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1.
Nat Immunol ; 20(1): 10-17, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30538328

RESUMO

Interleukin 15 (IL-15) is one of the most important cytokines that regulate the biology of natural killer (NK) cells1. Here we identified a signaling pathway-involving the serine-threonine kinase AKT and the transcription factor XBP1s, which regulates unfolded protein response genes2,3-that was activated in response to IL-15 in human NK cells. IL-15 induced the phosphorylation of AKT, which led to the deubiquitination, increased stability and nuclear accumulation of XBP1s protein. XBP1s bound to and recruited the transcription factor T-BET to the gene encoding granzyme B, leading to increased transcription. XBP1s positively regulated the cytolytic activity of NK cells against leukemia cells and was also required for IL-15-mediated NK cell survival through an anti-apoptotic mechanism. Thus, the newly identified IL-15-AKT-XBP1s signaling pathway contributes to enhanced effector functions and survival of human NK cells.


Assuntos
Interleucina-15/metabolismo , Células Matadoras Naturais/imunologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas com Domínio T/metabolismo , Proteína 1 de Ligação a X-Box/metabolismo , Sobrevivência Celular , Células Cultivadas , Citotoxicidade Imunológica , Regulação da Expressão Gênica , Granzimas/genética , Granzimas/metabolismo , Humanos , Fosforilação , Ligação Proteica , Estabilidade Proteica , Transdução de Sinais , Ubiquitinação , Resposta a Proteínas não Dobradas
2.
Mol Cell ; 71(1): 142-154.e6, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-30008318

RESUMO

Nitric oxide (NO) regulates diverse cellular signaling through S-nitrosylation of specific Cys residues of target proteins. The intracellular level of S-nitrosoglutathione (GSNO), a major bioactive NO species, is regulated by GSNO reductase (GSNOR), a highly conserved master regulator of NO signaling. However, little is known about how the activity of GSNOR is regulated. Here, we show that S-nitrosylation induces selective autophagy of Arabidopsis GSNOR1 during hypoxia responses. S-nitrosylation of GSNOR1 at Cys-10 induces conformational changes, exposing its AUTOPHAGY-RELATED8 (ATG8)-interacting motif (AIM) accessible by autophagy machinery. Upon binding by ATG8, GSNOR1 is recruited into the autophagosome and degraded in an AIM-dependent manner. Physiologically, the S-nitrosylation-induced selective autophagy of GSNOR1 is relevant to hypoxia responses. Our discovery reveals a unique mechanism by which S-nitrosylation mediates selective autophagy of GSNOR1, thereby establishing a molecular link between NO signaling and autophagy.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Autofagia , Glutationa Redutase/metabolismo , Óxido Nítrico/metabolismo , Transdução de Sinais , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Família da Proteína 8 Relacionada à Autofagia/genética , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Hipóxia Celular , Glutationa Redutase/genética
3.
Ann Hepatol ; 28(6): 101137, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37451515

RESUMO

Most cases of hepatocellular carcinoma (HCC) are able to be diagnosed through regular surveillance in an identifiable patient population with chronic hepatitis B or cirrhosis. Nevertheless, 50% of global cases might present incidentally owing to symptomatic advanced-stage HCC after worsening of liver dysfunction. A systematic search based on PUBMED was performed to identify relevant outcomes, covering newer surveillance modalities including secretory proteins, DNA methylation, miRNAs, and genome sequencing analysis which proposed molecular expression signatures as ideal tools in the early-stage HCC detection. In the face of low accuracy without harmonization on the analytical approaches and data interpretation for liquid biopsy, a more accurate incidence of HCC will be unveiled by using deep machine learning system and multiplex immunohistochemistry analysis. A combination of molecular-secretory biomarkers, high-definition imaging and bedside clinical indexes in a surveillance setting offers a comprehensive range of HCC potential indicators. In addition, the sequential use of numerous lines of systemic anti-HCC therapies will simultaneously benefit more patients in survival. This review provides an overview on the most recent developments in HCC theranostic platform.

