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1.
Cell ; 186(9): 1912-1929.e18, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37044097

RESUMO

The spectrin-based membrane skeleton is a ubiquitous membrane-associated two-dimensional cytoskeleton underneath the lipid membrane of metazoan cells. Mutations of skeleton proteins impair the mechanical strength and functions of the membrane, leading to several different types of human diseases. Here, we report the cryo-EM structures of the native spectrin-actin junctional complex (from porcine erythrocytes), which is a specialized short F-actin acting as the central organizational unit of the membrane skeleton. While an α-/ß-adducin hetero-tetramer binds to the barbed end of F-actin as a flexible cap, tropomodulin and SH3BGRL2 together create an absolute cap at the pointed end. The junctional complex is strengthened by ring-like structures of dematin in the middle actin layers and by patterned periodic interactions with tropomyosin over its entire length. This work serves as a structural framework for understanding the assembly and dynamics of membrane skeleton and offers insights into mechanisms of various ubiquitous F-actin-binding factors in other F-actin systems.


Assuntos
Citoesqueleto , Eritrócitos , Animais , Humanos , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Citoesqueleto/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , Espectrina/análise , Espectrina/metabolismo , Suínos
2.
Mol Cell ; 83(16): 2959-2975.e7, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37595557

RESUMO

Various hormones, kinases, and stressors (fasting, heat shock) stimulate 26S proteasome activity. To understand how its capacity to degrade ubiquitylated proteins can increase, we studied mouse ZFAND5, which promotes protein degradation during muscle atrophy. Cryo-electron microscopy showed that ZFAND5 induces large conformational changes in the 19S regulatory particle. ZFAND5's AN1 Zn-finger domain interacts with the Rpt5 ATPase and its C terminus with Rpt1 ATPase and Rpn1, a ubiquitin-binding subunit. Upon proteasome binding, ZFAND5 widens the entrance of the substrate translocation channel, yet it associates only transiently with the proteasome. Dissociation of ZFAND5 then stimulates opening of the 20S proteasome gate. Using single-molecule microscopy, we showed that ZFAND5 binds ubiquitylated substrates, prolongs their association with proteasomes, and increases the likelihood that bound substrates undergo degradation, even though ZFAND5 dissociates before substrate deubiquitylation. These changes in proteasome conformation and reaction cycle can explain the accelerated degradation and suggest how other proteasome activators may stimulate proteolysis.


Assuntos
Complexo de Endopeptidases do Proteassoma , Animais , Camundongos , Adenosina Trifosfatases , Microscopia Crioeletrônica , Citoplasma
3.
Plant Cell ; 35(10): 3697-3711, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37378548

RESUMO

FLOWERING PROMOTING FACTOR1 (FPF1), a small protein without any known domains, promotes flowering in several plants; however, its functional mechanism remains unknown. Here, we characterized 2 FPF1-like proteins, FPL1 and FPL7, which, in contrast, function as flowering repressors in Brachypodium distachyon. FPL1 and FPL7 interact with the components of the florigen activation complex (FAC) and inhibit FAC activity to restrict expression of its critical target, VERNALIZATION1 (VRN1), in leaves, thereby preventing overaccumulation of FLOWERING LOCUS T1 (FT1) at the juvenile stage. Further, VRN1 can directly bind to the FPL1 promoter and repress FPL1 expression; hence, as VRN1 gradually accumulates during the late vegetative stage, FAC is released. This accurate feedback regulation of FPL1 by VRN1 allows proper FT1 expression in leaves and ensures sufficient FAC formation in shoot apical meristems to trigger timely flowering. Overall, we define a sophisticated modulatory loop for flowering initiation in a temperate grass, providing insights toward resolving the molecular basis underlying fine-tuning flowering time in plants.

