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1.
Mol Cell ; 83(8): 1251-1263.e6, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-36996811

RESUMO

Nucleosomes drastically limit transcription factor (TF) occupancy, while pioneer transcription factors (PFs) somehow circumvent this nucleosome barrier. In this study, we compare nucleosome binding of two conserved S. cerevisiae basic helix-loop-helix (bHLH) TFs, Cbf1 and Pho4. A cryo-EM structure of Cbf1 in complex with the nucleosome reveals that the Cbf1 HLH region can electrostatically interact with exposed histone residues within a partially unwrapped nucleosome. Single-molecule fluorescence studies show that the Cbf1 HLH region facilitates efficient nucleosome invasion by slowing its dissociation rate relative to DNA through interactions with histones, whereas the Pho4 HLH region does not. In vivo studies show that this enhanced binding provided by the Cbf1 HLH region enables nucleosome invasion and ensuing repositioning. These structural, single-molecule, and in vivo studies reveal the mechanistic basis of dissociation rate compensation by PFs and how this translates to facilitating chromatin opening inside cells.


Assuntos
Nucleossomos , Proteínas de Saccharomyces cerevisiae , Nucleossomos/genética , Nucleossomos/metabolismo , Histonas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Cromatina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética
2.
Immunity ; 54(5): 931-946.e11, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33838102

RESUMO

Activation of the STAT5 transcription factor downstream of the Interleukin-2 receptor (IL-2R) induces expression of Foxp3, a critical step in the differentiation of regulatory T (Treg) cells. Due to the pleiotropic effects of IL-2R signaling, it is unclear how STAT5 acts directly on the Foxp3 locus to promote its expression. Here, we report that IL-2 - STAT5 signaling converged on an enhancer (CNS0) during Foxp3 induction. CNS0 facilitated the IL-2 dependent CD25+Foxp3- precursor to Treg cell transition in the thymus. Its deficiency resulted in impaired Treg cell generation in neonates, which was partially mitigated with age. While the thymic Treg cell paucity caused by CNS0 deficiency did not result in autoimmunity on its own, it exacerbated autoimmune manifestations caused by disruption of the Aire gene. Thus, CNS0 enhancer activity ensures robust Treg cell differentiation early in postnatal life and cooperatively with other tolerance mechanisms minimizes autoimmunity.


Assuntos
Linhagem da Célula/imunologia , Fatores de Transcrição Forkhead/imunologia , Tolerância Imunológica/imunologia , Interleucina-2/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoimunidade/imunologia , Diferenciação Celular/imunologia , Elementos Facilitadores Genéticos/imunologia , Feminino , Humanos , Subunidade alfa de Receptor de Interleucina-2/imunologia , Masculino , Camundongos , Receptores de Interleucina-2/imunologia , Fator de Transcrição STAT5/imunologia , Transdução de Sinais/imunologia
3.
Crit Rev Biochem Mol Biol ; : 1-15, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778580

RESUMO

Chromatin is densely packed with nucleosomes, which limits the accessibility of many chromatin-associated proteins. Pioneer factors (PFs) are usually viewed as a special group of sequence-specific transcription factors (TFs) that can recognize nucleosome-embedded motifs, invade compact chromatin, and generate open chromatin regions. Through this process, PFs initiate a cascade of events that play key roles in gene regulation and cell differentiation. A current debate in the field is if PFs belong to a unique subset of TFs with intrinsic "pioneering activity", or if all TFs have the potential to function as PFs within certain cellular contexts. There are also different views regarding the key feature(s) that define pioneering activity. In this review, we present evidence from the literature related to these alternative views and discuss how to potentially reconcile them. It is possible that both intrinsic properties, like tight nucleosome binding and structural compatibility, and cellular conditions, like concentration and co-factor availability, are important for PF function.