4.
Pestic Biochem Physiol ; 196: 105594, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37945244

RESUMO

The toxic effects of neonicotinoid pesticides on honeybees is a global concern, whereas little is known about the effect of stereoisomeric pesticides among honeybee social behavior. In this study, we investigated the effects of stereoisomeric dinotefuran on honeybee social behavior. We found that honeybees exhibit a preference for consuming food containing S-dinotefuran, actively engage in trophallaxis with S-dinotefuran-consuming peers, and consequently acquire higher levels of S-dinotefuran compared with R-dinotefuran. In comparison to R-dinotefuran, S-dinotefuran stimulates honeybees to elevate their body temperature, thereby attracting more peers for trophallaxis. Transcriptome analysis revealed a significant enrichment of thermogenesis pathways due to S-dinotefuran exposure. Additionally, metabolome data indicated that S-dinotefuran may enhance body temperature by promoting lipid synthesis in the lysine degradation pathway. Consequently, body temperature emerges as a key factor influencing honeybee social behavior. Our study is the first to highlight the propensity of S-dinotefuran to raise honeybee body temperature, which prompts honeybee to preferentially engage in trophallaxis with peers exhibiting higher body temperatures. This preference may lead honeybees to collect more dinotefuran-contaminated food in the wild, significantly accelerating dinotefuran transmission within a population. Proactive trophallaxis further amplifies the risk of neonicotinoid pesticide transmission within a population, making honeybees that have consumed S-dinotefuran particularly favored within their colonies. These findings may contribute to our understanding of the higher risk associated with neonicotinoid use compared with other pesticides.


Assuntos
Praguicidas , Abelhas , Animais , Neonicotinoides/toxicidade , Praguicidas/toxicidade , Nitrocompostos/toxicidade , Guanidinas/toxicidade
5.
Proc Natl Acad Sci U S A ; 116(1): 96-105, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30559207

RESUMO

Despite significant recent progress, machine vision systems lag considerably behind their biological counterparts in performance, scalability, and robustness. A distinctive hallmark of the brain is its ability to automatically discover and model objects, at multiscale resolutions, from repeated exposures to unlabeled contextual data and then to be able to robustly detect the learned objects under various nonideal circumstances, such as partial occlusion and different view angles. Replication of such capabilities in a machine would require three key ingredients: (i) access to large-scale perceptual data of the kind that humans experience, (ii) flexible representations of objects, and (iii) an efficient unsupervised learning algorithm. The Internet fortunately provides unprecedented access to vast amounts of visual data. This paper leverages the availability of such data to develop a scalable framework for unsupervised learning of object prototypes-brain-inspired flexible, scale, and shift invariant representations of deformable objects (e.g., humans, motorcycles, cars, airplanes) comprised of parts, their different configurations and views, and their spatial relationships. Computationally, the object prototypes are represented as geometric associative networks using probabilistic constructs such as Markov random fields. We apply our framework to various datasets and show that our approach is computationally scalable and can construct accurate and operational part-aware object models much more efficiently than in much of the recent computer vision literature. We also present efficient algorithms for detection and localization in new scenes of objects and their partial views.


Assuntos
Inteligência Artificial , Aprendizado de Máquina não Supervisionado , Algoritmos , Encéfalo/fisiologia , Simulação por Computador , Reconhecimento Facial , Sistemas de Informação Geográfica , Humanos , Reconhecimento Visual de Modelos , Percepção Visual
6.
Int J Mol Sci ; 23(9)2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35563460

RESUMO

The radiosensitization of tumor cells is one of the promising approaches for enhancing radiation damage to cancer cells and limiting radiation effects on normal tissue. In this study, we performed a comprehensive screening of radiosensitization targets in human lung cancer cell line A549 using an shRNA library and identified apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G: A3G) as a candidate target. APOBEC3G is an innate restriction factor that inhibits HIV-1 infection as a cytidine deaminase. APOBEC3G knockdown with siRNA showed an increased radiosensitivity in several cancer cell lines, including pancreatic cancer MIAPaCa2 cells and lung cancer A549 cells. Cell cycle analysis revealed that APOBEC3G knockdown increased S-phase arrest in MIAPaCa2 and G2/M arrest in A549 cells after γ-irradiation. DNA double-strand break marker γH2AX level was increased in APOBEC3G-knocked-down MIAPaCa2 cells after γ-irradiation. Using a xenograft model of A549 in mice, enhanced radiosensitivity by a combination of X-ray irradiation and APOBEC3G knockdown was observed. These results suggest that the functional inhibition of APOBEC3G sensitizes cancer cells to radiation by attenuating the activation of the DNA repair pathway, suggesting that APOBEC3G could be useful as a target for the radiosensitization of cancer therapy.


