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Flowering is critical for sexual reproduction and fruit production. Several pear (Pyrus sp.) varieties produce few flower buds, but the underlying mechanisms are unknown. The circadian clock regulator EARLY FLOWERING3 (ELF3) serves as a scaffold protein in the evening complex that controls flowering. Here, we report that the absence of a 58-bp sequence in the 2nd intron of PbELF3 is genetically associated with the production of fewer flower buds in pear. From rapid amplification of cDNA ends sequencing results, we identified a short, previously unknown transcript from the PbELF3 locus, which we termed PbELF3ß, whose transcript level was significantly lower in pear cultivars that lacked the 58-bp region. The heterologous expression of PbELF3ß in Arabidopsis (Arabidopsis thaliana) accelerated flowering, whereas the heterologous expression of the full-length transcript PbELF3α caused late flowering. Notably, ELF3ß was functionally conserved in other plants. Deletion of the 2nd intron reduced AtELF3ß expression and caused delayed flowering time in Arabidopsis. AtELF3ß physically interacted with AtELF3α, disrupting the formation of the evening complex and consequently releasing its repression of flower induction genes such as GIGANTEA (GI). AtELF3ß had no effect in the absence of AtELF3α, supporting the idea that AtELF3ß promotes flower induction by blocking AtELF3α function. Our findings show that alternative promoter usage at the ELF3 locus allows plants to fine-tune flower induction.
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Proteínas de Arabidopsis , Arabidopsis , Relojes Circadianos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Relojes Circadianos/fisiología , Plantas/metabolismo , Flores/metabolismoRESUMEN
The maintenance of lysosome homeostasis is crucial for cell growth. Lysosome-dependent degradation and metabolism sustain tumor cell survival. Here, we demonstrate that CCDC50 serves as a lysophagy receptor, promoting tumor progression and invasion by controlling lysosomal integrity and renewal. CCDC50 monitors lysosomal damage, recognizes galectin-3 and K63-linked polyubiquitination on damaged lysosomes, and specifically targets them for autophagy-dependent degradation. CCDC50 deficiency causes the accumulation of ruptured lysosomes, impaired autophagic flux, and superfluous reactive oxygen species, consequently leading to cell death and tumor suppression. CCDC50 expression is associated with malignancy, progression to metastasis, and poor overall survival in human melanoma. Targeting CCDC50 suppresses tumor growth and lung metastasis, and enhances the effect of BRAFV600E inhibition. Thus, we demonstrate critical roles of CCDC50-mediated clearance of damaged lysosomes in supporting tumor growth, hereby identifying a potential therapeutic target of melanoma.
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SignificanceScramblases translocate lipids across the lipid bilayer without consumption of ATP, thereby regulating lipid distributions in cellular membranes. Cytosol-to-lumen translocation across the endoplasmic reticulum (ER) membrane is a common process among lipid glycoconjugates involved in posttranslational protein modifications in eukaryotes. These translocations are thought to be mediated by specific ER-resident scramblases, but the identity of these proteins and the underlying molecular mechanisms have been elusive. Here, we show that CLPTM1L, an integral membrane protein with eight putative transmembrane domains, is the major lipid scramblase involved in efficient glycosylphosphatidylinositol biosynthesis in the ER membrane. Our results validate the long-standing hypothesis that lipid scramblases ensure the efficient translocations of lipid glycoconjugates across the ER membrane for protein glycosylation pathways.
