabolismo , Fatores de Transcrição/metabolismo
3.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38340092

RESUMO

De novo peptide sequencing is a promising approach for novel peptide discovery, highlighting the performance improvements for the state-of-the-art models. The quality of mass spectra often varies due to unexpected missing of certain ions, presenting a significant challenge in de novo peptide sequencing. Here, we use a novel concept of complementary spectra to enhance ion information of the experimental spectrum and demonstrate it through conceptual and practical analyses. Afterward, we design suitable encoders to encode the experimental spectrum and the corresponding complementary spectrum and propose a de novo sequencing model $\pi$-HelixNovo based on the Transformer architecture. We first demonstrated that $\pi$-HelixNovo outperforms other state-of-the-art models using a series of comparative experiments. Then, we utilized $\pi$-HelixNovo to de novo gut metaproteome peptides for the first time. The results show $\pi$-HelixNovo increases the identification coverage and accuracy of gut metaproteome and enhances the taxonomic resolution of gut metaproteome. We finally trained a powerful $\pi$-HelixNovo utilizing a larger training dataset, and as expected, $\pi$-HelixNovo achieves unprecedented performance, even for peptide-spectrum matches with never-before-seen peptide sequences. We also use the powerful $\pi$-HelixNovo to identify antibody peptides and multi-enzyme cleavage peptides, and $\pi$-HelixNovo is highly robust in these applications. Our results demonstrate the effectivity of the complementary spectrum and take a significant step forward in de novo peptide sequencing.


Assuntos
Análise de Sequência de Proteína , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Análise de Sequência de Proteína/métodos , Peptídeos , Sequência de Aminoácidos , Anticorpos , Algoritmos
4.
Nucleic Acids Res ; 52(1): e3, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-37941140

RESUMO

Compared with proteins, DNA and RNA are more difficult languages to interpret because four-letter coded DNA/RNA sequences have less information content than 20-letter coded protein sequences. While BERT (Bidirectional Encoder Representations from Transformers)-like language models have been developed for RNA, they are ineffective at capturing the evolutionary information from homologous sequences because unlike proteins, RNA sequences are less conserved. Here, we have developed an unsupervised multiple sequence alignment-based RNA language model (RNA-MSM) by utilizing homologous sequences from an automatic pipeline, RNAcmap, as it can provide significantly more homologous sequences than manually annotated Rfam. We demonstrate that the resulting unsupervised, two-dimensional attention maps and one-dimensional embeddings from RNA-MSM contain structural information. In fact, they can be directly mapped with high accuracy to 2D base pairing probabilities and 1D solvent accessibilities, respectively. Further fine-tuning led to significantly improved performance on these two downstream tasks compared with existing state-of-the-art techniques including SPOT-RNA2 and RNAsnap2. By comparison, RNA-FM, a BERT-based RNA language model, performs worse than one-hot encoding with its embedding in base pair and solvent-accessible surface area prediction. We anticipate that the pre-trained RNA-MSM model can be fine-tuned on many other tasks related to RNA structure and function.


Assuntos
Aprendizado de Máquina , RNA , Alinhamento de Sequência , DNA/química , Proteínas , RNA/química , Solventes
5.
Brief Bioinform ; 24(1)2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36631407

RESUMO

Recently, peptide-based drugs have gained unprecedented interest in discovering and developing antifungal drugs due to their high efficacy, broad-spectrum activity, low toxicity and few side effects. However, it is time-consuming and expensive to identify antifungal peptides (AFPs) experimentally. Therefore, computational methods for accurately predicting AFPs are highly required. In this work, we develop AFP-MFL, a novel deep learning model that predicts AFPs only relying on peptide sequences without using any structural information. AFP-MFL first constructs comprehensive feature profiles of AFPs, including contextual semantic information derived from a pre-trained protein language model, evolutionary information, and physicochemical properties. Subsequently, the co-attention mechanism is utilized to integrate contextual semantic information with evolutionary information and physicochemical properties separately. Extensive experiments show that AFP-MFL outperforms state-of-the-art models on four independent test datasets. Furthermore, the SHAP method is employed to explore each feature contribution to the AFPs prediction. Finally, a user-friendly web server of the proposed AFP-MFL is developed and freely accessible at http://inner.wei-group.net/AFPMFL/, which can be considered as a powerful tool for the rapid screening and identification of novel AFPs.