4.
Mol Cell ; 71(2): 294-305.e4, 2018 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-30017582

RESUMO

Nucleosomes present a barrier for the binding of most transcription factors (TFs). However, special TFs known as nucleosome-displacing factors (NDFs) can access embedded sites and cause the depletion of the local nucleosomes as well as repositioning of the neighboring nucleosomes. Here, we developed a novel high-throughput method in yeast to identify NDFs among 104 TFs and systematically characterized the impact of orientation, affinity, location, and copy number of their binding motifs on the nucleosome occupancy. Using this assay, we identified 29 NDF motifs and divided the nuclear TFs into three groups with strong, weak, and no nucleosome-displacing activities. Further studies revealed that tight DNA binding is the key property that underlies NDF activity, and the NDFs may partially rely on the DNA replication to compete with nucleosome. Overall, our study presents a framework to functionally characterize NDFs and elucidate the mechanism of nucleosome invasion.


Assuntos
Nucleossomos/metabolismo , Saccharomycetales/metabolismo , Cromatina/metabolismo , Replicação do DNA , DNA Fúngico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Histonas/metabolismo , Humanos , Modelos Moleculares , Nucleossomos/genética , Regiões Promotoras Genéticas , Ligação Proteica , Multimerização Proteica , Saccharomycetales/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
J Biol Chem ; 300(4): 106793, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38403250

RESUMO

RNA 5-methylcytosine (m5C) is an abundant chemical modification in mammalian RNAs and plays crucial roles in regulating vital physiological and pathological processes, especially in cancer. However, the dysregulation of m5C and its underlying mechanisms in non-small cell lung cancer (NSCLC) remain unclear. Here we identified that NSUN2, a key RNA m5C methyltransferase, is highly expressed in NSCLC tumor tissue. We found elevated NSUN2 expression levels strongly correlate with tumor grade and size, predicting poor outcomes for NSCLC patients. Furthermore, RNA-seq and subsequent confirmation studies revealed the antioxidant-promoting transcription factor NRF2 is a target of NSUN2, and depleting NSUN2 decreases the expression of NRF2 and increases the sensitivity of NSCLC cells to ferroptosis activators both in vitro and in vivo. Intriguingly, the methylated-RIP-qPCR assay results indicated that NRF2 mRNA has a higher m5C level when NSUN2 is overexpressed in NSCLC cells but shows no significant changes in the NSUN2 methyltransferase-deficient group. Mechanistically, we confirmed that NSUN2 upregulates the expression of NRF2 by enhancing the stability of NRF2 mRNA through the m5C modification within its 5'UTR region recognized by the specific m5C reader protein YBX1, rather than influencing its translation. In subsequent rescue experiments, we show knocking down NRF2 diminished the proliferation, migration, and ferroptosis tolerance mediated by NSUN2 overexpression. In conclusion, our study unveils a novel regulatory mechanism in which NSUN2 sustains NRF2 expression through an m5C-YBX1-axis, suggesting that targeting NSUN2 and its regulated ferroptosis pathway might offer promising therapeutic strategies for NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Ferroptose , Neoplasias Pulmonares , Fator 2 Relacionado a NF-E2 , Animais , Humanos , Camundongos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Camundongos Nus , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/genética , Masculino , Feminino , Pessoa de Meia-Idade
6.
Development ; 149(20)2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35815787

RESUMO

Embryogenesis is guided by a limited set of signaling pathways dynamically expressed in different places. How a context-dependent signaling response is generated has been a central question of developmental biology, which can now be addressed with in vitro models of human embryos that are derived from embryonic stem cells (hESCs). Our previous work demonstrated that during early stages of hESC differentiation, cells chronicle signaling hierarchy. Only cells that have been exposed (primed) by WNT signaling can respond to subsequent activin exposure and differentiate to mesendodermal (ME) fates. Here, we show that WNT priming does not alter SMAD2 binding nor its chromatin opening but, instead, acts by inducing the expression of the SMAD2 co-factor EOMES. Expression of EOMES is sufficient to replace WNT upstream of activin-mediated ME differentiation, thus unveiling the mechanistic basis for priming and cellular memory in early development.