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Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Glicosilfosfatidilinositoles , Retículo Endoplásmico/metabolismo , Glicosilfosfatidilinositoles/metabolismo , Lipogénesis , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismoRESUMEN
Pear fruit stone cells have thick walls and are formed by the secondary deposition of lignin in the primary cell wall of thin-walled cells. Their content and size seriously affect fruit characteristics related to edibility. To reveal the regulatory mechanism underlying stone cell formation during pear fruit development and to identify hub genes, we examined the stone cell and lignin contents of 30 'Shannongsu' pear flesh samples and analyzed the transcriptomes of 15 pear flesh samples collected at five developmental stages. On the basis of the RNA-seq data, 35 874 differentially expressed genes were detected. Additionally, two stone cell-related modules were identified according to a WGCNA. A total of 42 lignin-related structural genes were subsequently obtained. Furthermore, nine hub structural genes were identified in the lignin regulatory network. We also identified PbMYB61 and PbMYB308 as candidate transcriptional regulators of stone cell formation after analyzing co-expression networks and phylogenetic relationships. Finally, we experimentally validated and characterized the candidate transcription factors and revealed that PbMYB61 regulates stone cell lignin formation by binding to the AC element in the PbLAC1 promoter to upregulate expression. However, PbMYB308 negatively regulates stone cell lignin synthesis by binding to PbMYB61 to form a dimer that cannot activate PbLAC1 expression. In this study, we explored the lignin synthesis-related functions of MYB family members. The results presented herein are useful for elucidating the complex mechanisms underlying lignin biosynthesis during pear fruit stone cell development.
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Frutas , Pyrus , Frutas/metabolismo , Pyrus/metabolismo , Lignina/metabolismo , Filogenia , Regulación de la Expresión Génica de las Plantas/genética , Perfilación de la Expresión Génica/métodos , Transcriptoma , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
BACKGROUND: Pediatric acute myeloid leukemia (AML) chemotherapy increases the risk of life-threatening complications, including septic shock (SS). An area-based measure of social determinants of health, the social disorganization index (SDI), was hypothesized to be associated with SS and SS-associated death (SS-death). METHODS: Children treated for de novo AML on two Children's Oncology Group trials at institutions contributing to the Pediatric Health Information System (PHIS) database were included. The SDI was calculated via residential zip code data from the US Census Bureau. SS was identified via PHIS resource utilization codes. SS-death was defined as death within 2 weeks of an antecedent SS event. Patients were followed from 7 days after the start of chemotherapy until the first of end of front-line therapy, death, relapse, or removal from study. Multivariable-adjusted Cox regressions estimated hazard ratios (HRs) comparing time to first SS by SDI group. RESULTS: The assembled cohort included 700 patients, with 207 (29.6%) sustaining at least one SS event. There were 233 (33%) in the SDI-5 group (highest disorganization). Adjusted time to incident SS did not statistically significantly differ by SDI (reference, SDI-1; SDI-2: HR, 0.84 [95% confidence interval (CI), 0.51-1.41]; SDI-3: HR, 0.70 [95% CI, 0.42-1.16]; SDI-4: HR, 0.97 [95% CI, 0.61-1.53]; SDI-5: HR, 0.72 [95% CI, 0.45-1.14]). Nine patients (4.4%) with SS experienced SS-death; seven of these patients (78%) were in SDI-4 or SDI-5. CONCLUSIONS: In a large, nationally representative cohort of trial-enrolled pediatric patients with AML, there was no significant association between the SDI and time to SS.