4.
Plant J ; 118(6): 1955-1971, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38491864

RESUMO

Photoperiod employs complicated networks to regulate various developmental processes in plants, including flowering transition. However, the specific mechanisms by which photoperiod affects epigenetic modifications and gene expression variations in plants remain elusive. In this study, we conducted a comprehensive analysis of DNA methylation, small RNA (sRNA) accumulation, and gene expressions under different daylengths in facultative long-day (LD) grass Brachypodium distachyon and short-day (SD) grass rice. Our results showed that while overall DNA methylation levels were minimally affected by different photoperiods, CHH methylation levels were repressed under their favorable light conditions, particularly in rice. We identified numerous differentially methylated regions (DMRs) that were influenced by photoperiod in both plant species. Apart from differential sRNA clusters, we observed alterations in the expression of key components of the RNA-directed DNA methylation pathway, DNA methyltransferases, and demethylases, which may contribute to the identified photoperiod-influenced CHH DMRs. Furthermore, we identified many differentially expressed genes in response to different daylengths, some of which were associated with the DMRs. Notably, we discovered a photoperiod-responsive gene MYB11 in the transcriptome of B. distachyon, and further demonstrated its role as a flowering inhibitor by repressing FT1 transcription. Together, our comparative and functional analysis sheds light on the effects of daylength on DNA methylation, sRNA accumulation, and gene expression variations in LD and SD plants, thereby facilitating better designing breeding programs aimed at developing high-yield crops that can adapt to local growing seasons.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica de Plantas , Oryza , Fotoperíodo , RNA de Plantas , Oryza/genética , Oryza/metabolismo , Oryza/fisiologia , RNA de Plantas/genética , RNA de Plantas/metabolismo , Brachypodium/genética , Brachypodium/metabolismo , Brachypodium/fisiologia , Epigênese Genética , Flores/genética , Flores/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
Cereb Cortex ; 34(1)2024 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-38037371

RESUMO

Our perception and decision-making are susceptible to prior context. Such sequential dependence has been extensively studied in the visual domain, but less is known about its impact on time perception. Moreover, there are ongoing debates about whether these sequential biases occur at the perceptual stage or during subsequent post-perceptual processing. Using functional magnetic resonance imaging, we investigated neural mechanisms underlying temporal sequential dependence and the role of action in time judgments across trials. Participants performed a timing task where they had to remember the duration of green coherent motion and were cued to either actively reproduce its duration or simply view it passively. We found that sequential biases in time perception were only evident when the preceding task involved active duration reproduction. Merely encoding a prior duration without reproduction failed to induce such biases. Neurally, we observed activation in networks associated with timing, such as striato-thalamo-cortical circuits, and performance monitoring networks, particularly when a "Response" trial was anticipated. Importantly, the hippocampus showed sensitivity to these sequential biases, and its activation negatively correlated with the individual's sequential bias following active reproduction trials. These findings highlight the significant role of memory networks in shaping time-related sequential biases at the post-perceptual stages.


Assuntos
Percepção do Tempo , Humanos , Percepção do Tempo/fisiologia , Memória/fisiologia , Sinais (Psicologia) , Imageamento por Ressonância Magnética , Julgamento , Percepção Visual/fisiologia
6.
Nucleic Acids Res ; 51(D1): D39-D45, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36268869

RESUMO

Transcription factors (TFs) are proteins that interact with specific DNA sequences to regulate gene expression and play crucial roles in all kinds of biological processes. To keep up with new data and provide a more comprehensive resource for TF research, we updated the Animal Transcription Factor Database (AnimalTFDB) to version 4.0 (http://bioinfo.life.hust.edu.cn/AnimalTFDB4/) with up-to-date data and functions. We refined the TF family rules and prediction pipeline to predict TFs in genome-wide protein sequences from Ensembl. As a result, we predicted 274 633 TF genes and 150 726 transcription cofactor genes in AnimalTFDB 4.0 in 183 animal genomes, which are 86 more species than AnimalTFDB 3.0. Besides double data volume, we also added the following new annotations and functions to the database: (i) variations (including mutations) on TF genes in various human cancers and other diseases; (ii) predicted post-translational modification sites (including phosphorylation, acetylation, methylation and ubiquitination sites) on TFs in 8 species; (iii) TF regulation in autophagy; (iv) comprehensive TF expression annotation for 38 species; (v) exact and batch search functions allow users to search AnimalTFDB flexibly. AnimalTFDB 4.0 is a useful resource for studying TF and transcription regulation, which contains comprehensive annotation and classification of TFs and transcription cofactors.