Assuntos
Desaminase APOBEC-3G , Raios gama , Tolerância a Radiação , Desaminase APOBEC-3G/antagonistas & inibidores , Desaminase APOBEC-3G/farmacologia , Animais , Apoptose , Linhagem Celular Tumoral , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular , Raios gama/uso terapêutico , Humanos , Neoplasias Pulmonares/radioterapia , Camundongos , Tolerância a Radiação/genética , Tolerância a Radiação/fisiologia
7.
Bull Environ Contam Toxicol ; 109(5): 823-830, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36074130

RESUMO

Studying the bioaccumulation behavior and toxicity of triazole fungicides is a crucial part of comprehensively evaluating the environmental fate and aquatic toxicity.The current research aimed to reveal the toxic effects of propiconazole and difenoconazole on fish through acute toxicity test, bioaccumulation test and oxidase system activity determination. Here, the propiconazole and difenoconazole concentrations were 11.3 mg/L and 31.2 mg/L for LC50-96 h, both having low toxicity. LC-MS/MS was used to determine the propiconazole and difenoconazole concentrations in five organs (muscle, gill, liver, intestine, and kidney) of Procypris meru. The findings indicate that the bioconcentration coefficients of propiconazole and difenoconazole in grass flower carp were 0.66-27.08 and 2.43-22.72, which belonged to medium enrichment pesticides. The bioconcentration coefficients decreased with the increase of exposure concentration. The two fungicides could induce oxidative stress in fish liver, and the activities of three antioxidant enzymes were inhibited in varying degrees (p < 0.05). The results showed that the content of T3 increased, and T4 decreased when exposed to one-tenth LC50 for 7 days. This study shows that triazole pesticides have bioaccumulation risks on aquatic organisms and clear environmental hormonal effects.


Assuntos
Cyprinidae , Fungicidas Industriais , Praguicidas , Animais , Fungicidas Industriais/toxicidade , Fungicidas Industriais/análise , Bioacumulação , Cromatografia Líquida , Espectrometria de Massas em Tandem , Triazóis/toxicidade , Hormônios
8.
Ecotoxicol Environ Saf ; 225: 112744, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481358

RESUMO

Thiamethoxam, an insecticide with high usage and large amounts of environmental residues, has been reported to affect the pupation and survival of honey bee larvae at sublethal concentrations. The molecular mechanisms are not fully understood. In this study, we measured the response of juvenile hormone (JH) to environmental concentrations of thiamethoxam using liquid chromatography-tandem mass spectrometry (LC-MS/MS), monitored the dynamic changes in the transcription of genes encoding major JH metabolic enzymes (CYP15A1, FAMET, JHAMT and JHE) using RT-qPCR, and analysed the transcriptome changes in worker larvae under thiamethoxam stress using RNA-seq. Thiamethoxam significantly increased the levels of JH3 in honey bee larvae, but no significant changes in the transcript levels of the four major metabolic enzymes were observed. Thiamethoxam exposure resulted in 140 differentially expressed genes (DEGs). P450 CYP6AS5 was upregulated, and some ion-related, odourant-related and gustatory receptors for sugar taste genes were altered significantly. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that amino acid metabolism and protein digestion and absorption were influenced by thiamethoxam. These changes may do harm to honey bee caste differentiation, foraging behaviour related to sensory perception and nutrient levels of bee colonies. These results represent the first assessment of the effects of thiamethoxam on JH in honey bee larvae and provides a new perspective and molecular basis for the study of JH regulation and thiamethoxam toxicity to honey bees.


Assuntos
Hormônios Juvenis , Espectrometria de Massas em Tandem , Animais , Abelhas/genética , Cromatografia Líquida , Hormônios Juvenis/toxicidade , Larva/genética , Tiametoxam
9.
J Integr Plant Biol ; 61(12): 1206-1223, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30663237

RESUMO

Nitric oxide (NO) is an important signaling molecule regulating diverse biological processes in all living organisms. A major physiological function of NO is executed via protein S-nitrosylation, a redox-based posttranslational modification by covalently adding a NO molecule to a reactive cysteine thiol of a target protein. S-nitrosylation is an evolutionarily conserved mechanism modulating multiple aspects of cellular signaling. During the past decade, significant progress has been made in functional characterization of S-nitrosylated proteins in plants. Emerging evidence indicates that protein S-nitrosylation is ubiquitously involved in the regulation of plant development and stress responses. Here we review current understanding on the regulatory mechanisms of protein S-nitrosylation in various biological processes in plants and highlight key challenges in this field.