Assuntos
Antifúngicos , alfa-Fetoproteínas , Antifúngicos/farmacologia , Algoritmos , Peptídeos/química , Biologia Computacional/métodos
6.
Chem Rev ; 123(12): 7953-8039, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37262362

RESUMO

Whole blood, as one of the most significant biological fluids, provides critical information for health management and disease monitoring. Over the past 10 years, advances in nanotechnology, microfluidics, and biomarker research have spurred the development of powerful miniaturized diagnostic systems for whole blood testing toward the goal of disease monitoring and treatment. Among the techniques employed for whole-blood diagnostics, electrochemical biosensors, as known to be rapid, sensitive, capable of miniaturization, reagentless and washing free, become a class of emerging technology to achieve the target detection specifically and directly in complex media, e.g., whole blood or even in the living body. Here we are aiming to provide a comprehensive review to summarize advances over the past decade in the development of electrochemical sensors for whole blood analysis. Further, we address the remaining challenges and opportunities to integrate electrochemical sensing platforms.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Nanotecnologia/métodos , Biomarcadores , Microfluídica
7.
J Am Chem Soc ; 146(23): 15843-15849, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38815616

RESUMO

Heptazine derivatives have attracted significant interest due to their small S1-T1 gap, which contributes to their unique electronic and optical properties. However, the nature of the lowest excited state remains ambiguous. In the present study, we characterize the lowest optical transition of heptazine by its magnetic transition dipole moment. To measure the magnetic transition dipole moment, the flat heptazine must be chiroptically active, which is difficult to achieve for single heptazine molecules. Therefore, we used supramolecular polymerization as an approach to make homochiral stacks of heptazine derivatives. Upon formation of the supramolecular polymers, the preferred helical stacking of heptazine introduces circular polarization of absorption and fluorescence. The magnetic transition dipole moments for the S1 ← S0 and S1 → S0 are determined to be 0.35 and 0.36 Bohr magneton, respectively. These high values of magnetic transition dipole moments support the intramolecular charge transfer nature of the lowest excited state from nitrogen to carbon in heptazine and further confirm the degeneracy of S1 and T1.

8.
Mol Cancer ; 23(1): 47, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459511

RESUMO

BACKGROUND: Cancer-associated fibroblasts (CAFs) orchestrate a supportive niche that fuels cancer metastatic development in non-small cell lung cancer (NSCLC). Due to the heterogeneity and plasticity of CAFs, manipulating the activated phenotype of fibroblasts is a promising strategy for cancer therapy. However, the underlying mechanisms of fibroblast activation and phenotype switching that drive metastasis remain elusive. METHODS: The clinical implications of fibroblast activation protein (FAP)-positive CAFs (FAP+CAFs) were evaluated based on tumor specimens from NSCLC patients and bioinformatic analysis of online databases. CAF-specific circular RNAs (circRNAs) were screened by circRNA microarrays of primary human CAFs and matched normal fibroblasts (NFs). Survival analyses were performed to assess the prognostic value of circNOX4 in NSCLC clinical samples. The biological effects of circNOX4 were investigated by gain- and loss-of-function experiments in vitro and in vivo. Fluorescence in situ hybridization, luciferase reporter assays, RNA immunoprecipitation, and miRNA rescue experiments were conducted to elucidate the underlying mechanisms of fibroblast activation. Cytokine antibody array, transwell coculture system, and enzyme-linked immunosorbent assay (ELISA) were performed to investigate the downstream effectors that promote cancer metastasis. RESULTS: FAP+CAFs were significantly enriched in metastatic cancer samples, and their higher abundance was correlated with the worse overall survival in NSCLC patients. A novel CAF-specific circRNA, circNOX4 (hsa_circ_0023988), evoked the phenotypic transition from NFs into CAFs and promoted the migration and invasion of NSCLC in vitro and in vivo. Clinically, circNOX4 correlated with the poor prognosis of advanced NSCLC patients. Mechanistically, circNOX4 upregulated FAP by sponging miR-329-5p, which led to fibroblast activation. Furthermore, the circNOX4/miR-329-5p/FAP axis activated an inflammatory fibroblast niche by preferentially inducing interleukin-6 (IL-6) and eventually promoting NSCLC progression. Disruption of the intercellular circNOX4/IL-6 axis significantly suppressed tumor growth and metastatic colonization in vivo. CONCLUSIONS: Our study reveals a role of the circRNA-induced fibroblast niche in tumor metastasis and highlights that targeting the circNOX4/FAP/IL-6 axis is a promising strategy for the intervention of NSCLC metastasis.