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Leucemia Mieloide Aguda , Choque Séptico , Niño , Humanos , Choque Séptico/epidemiología , Choque Séptico/complicaciones , Anomia (Social) , Leucemia Mieloide Aguda/terapia , Modelos de Riesgos Proporcionales , RecurrenciaRESUMEN
BACKGROUND: Walnut anthracnose caused by Colletotrichum gloeosporioides seriously endangers the yield and quality of walnut, and has now become a catastrophic disease in the walnut industry. Therefore, understanding both pathogen invasion mechanisms and host response processes is crucial to defense against C. gloeosporioides infection. RESULTS: Here, we investigated the mechanisms of interaction between walnut fruits (anthracnose-resistant F26 fruit bracts and anthracnose-susceptible F423 fruit bracts) and C. gloeosporioides at three infection time points (24hpi, 48hpi, and 72hpi) using a high-resolution time series dual transcriptomic analysis, characterizing the arms race between walnut and C. gloeosporioides. A total of 20,780 and 6670 differentially expressed genes (DEGs) were identified in walnut and C. gloeosporioides against 24hpi, respectively. Generous DEGs in walnut exhibited opposite expression patterns between F26 and F423, which indicated that different resistant materials exhibited different transcriptional responses to C. gloeosporioides during the infection process. KEGG functional enrichment analysis indicated that F26 displayed a broader response to C. gloeosporioides than F423. Meanwhile, the functional analysis of the C. gloeosporioides transcriptome was conducted and found that PHI, SignalP, CAZy, TCDB genes, the Fungal Zn (2)-Cys (6) binuclear cluster domain (PF00172.19) and the Cytochrome P450 (PF00067.23) were largely prominent in F26 fruit. These results suggested that C. gloeosporioides secreted some type of effector proteins in walnut fruit and appeared a different behavior based on the developmental stage of the walnut. CONCLUSIONS: Our present results shed light on the arms race process by which C. gloeosporioides attacked host and walnut against pathogen infection, laying the foundation for the green prevention of walnut anthracnose.
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Colletotrichum , Juglans , Enfermedades de las Plantas , Juglans/microbiología , Juglans/genética , Colletotrichum/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , RNA-Seq , Frutas/microbiología , Frutas/genética , Transcriptoma , Regulación de la Expresión Génica de las Plantas , Perfilación de la Expresión Génica , Interacciones Huésped-Patógeno/genética , Resistencia a la Enfermedad/genéticaRESUMEN
S-RNase-mediated self-incompatibility (SI) prevents self-fertilization and promotes outbreeding to ensure genetic diversity in many flowering plants, including pear (Pyrus sp.). Brassinosteroids (BRs) have well-documented functions in cell elongation, but their molecular mechanisms in pollen tube growth, especially in the SI response, remain elusive. Here, exogenously applied brassinolide (BL), an active BR, countered incompatible pollen tube growth inhibition during the SI response in pear. Antisense repression of BRASSINAZOLE-RESISTANT1 (PbrBZR1), a critical component of BR signaling, blocked the positive effect of BL on pollen tube elongation. Further analyses revealed that PbrBZR1 binds to the promoter of EXPANSIN-LIKE A3 (PbrEXLA3) to activate its expression. PbrEXLA3 encodes an expansin that promotes pollen tube elongation in pear. The stability of dephosphorylated PbrBZR1 was substantially reduced in incompatible pollen tubes, where it is targeted by ARIADNE2.3 (PbrARI2.3), an E3 ubiquitin ligase that is strongly expressed in pollen. Our results show that during the SI response, PbrARI2.3 accumulates and negatively regulates pollen tube growth by accelerating the degradation of PbrBZR1 via the 26S proteasome pathway. Together, our results show that an ubiquitin-mediated modification participates in BR signaling in pollen and reveal the molecular mechanism by which BRs regulate S-RNase-based SI.
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Brasinoesteroides , Tubo Polínico , Pyrus , Brasinoesteroides/metabolismo , Endorribonucleasas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/genética , Pyrus/metabolismo , Ribonucleasas/genética , Ribonucleasas/metabolismoRESUMEN
We report on a GHz fundamental repetition rate Kerr-lens mode-locked Ho:CALGO laser emitting at 2.1â µm. The laser employs a ring cavity to increase the fundamental repetition rate to 1.179â GHz and can be made to oscillate in both directions stably with nearly identical performance: for the counterclockwise oscillation, it generates 93-fs pulses at 1.68â W of average power, whereas 92â fs and 1.69â W were measured for the clockwise operation. Our current results represent the highest average power from a 2-µm GHz oscillator and, to our knowledge, the first sub-100-fs pulse duration from a Ho-based oscillator.