Assuntos
Proteínas de Plantas/metabolismo , Óxido Nítrico/metabolismo , Nitrosação , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Plantas/imunologia , Plantas/metabolismo
10.
J Nat Prod ; 81(3): 554-561, 2018 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-29350920

RESUMO

The molecular structures of three parthenolide analogues, (-)-goyazensolide (1), (-)-15-deoxygoyazensolide (2), and (-)-ereglomerulide (3), isolated from the leaves of Piptocoma rufescens in a previous study were determined by X-ray analysis, and the absolute configuration of (-)-goyazensolide (1) was confirmed crystallographically using Cu Kα radiation at low temperature. Compounds 1-3, (+)-rufesolide A (4), and commercial parthenolide were found to be growth inhibitory toward MOLM-13 and EOL-1 human acute myeloid leukemia cells using PKC412 (midostaurin) as the positive control, with 1-3 being more active than parthenolide. Also, compounds 1-4 exhibited synergistic effects when tested with PKC412, but parthenolide did not show this type of activity. At a concentration lower than 2.0 µM, both 1 and 2 induced approximately 50% of the cells to become apoptotic at a late stage of the cell cycle, but no similar apoptotic effects were observed for 3, 4, or parthenolide. Leukemia cell apoptosis was induced by these compounds through the activation of caspase-3 and the inhibition of NF-κB, as indicated by immunoblotting analysis, and compounds 1 and 2 seem to be promising leads for development as potential antileukemic agents.


Assuntos
Apoptose/efeitos dos fármacos , Asteraceae/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , NF-kappa B/metabolismo
11.
Proc Natl Acad Sci U S A ; 112(11): 3535-40, 2015 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-25733878

RESUMO

Cortical gamma band oscillations (GBO, 30-80 Hz, typically ∼40 Hz) are involved in higher cognitive functions such as feature binding, attention, and working memory. GBO abnormalities are a feature of several neuropsychiatric disorders associated with dysfunction of cortical fast-spiking interneurons containing the calcium-binding protein parvalbumin (PV). GBO vary according to the state of arousal, are modulated by attention, and are correlated with conscious awareness. However, the subcortical cell types underlying the state-dependent control of GBO are not well understood. Here we tested the role of one cell type in the wakefulness-promoting basal forebrain (BF) region, cortically projecting GABAergic neurons containing PV, whose virally transduced fibers we found apposed cortical PV interneurons involved in generating GBO. Optogenetic stimulation of BF PV neurons in mice preferentially increased cortical GBO power by entraining a cortical oscillator with a resonant frequency of ∼40 Hz, as revealed by analysis of both rhythmic and nonrhythmic BF PV stimulation. Selective saporin lesions of BF cholinergic neurons did not alter the enhancement of cortical GBO power induced by BF PV stimulation. Importantly, bilateral optogenetic inhibition of BF PV neurons decreased the power of the 40-Hz auditory steady-state response, a read-out of the ability of the cortex to generate GBO used in clinical studies. Our results are surprising and novel in indicating that this presumptively inhibitory BF PV input controls cortical GBO, likely by synchronizing the activity of cortical PV interneurons. BF PV neurons may represent a previously unidentified therapeutic target to treat disorders involving abnormal GBO, such as schizophrenia.


Assuntos
Prosencéfalo Basal/fisiologia , Ritmo Gama/fisiologia , Neurônios/fisiologia , Parvalbuminas/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Channelrhodopsins , Neurônios Colinérgicos/fisiologia , Potenciais Evocados Auditivos/fisiologia , Proteínas Luminescentes/metabolismo , Camundongos , Optogenética , Reprodutibilidade dos Testes , Transdução Genética
12.
Plant Physiol ; 167(4): 1604-15, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25667317