Assuntos
Células-Tronco Embrionárias Humanas , Ativinas/metabolismo , Ativinas/farmacologia , Diferenciação Celular/fisiologia , Células-Tronco Embrionárias , Humanos , Via de Sinalização Wnt
7.
Hepatology ; 79(1): 61-78, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36683360

RESUMO

BACKGROUND AND AIMS: Deregulation of adenosine-to-inosine editing by adenosine deaminase acting on RNA 1 (ADAR1) leads to tumor-specific transcriptome diversity with prognostic values for HCC. However, ADAR1 editase-dependent mechanisms governing liver cancer stem cell (LCSC) generation and maintenance have remained elusive. APPROACH AND RESULTS: RNA-seq profiling identified ADAR1-responsive recoding editing events in HCC and showed editing frequency of GLI1 , rather than transcript abundance was clinically relevant. Functional differences in LCSC self-renewal and tumor aggressiveness between wild-type (GLI1 wt ) and edited GLI1 (GLI1 edit ) were elucidated. We showed that overediting of GLI1 induced an arginine-to-glycine (R701G) substitution, augmenting tumor-initiating potential and exhibiting a more aggressive phenotype. GLI1 R701G harbored weak affinity to SUFU, which in turn, promoted its cytoplasmic-to-nuclear translocation to support LCSC self-renewal by increased pluripotency gene expression. Moreover, editing predisposed to stabilize GLI1 by abrogating ß-TrCP-GLI1 interaction. Integrative analysis of single-cell transcriptome further revealed hyperactivated mitophagy in ADAR1-enriched LCSCs. GLI1 editing promoted a metabolic switch to oxidative phosphorylation to control stress and stem-like state through PINK1-Parkin-mediated mitophagy in HCC, thereby conferring exclusive metastatic and sorafenib-resistant capacities. CONCLUSIONS: Our findings demonstrate a novel role of ADAR1 as an active regulator for LCSCs properties through editing GLI1 in the highly heterogeneous HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/patologia , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteínas de Ligação a RNA/metabolismo , Mitofagia , Células-Tronco Neoplásicas/metabolismo
8.
Proc Natl Acad Sci U S A ; 119(42): e2211568119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215487

RESUMO

Eukaryotic DNA replication is initiated at multiple chromosomal sites known as origins of replication that are specifically recognized by the origin recognition complex (ORC) containing multiple ATPase sites. In budding yeast, ORC binds to specific DNA sequences known as autonomously replicating sequences (ARSs) that are mostly nucleosome depleted. However, nucleosomes may still inhibit the licensing of some origins by occluding ORC binding and subsequent MCM helicase loading. Using purified proteins and single-molecule visualization, we find here that the ORC can eject histones from a nucleosome in an ATP-dependent manner. The ORC selectively evicts H2A-H2B dimers but leaves the (H3-H4)2 tetramer on DNA. It also discriminates canonical H2A from the H2A.Z variant, evicting the former while retaining the latter. Finally, the bromo-adjacent homology (BAH) domain of the Orc1 subunit is essential for ORC-mediated histone eviction. These findings suggest that the ORC is a bona fide nucleosome remodeler that functions to create a local chromatin environment optimal for origin activity.


Assuntos
Nucleossomos , Complexo de Reconhecimento de Origem , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina , Cromatina , DNA/metabolismo , Replicação do DNA , Histonas/metabolismo , Nucleossomos/genética , Complexo de Reconhecimento de Origem/metabolismo , Origem de Replicação
9.
Chromosoma ; 132(3): 167-189, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37184694

RESUMO

Despite the recent explosion in genome-wide studies in chromatin and gene regulation, we are still far from extracting a set of genetic rules that can predict the function of the regulatory genome. One major reason for this deficiency is that gene regulation is a multi-layered process that involves an enormous variable space, which cannot be fully explored using native genomes. This problem can be partially solved by introducing synthetic DNA libraries into cells, a method that can test the regulatory roles of thousands to millions of sequences with limited variables. Here, we review recent applications of this method to study transcription factor (TF) binding, nucleosome positioning, and transcriptional activity. We discuss the design principles, experimental procedures, and major findings from these studies and compare the pros and cons of different approaches.