Assuntos
Fibroblastos Associados a Câncer , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Interleucina-6/genética , Interleucina-6/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/patologia , Fibroblastos , MicroRNAs/genética , MicroRNAs/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Linhagem Celular Tumoral , Proliferação de Células
9.
Anal Chem ; 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38946062

RESUMO

Single-molecule localization microscopy (SMLM) is a versatile tool for realizing nanoscale imaging with visible light and providing unprecedented opportunities to observe bioprocesses. The integration of machine learning with SMLM enhances data analysis by improving efficiency and accuracy. This tutorial aims to provide a comprehensive overview of the data analysis process and theoretical aspects of SMLM, while also highlighting the typical applications of machine learning in this field. By leveraging advanced analytical techniques, SMLM is becoming a powerful quantitative analysis tool for biological research.

10.
Planta ; 260(1): 25, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861219

RESUMO

MAIN CONCLUSION: In this review, we summarize how chlorophyll metabolism in angiosperm is affected by the environmental factors: light, temperature, metal ions, water, oxygen, and altitude. The significance of chlorophyll (Chl) in plant leaf morphogenesis and photosynthesis cannot be overstated. Over time, researchers have made significant advancements in comprehending the biosynthetic pathway of Chl in angiosperms, along with the pivotal enzymes and genes involved in this process, particularly those related to heme synthesis and light-responsive mechanisms. Various environmental factors influence the stability of Chl content in angiosperms by modulating Chl metabolic pathways. Understanding the interplay between plants Chl metabolism and environmental factors has been a prominent research topic. This review mainly focuses on angiosperms, provides an overview of the regulatory mechanisms governing Chl metabolism, and the impact of environmental factors such as light, temperature, metal ions (iron and magnesium), water, oxygen, and altitude on Chl metabolism. Understanding these effects is crucial for comprehending and preserving the homeostasis of Chl metabolism.


Assuntos
Clorofila , Luz , Magnoliopsida , Temperatura , Clorofila/metabolismo , Magnoliopsida/metabolismo , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/fisiologia , Magnoliopsida/genética , Água/metabolismo , Oxigênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Meio Ambiente , Altitude
11.
New Phytol ; 241(1): 430-443, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37920109