RESUMO

Nitric oxide (NO) and reactive oxygen species (ROS) are two classes of key signaling molecules involved in various developmental processes and stress responses in plants. The burst of NO and ROS triggered by various stimuli activates downstream signaling pathways to cope with abiotic and biotic stresses. Emerging evidence suggests that the interplay of NO and ROS plays a critical role in regulating stress responses. However, the underpinning molecular mechanism remains poorly understood. Here, we show that NO positively regulates the activity of the Arabidopsis (Arabidopsis thaliana) cytosolic ascorbate peroxidase1 (APX1). We found that S-nitrosylation of APX1 at cysteine (Cys)-32 enhances its enzymatic activity of scavenging hydrogen peroxide, leading to the increased resistance to oxidative stress, whereas a substitution mutation at Cys-32 causes the reduction of ascorbate peroxidase activity and abolishes its responsiveness to the NO-enhanced enzymatic activity. Moreover, S-nitrosylation of APX1 at Cys-32 also plays an important role in regulating immune responses. These findings illustrate a unique mechanism by which NO regulates hydrogen peroxide homeostasis in plants, thereby establishing a molecular link between NO and ROS signaling pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Ascorbato Peroxidases/metabolismo , Regulação da Expressão Gênica de Plantas , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Ascorbato Peroxidases/genética , Citosol/metabolismo , Peróxido de Hidrogênio/metabolismo , Luz , Estresse Oxidativo , Plantas Geneticamente Modificadas , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Plântula/efeitos da radiação , Transdução de Sinais
13.
Plant Physiol ; 167(4): 1731-46, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25699590

RESUMO

Nitric oxide (NO) regulates multiple developmental events and stress responses in plants. A major biologically active species of NO is S-nitrosoglutathione (GSNO), which is irreversibly degraded by GSNO reductase (GSNOR). The major physiological effect of NO is protein S-nitrosylation, a redox-based posttranslational modification mechanism by covalently linking an NO molecule to a cysteine thiol. However, little is known about the mechanisms of S-nitrosylation-regulated signaling, partly due to limited S-nitrosylated proteins being identified. In this study, we identified 1,195 endogenously S-nitrosylated peptides in 926 proteins from the Arabidopsis (Arabidopsis thaliana) by a site-specific nitrosoproteomic approach, which, to date, is the largest data set of S-nitrosylated proteins among all organisms. Consensus sequence analysis of these peptides identified several motifs that contain acidic, but not basic, amino acid residues flanking the S-nitrosylated cysteine residues. These S-nitrosylated proteins are involved in a wide range of biological processes and are significantly enriched in chlorophyll metabolism, photosynthesis, carbohydrate metabolism, and stress responses. Consistently, the gsnor1-3 mutant shows the decreased chlorophyll content and altered photosynthetic properties, suggesting that S-nitrosylation is an important regulatory mechanism in these processes. These results have provided valuable resources and new clues to the studies on S-nitrosylation-regulated signaling in plants.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Glutationa Redutase/genética , Óxido Nítrico/metabolismo , Processamento de Proteína Pós-Traducional , Proteômica , S-Nitrosoglutationa/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Cisteína/metabolismo , Glutationa Redutase/metabolismo , Dados de Sequência Molecular , Oxirredução , Plântula/genética , Plântula/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Compostos de Sulfidrila/metabolismo
14.
Metab Brain Dis ; 30(6): 1505-14, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26220010

RESUMO

The lifetime prevalence rate for major depressive disorder (MDD) is approximately 17 % for most developed countries around the world. Dietary polyphenols are currently used as an adjuvant therapy to accelerate the therapeutic efficacy on depression. Ferulic acid (FA) or 4-hydroxy-3-methoxy-cinnamic acid (Fig. 1a) is a main polyphenolic component of Chinese herb Radix Angelicae Sinensis, which is found to have antidepressant-like effects through regulating serotonergic and noradrenergic function. The present study examined the synergistic effect of low doses of FA combined with subthreshold dose of piperine, a bioavailability enhancer, on depression-like behaviors in mice, and investigated the possible mechanism. The administration of FA, even in the highest dose tested, reduced immobility time by 60 % in the tail suspension and forced swimming tests (TST and FST) in mice when compared to control. The maximal antidepressant-like effect of FA was obtained with 200 mg/kg. In addition, piperine only produced a weak antidepressant-like effect in the TST and FST. However, the evidence from the interaction analysis suggested a synergistic effect when low doses of FA were combined with a subthreshold dose of piperine. Further neurochemical evidence such as monoamine levels in the frontal cortex, hippocampus, and hypothalamus and measurements of monoamine oxidase activity also supported a synergistic effect of FA and piperine in the enhancement of monoaminergic function. This finding supports the concept that the combination strategy might be an alternative therapy in the treatment of psychiatric disorders with high efficacy and low side effects.