Assuntos
Cromatina , Regulação da Expressão Gênica , Cromatina/genética , Nucleossomos/genética , Biblioteca Gênica , Ligação Proteica
10.
Br J Haematol ; 204(2): 585-594, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37658699

RESUMO

Data from 200 children with high-risk acute myeloid leukaemia who underwent their first haploidentical haematopoietic stem cell transplantation (haplo-HSCT) between 2015 and 2021 at our institution were analysed. The 4-year overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse (CIR) were 71.9%, 62.3% and 32.4% respectively. The 100-day cumulative incidences of grade II-IV and III-IV acute graft-versus-host disease (aGVHD) were 41.1% and 9.5% respectively. The 4-year cumulative incidence of chronic GVHD (cGVHD) was 56.1%, and that of moderate-to-severe cGVHD was 27.3%. Minimal residual disease (MRD)-positive (MRD+) status pre-HSCT was significantly associated with lower survival and a higher risk of relapse. The 4-year OS, EFS and CIR differed significantly between patients with MRD+ pre-HSCT (n = 97; 63.4%, 51.4% and 41.0% respectively) and those with MRD-negative (MRD-) pre-HSCT (n = 103; 80.5%, 73.3% and 23.8% respectively). Multivariate analysis also revealed that acute megakaryoblastic leukaemia without Down syndrome (non-DS-AMKL) was associated with extremely poor outcomes (hazard ratios and 95% CIs for OS, EFS and CIR: 3.110 (1.430-6.763), 3.145 (1.628-6.074) and 3.250 (1.529-6.910) respectively; p-values were 0.004, 0.001 and 0.002 respectively). Thus, haplo-HSCT can be a therapy option for these patients, and MRD status pre-HSCT significantly affects the outcomes. As patients with non-DS-AMKL have extremely poor outcomes, even with haplo-HSCT, a combination of novel therapies is urgently needed.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia Megacarioblástica Aguda , Leucemia Mieloide Aguda , Criança , Humanos , Seguimentos , Recidiva Local de Neoplasia/etiologia , Leucemia Mieloide Aguda/terapia , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia Megacarioblástica Aguda/complicações , Recidiva , Estudos Retrospectivos
11.
BMC Plant Biol ; 24(1): 321, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38654179

RESUMO

BACKGROUND: pOsNAR2.1:OsNAR2.1 expression could significantly increase nitrogen uptake efficiency and grain yield of rice. RESULT: This study reported the effects of overexpression of OsNAR2.1 by OsNAR2.1 promoter on physiological and agronomic traits associated with drought tolerance. In comparison to the wild-type (WT), the pOsNAR2.1:OsNAR2.1 transgenic lines exhibited a significant improvement in survival rate when subjected to drought stress and then irrigation. Under limited water supply conditions, compared with WT, the photosynthesis and water use efficiency (WUE) of transgenic lines were increased by 39.2% and 28.8%, respectively. Finally, the transgenic lines had 25.5% and 66.4% higher grain yield than the WT under full watering and limited water supply conditions, respectively. Compared with the WT, the agronomic nitrogen use efficiency (NUE) of transgenic lines increased by 25.5% and 66.4% under full watering and limited water supply conditions, and the N recovery efficiency of transgenic lines increased by 29.3% and 50.2%, respectively. The interaction between OsNAR2.1 protein and OsPLDα1 protein was verified by yeast hybrids. After drought treatment, PLDα activity on the plasma membrane of the transgenic line increased 85.0% compared with WT. CONCLUSION: These results indicated that pOsNAR2.1:OsNAR2.1 expression could improve the drought resistance of rice by increasing nitrogen uptake and regulating the expression of OsPLDα1.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Oryza , Proteínas de Plantas , Regiões Promotoras Genéticas , Resistência à Seca , Nitrogênio/metabolismo , Oryza/genética , Oryza/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas
12.
Plant Cell Environ ; 47(8): 2954-2970, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38629794

RESUMO

Increasing the tolerance of crops to water deficit is crucial for the improvement of crop production in water-restricted regions. Here, a wheat peroxidase gene (TaPrx109-B1) belonging to the class III peroxidase gene family was identified and its function in water deficit tolerance was revealed. We demonstrated that overexpression of TaPrx109-B1 reduced leaf H2O2 level and stomatal density, increased leaf relative water content, water use efficiency, and tolerance to water deficit. The expression of TaEPF1 and TaEPF2, two key negative regulators of stomatal development, were significantly upregulated in TaPrx109-B1 overexpression lines. Furthermore, exogenous H2O2 downregulated the expression of TaEPF1 and TaEPF2 and increased stomatal density, while exogenous application of diphenyleneiodonium chloride, a potent NADPH oxidase inhibitor that repressed the synthesis of H2O2, upregulated the expression of TaEPF1 and TaEPF2, decreased stomatal density, and enhanced wheat tolerance to water deficit. These findings suggest that TaPrx109-B1 influences leaf stomatal density by modulation of H2O2 level and the expression of TaEPF1 and TaEPF2. The results of the field trial showed that overexpressing TaPrx109-B1 increased grain number per spike, which reduced the yield loss caused by water deficiency. Therefore, TaPrx109-B1 has great potential in breeding wheat varieties with improved water deficit tolerance.