RESUMO

Metacaspases (MCs) are structural homologs of mammalian caspases found in plants, fungi, and protozoa. Type-I MCs carry an N-terminal prodomain, the function of which is unclear. Through genetic analysis of Arabidopsis mc2-1, a T-DNA insertion mutant of MC2, we demonstrated that the prodomain of metacaspase 2 (MC2) promotes immune signaling mediated by pattern-recognition receptors (PRRs). In mc2-1, immune responses are constitutively activated. The receptor-like kinases (RLKs) BAK1/BKK1 and SOBIR1 are required for the autoimmune phenotype of mc2-1, suggesting that immune signaling mediated by the receptor-like protein (RLP)-type PRRs is activated in mc2-1. A suppressor screen identified multiple mutations in the first exon of MC2, which suppress the autoimmunity in mc2-1. Further analysis revealed that the T-DNA insertion at the end of exon 1 of MC2 causes elevated expression of the MC2 prodomain, and overexpression of the MC2 prodomain in wild-type (WT) plants results in the activation of immune responses. The MC2 prodomain interacts with BIR1, which inhibits RLP-mediated immune signaling by interacting with BAK1, suggesting that the MC2 prodomain promotes plant defense responses by interfering with the function of BIR1. Our study uncovers an unexpected function of the prodomain of a MC in plant immunity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Imunidade Vegetal/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Transdução de Sinais
12.
Cancer Cell Int ; 24(1): 235, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970064

RESUMO

BACKGROUND: Colorectal cancer is among the most common malignant tumors affecting the gastrointestinal tract. Liver metastases, a complication present in approximately 50% of colorectal cancer patients, are a considerable concern. Recently, studies have revealed the crucial role of miR-455 in tumor pathogenesis. However, the effect of miR-455 on the progression of liver metastases in colorectal cancer remains controversial. As an antagonist of bone morphogenetic protein(BMP), Gremlin 1 (GREM1) may impact organogenesis, body patterning, and tissue differentiation. Nevertheless, the role of miR-455 in regulating GREM1 in colorectal cancer liver metastases and how miR-455/GREM1 axis influences tumour immune microenvironment is unclear. METHODS: Bioinformatics analysis shows that miR-455/GREM1 axis plays crucial role in liver metastasis of intestinal cancer and predicts its possible mechanism. To investigate the impact of miR-455/GREM1 axis on the proliferation, invasion, and migration of colorectal cancer cells, colony formation assay, wound healing and transwell assay were examined in vitro. The Dual-Luciferase reporter gene assay and RNA pull-down assay confirmed a possible regulatory effect between miR-455 and GREM1. In vivo, colorectal cancer liver metastasis(CRLM) model mice was established to inquiry the effect of miR-455/GREM1 axis on tumor growth and macrophage polarization. The marker of macrophage polarization was tested using immunofluorescence(IF) and quantitative real-time polymerase chain reaction(qRT-PCR). By enzyme-linked immunosorbent assay (ELISA), cytokines were detected in culture medium supernatants. RESULTS: We found that miR-455 and BMP6 expression was increased and GREM1 expression was decreased in liver metastase compared with primary tumor. miR-455/GREM1 axis promotes colorectal cancer cells proliferation, migration, invasion via affected PI3K/AKT pathway. Moreover, downregulating GREM1 augmented BMP6 expression in MC38 cell lines, inducing M2 polarization of macrophages, and promoting liver metastasis growth in CRLM model mice. CONCLUSION: These data suggest that miR-455/GREM1 axis promotes colorectal cancer progression and liver metastasis by affecting PI3K/AKT pathway and inducing M2 macrophage polarization. These results offer valuable insights and direction for future research and treatment of CRLM.

13.
Calcif Tissue Int ; 114(6): 614-624, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38714533

RESUMO

To construct a nomogram based on clinical factors and paraspinal muscle features to predict vertebral fractures occurring after acute osteoporotic vertebral compression fracture (OVCF). We retrospectively enrolled 307 patients with acute OVCF between January 2013 and August 2022, and performed magnetic resonance imaging of the L3/4 and L4/5 intervertebral discs (IVDs) to estimate the cross-sectional area (CSA) and degree of fatty infiltration (FI) of the paraspinal muscles. We also collected clinical and radiographic data. We used univariable and multivariable Cox proportional hazards models to identify factors that should be included in the predictive nomogram. Post-OVCF vertebral fracture occurred within 3, 12, and 24 months in 33, 69, and 98 out of the 307 patients (10.8%, 22.5%, and 31.9%, respectively). Multivariate analysis revealed that this event was associated with percutaneous vertebroplasty treatment, higher FI at the L3/4 IVD levels of the psoas muscle, and lower relative CSA of functional muscle at the L4/5 IVD levels of the multifidus muscle. Area under the curve values for subsequent vertebral fracture at 3, 12, and 24 months were 0.711, 0.724, and 0.737, respectively, indicating remarkable accuracy of the nomogram. We developed a model for predicting post-OVCF vertebral fracture from diagnostic information about prescribed treatment, FI at the L3/4 IVD levels of the psoas muscle, and relative CSA of functional muscle at the L4/5 IVD levels of the multifidus muscle. This model could facilitate personalized predictions and preventive strategies.