Assuntos
Alcaloides/farmacologia , Antidepressivos/farmacologia , Benzodioxóis/farmacologia , Monoaminas Biogênicas/metabolismo , Ácidos Cumáricos/farmacologia , Neurotransmissores/metabolismo , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Animais , Disponibilidade Biológica , Química Encefálica/efeitos dos fármacos , Depressão/tratamento farmacológico , Depressão/metabolismo , Sinergismo Farmacológico , Elevação dos Membros Posteriores/psicologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Monoaminoxidase/metabolismo , Atividade Motora/efeitos dos fármacos , Natação/psicologia
15.
Plant Physiol ; 163(2): 1059-70, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23958864

RESUMO

LESION SIMULATING DISEASE1 (lsd1) is an important negative regulator of programmed cell death (PCD) in Arabidopsis (Arabidopsis thaliana). The loss-of-function mutations in lsd1 cause runaway cell death triggered by reactive oxygen species. lsd1 encodes a novel zinc finger protein with unknown biochemical activities. Here, we report the identification of CATALASE3 (CAT3) as an lsd1-interacting protein by affinity purification and mass spectrometry-based proteomic analysis. The Arabidopsis genome contains three homologous catalase genes (CAT1, CAT2, and CAT3). Yeast two-hybrid and coimmunoprecipitation analyses demonstrated that lsd1 interacted with all three catalases both in vitro and in vivo, and the interaction required the zinc fingers of lsd1. We found that the catalase enzymatic activity was reduced in the lsd1 mutant, indicating that the catalase enzyme activity was partially dependent on lsd1. Consistently, the lsd1 mutant was more sensitive to the catalase inhibitor 3-amino-1,2,4-triazole than the wild type, suggesting that the interaction between lsd1 and catalases is involved in the regulation of the reactive oxygen species generated in the peroxisome. Genetic studies revealed that lsd1 interacted with CATALASE genes to regulate light-dependent runaway cell death and hypersensitive-type cell death. Moreover, the accumulation of salicylic acid was required for PCD regulated by the interaction between lsd1 and catalases. These results suggest that the lsd1-catalase interaction plays an important role in regulating PCD in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/enzimologia , Catalase/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Amitrol (Herbicida)/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Catalase/antagonistas & inibidores , Catalase/química , Catalase/genética , Morte Celular/efeitos dos fármacos , Genes de Plantas/genética , Luz , Dados de Sequência Molecular , Mutação/genética , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Pseudomonas syringae/fisiologia , Ácido Salicílico/metabolismo , Dedos de Zinco
16.
ACS Omega ; 9(23): 25283-25296, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38882128

RESUMO

During the development of deep coalbed methane (CBM), the production of coal fines is common and suppresses the yield of CBM. This work takes the deep CBM wells in the Qinshui Basin as a case study, and the output, composition, morphology, and sources of coal fines were investigated through scanning electron microscopy, X-ray diffraction, proximate analysis, and particle size measurement including image analysis, laser diffraction, and dynamic light scattering. The results indicate that, in comparison with shallow CBM wells, deep wells produce a greater quantity of coal fines which are darker in color and have smaller particle sizes, with the majority being less than 10 µm. The coal fines exist predominantly as aggregates that contained the iron-bearing and clay minerals. Based on the Liddinger particle settling model, the water production volume required for the coal fines to return to the surface in the Wuxiang block was calculated to be 8.55 m3/d. This work can provide a scientific basis for the prevention and control of coal fines in deep CBM wells.