Assuntos
Peróxido de Hidrogênio , Proteínas de Plantas , Estômatos de Plantas , Plantas Geneticamente Modificadas , Triticum , Triticum/genética , Triticum/fisiologia , Estômatos de Plantas/fisiologia , Estômatos de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Peróxido de Hidrogênio/metabolismo , Água/metabolismo , Regulação da Expressão Gênica de Plantas , Secas , Peroxidase/metabolismo , Peroxidase/genética , Folhas de Planta/fisiologia , Folhas de Planta/genética , Desidratação
13.
BMC Cancer ; 24(1): 520, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658865

RESUMO

Acute myeloid leukaemia (AML) is a fatal haematopoietic malignancy and is treated with the conventional combination of cytarabine (Ara-C) and daunorubicin (Dau). The survival rate of AML patients is lower due to the cardiotoxicity of daunorubicin. Clinically, homoharringtonine (HHT) plus Ara-C has been reported to be equally effective as Dau plus Ara-C in some types of AML patients with less toxic effects. We utilized the clinical use of homoharringtonine in combination with Ara-C to test its combination mechanism. We found that the insensitivity of AML cells to cytarabine-induced apoptosis is associated with increased Mcl-1 stability and p38 inactivation. HHT downregulates Mcl-1, phosphorylates H2AX and induces apoptosis by activating p38 MAPK. Inactivation of p38 through inhibitors and siRNA blocks apoptosis, H2AX phosphorylation and Mcl-1 reduction. HHT enhances Ara-C activation of the p38 MAPK signalling pathway, overcoming Ara-C tolerance to cell apoptosis by regulating the p38/H2AX/Mcl-1 axis. The optimal ratio of HHT to Ara-C for synergistic lethality in AML cells is 1:4 (M/M). HHT synergistically induces apoptosis in combination with Ara-C in vitro and prolongs the survival of xenografts. We provide a new mechanism for AML treatment by regulating the p38 MAPK/H2AX/Mcl-1 axis to improve cytarabine therapy.


Assuntos
Apoptose , Citarabina , Histonas , Mepesuccinato de Omacetaxina , Leucemia Mieloide Aguda , Proteína de Sequência 1 de Leucemia de Células Mieloides , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas Quinases p38 Ativadas por Mitógeno , Humanos , Mepesuccinato de Omacetaxina/farmacologia , Citarabina/farmacologia , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/genética , Apoptose/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Camundongos , Histonas/metabolismo , Linhagem Celular Tumoral , Sinergismo Farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fosforilação/efeitos dos fármacos , Feminino
14.
Mol Pharm ; 21(5): 2425-2434, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38554143