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The NLRP3-directed inflammasome complex is crucial for the host to resist microbial infection and monitor cellular damage. However, the hyperactivation of NLRP3 inflammasome is implicated in pathogenesis of inflammatory diseases, including inflammatory bowel disease (IBD). Autophagy and autophagy-related genes are closely linked to NLRP3-mediated inflammation in these inflammatory disorders. Here, we report that CCDC50, a novel autophagy cargo receptor, negatively regulates NLRP3 inflammasome assembly and suppresses the cleavage of pro-caspase-1 and interleukin 1ß (IL-1ß) release by delivering NLRP3 for autophagic degradation. Transcriptome analysis showed that knockdown of CCDC50 results in upregulation of signaling pathways associated with autoinflammatory diseases. CCDC50 deficiency leads to enhanced proinflammatory cytokine response triggered by a wide range of endogenous and exogenous NLRP3 stimuli. Ccdc50-deficient mice are more susceptible to dextran sulfate (DSS)-induced colitis and exhibit more severe gut inflammation with elevated NLRP3 inflammasome activity. These results illustrate the physiological significance of CCDC50 in the pathogenicity of inflammatory diseases, suggesting protective roles of CCDC50 in keeping gut inflammation under control.
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Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Animales , Autofagia , Sulfato de Dextran/toxicidad , Inflamasomas/genética , Inflamación , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/genéticaRESUMEN
Rapid urbanization worldwide, poses numerous environmental challenges between escalating land use land cover (LULC) changes and groundwater quality dynamics. The main objective of this study was to investigate the dynamics of groundwater quality and LULC changes in Sargodha district, Punjab, Pakistan. Groundwater hydrochemistry reveals acceptable pH levels (<8) but total dissolved solids (TDS), electrical conductivity (EC) and HCO3- showed dynamic fluctuations by exceeding WHO limits. Piper diagrams, indicated dominance by magnesium and bicarbonate types, underscoring the influence of natural processes and anthropogenic activities. Major ion relationships in 2010, 2015, and 2021 showed a high correlation (R2 > 0.85) between Na+ and Cl-, suggesting salinization. whereas, the poor correlation (<0.17) between Ca2+ and HCO3- does not support calcite dissolution as the primary process affecting groundwater composition. The examination of nitrate contamination in groundwater across the years 2010, 2015, and 2021 was found to be high in the municipal sewage zone, suggesting a prevailing issue of nitrate contamination attributed to urban activities. The Nitrate Pollution Index (NPI) reveals a concerning trend, with a higher proportion of samples classified under moderate to high pollution categories in 2015 and 2021 compared to 2010. The qualitative assessment of nitrate concentration on spatiotemporal scale showed lower values in 2010 while a consistent rise from 2015 to 2021 in north-east and western parts of district. Likewise, NPI was high in the north-eastern and south-western regions in 2010, then reduced in subsequent years, which may be attributed to effective waste management practices and alterations in agricultural practices. The health risk assessment of 2010 indicated Total Health Hazard Quotient (THQ) within the standard limit, while in 2015 and 2021, elevated health risk was observed. This study emphasizes the need to use multiple approaches to groundwater management for sustainable land use planning and regulations that prioritize groundwater quality conservation.
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BACKGROUND: The effect of continuous myocardial perfusion (CMP) on the surgical results of acute type A aortic dissection (ATAAD) remains unclear. METHODS: From January 2017 to March 2022, 141 patients who underwent ATAAD (90.8%) or intramural hematoma (9.2%) surgery were reviewed. Fifty-one patients (36.2%) received proximal-first aortic reconstruction and CMP during distal anastomosis. Ninety patients (63.8%) underwent distal-first aortic reconstruction and were placed in traditional cold blood cardioplegic arrest (CA; 4°C, 4:1 blood-to-Plegisol) throughout the procedure. The preoperative presentations and intraoperative details were balanced using inverse probability of treatment weighting (IPTW). Their postoperative morbidity and mortality were analyzed. RESULTS: The median age was 60 years. The incidence of arch reconstruction in the unweighted data was higher in the CMP compared with the CA group (74.5 vs 52.2%, p = 0.017) but was balanced after IPTW (62.4 vs 58.9%, p = 0.932, standardized mean difference = 0.073). The median cardiac ischemic time was lower in the CMP group (60.0 vs 130.9 minutes, p < 0.001), but cerebral perfusion time and cardiopulmonary bypass time were similar. The CMP group did not demonstrate any benefit in the reduction of the postoperative maximum creatine kinase-MB ratio (4.4 vs 5.1% in CA, p = 0.437) or postoperative low cardiac output (36.6 vs 24.8%, p = 0.237). Surgical mortality was comparable between groups (15.5% in CMP vs 7.5% in the CA group, p = 0.265). CONCLUSION: Application of CMP during distal anastomosis in ATAAD surgery, irrespective of the extent of aortic reconstruction, reduced myocardial ischemic time but did not improve cardiac outcome or mortality.