Assuntos
Bases de Dados Genéticas , Regulação da Expressão Gênica , Fatores de Transcrição , Animais , Humanos , Bases de Dados de Proteínas , Anotação de Sequência Molecular , Fatores de Transcrição/metabolismo
7.
Genet Epidemiol ; 47(8): 585-599, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37573486

RESUMO

We propose structural equation models (SEMs) as a general framework to infer causal networks for metabolites and other complex traits. Traditionally SEMs are used only for individual-level data under the assumption that all instrumental variables (IVs) are valid. To overcome these limitations, we propose both one- and two-sample approaches for causal network inference based on SEMs that can: (1) perform causal analysis and discover causal relationships among multiple traits; (2) account for the possible presence of some invalid IVs; (3) allow for data analysis using only genome-wide association studies (GWAS) summary statistics when individual-level data are not available; (4) consider the possibility of bidirectional relationships between traits. Our method employs a simple stepwise selection to identify invalid IVs, thus avoiding false positives while possibly increasing true discoveries based on two-stage least squares (2SLS). We use both real GWAS data and simulated data to demonstrate the superior performance of our method over the standard 2SLS/SEMs. For real data analysis, our proposed approach is applied to a human blood metabolite GWAS summary data set to uncover putative causal relationships among the metabolites; we also identify some metabolites (putative) causal to Alzheimer's disease (AD), which, along with the inferred causal metabolite network, suggest some possible pathways of metabolites involved in AD.


Assuntos
Doença de Alzheimer , Estudo de Associação Genômica Ampla , Humanos , Estudo de Associação Genômica Ampla/métodos , Modelos Genéticos , Fenótipo , Doença de Alzheimer/genética
8.
Neuroimage ; 294: 120640, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38719154

RESUMO

Attentional control, guided by top-down processes, enables selective focus on pertinent information, while habituation, influenced by bottom-up factors and prior experiences, shapes cognitive responses by emphasizing stimulus relevance. These two fundamental processes collaborate to regulate cognitive behavior, with the prefrontal cortex and its subregions playing a pivotal role. Nevertheless, the intricate neural mechanisms underlying the interaction between attentional control and habituation are still a subject of ongoing exploration. To our knowledge, there is a dearth of comprehensive studies on the functional connectivity between subsystems within the prefrontal cortex during attentional control processes in both primates and humans. Utilizing stereo-electroencephalogram (SEEG) recordings during the Stroop task, we observed top-down dominance effects and corresponding connectivity patterns among the orbitofrontal cortex (OFC), the middle frontal gyrus (MFG), and the inferior frontal gyrus (IFG) during heightened attentional control. These findings highlighting the involvement of OFC in habituation through top-down attention. Our study unveils unique connectivity profiles, shedding light on the neural interplay between top-down and bottom-up attentional control processes, shaping goal-directed attention.


Assuntos
Atenção , Eletroencefalografia , Habituação Psicofisiológica , Córtex Pré-Frontal , Humanos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Atenção/fisiologia , Masculino , Feminino , Eletroencefalografia/métodos , Habituação Psicofisiológica/fisiologia , Adulto , Adulto Jovem , Teste de Stroop
9.
Eur Radiol ; 34(2): 899-913, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37597033