Assuntos
Fraturas por Osteoporose , Músculos Paraespinais , Fraturas da Coluna Vertebral , Humanos , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas por Osteoporose/epidemiologia , Músculos Paraespinais/patologia , Músculos Paraespinais/diagnóstico por imagem , Feminino , Masculino , Idoso , Estudos Retrospectivos , Idoso de 80 Anos ou mais , Fraturas por Compressão/diagnóstico por imagem , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Nomogramas
14.
J Magn Reson Imaging ; 59(5): 1787-1797, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37671487

RESUMO

BACKGROUND: A referenced MRI-based classification associated with focused ultrasound ablation surgery (FUAS) outcomes is lacking in adenomyosis. PURPOSE: To identify an MRI-based classification system for informing the FUAS outcomes. STUDY TYPE: Retrospective. POPULATION: Patients with FUAS for adenomyosis, were divided into a training set (N = 643; 355 with post-FUAS gonadotropin-releasing hormone/levonorgestrel, 288 without post-FUAS therapy) and an external validation set (N = 135; all without post-FUAS therapy). FIELD STRENGTH/SEQUENCE: 1.5 T, turbo spin-echo T2-weighted imaging and single-shot echo-planar diffusion-weighted imaging sequences. ASSESSMENT: Five MRI-based adenomyosis classifications: classification 1 (C1) (diffuse, focal, and mild), C2 (intrinsic, extrinsic, intramural, and indeterminate), C3 (internal, adenomyomas, and external), C4 (six subtypes on areas [internal or external] and volumes [<1/3 or ≥2/3]), and C5 (internal [asymmetric or symmetric], external, intramural, full thickness [asymmetric or symmetric]) for FUAS outcomes (symptom relief and recurrence). STATISTICAL TESTS: The optimal classification was significantly associated with the most subtypes of FUAS outcomes. Relating to the timing of recurrence was measured using Cox regression analysis and median recurrence time was estimated by a Kaplan-Meier curve. A P value <0.05 was considered statistically significant. RESULTS: Dysmenorrhea relief and recurrence were only associated with C2 in training patients undergoing FUAS alone. Compared with other subtypes, the extrinsic subtype of C2 was significantly associated with dysmenorrhea recurrence in the FUAS group. Besides, the median dysmenorrhea recurrence time of extrinsic subtype was significantly shorter than that of other subtypes (42.0 months vs. 50.3 months). In the validation cohort, C2 was confirmed as the optimal system and its extrinsic subtype was confirmed to have a significantly shorter dysmenorrhea recurrence time than other subtypes. DATA CONCLUSION: Classification 2 can inform dysmenorrhea relief and recurrence in patients with adenomyosis undergoing FAUS only. Itsextrinsic subtype was associated with an earlier onset of dysmenorrhea recurrence after treatment. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 5.