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Aneurisma de la Aorta Torácica , Disección Aórtica , Humanos , Persona de Mediana Edad , Resultado del Tratamiento , Disección Aórtica/diagnóstico por imagen , Disección Aórtica/cirugía , Paro Cardíaco Inducido/efectos adversos , Paro Cardíaco Inducido/métodos , Perfusión/métodos , Anastomosis Quirúrgica , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/cirugía , Estudios RetrospectivosRESUMEN
High malignancy is a prominent characteristic of epithelial ovarian cancer (EOC), emphasizing the necessity for further elucidation of the potential mechanisms underlying cancer progression. Aneuploidy and copy number variation (CNV) partially contribute to the heightened malignancy observed in EOC; however, the precise features of aneuploidy and their underlying molecular patterns, as well as the relationship between CNV and aneuploidy in EOC, remain unclear. In this study, we employed single-cell sequencing data along with The Cancer Genome Atlas (TCGA) to investigate aneuploidy and CNV in EOC. The technique of fluorescence in situ hybridization (FISH) was employed using specific probes. The copy number variation within the genomic region of chromosome 8 (42754568-47889815) was assessed and utilized as a representative measure for the ploidy status of individual cells in chromosome 8. Differential expression analysis was performed between different subgroups based on chromosome 8 ploidy. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI), and hub-gene analyses were subsequently utilized to identify crucial genes involved. By classifying enriched tumor cells into distinct subtypes based on chromosome 8 ploidy combined with TCGA data integration, we identified key genes driving chromosome 8 aneuploidy in EOC, revealing that PRKDC gene involvement through the mediated non-homologous end-joining pathway may play a pivotal role in disease progression. Further validation through analysis of the GEO and TCGA database and survival assessment, considering both mRNA expression levels and CNV status of PRKDC, has confirmed its involvement in the progression of EOC. Further functional analysis revealed an upregulation of PRKDC in both ovarian EOC cells and tissues, with its expression showing a significant correlation with the extent of copy number variation (CNV) on chromosome 8. Taken together, CNV amplification and aneuploidy of chromosome 8 are important characteristics of EOC. PRKDC and the mediated NHEJ pathway may play a crucial role in driving aneuploidy on chromosome 8 during the progression of EOC.
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Aneuploidia , Cromosomas Humanos Par 8 , Variaciones en el Número de Copia de ADN , Progresión de la Enfermedad , Neoplasias Ováricas , Femenino , Humanos , Carcinoma Epitelial de Ovario/genética , Carcinoma Epitelial de Ovario/patología , Cromosomas Humanos Par 8/genética , Regulación Neoplásica de la Expresión Génica , Hibridación Fluorescente in Situ , Neoplasias Ováricas/genética , Neoplasias Ováricas/patologíaRESUMEN
Mental load is a major cause of human-induced accidents. In this study, an explosive impact sensitivity experiment was used to induce mental load. A combination of subjective questionnaires and objective prospective time-distance tests were used to judge whether subjects experienced mental load. Four indicators, namely, ß, γ, mean pupil diameter, and fixation time were selected by statistical analysis and PCA for the construction of a mental load assessment model. The study found that the occipital lobe was the most sensitive to mental load, especially ß and γ bands. Lastly, it was found that subjects showed different degrees of mental load for the same mental load induction task. The results of the study are applicable to the evaluation and monitoring of the mental characteristics of workers and provide a scientific basis for adjusting the mental load of workers over time to reduce the rate of accidents and enhance production efficiency.