RESUMO

GRP78, a member of the HSP70 superfamily, is an endoplasmic reticulum chaperone protein overexpressed in various cancers, making it a promising target for cancer imaging and therapy. Positron emission tomography (PET) imaging offers unique advantages in real time, noninvasive tumor imaging, rendering it a suitable tool for targeting GRP78 in tumor imaging to guide targeted therapy. Several studies have reported successful tumor imaging using PET probes targeting GRP78. However, existing PET probes face challenges such as low tumor uptake, inadequate in vivo distribution, and high abdominal background signal. Therefore, this study introduces a novel peptide PET probe, [18F]AlF-NOTA-c-DVAP, for targeted tumor imaging of GRP78. [18F]AlF-NOTA-c-DVAP was radiolabeled with fluoride-18 using the aluminum-[18F]fluoride ([18F]AlF) method. The study assessed the partition coefficients, stability in vitro, and metabolic stability of [18F]AlF-NOTA-c-DVAP. Micro-PET imaging, pharmacokinetic analysis, and biodistribution studies were carried out in tumor-bearing mice to evaluate the probe's performance. Docking studies and pharmacokinetic analyses of [18F]AlF-NOTA-c-DVAP were also performed. Immunohistochemical and immunofluorescence analyses were conducted to confirm GRP78 expression in tumor tissues. The probe's binding affinity to GRP78 was analyzed by molecular docking simulation. [18F]AlF-NOTA-c-DVAP was radiolabeled in just 25 min with a high yield of 51 ± 16%, a radiochemical purity of 99%, and molar activity within the range of 20-50 GBq/µmol. [18F]AlF-NOTA-c-DVAP demonstrated high stability in vitro and in vivo, with a logD value of -3.41 ± 0.03. Dynamic PET imaging of [18F]AlF-NOTA-c-DVAP in tumors showed rapid uptake and sustained retention, with minimal background uptake. Biodistribution studies revealed rapid blood clearance and excretion through the kidneys following a single-compartment reversible metabolic model. In PET imaging, the T/M ratios for A549 tumors (high GRP78 expression), MDA-MB-231 tumors (medium expression), and HepG2 tumors (low expression) at 60 min postintravenous injection were 10.48 ± 1.39, 6.25 ± 0.47, and 3.15 ± 1.15% ID/g, respectively, indicating a positive correlation with GRP78 expression. This study demonstrates the feasibility of using [18F]AlF-NOTA-c-DVAP as a PET tracer for imaging GRP78 in tumors. The probe shows promising results in terms of stability, specificity, and tumor targeting. Further research may explore the clinical utility and potential therapeutic applications of this PET tracer for cancer diagnosis.


Assuntos
Chaperona BiP do Retículo Endoplasmático , Radioisótopos de Flúor , Proteínas de Choque Térmico , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Animais , Camundongos , Humanos , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos de Flúor/farmacocinética , Distribuição Tecidual , Proteínas de Choque Térmico/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/administração & dosagem , Linhagem Celular Tumoral , Camundongos Nus , Feminino , Camundongos Endogâmicos BALB C , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/farmacocinética , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacocinética
15.
Artigo em Inglês | MEDLINE | ID: mdl-38728210

RESUMO

Two rod-shaped, obligate anaerobic, Gram-stain-positive bacteria isolated from the pig faeces were designated YH-ols2216 and YH-ols2217T. Analysis of 16S rRNA gene sequences revealed that these isolates were most related to the members of the family Atopobiaceae, within the order Coriobacteriales, and Granulimonas faecalis KCTC 25474T with 92.0 and 92.5% similarities, respectively. The 16S rRNA gene sequence similarity within isolates was 99.9 %; and those between isolates YH-ols2216 and YH-ols2217T, and Atopobium minutum DSM 20586T, the type species of the type genus Atopobium within the family Atopobiaceae, were 88.5 and 88.7 %, respectively. Those between isolates and Coriobacterium glomerans PW2T, the type species of the type genus Coriobacterium within the family Coriobacteriaceae, were 88.7 and 89.1 %, respectively. The multi-locus sequence tree revealed that the isolates, alongside the genera Granulimonas and Leptogranulimonas, formed a distinct cluster between the families Atopobiaceae and Coriobacteriaceae. The average nucleotide identities and digital DNA-DNA hybridization values for the isolates and their most closely related strains ranged from 67.7 to 76.2 % and from 18.4 to 23.3 %, respectively. The main cellular fatty acids of the isolates were C18 : 0 DMA, C18 : 1 ω9c, C18 : 0 12OH, C18 : 0, and C16 : 0. The cell wall contained the peptidoglycan meso-diaminopimelic acid. Lactate was the main end-product of the isolates. The major polar lipids of isolate YH-ols2217T were aminophospholipid, aminolipids, and lipids. Menaquinones were not identified in the cells of the isolates. The DNA G+C contents of isolates YH-ols2216 and YH-ols2217T were 67.5 and 67.6 mol%, respectively. Considering these chemotaxonomic, phenotypic, and phylogenetic properties, Kribbibacteriaceae fam. nov. is proposed within the order Coriobacteriales. YH-ols2216 (=KCTC 25708=NBRC 116429) and YH-ols2217T (=KCTC 25709T=NBRC 116430T) represent a novel taxon within this new family and the name Kribbibacterium absianum gen. nov., sp. nov. is proposed. In addition, the genera Granulimonas and Leptogranulimonas are transferred to the family Kribbibacteriaceae fam. nov.


Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Fezes , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , Ácidos Graxos/análise , DNA Bacteriano/genética , Animais , Fezes/microbiologia , Suínos , Hibridização de Ácido Nucleico , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Peptidoglicano
16.
Artigo em Inglês | MEDLINE | ID: mdl-38415779

RESUMO

Two cocci-shaped, facultatively anaerobic, Gram-positive bacteria isolated from the faeces of a pig were designated as strains YH-aer221T and YH-aer222. Analysis of the 16S rRNA gene sequences revealed that the isolates were most closely related to Aerococcus suis JCM 18035T with 96.6 % similarity. The multi-locus sequence tree revealed that the isolates formed a sub-cluster adjacent to A. suis JCM 18035T. The average nucleotide identity values for the isolates and their most closely related strains were 71.8 and 71.7 %, respectively; and the digital DNA-DNA hybridization values for the isolates and their most closely related strains were 25.6 and 25.5 %, respectively. The main fatty acids were C18 : 1ω9c, C16 : 0 and C18 : 0. The cell wall contained the meso-diaminopimelic acid-based peptidoglycan. The two isolates shared the same metabolic pathways. Isolates YH-aer221T and YH-aer222 harboured the same CRISPR array with 33 and 46 spacers, respectively. Single-genome vs. metagenome analysis showed that the genomes of the isolates were not found in the available metagenome database. Given their chemotaxonomic, phenotypic and phylogenetic properties, YH-aer221T (= KCTC 25571T=JCM 35699T) and YH-aer222 (=KCTC 25573=JCM 35700) represent a novel taxon. The name Aerococcus kribbianus sp. nov. is proposed.


Assuntos
Aerococcus , Suínos , Animais , Anaerobiose , Composição de Bases , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Bactérias Anaeróbias , Fezes
17.
BMC Med Res Methodol ; 24(1): 105, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702624

RESUMO

BACKGROUND: Survival prediction using high-dimensional molecular data is a hot topic in the field of genomics and precision medicine, especially for cancer studies. Considering that carcinogenesis has a pathway-based pathogenesis, developing models using such group structures is a closer mimic of disease progression and prognosis. Many approaches can be used to integrate group information; however, most of them are single-model methods, which may account for unstable prediction. METHODS: We introduced a novel survival stacking method that modeled using group structure information to improve the robustness of cancer survival prediction in the context of high-dimensional omics data. With a super learner, survival stacking combines the prediction from multiple sub-models that are independently trained using the features in pre-grouped biological pathways. In addition to a non-negative linear combination of sub-models, we extended the super learner to non-negative Bayesian hierarchical generalized linear model and artificial neural network. We compared the proposed modeling strategy with the widely used survival penalized method Lasso Cox and several group penalized methods, e.g., group Lasso Cox, via simulation study and real-world data application. RESULTS: The proposed survival stacking method showed superior and robust performance in terms of discrimination compared with single-model methods in case of high-noise simulated data and real-world data. The non-negative Bayesian stacking method can identify important biological signal pathways and genes that are associated with the prognosis of cancer. CONCLUSIONS: This study proposed a novel survival stacking strategy incorporating biological group information into the cancer prognosis models. Additionally, this study extended the super learner to non-negative Bayesian model and ANN, enriching the combination of sub-models. The proposed Bayesian stacking strategy exhibited favorable properties in the prediction and interpretation of complex survival data, which may aid in discovering cancer targets.