RESUMO

OBJECTIVE: This study aimed to establish a MRI-based deep learning radiomics (DLR) signature to predict the human epidermal growth factor receptor 2 (HER2)-low-positive status and further verified the difference in prognosis by the DLR model. METHODS: A total of 481 patients with breast cancer who underwent preoperative MRI were retrospectively recruited from two institutions. Traditional radiomics features and deep semantic segmentation feature-based radiomics (DSFR) features were extracted from segmented tumors to construct models separately. Then, the DLR model was constructed to assess the HER2 status by averaging the output probabilities of the two models. Finally, a Kaplan‒Meier survival analysis was conducted to explore the disease-free survival (DFS) in patients with HER2-low-positive status. The multivariate Cox proportional hazard model was constructed to further determine the factors associated with DFS. RESULTS: First, the DLR model distinguished between HER2-negative and HER2-overexpressing patients with AUCs of 0.868 and 0.763 in the training and validation cohorts, respectively. Furthermore, the DLR model distinguished between HER2-low-positive and HER2-zero patients with AUCs of 0.855 and 0.750, respectively. Cox regression analysis showed that the prediction score obtained using the DLR model (HR, 0.175; p = 0.024) and lesion size (HR, 1.043; p = 0.009) were significant, independent predictors of DFS. CONCLUSIONS: We successfully constructed a DLR model based on MRI to noninvasively evaluate the HER2 status and further revealed prospects for predicting the DFS of patients with HER2-low-positive status. CLINICAL RELEVANCE STATEMENT: The MRI-based DLR model could noninvasively identify HER2-low-positive status, which is considered a novel prognostic predictor and therapeutic target. KEY POINTS: • The DLR model effectively distinguished the HER2 status of breast cancer patients, especially the HER2-low-positive status. • The DLR model was better than the traditional radiomics model or DSFR model in distinguishing HER2 expression. • The prediction score obtained using the model and lesion size were significant independent predictors of DFS.


Assuntos
Neoplasias da Mama , Aprendizado Profundo , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Intervalo Livre de Doença , Estudos Retrospectivos , Radiômica , Imageamento por Ressonância Magnética
10.
Psychophysiology ; 61(7): e14557, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38459638

RESUMO

When memorizing an integrated object such as a Kanizsa figure, the completion of parts into a coherent whole is attained by grouping processes which render a whole-object representation in visual working memory (VWM). The present study measured event-related potentials (ERPs) and oscillatory amplitudes to track these processes of encoding and representing multiple features of an object in VWM. To this end, a change detection task was performed, which required observers to memorize both the orientations and colors of six "pacman" items while inducing configurations of the pacmen that systematically varied in terms of their grouping strength. The results revealed an effect of object configuration in VWM despite physically constant visual input: change detection for both orientation and color features was more accurate with increased grouping strength. At the electrophysiological level, the lateralized ERPs and alpha activity mirrored this behavioral pattern. Perception of the orientation features gave rise to the encoding of a grouped object as reflected by the amplitudes of the Ppc. The grouped object structure, in turn, modulated attention to both orientation and color features as indicated by the enhanced N1pc and N2pc. Finally, during item retention, the representation of individual objects and the concurrent allocation of attention to these memorized objects were modulated by grouping, as reflected by variations in the CDA amplitude and a concurrent lateralized alpha suppression, respectively. These results indicate that memorizing multiple features of grouped, to-be-integrated objects involves multiple, sequential stages of processing, providing support for a hierarchical model of object representations in VWM.


Assuntos
Ritmo alfa , Eletroencefalografia , Potenciais Evocados , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Masculino , Feminino , Adulto Jovem , Ritmo alfa/fisiologia , Potenciais Evocados/fisiologia , Adulto , Percepção Visual/fisiologia , Atenção/fisiologia , Estimulação Luminosa , Reconhecimento Visual de Modelos/fisiologia
11.
Org Biomol Chem ; 22(6): 1269-1278, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38258380

RESUMO

Biocatalytic oxidation is one of the most important and indispensable organic reactions for the development of green and sustainable biomanufacturing processes. NAD(P)+-dependent aldehyde dehydrogenase (ALDH) catalyzes the oxidation of aldehydes to carboxylic acids. Here, two ALDHs, SpALDH1 and SpALDH2, were identified from Sphingobium sp. SYK-6. They belong to different ALDH families and share only 32.30% amino acid identity. Interestingly, SpALDH1 and SpALDH2 exhibit significantly different enzymatic properties and substrate profiles. SpALDH2 has better thermostability than SpALDH1. SpALDH1 is a metalloenzyme and is activated by potassium ions, while SpALDH2 is not metallic-dependent. Compared with SpALDH1, SpALDH2 has a relatively broad substrate spectrum toward aromatic aldehydes. Based on homology modeling and molecular docking analysis, mechanisms underlying the substrate specificity of ALDHs were elucidated. For both ALDHs, hydrophobicity of substrate binding pockets is important for the catalytic properties, especially substrate specificity. Notably, optimization of the flexible loop 444-457 reforms a hydrogen bond between pyridine substrates and SpALDH1, contributing to the high catalytic activity. Finally, a coupling reaction catalyzed by ALDHs and NOX was constructed for efficient production of aromatic carboxylic acids.