Mental load is the main cause of human-induced accidents. This study used an explosive impact sensitivity experiment to induce mental load in subjects. We found that the mean pupil diameter and fixation time, as well as the beta and gamma bands in the occipital lobe were most sensitive to mental load.
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A palladium-catalyzed highly CâS-selective Stille cross-coupling between aryl thianthrenium salts and tri- or tetrasubstituted alkenyl stannanes is described. Herein, critical challenges including site- and chemoselectivity control are well addressed through CâH thianthrenation and CâS alkenylation, thereby providing an expedient access to stereodefined tri- and tetrasubstituted alkenes in a stereoretentive fashion. Indeed, the palladium-catalyzed Stille-alkenylation of poly(pseudo)halogenated arenes displays privileged capability to differentiate CâS over CâI, CâBr, CâCl bonds, as well as oxygen-based triflates (CâOTf), tosylates (CâOTs), carbamates and sulfamates under mild reaction conditions. Sequential and multiple cross-couplings via selective CâX functionalization should be widely applicable for increasing functional molecular complexity. Modular installation of stereospecific alkene motifs into pharmaceuticals illustrated the synthetic application of the present protocol in drug discovery.
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Single-atom catalysts have received significant attention for their ability to enable highly selective reactions. However, many reactions require more than one adjacent site to align reactants or break specific bonds. For example, breaking a C-O or O-H bond may be facilitated by a dual site containing an oxophilic element and a carbophilic or "hydrogenphilic" element that binds each molecular fragment. However, design of stable and well-defined dual-atom sites with desirable reactivity is difficult due to the complexity of multicomponent catalytic surfaces. Here, we describe a new type of dual-atom system, trimetallic dual-atom alloys, which were designed via computation of the alloying energetics. Through a broad computational screening we discovered that Pt-Cr dimers embedded in Ag(111) can be formed by virtue of the negative mixing enthalpy of Pt and Cr in Ag and the favorable interaction between Pt and Cr. These dual-atom alloy sites were then realized experimentally through surface science experiments that enabled the active sites to be imaged and their reactivity related to their atomic-scale structure. Specifically, Pt-Cr sites in Ag(111) can convert ethanol, whereas PtAg and CrAg are unreactive toward ethanol. Calculations show that the oxophilic Cr atom and the hydrogenphilic Pt atom act synergistically to break the O-H bond. Furthermore, ensembles with more than one Cr atom, present at higher dopant loadings, produce ethylene. Our calculations have identified many other thermodynamically favorable dual-atom alloy sites, and hence this work highlights a new class of materials that should offer new and useful chemical reactivity beyond the single-atom paradigm.
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It has been reported that cadherin 6 (CDH6) upregulation is associated with enhanced epithelial-to-mesenchymal transition (EMT) in several types of solid tumor cells. The current study aimed to explore the effect of CDH6 on the migration and invasion of stomach adenocarcinoma (STAD) cells, the transcription factors involved in CDH6 dysregulation and their effect on mitochondrial fission. Bioinformatics analysis was performed using data extracted from the Genotype-Tissue Expression Project, the Cancer Genome Atlas and Kaplan-Meier plotter. AGS and HGC27 cells were used to establish an in vitro STAD cell model. The results showed that higher CDH6 expression was associated with significantly shorter overall survival in patients with STAD. In addition, CDH6 overexpression promoted wound healing, enhanced the invasion ability of tumor cells and increased mitochondrial fission. Glioma-associated oncogene family zinc finger 2 (GLI2) could bind to the CDH6 promoter and activate its transcription. Fluorescent labeling also showed that GLI2 overexpression promoted mitochondrial fission. However, CDH6 silencing significantly reduced mitochondrial fragmentation. Besides, GLI2 overexpression notably upregulated phosphorylated-focal adhesion kinase and dynamin-related protein 1. However, the above effects were largely abrogated by CDH6 knockdown. In conclusion, the present study suggested that the novel GLI2/CDH6 axis could enhance the migration, invasion and mitochondrial fission of STAD cells.