Assuntos
Teorema de Bayes , Genômica , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/mortalidade , Genômica/métodos , Prognóstico , Algoritmos , Modelos de Riscos Proporcionais , Redes Neurais de Computação , Análise de Sobrevida , Biologia Computacional/métodos
18.
Analyst ; 149(13): 3625-3635, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38775334

RESUMO

Urine provides an ideal source for disease biomarker discovery. High-adhesion contaminants such as urobilin, which are difficult to remove from urine, can severely interfere with urinary proteomic analysis. Here, we aimed to establish a strategy based on single-pot, solid-phase-enhanced sample preparation (SP3) technology to prepare samples for urinary proteomics analysis that almost completely eliminates the impact of urobilin. A systematic evaluation of the effects of two urinary protein precipitation methods, two types of protein lysis buffers, and different ratios of magnetic digestion beads on the identification and quantification of the microscale urinary proteome was conducted. Our results indicate that methanol-chloroform precipitation, coupled with efficient lysis facilitated by urea, and subsequent enzymatic digestion using a mix of hydrophilic and hydrophobic magnetic beads offers the best performance. Further applying this strategy to the urine of patients with benign prostatic hyperplasia, prostate cancer and healthy individuals, combined with a narrow window of data-independent acquisition, FGFR4, MYLK, ORM2, GOLM1, SPP1, CD55, CSF1, DLD and TIMP3 were identified as potential biomarkers to discriminate benign prostatic hyperplasia and prostate cancer patients.


Assuntos
Neoplasias da Próstata , Proteômica , Humanos , Proteômica/métodos , Masculino , Neoplasias da Próstata/urina , Hiperplasia Prostática/urina , Proteoma/análise , Biomarcadores/urina , Microesferas , Pessoa de Meia-Idade
19.
Bioorg Chem ; 145: 107193, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442611

RESUMO

Immunotherapy has brought great benefits to cancer patients, but only some patients benefit from it. Noninvasive, real-time and dynamic monitoring of the effectiveness of immunotherapy through PET imaging may provide assistance for the treatment plan of immunotherapy. In this study, we designed and synthesized a new targeted PD-L1 peptide NOTA-PEG2-Asp2-PDL1P, which was labeled with nuclide 18F to obtain a new imaging agent [18F]AlF-NOTA-PEG2-Asp2-PDL1P. The total radiochemical yield of [18F]AlF-NOTA-PEG2-Asp2-PDL1P was 13.7 % (Uncorrected radiochemical yield, n > 5). [18F]AlF-NOTA-PEG2-Asp2-PDL1P achieved high radiochemical purity (>95 %) with a molar activity more than 51.2 GBq/µmol. [18F]AlF-NOTA-PEG2-Asp2-PDL1P exhibited good hydrophilicity and had good stability both in vivo and in vitro, it can specifically targets B16F10 tumor with PD-L1 expression, and had a relatively high retention in tumor, a relatively fast clearance in vivo and a higher tumor-to-non-target ratio, all of which could make [18F]AlF-NOTA-PEG2-Asp2-PDL1P a potential tracer for PD-L1 prediction before clinical immunotherapy.


Assuntos
Compostos Heterocíclicos com 1 Anel , Compostos Heterocíclicos , Neoplasias , Humanos , Compostos Heterocíclicos/química , Sondas Moleculares , Antígeno B7-H1/metabolismo , Radioisótopos de Flúor/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Linhagem Celular Tumoral
20.
BMC Psychiatry ; 24(1): 283, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627661

RESUMO

BACKGROUND: Depressive episodes in adolescents are often accompanied by various physical symptoms, but few studies have explored the association between depression and fever, This case study is the first to report the relationship between unexplained recurrent high fever and depression. CASE PRESENTATION: H is a 15 year old adolescent female currently in junior year. 2 + months ago, H gradually felt depressed after a class change. Around the time, the patient suddenly developed chills with no obvious trigger and fever. H was treated with anti-infective and anti-viral treatments all of which did not show significant improvement. No significant abnormality was seen in any of the related examinations. Considering that the patient's anxiety, depression and somatic symptoms were obvious during the course of the disease, she was given venlafaxine hydrochloride extended-release capsule 75 mg/d; tandospirone citrate capsule 10 mg Bid; alprazolam tablets 0.4 mg qn to improve mood and sleep; supplemented with transcranial repetitive magnetic stimulation therapy 2 times/d; visible light therapy 1 time/d and psychological counseling once. Over the 6 days of treatment, the patient's body temperature gradually returned to the normal range and her mood improved significantly. CONCLUSION: Depression should be considered a potential cause of unexplained recurrent fevers in adolescents, even when the temperature is significantly outside the normal range.


Assuntos
Psicoterapia , Humanos , Adolescente , Feminino , Cloridrato de Venlafaxina/uso terapêutico
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