Assuntos
Aldeído Desidrogenase , Aldeídos , Humanos , Simulação de Acoplamento Molecular , Aldeído Desidrogenase/química , Aldeído Desidrogenase/metabolismo , Aldeídos/química , Catálise , Ácidos Carboxílicos , Especificidade por Substrato
12.
Org Biomol Chem ; 22(11): 2197-2202, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38411569

RESUMO

Herein, an efficient, substrate-directed divergent [2 + 3]/[2 + 1] annulation of tetra-substituted oxa-dienes and allylic sulfur ylides has been successfully developed. Under precise annulation regulation, a series of functionalized bispirocyclopentane and bispirocyclopropane derivatives were synthesized in a highly stereoselective and economical manner (up to 95% yield, >20 : 1 dr or >20 : 1 E/Z). This protocol offers the advantages of mild conditions, high chemo-, regio- and diastereoselectivity and broad substrate compatibility. In addition, the synthetic practicality of this protocol was evaluated through a scale-up preparation and a series of three-component reactions utilizing in situ generated sulfur ylides.

13.
Acta Pharmacol Sin ; 45(1): 180-192, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37644132

RESUMO

Adhesion molecules play essential roles in the homeostatic regulation and malignant transformation of hematopoietic cells. The dysregulated expression of adhesion molecules in leukemic cells accelerates disease progression and the development of drug resistance. Thus, targeting adhesion molecules represents an attractive anti-leukemic therapeutic strategy. In this study, we investigated the prognostic role and functional significance of cytohesin-1 (CYTH1) in acute myeloid leukemia (AML). Analysis of AML patient data from the GEPIA and BloodSpot databases revealed that CYTH1 was significantly overexpressed in AML and independently correlated with prognosis. Functional assays using AML cell lines and an AML xenograft mouse model confirmed that CYTH1 depletion significantly inhibited the adhesion, migration, homing, and engraftment of leukemic cells, delaying disease progression and prolonging animal survival. The CYTH1 inhibitor SecinH3 exerted in vitro and in vivo anti-leukemic effects by disrupting leukemic adhesion and survival programs. In line with the CYTH1 knockdown results, targeting CYTH1 by SecinH3 suppressed integrin-associated adhesion signaling by reducing ITGB2 expression. SecinH3 treatment efficiently induced the apoptosis and inhibited the growth of a panel of AML cell lines (MOLM-13, MV4-11 and THP-1) with mixed-lineage leukemia gene rearrangement, partly by reducing the expression of the anti-apoptotic protein MCL1. Moreover, we showed that SecinH3 synergized with the BCL2-selective inhibitor ABT-199 (venetoclax) to inhibit the proliferation and promote the apoptosis of ABT-199-resistant leukemic cells. Taken together, our results not only shed light on the role of CYTH1 in cell-adhesion-mediated leukemogenesis but also propose a novel combination treatment strategy for AML.


Assuntos
Antineoplásicos , Leucemia Mieloide Aguda , Humanos , Camundongos , Animais , Leucemia Mieloide Aguda/tratamento farmacológico , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Moléculas de Adesão Celular , Progressão da Doença , Linhagem Celular Tumoral
14.
BMC Med Inform Decis Mak ; 24(1): 36, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317140