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Adenocarcinoma , Neoplasias Gástricas , Humanos , Adenocarcinoma/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Movimiento Celular/genética , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Dinámicas Mitocondriales , Proteínas Nucleares/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Proteína Gli2 con Dedos de Zinc/metabolismoRESUMEN
Glycerophospholipids, sphingolipids and cholesterol assemble into lipid bilayers that form the scaffold of cellular membranes, in which proteins are embedded. Membrane composition and membrane protein profiles differ between plasma and intracellular membranes and between the two leaflets of a membrane. Lipid distributions between two leaflets are mediated by lipid translocases, including flippases and scramblases. Flippases use ATP to catalyze the inward movement of specific lipids between leaflets. In contrast, bidirectional flip-flop movements of lipids across the membrane are mediated by scramblases in an ATP-independent manner. Scramblases have been implicated in disrupting the lipid asymmetry of the plasma membrane, protein glycosylation, autophagosome biogenesis, lipoprotein secretion, lipid droplet formation and communications between organelles. Although scramblases in plasma membranes were identified over 10 years ago, most progress about scramblases localized in intracellular membranes has been made in the last few years. Herein, we review the role of scramblases in regulating lipid distributions in cellular membranes, focusing primarily on intracellular membrane-localized scramblases.
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Membranas Intracelulares , Membrana Dobles de Lípidos , Membrana Celular/metabolismo , Membrana Dobles de Lípidos/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/metabolismo , Adenosina Trifosfato/metabolismo , Fosfolípidos/metabolismo , Proteínas de Transferencia de Fosfolípidos/metabolismoRESUMEN
The anthocyanin content is an important indicator of the nutritional value of most fruits, including apple (Malus domestica). Anthocyanin synthesis is coordinately regulated by light and various phytohormones. In this study on apple, we revealed the antagonistic relationship between light and brassinosteroid (BR) signaling pathways, which is mediated by BRASSINAZOLE-RESISTANT 1 (MdBZR1) and the B-box protein MdCOL6. The exogenous application of brassinolide inhibited the high-light-induced anthocyanin accumulation in red-fleshed apple seedlings, whereas increases in the light intensity decreased the endogenous BR content. The overexpression of MdBZR1 inhibited the anthocyanin synthesis in apple plants. An exposure to a high-light intensity induced the degradation of dephosphorylated MdBZR1, resulting in functional impairment. MdBZR1 was identified as an upstream repressor of MdCOL6, which promotes anthocyanin synthesis in apple plants. Furthermore, MdBZR1 interacts with MdCOL6 to attenuate its ability to activate MdUFGT and MdANS transcription. Thus, MdBZR1 negatively regulates MdCOL6-mediated anthocyanin accumulation. Our study findings have clarified the molecular basis of the integration of light and BR signals during the regulation of anthocyanin biosynthesis, which is an important process influencing fruit quality.