Assuntos
Adenomiose , Ablação por Ultrassom Focalizado de Alta Intensidade , Feminino , Humanos , Adenomiose/diagnóstico por imagem , Adenomiose/cirurgia , Dismenorreia/diagnóstico por imagem , Dismenorreia/complicações , Dismenorreia/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Imageamento por Ressonância Magnética/métodos , Ultrassonografia de Intervenção/métodos
15.
Lupus ; 33(4): 403-408, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38407846

RESUMO

OBJECTIVE: Interleukin-18 (IL-18) is a proinflammatory cytokine. This study aims to determine whether there is a causal relationship between circulating IL-18 concentrations and the risk of inflammatory and autoimmune diseases. METHODS: We collected significant single nucleotide polymorphisms (SNPs) associated with circulating IL-18 levels (p < 5 × 10-8) as instrumental variables (IVs) from a genome-wide association study (GWAS) involving 21,758 individuals of European descent. We mainly employed the inverse-variance weighed (IVW) method of two-sample Mendelian randomization (TSMR) analysis to estimate the causality of circulating IL-18 levels on inflammatory and autoimmune diseases. RESULTS: The IVW method results showed evidence of a causal relationship between IL-18 and the risk of systemic lupus erythematosus (SLE) (OR = 1.32; 95% CI 1.15, 1.50; p < .001) and type 1 diabetes (T1D) (OR = 1.22; 95% CI 1.06, 1.42; p = .007) in individuals of European ancestry. No significant heterogeneity or horizontal pleiotropy for SLE and T1D was detected. The sensitivity analysis, which involved removing confounding SNP, produced similar results for SLE and T1D. The results of sensitivity analysis using leave-one-out method indicated no single SNP significantly influenced the analysis results. However, we did not find any significant findings for multiple sclerosis, psoriasis, asthma, and osteoarthritis. CONCLUSIONS: Our analyses suggest that circulating IL-18 is significantly related to SLE and T1D and may serve as a potential target for the treatment of these diseases.


Assuntos
Doenças Autoimunes , Diabetes Mellitus Tipo 1 , Lúpus Eritematoso Sistêmico , Humanos , Diabetes Mellitus Tipo 1/genética , Estudo de Associação Genômica Ampla , Interleucina-18/genética , Lúpus Eritematoso Sistêmico/genética
16.
Pharmacol Res ; 199: 106990, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37984506

RESUMO

Resistance to temozolomide (TMZ), the frontline chemotherapeutic agent for glioblastoma (GBM), has emerged as a formidable obstacle, underscoring the imperative to identify alternative therapeutic strategies to improve patient outcomes. In this study, we comprehensively evaluated a novel agent, O6-methyl-2'-deoxyguanosine-5'-triphosphate (O6-methyl-dGTP) for its anti-GBM activity both in vitro and in vivo. Notably, O6-methyl-dGTP exhibited pronounced cytotoxicity against GBM cells, including those resistant to TMZ and overexpressing O6-methylguanine-DNA methyltransferase (MGMT). Mechanistic investigations revealed that O6-methyl-dGTP could be incorporated into genomic DNA, disrupting nucleotide pools balance, and inducing replication stress, resulting in S-phase arrest and DNA damage. The compound exerted its anti-tumor properties through the activation of AIF-mediated apoptosis and the parthanatos pathway. In vivo studies using U251 and Ln229 cell xenografts supported the robust tumor-inhibitory capacity of O6-methyl-dGTP. In an orthotopic transplantation model with U87MG cells, O6-methyl-dGTP showcased marginally superior tumor-suppressive activity compared to TMZ. In summary, our research, for the first time, underscores the potential of O6-methyl-dGTP as an effective candidate against GBM, laying a robust scientific groundwork for its potential clinical adoption in GBM treatment regimens.


Assuntos
Glioblastoma , Polifosfatos , Humanos , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Nucleosídeos/farmacologia , Nucleosídeos/uso terapêutico , Caspases , Linhagem Celular Tumoral , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Nucleotídeos , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , O(6)-Metilguanina-DNA Metiltransferase/farmacologia , O(6)-Metilguanina-DNA Metiltransferase/uso terapêutico , Desoxiguanosina/farmacologia , Desoxiguanosina/uso terapêutico , DNA , Resistencia a Medicamentos Antineoplásicos
17.
Microb Cell Fact ; 23(1): 159, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822377