RESUMO

INTRODUCTION: Chronic kidney disease-mineral and bone disorder (CKD-MBD) is characterized by bone abnormalities, vascular calcification, and some other complications. Although there are diagnostic criteria for CKD-MBD, in situations when conducting target feature examining are unavailable, there is a need to investigate and discover alternative biochemical criteria that are easy to obtain. Moreover, studying the correlations between the newly discovered biomarkers and the existing ones may provide insights into the underlying molecular mechanisms of CKD-MBD. METHODS: We collected a cohort of 116 individuals, consisting of three subtypes of CKD-MBD: calcium abnormality, phosphorus abnormality, and PTH abnormality. To identify the best biomarker panel for discrimination, we conducted six machine learning prediction methods and employed a sequential forward feature selection approach for each subtype. Additionally, we collected a separate prospective cohort of 114 samples to validate the discriminative power of the trained prediction models. RESULTS: Using machine learning under cross validation setting, the feature selection method selected a concise biomarker panel for each CKD-MBD subtype as well as for the general one. Using the consensus of these features, best area under ROC curve reached up to 0.95 for the training dataset and 0.74 for the perspective dataset, respectively. DISCUSSION/CONCLUSION: For the first time, we utilized machine learning methods to analyze biochemical criteria associated with CKD-MBD. Our aim was to identify alternative biomarkers that could serve not only as early detection indicators for CKD-MBD, but also as potential candidates for studying the underlying molecular mechanisms of the condition.


Assuntos
Distúrbio Mineral e Ósseo na Doença Renal Crônica , Insuficiência Renal Crônica , Humanos , Distúrbio Mineral e Ósseo na Doença Renal Crônica/diagnóstico , Estudos Prospectivos , Biomarcadores , Cálcio , Insuficiência Renal Crônica/diagnóstico
15.
Environ Toxicol ; 39(2): 751-767, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37755325

RESUMO

An increasing number of studies have shown that oxidative stress plays an important role in the development and progression of cancer. Cervical cancer (CC) is a disease of unique complexity that tends to exhibit high heterogeneity in molecular phenotypes. We aim here to characterize molecular features of cervical cancer by developing a classification system based on oxidative stress-related gene expression profiles. In this study, we obtained gene expression profiling data for cervical cancer from the TCGA (The Cancer Genome Atlas) and GEO (Gene Expression Omnibus) (GSE44001) databases. Oxidative stress-related genes used for clustering were obtained from GeneCards. Patients with cervical cancer were divided into two subtypes (C1 and C2) by non-negative matrix factorization (NMF) classification. By performing Kaplan-Meier survival analysis, differential expression analysis, and gene set enrichment analysis (GSEA) between the two subtypes, we found that subtype C2 had a worse prognosis and was highly enriched for immune-related pathways as well as epithelial-mesenchymal transition (EMT) pathways. Subsequently, we performed metabolic pathway analysis, gene mutation landscape analysis, immune microenvironment analysis, immunotherapy response analysis, and drug sensitivity analysis of the two isoforms. The results showed that the isoforms were significantly different between metabolic pathway enrichment and the immune microenvironment, and the chromosomes of subtype C1 were more unstable. In addition, we found that subtype C2 tends to respond to treatment with anti-CTLA4 agents, a conclusion that coincides with high chromosomal variation in C1, as well as C2 enrichment of immune-related pathways. Then, we screened 10 agents that were significantly susceptible to C2 subtype. Finally, we constructed pathogenomics models based on pathological features and linked them to molecular subtypes. This study establishes a novel CC classification based on gene expression profiles of oxidative stress-related genes and elucidates differences between immune microenvironments between CC subtypes, contributing to subtype-specific immunotherapy and drug therapy.


Assuntos
Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/genética , Medicina de Precisão , Estresse Oxidativo/genética , Isoformas de Proteínas , Expressão Gênica , Microambiente Tumoral/genética
16.
Foodborne Pathog Dis ; 21(2): 119-126, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38010814

RESUMO

Desiccation stress could induce crossprotection and even affect virulence of Salmonella enterica. However, the influence of food matrices with low-water activity on desiccation adaptation of Salmonella still remains unclear. This study investigated the survival and adaptation of Salmonella Enteritidis in skim milk powder, ginger powder, and chocolate powder under desiccation storage conditions for a total of 12 weeks. High survival rates of Salmonella Enteritidis in all food matrices maintained over the long-term desiccation storage. Desiccation-adapted Salmonella Enteritidis enhanced heat resistance (p < 0.05) with the increase of storage time. Food composition plays an important role in the induction of crossresistance of desiccation-adapted Salmonella. After desiccation storage, Salmonella Enteritidis in ginger powder was most tolerant to heat treatment. Salmonella Enteritidis in skim milk powder was most resistant to the gastrointestinal simulation environment, and had strongest adhesion to Caco-2 cells. The effects of food composition on gene expression (rpoS, proV, otsA, otsB, grpE, dnaK, rpoH, and sigDE) in desiccation-adapted Salmonella Enteritidis were not significant (p > 0.05). At initial desiccation storage, osmotic protection-related genes (fadA, proV, otsA, and otsB), stress response regulator (rpoS), and heat-resistance-related genes (grpE, dnaK, and rpoH) were all significantly upregulated (p < 0.05). However, after 4-week storage, the expression level of desiccation-related genes, proV, otsA, otsB, grpE, dnaK, and rpoH, significantly decreased (p < 0.05). This study enables a better understanding of Salmonella's responses to long-term desiccation stress in different kinds of low-water activity foods.