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Malus , Malus/metabolismo , Antocianinas/metabolismo , Brasinoesteroides/farmacología , Brasinoesteroides/metabolismo , Proteínas de Plantas/metabolismo , Frutas/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Biallelic CEBPA mutations are associated with favorable outcomes in acute myeloid leukemia (AML). We evaluated the clinical and biologic implications of CEBPA-basic leucine zipper (CEBPA-bZip) mutations in children and young adults with newly diagnosed AML. CEBPA-bZip mutation status was determined in 2958 patients with AML enrolled on Children's Oncology Group trials (NCT00003790, NCT0007174, NCT00372593, NCT01379181). Next-generation sequencing (NGS) was performed in 1863 patients (107 with CEBPA mutations) to characterize the co-occurring mutations. CEBPA mutational status was correlated with disease characteristics and clinical outcomes. CEBPA-bZip mutations were identified in 160 (5.4%) of 2958 patients, with 132 (82.5%) harboring a second CEBPA mutation (CEBPA-double-mutated [CEBPA-dm]) and 28 (17.5%) had a single CEBPA-bZip only mutation. The clinical and laboratory features of the 2 CEBPA cohorts were very similar. Patients with CEBPA-dm and CEBPA-bZip experienced identical event-free survival (EFS) of 64% and similar overall survival (OS) of 81% and 89%, respectively (P = .259); this compared favorably to EFS of 46% and OS of 61% in patients with CEBPA-wild-type (CEBPA-WT) (both P < .001). Transcriptome analysis demonstrated similar expression profiles for patients with CEBPA-bZip and CEBPA-dm. Comprehensive NGS of patients with CEBPA mutations identified co-occurring CSF3R mutations in 13.1% of patients and GATA2 mutations in 21.5% of patients. Patients with dual CEBPA and CSF3R mutations had an EFS of 17% vs 63% for patients with CEBPA-mutant or CSF3R-WT (P < .001) with a corresponding relapse rate (RR) of 83% vs 22%, respectively (P < .001); GATA2 co-occurrence did not have an impact on outcome. CEBPA-bZip domain mutations are associated with favorable clinical outcomes, regardless of monoallelic or biallelic status. Co-occurring CSF3R and CEBPA mutations are associated with a high RR that nullifies the favorable prognostic impact of CEBPA mutations.
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Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Proteínas Potenciadoras de Unión a CCAAT/genética , Leucemia Mieloide Aguda/genética , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Leucemia Mieloide Aguda/diagnóstico , Masculino , Mutación , Pronóstico , Transcriptoma , Adulto JovenRESUMEN
In brief: Impaired spermatogenesis resulting from disturbed cholesterol metabolism due to intake of high-fat diet (HFD) has been widely recognized, however, the role of preprotein invertase subtilin 9 (PCSK9), which is a negative regulator of cholesterol metabolism, has never been reported. This study aims to reveal the role of PCSK9 on spermatogenesis induced by HFD in mice. Abstract: Long-term consumption of a high-fat diet (HFD) is an important factor that leads to impaired spermatogenesis exhibiting poor sperm quantity and quality. However, the mechanism of this is yet to be elucidated. Disrupted cholesterol homeostasis is one of many crucial pathological factors which could contribute to impaired spermatogenesis. As a negative regulator of cholesterol metabolism, preprotein invertase subtilin 9 (PCSK9) mediates low density lipoprotein receptor (LDLR) degradation to the lysosome, thereby reducing the expression of LDLR on the cell membrane and increasing serum low-density lipoprotein cholesterol level, resulting in lipid metabolism disorders. Here, we aim to study whether PCSK9 is a pathological factor for impaired spermatogenesis induced by HFD and the underlying mechanism. To meet the purpose of our study, we utilized wild-type C57BL/6 male mice and PCSK9 knockout mice with same background as experimental subjects and alirocumab, a PCSK9 inhibitor, was used for treatment. Results indicated that HFD induced higher PCSK9 expression in serum, liver, and testes, and serum PCSK9 is negatively correlated with spermatogenesis, while both PCSK9 inhibitor treatment and PCSK9 knockout methodologies ameliorated impaired lipid metabolism and spermatogenesis in mice fed a HFD. This could be due to the overexpression of PCSK9 induced by HFD leading to dyslipidemia, resulting in testicular lipotoxicity, thus activating the Bcl-2-Bax-Caspase3 apoptosis signaling pathway in testes, particularly in Leydig cells. Our study demonstrates that PCSK9 is an important pathological factor in the dysfunction of spermatogenesis in mice induced by HFD. This finding could provide innovative ideas for the diagnosis and treatment of male infertility.