RESUMO

BACKGROUND: Bacillus subtilis is widely used in industrial-scale riboflavin production. Previous studies have shown that targeted mutagenesis of the ribulose 5-phosphate 3-epimerase in B. subtilis can significantly enhance riboflavin production. This modification also leads to an increase in purine intermediate concentrations in the medium. Interestingly, B. subtilis exhibits remarkable efficiency in purine nucleoside synthesis, often exceeding riboflavin yields. These observations highlight the importance of the conversion steps from inosine-5'-monophosphate (IMP) to 2,5-diamino-6-ribosylamino-4(3 H)-pyrimidinone-5'-phosphate (DARPP) in riboflavin production by B. subtilis. However, research elucidating the specific impact of these reactions on riboflavin production remains limited. RESULT: We expressed the genes encoding enzymes involved in these reactions (guaB, guaA, gmk, ndk, ribA) using a synthetic operon. Introduction of the plasmid carrying this synthetic operon led to a 3.09-fold increase in riboflavin production compared to the control strain. Exclusion of gmk from the synthetic operon resulted in a 36% decrease in riboflavin production, which was further reduced when guaB and guaA were not co-expressed. By integrating the synthetic operon into the genome and employing additional engineering strategies, we achieved riboflavin production levels of 2702 mg/L. Medium optimization further increased production to 3477 mg/L, with a yield of 0.0869 g riboflavin per g of sucrose. CONCLUSION: The conversion steps from IMP to DARPP play a critical role in riboflavin production by B. subtilis. Our overexpression strategies have demonstrated their effectiveness in overcoming these limiting factors and enhancing riboflavin production.


Assuntos
Bacillus subtilis , Vias Biossintéticas , Engenharia Metabólica , Purinas , Riboflavina , Riboflavina/biossíntese , Riboflavina/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Purinas/biossíntese , Purinas/metabolismo , Engenharia Metabólica/métodos , Óperon , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
18.
J Pineal Res ; 76(1): e12916, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37786968

RESUMO

Normal tension glaucoma (NTG) is referred to as a progressive degenerative disorder of the retinal ganglion cells (RGCs), resulting in nonreversible visual defects, despite intraocular pressure levels within the statistically normal range. Current therapeutic strategies for NTG yield limited benefits. Excitatory amino acid carrier 1 (EAAC1) knockout (EAAC1-/- ) in mice has been shown to induce RGC degeneration without elevating intraocular pressure, mimicking pathological characteristics of NTG. In this study, we explored whether daily oral administration of melatonin could block RGCs loss and prevent retinal morphology and function defects associated with EAAC1 deletion. We also explored the molecular mechanisms underlying EAAC1 deletion-induced RGC degeneration and the neuroprotective effects of melatonin. Our RNA sequencing and in vivo data indicated EAAC1 deletion caused elevated oxidative stress, activation of apoptosis and cellular senescence pathways, and neuroinflammation in RGCs. However, melatonin administration efficiently prevented these detrimental effects. Furthermore, we investigated the potential role of apoptosis- and senescence-related redox-sensitive factors in EAAC1 deletion-induced RGCs degeneration and the neuroprotective effects of melatonin administration. We observed remarkable upregulation of p53, whereas NRF2 and Sirt1 expression were significantly decreased in EAAC1-/- mice, which were prevented by melatonin treatment, suggesting that melatonin exerted its neuroprotective effects possibly through modulating NRF2/p53/Sirt1 redox-sensitive signaling pathways. Overall, our study provided a solid foundation for the application of melatonin in the management of NTG.