Assuntos
Temperatura Alta , Salmonella enteritidis , Humanos , Salmonella enteritidis/genética , Virulência/genética , Água/farmacologia , Dessecação , Células CACO-2 , Pós , Expressão Gênica
17.
Foodborne Pathog Dis ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695190

RESUMO

Trans-cinnamaldehyde (TC), a typical plant-derived compound, has been widely used in the control of foodborne pathogen contamination. Nevertheless, the risk associated with the occurrence of viable but nonculturable (VBNC) bacteria induced by TC remains unclear. The results of this study showed that Salmonella Enteritidis (S. Enteritidis) entered the VBNC state after being induced by TC at a minimum inhibitory concentration of 312.5 µg/mL and survived for at least 22 days under TC treatment. Enhanced resistance was found against heat treatment (75°C, 30 s), antibiotics (i.e., ampicillin, ceftriaxone sodium, chloramphenicol), and hydrogen peroxide (3%) in VBNC S. Enteritidis. A synergistic effect against VBNC S. Enteritidis occurred when TC was combined with acid treatment, including lactic acid and acetic acid (pH = 3.5). VBNC and resuscitated S. Enteritidis by sodium pyruvate treatment (100 mM) were found to retain the infectious ability to Caco-2 cells. Relative expression levels of the stress-related genes relA, spoT, ppx, lon, katG, sodA, dnaK, and grpE were upregulated in VBNC S. Enteritidis. Accumulation of reactive oxygen species (ROS) and protein aggregates was observed in VBNC cells. Besides, the resuscitation of VBNC cells was accompanied with clearance of ROS and protein aggregates. In summary, this study presents a comprehensive characterization of stress tolerance and resuscitation of VBNC S. Enteritidis induced by cinnamaldehyde, and the results provide useful information for the development of effective control strategy against VBNC pathogenic bacteria in food production.

18.
Zhongguo Zhong Yao Za Zhi ; 49(1): 197-207, 2024 Jan.
Artigo em Zh | MEDLINE | ID: mdl-38403352

RESUMO

This study aims to reveal the mechanism of prenatal stress in affecting the testicular development of offspring rats and the intervention effects of Zuogui Pills via connexin 43(Cx43). Forty pregnant SD rats were randomized into a blank control group, a mo-del group, a high-dose(18.9 g·kg~(-1)) Zuogui Pills group, a low-dose(9.45 g·kg~(-1)) Zuogui Pills group, and a vitamin E(1.44 mg·kg~(-1)) group. The other groups except the blank control group was subjected to chronic unpredictable mild stress for the modeling of prenatal stress. The model was evaluated by sucrose preference test, open field test, and enzyme-linked immunosorbent assay(ELISA) of the glucocorticoid level. ELISA was employed to measure the thyroxine 4(T4), testosterone(T), and follicle-stimulating hormone(FSH) levels to assess kidney deficiency. Hematoxylin-eosin(HE) staining was employed to evaluate the status of testicular germ cells. An automatic sperm analyzer was used to measure the sperm quality. Immunofluorescence double staining was employed to detect the expression of Cx43 and follicle-stimulating hormone receptor(FSHR) in the testes of offspring rats. The mRNA and protein levels of Cx43, FSHR, phosphatidylinositol 3-kinase(PI3K), and protein kinase B(Akt) were determined by real-time fluorescence quantitative polymerase chain reaction and Western blot, respectively. Prenatal stress induced testicular development disorders in offspring rats. The HE staining results showed that on the day of birth, the model group had reduced seminiferous tubules in the testes, elevated FSH level in the serum, and lowered Cx43 level in the testicular tissue. Male offspring rats of 60 days old had reduced testicular spermatogenic function, decreased sperm quality, elevated FSH level and lowered T level in the serum, and down-regulated protein and mRNA levels of Cx43, FSHR, PI3K, and Akt in the testicular tissue. Zuogui Pills alleviated the abnormal development and dysfunction of testicles in the offspring rats caused by prenatal stress. In summary, Zuogui Pills may weaken the effects of prenatal stress on testicular development and spermatogenic function of offspring rats by activating the PI3K/Akt pathway to regulate Cx43 expression in the testicular tissue.


Assuntos
Conexina 43 , Medicamentos de Ervas Chinesas , Proteínas Proto-Oncogênicas c-akt , Ratos , Masculino , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Conexina 43/genética , Conexina 43/metabolismo , Conexina 43/farmacologia , Ratos Sprague-Dawley , Fosfatidilinositol 3-Quinases/metabolismo , Sêmen/metabolismo , Testículo , Hormônio Foliculoestimulante/metabolismo , Hormônio Foliculoestimulante/farmacologia , RNA Mensageiro/metabolismo
19.
Angew Chem Int Ed Engl ; : e202406043, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866704

RESUMO

Metal atom catalysts have been among the most important research objects due to their specific physical and chemical properties. However, precise control of the anchoring of metal atoms is still challenging to achieve. Cobalt and iridium atomic arrays formed sequentially ordered stable arrays in graphdiyne (GDY) triangular cavities depending on their intrinsic chemical properties and interactions. The success of this method was attributed to multifunctional integration of GDY, enabling selective growth from one to several atoms and various atomic densities. The bimetallic atom arrays show several advantages resulting from reducibility of acetylene bonds, space limiting effect, incomplete charge transfer between GDY and metal atoms, and sp-C hybridized triple bond skeleton. This well-designed system exhibits unprecedented oxygen evolution reaction (OER) performance with a mass activity of 2.6 A mgcat.-1 at a low overpotential of 300 mV, which is 216.6 times higher than the state-of-the-art IrO2 catalyst, and long-term stability.

20.
Biol Reprod ; 109(2): 172-183, 2023 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-37338142

RESUMO

Endometrial decidualization is critical to successful uterine receptivity and embryo implantation. Dysfunction of decidualization is associated with some pregnancy-related disorders, including miscarriage. Protein glycosylation is involved in many physiological and pathological processes. Protein O-fucosyltransferase 1 (poFUT1) is a key enzyme responsible for O-fucosylation biosynthesis on glycoproteins. Bone morphogenetic protein 1 (BMP1) is an essential glycoprotein in reproduction. However, the role and molecular mechanism of fucosylated BMP1 in endometrial stromal cell decidualization are still unknown. In the current study, we found that BMP1 contains a potential O-fucosylation site. Moreover, poFUT1 and BMP1 levels in the secretory phase are higher than those in the proliferative phase, and the highest level was observed in the human uterine tissues of early pregnancy, while a decrease of poFUT1 and BMP1 in the decidua was observed in miscarriage patients. Using human endometrial stromal cells (hESCs), we demonstrated that O-fucosylation of BMP1 was elevated after induced decidualization. Moreover, the increase of BMP1 O-fucosylation by poFUT1 promoted BMP1 secretion to the extracellular matrix, and more actively binds to CHRD. The binding of BMP1 and CHRD further released BMP4 originally bound to CHRD, and activated BMP/Smad signaling pathway, thereby accelerating the decidualization of human endometrial stromal cells. In summary, these results suggest that BMP1 O-fucosylation by poFUT1 could be a potential diagnostic and therapeutic target to predict miscarriage in early pregnancy examinations.


Assuntos
Aborto Espontâneo , Gravidez , Feminino , Humanos , Glicosilação , Proteína Morfogenética Óssea 1/metabolismo , Endométrio/metabolismo , Transdução de Sinais/fisiologia , Células Estromais/metabolismo , Decídua/metabolismo
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