17.
Eur J Neurosci ; 37(6): 957-63, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23282008

RESUMO

Dysfunction of the orexin/hypocretin neurotransmitter system causes the sleep disorder narcolepsy, characterized by intrusion of rapid eye movement (REM) sleep-like events into normal wakefulness. The sites where orexins act to suppress REM sleep are incompletely understood. Previous studies suggested that the lateral pontomesencephalic tegmentum (lPMT) contains an important REM sleep inhibitory area, and proposed that orexins inhibit REM sleep via orexin type 2 receptors (OxR2) in this region. However, this hypothesis has heretofore not been tested. We thus performed bilateral injection of small interfering RNAs (siRNAs) targeting Ox2R into the lPMT on two consecutive days. This led to a approximately 30% increase of time spent in REM sleep in both the dark and light periods for the first 2 days after injection, with a return to baseline over the next two post-injection days. This increase was mainly due to longer (> 120 s) REM episodes. Cataplexy-like episodes were not observed. The percentage of time spent in wakefulness and non-(N)REM sleep, as well as the power spectral profile of NREM and REM sleep, were unaffected. Control animals injected with scrambled siRNA had no sleep changes post-injection. Quantification of the knockdown revealed that unilateral microinjection of siRNAs targeting OxR2 into the lPMT induced a approximately 40% reduction of OxR2 mRNA 2 days following the injections when compared with the contralateral side receiving control (scrambled) siRNA. Orexin type 1 receptor mRNA level was unaffected. Our results indicate that removal of OxR2 neurotransmission in the lPMT enhances REM sleep by increasing the duration of REM episodes.


Assuntos
Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Sono REM/genética , Tegmento Mesencefálico/fisiologia , Animais , Inativação Gênica , Masculino , Receptores de Orexina , Fotoperíodo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/genética , Receptores de Neuropeptídeos/genética , Tegmento Mesencefálico/metabolismo , Transcrição Gênica , Vigília
18.
Cells ; 12(12)2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37371031

RESUMO

Boron neutron capture therapy (BNCT) is a selective radiotherapy based on nuclear reaction that occurs when 10B atoms accumulated in cancer cells are irradiated by thermal neutrons, triggering a nuclear fission response leading to cell death. Despite its growing importance in cancer treatment, molecular characterization of its effects is still lacking. In this context, proteomics investigation can be useful to study BNCT effect and identify potential biomarkers. Hence, we performed proteomic analysis with nanoLC-MS/MS (liquid chromatography coupled to tandem mass spectrometry) on extracellular vesicles (EVs) isolated from SAS cultures treated or not with 10B-boronophenylalanine (BPA) and different doses of neutron irradiation, to study the cellular response related to both boron administration and neutrons action. Despite the interference of fetal bovine serum in the medium, we were able to stratify BPA- and BPA+ conditions and to identify EVs-derived proteins characterizing pathways potentially related to a BNCT effect such as apoptosis, DNA repair and inflammatory response. In particular, KLF11, SERPINA1 and SERPINF2 were up-regulated in BPA+, while POLE and SERPINC1 were up-regulated in BPA-. These results provide the first proteomic investigation of EVs treated with BNCT in different conditions and highlight the potentiality of proteomics for improving biomarkers identification and mechanisms understanding of BNCT.


Assuntos
Terapia por Captura de Nêutron de Boro , Vesículas Extracelulares , Compostos de Boro/uso terapêutico , Proteômica , Espectrometria de Massas em Tandem , Terapia por Captura de Nêutron de Boro/métodos , Nêutrons
20.
Front Neurosci ; 17: 1145065, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37123360

RESUMO

Hyperbaric oxygen (HBO) therapy is an effective treatment for patients with disorders of consciousness (DOC). In this study, real-time electroencephalogram (EEG) recordings were obtained from patients with DOC during HBO therapy. EEG microstate indicators including mean microstate duration (MMD), ratio of total time covered (RTT), global explained variance (GEV), transition probability, mean occurrence, and mean global field power (GFP) were compared before and during HBO therapy. The results showed that the duration of microstate C in all patients with DOC increased after 20 min of HBO therapy (p < 0.05). Further statistical analysis found that the duration of microstate C was longer in the higher CRS-R group (≥8, 17 cases) than in the lower group (<8, 24 cases) during HBO treatment. In the higher CRS-R group, the transition probabilities from microstate A to microstate C and from microstate C to microstate A also increased significantly compared with the probability before treatment (p < 0.05). Microstate C is generally considered to be related to a salience network; an increase in the transition probability between microstate A and microstate C indicates increased information exchange between the auditory network and the salience network. The results of this study show that HBO therapy has a specific activating effect on attention and cognitive control in patients and causes increased activity in the primary sensory cortex (temporal lobe and occipital lobe). This study demonstrates that real-time EEG detection and analysis during HBO is a clinically feasible method for assessing brain function in patients with DOC. During HBO therapy, some EEG microstate indicators show significant changes related to the state of consciousness in patients with chronic DOC. This will be complementary to important electrophysiological indicators for assessing consciousness and may also provide an objective foundation for the precise treatment of patients with DOC.

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