Assuntos
Melatonina , Fármacos Neuroprotetores , Animais , Camundongos , Células Ganglionares da Retina/metabolismo , Melatonina/farmacologia , Melatonina/metabolismo , Sirtuína 1/metabolismo , Fármacos Neuroprotetores/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Apoptose , Modelos Animais de Doenças
19.
Cell Mol Life Sci ; 80(6): 156, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37208565

RESUMO

It has been reported that heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) is highly expressed in prostate cancer (PCa) and associated with poor prognosis of patients with PCa. Nevertheless, the specific mechanism underlying HNRNPA2B1 functions in PCa remains not clear. In our study, we proved that HNRNPA2B1 promoted the progression of PCa through in vitro and in vivo experiments. Further, we found that HNRNPA2B1 induced the maturation of miR-25-3p/miR-93-5p by recognizing primary miR-25/93 (pri-miR-25/93) through N6-methyladenosine (m6A)-dependent manner. In addition, both miR-93-5p and miR-25-3p were proven as tumor promoters in PCa. Interestingly, by mass spectrometry analysis and mechanical experiments, we found that casein kinase 1 delta (CSNK1D) could mediate the phosphorylation of HNRNPA2B1 to enhance its stability. Moreover, we further proved that miR-93-5p targeted BMP and activin membrane-bound inhibitor (BAMBI) mRNA to reduce its expression, thereby activating transforming growth factor ß (TGF-ß) pathway. At the same time, miR-25-3p targeted forkhead box O3 (FOXO3) to inactivate FOXO pathway. These results collectively indicated that CSNK1D stabilized HNRNPA2B1 facilitates the processing of miR-25-3p/miR-93-5p to regulate TGF-ß and FOXO pathways, resulting in PCa progression. Our findings supported that HNRNPA2B1 might be a promising target for PCa treatment.


Assuntos
Caseína Quinase Idelta , MicroRNAs , Neoplasias da Próstata , Masculino , Humanos , MicroRNAs/metabolismo , Caseína Quinase Idelta/metabolismo , Fosforilação , Linhagem Celular Tumoral , Neoplasias da Próstata/patologia , Fator de Crescimento Transformador beta/metabolismo , Proliferação de Células/genética
20.
BMC Med Imaging ; 24(1): 27, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273242

RESUMO

PURPOSE: To construct a gadoxetic acid-enhanced MRI (EOB-MRI) -based multivariable model to predict Ki-67 expression levels in hepatocellular carcinoma (HCC) using LI-RADS v2018 imaging features. METHODS: A total of 121 patients with HCC who underwent EOB-MRI were enrolled in this study. The patients were divided into three groups according to Ki-67 cut-offs: Ki-67 ≥ 20% (n = 86) vs. Ki-67 < 20% (n = 35); Ki-67 ≥ 30% (n = 73) vs. Ki-67 < 30% (n = 48); Ki-67 ≥ 50% (n = 45) vs. Ki-67 < 50% (n = 76). MRI features were analyzed to be associated with high Ki-67 expression using logistic regression to construct multivariable models. The performance characteristic of the models for the prediction of high Ki-67 expression was assessed using receiver operating characteristic curves. RESULTS: The presence of mosaic architecture (p = 0.045), the presence of infiltrative appearance (p = 0.039), and the absence of targetoid hepatobiliary phase (HBP, p = 0.035) were independent differential factors for the prediction of high Ki-67 status (≥ 50% vs. < 50%) in HCC patients, while no features could predict high Ki-67 status with thresholds of 20% (≥ 20% vs. < 20%) and 30% (≥ 30% vs. < 30%) (p > 0.05). Four models were constructed including model A (mosaic architecture and infiltrated appearance), model B (mosaic architecture and targetoid HBP), model C (infiltrated appearance and targetoid HBP), and model D (mosaic architecture, infiltrated appearance and targetoid HBP). The model D yielded better diagnostic performance than the model C (0.776 vs. 0.669, p = 0.002), but a comparable AUC than model A (0.776 vs. 0.781, p = 0.855) and model B (0.776 vs. 0.746, p = 0.076). CONCLUSIONS: Mosaic architecture, infiltrated appearance and targetoid HBP were sensitive imaging features for predicting Ki-67 index ≥ 50% and EOB-MRI model based on LI-RADS v2018 features may be an effective imaging approach for the risk stratification of patients with HCC before surgery.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Antígeno Ki-67 , Meios de Contraste , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA