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Acute physical activity leads to several changes in metabolic, cardiovascular, and immune pathways. Although studies have examined selected changes in these pathways, the system-wide molecular response to an acute bout of exercise has not been fully characterized. We performed longitudinal multi-omic profiling of plasma and peripheral blood mononuclear cells including metabolome, lipidome, immunome, proteome, and transcriptome from 36 well-characterized volunteers, before and after a controlled bout of symptom-limited exercise. Time-series analysis revealed thousands of molecular changes and an orchestrated choreography of biological processes involving energy metabolism, oxidative stress, inflammation, tissue repair, and growth factor response, as well as regulatory pathways. Most of these processes were dampened and some were reversed in insulin-resistant participants. Finally, we discovered biological pathways involved in cardiopulmonary exercise response and developed prediction models revealing potential resting blood-based biomarkers of peak oxygen consumption.
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Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Idoso , Biomarcadores/metabolismo , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina , Leucócitos Mononucleares/metabolismo , Estudos Longitudinais , Masculino , Metaboloma , Pessoa de Meia-Idade , Oxigênio/metabolismo , Consumo de Oxigênio , Proteoma , TranscriptomaRESUMO
Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1-5), yet the experimental realization is hard to achieve6,7. The recently discovered vanadium-based kagome materials8, which exhibit both superconductivity9-11 and charge-density-wave orders12-14, are nonmagnetic8,9 and weakly correlated15,16. Thus these materials are unlikely to host the exotic superconductivity theoretically proposed. Here we report the discovery of a chromium-based kagome metal, CsCr3Sb5, which is contrastingly featured with strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. Under ambient pressure, this kagome metal undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4a0 structural modulation. At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with pressure and, remarkably, a superconducting dome emerges at 3.65-8.0 GPa. The maximum of the superconducting transition temperature, Tcmax = 6.4 K, appears when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behaviour, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors17,18. Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems.
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The major antioxidant L-ascorbic acid (AsA) plays important roles in plant growth, development, and stress responses. However, the importance of AsA concentration and the regulation of AsA metabolism in plant reproduction remain unclear. In Arabidopsis (Arabidopsis thaliana) anthers, the tapetum monolayer undergoes cell differentiation to support pollen development. Here, we report that a transcription factor, DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION 1 (TDF1), inhibits tapetal cell division leading to cell differentiation. We identified SKEWED5-SIMILAR 18 (SKS18) as a downstream target of TDF1. Enzymatic assays showed that SKS18, annotated as a multicopper oxidase-like protein, has ascorbate oxidase activity, leading to AsA oxidation. We also show that VITAMIN C DEFECTIVE1 (VTC1), an AsA biosynthetic enzyme, is negatively controlled by TDF1 to maintain proper AsA contents. Consistently, either knockout of SKS18 or VTC1 overexpression raised AsA concentrations, resulting in extra tapetal cells, while SKS18 overexpression in tdf1 or the vtc1-3 tdf1 double mutant mitigated their defective tapetum. We observed that high AsA concentrations caused lower accumulation of reactive oxygen species (ROS) in tapetal cells. Overexpression of ROS scavenging genes in tapetum restored excess cell divisions. Thus, our findings demonstrate that TDF1-regulated AsA balances cell division and cell differentiation in the tapetum through governing ROS homeostasis.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Ascórbico , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Divisão Celular , Diferenciação Celular/genética , Homeostase , Regulação da Expressão Gênica de PlantasRESUMO
Plant lipids are important as alternative sources of carbon and energy when sugars or starch are limited. Here, we applied combined heat and darkness or extended darkness to a panel of â¼300 Arabidopsis (Arabidopsis thaliana) accessions to study lipid remodeling under carbon starvation. Natural allelic variation at 3-KETOACYL-COENZYME A SYNTHASE4 (KCS4), a gene encoding an enzyme involved in very long chain fatty acid (VLCFA) synthesis, underlies the differential accumulation of polyunsaturated triacylglycerols (puTAGs) under stress. Ectopic expression of KCS4 in yeast and plants proved that KCS4 is a functional enzyme localized in the endoplasmic reticulum with specificity for C22 and C24 saturated acyl-CoA. Allelic mutants and transient overexpression in planta revealed the differential role of KCS4 alleles in VLCFA synthesis and leaf wax coverage, puTAG accumulation, and biomass. Moreover, the region harboring KCS4 is under high selective pressure and allelic variation at KCS4 correlates with environmental parameters from the locales of Arabidopsis accessions. Our results provide evidence that KCS4 plays a decisive role in the subsequent fate of fatty acids released from chloroplast membrane lipids under carbon starvation. This work sheds light on both plant response mechanisms and the evolutionary events shaping the lipidome under carbon starvation.
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Proteínas de Arabidopsis , Arabidopsis , Humanos , Arabidopsis/metabolismo , Coenzima A/genética , Coenzima A/metabolismo , Escuridão , Amigos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ácidos Graxos/metabolismo , Triglicerídeos/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Protein synthesis in response to neuronal activity, known as activity-dependent translation, is critical for synaptic plasticity and memory formation. However, the signaling cascades that couple neuronal activity to the translational events remain elusive. In this study, we identified the role of calmodulin (CaM), a conserved Ca2+-binding protein, in ribosomal RNA (rRNA) biogenesis in neurons. We found the CaM-regulated rRNA synthesis is Ca2+-dependent and necessary for nascent protein synthesis and axon growth in hippocampal neurons. Mechanistically, CaM interacts with nucleolar DEAD (Asp-Glu-Ala-Asp) box RNA helicase (DDX21) in a Ca2+-dependent manner to regulate nascent rRNA transcription within nucleoli. We further found CaM alters the conformation of DDX21 to liberate the DDX21-sequestered RPA194, the catalytic subunit of RNA polymerase I, to facilitate transcription of ribosomal DNA. Using high-throughput screening, we identified the small molecules batefenterol and indacaterol that attenuate the CaM-DDX21 interaction and suppress nascent rRNA synthesis and axon growth in hippocampal neurons. These results unveiled the previously unrecognized role of CaM as a messenger to link the activity-induced Ca2+ influx to the nucleolar events essential for protein synthesis. We thus identified the ability of CaM to transmit information to the nucleoli of neurons in response to stimulation.
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Calmodulina , RNA Helicases DEAD-box , Hipocampo , RNA Ribossômico , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Animais , RNA Ribossômico/metabolismo , Calmodulina/metabolismo , Hipocampo/metabolismo , Hipocampo/citologia , Humanos , Neurônios/metabolismo , Ratos , Nucléolo Celular/metabolismo , Células Cultivadas , Células HEK293 , Camundongos , Cálcio/metabolismoRESUMO
Thiram is a toxic fungicide extensively used for the management of pathogens in fruits. Although it is known that thiram degrades in plant tissues, the key enzymes involved in this process remain unexplored. In this study, we report that a tau class glutathione S-transferase (GST) from Carica papaya can degrade thiram. This enzyme was easily obtained by heterologous expression in Escherichia coli, showed low promiscuity toward other thiuram disulfides, and catalyzed thiram degradation under physiological reaction conditions. Site-directed mutagenesis indicated that G-site residue S67 shows a key influence for the enzymatic activity toward thiram, while mutation of residue S13, which reduced the GSH oxidase activity, did not significantly affect the thiram-degrading activity. The formation of dimethyl dithiocarbamate, which was subsequently converted into carbon disulfide, and dimethyl dithiocarbamoylsulfenic acid as the thiram degradation products suggested that thiram undergoes an alkaline hydrolysis that involves the rupture of the disulfide bond. Application of the GST selective inhibitor 4-chloro-7-nitro-2,1,3-benzoxadiazole reduced papaya peel thiram-degrading activity by 95%, indicating that this is the main degradation route of thiram in papaya. GST from Carica papaya also catalyzed the degradation of the fungicides chlorothalonil and thiabendazole, with residue S67 showing again a key influence for the enzymatic activity. These results fill an important knowledge gap in understanding the catalytic promiscuity of plant GSTs and reveal new insights into the fate and degradation products of thiram in fruits.
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Carica , Glutationa Transferase , Tiram , Carica/enzimologia , Carica/genética , Fungicidas Industriais/metabolismo , Glutationa Transferase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/química , Mutagênese Sítio-Dirigida , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tiram/metabolismo , Escherichia coli/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Human hematopoietic stem cells (HSCs), like their counterparts in mice, comprise a functionally and molecularly heterogeneous population of cells throughout life that collectively maintain required outputs of mature blood cells under homeostatic conditions. In both species, an early developmental change in the HSC population involves a postnatal switch from a state in which most of these cells exist in a rapidly cycling state and maintain a high self-renewal potential to a state in which the majority of cells are in a quiescent state with an overall reduced self-renewal potential. However, despite the well-established growth factor dependence of HSC proliferation, whether and how this mechanism of HSC regulation might be affected by aging has remained poorly understood. To address this knowledge gap, we isolated highly HSC-enriched CD34+CD38-CD45RA-CD90+CD49f+ (CD49f+) cells from cord blood, adult bone marrow, and mobilized peripheral blood samples obtained from normal humans spanning 7 decades of age and then measured their functional and molecular responses to growth factor stimulation in vitro and their regenerative activity in vivo in mice that had undergone transplantation. Initial experiments revealed that advancing donor age was accompanied by a significant and progressively delayed proliferative response but not the altered mature cell outputs seen in normal older individuals. Importantly, subsequent dose-response analyses revealed an age-associated reduction in the growth factor-stimulated proliferation of CD49f+ cells mediated by reduced activation of AKT and altered cell cycle entry and progression. These findings identify a new intrinsic, pervasive, and progressive aging-related alteration in the biological and signaling mechanisms required to drive the proliferation of very primitive, normal human hematopoietic cells.
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Células-Tronco Hematopoéticas , Mitógenos , Adulto , Humanos , Animais , Camundongos , Integrina alfa6/metabolismo , Mitógenos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Antígenos CD34/metabolismo , Proliferação de Células , Pontos de Checagem do Ciclo Celular , Ciclo Celular , Peptídeos e Proteínas de Sinalização Intercelular/metabolismoRESUMO
Vascular calcification is a major risk factor for cardiovascular disease mortality, with a significant prevalence in chronic kidney disease (CKD). Pharmacological inhibition of histone acetyltransferase has been proven to protect against from vascular calcification. However, the role of Histone Deacetylase 2 (HDAC2) and molecular mechanisms in vascular calcification of CKD remains unknown. An in vivo model of CKD was established using mouse fed with a high adenine and phosphate diet, and an in vitro model was produced using human aortic vascular smooth muscle cells (VSMCs) stimulated with ß-glycerophosphate (ß-GP). HDAC2 expression was found to be reduced in medial artery of CKD mice and ß-GP-induced VSMCs. Overexpression of HDAC2 attenuated OPN and OCN upregulation, α-SMA and SM22α downregulation, and calcium deposition in aortas of CKD. The in vitro results also demonstrated that ß-GP-induced osteogenic differentiation was inhibited by HDAC2. Furthermore, we found that HDAC2 overexpression caused an increase in LC3II/I, a decrease in p62, and an induction of autophagic flux. Inhibition of autophagy using its specific inhibitor 3-MA blocked HDAC2's protective effect on osteogenic differentiation in ß-GP-treated VSMCs. Taken together, these results suggest that HDAC2 may protect against vascular calcification by the activation of autophagy, laying out a novel insight for the molecular mechanism in vascular calcification of CKD.
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Glicerofosfatos , Insuficiência Renal Crônica , Calcificação Vascular , Humanos , Animais , Camundongos , Histona Desacetilase 2/genética , Osteogênese , AutofagiaRESUMO
There are two general approaches to developing artificial general intelligence (AGI)1: computer-science-oriented and neuroscience-oriented. Because of the fundamental differences in their formulations and coding schemes, these two approaches rely on distinct and incompatible platforms2-8, retarding the development of AGI. A general platform that could support the prevailing computer-science-based artificial neural networks as well as neuroscience-inspired models and algorithms is highly desirable. Here we present the Tianjic chip, which integrates the two approaches to provide a hybrid, synergistic platform. The Tianjic chip adopts a many-core architecture, reconfigurable building blocks and a streamlined dataflow with hybrid coding schemes, and can not only accommodate computer-science-based machine-learning algorithms, but also easily implement brain-inspired circuits and several coding schemes. Using just one chip, we demonstrate the simultaneous processing of versatile algorithms and models in an unmanned bicycle system, realizing real-time object detection, tracking, voice control, obstacle avoidance and balance control. Our study is expected to stimulate AGI development by paving the way to more generalized hardware platforms.
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The 2nd CASMS conference was held virtually through Gather. Town platform from October 17 to 21, 2022, with a total of 363 registrants including an outstanding and diverse group of scientists at the forefront of their research fields from both academia and industry worldwide, especially in the United States and China. The conference offered a 5-day agenda with an exciting scientific program consisting of two plenary lectures, 14 parallel symposia, and 4 special sessions in which a total of 97 invited speakers presented technological innovations and their applications in proteomics & biological mass spectrometry and metabo-lipidomics & pharmaceutical mass spectrometry. In addition, 18 invited speakers/panelists presented at 3 research-focused and 2 career development workshops. Moreover, 144 posters, 54 lightning talks, 5 sponsored workshops, and 14 exhibitions were presented, from which 20 posters and 8 lightning talks received presentation awards. Furthermore, the conference featured 1 MCP lectureship and 5 young investigator awardees for the first time to highlight outstanding mid-career and early-career rising stars in mass spectrometry from our society. The conference provided a unique scientific platform for young scientists (i.e., graduate students, postdocs and junior faculty/investigators) to present their research, meet with prominent scientists, and learn about career development and job opportunities (http://casms.org).
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Espectrometria de Massas , Sociedades Científicas , Humanos , China , Preparações Farmacêuticas , Proteômica , Estados UnidosRESUMO
Electrochemistry that empowers innovative nanoscopic analysis has long been pursued. Here, the concept of aggregation-enabled electrochemistry (AEE) in a confined nanopore is proposed and devised by reactive oxygen species (ROS)-responsive aggregation of CdS quantum dots (QDs) within a functional nanopipette. Complementary Faradaic and non-Faradaic operations of the CdS QDs aggregate could be conducted to simultaneously induce the signal-on of the photocurrents and the signal-off of the ionic signals. Such a rationale permits the cross-checking of the mutually corroborated signals and thus delivers more reliable results for single-cell ROS analysis. Combined with the rich biomatter-light interplay, the concept of AEE can be extended to other stimuli-responsive aggregations for electrochemical innovations.
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This study investigates genetic mutations and immune cell dynamics in stomach adenocarcinoma (STAD), focusing on identifying prognostic markers and therapeutic targets. Analysis of TCGA-STAD samples revealed C > A as the most common single nucleotide variant (SNV) in both high and low-risk groups. Key mutated driver genes included TTN, TP53 and MUC16, with frame-shift mutations more prevalent in the low-risk group and missense mutations in the high-risk group. Interaction analysis of hub genes such as C1QA and CD68 showed significant correlations, impacting immune cell infiltration patterns. Using ssGSEA, we found higher immune cell infiltration (B cells, CD4+ T cells, CD8+ T cells, DC cells, NK cells) in the high-risk group, correlated with increased risk scores. xCell algorithm results indicated distinct immune infiltration levels between the groups. The study's risk scoring model proved effective in prognosis prediction and immunotherapy efficacy assessment. Key molecules like CD28, CD27 and SLAMF7 correlated significantly with risk scores, suggesting potential targets for high-risk STAD patients. Drug sensitivity analysis showed a negative correlation between risk scores and sensitivity to certain treatments, indicating potential therapeutic options for high-risk STAD patients. We also validated the carcinogenic role of RPL14 in gastric cancer through phenotypic experiments, demonstrating its influence on cancer cell proliferation, invasion and migration. Overall, this research provides crucial insights into the genetic and immune aspects of STAD, highlighting the importance of a risk scoring model for personalized treatment strategies and clinical decision-making in gastric cancer management.
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Adenocarcinoma , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Linfócitos T CD8-Positivos , Imunoterapia , Mutação/genéticaRESUMO
Photoelectrochemical water splitting on n-type semiconductors is highly dependent on catalysis of the rate-determining reaction of O2 evolution. Conventionally, in electrochemistry and photoelectrochemistry O2 evolution is catalyzed by metal oxide catalysts like IrO2 and RuO2, whereas noble metals such as Pt are considered unsuitable for this purpose. However, our study finds that Pt, in its single-atom form, exhibits exceptional cocatalytic properties for photoelectrochemical water oxidation on a TiO2 photoanode, in contrast to Pt in a nanoparticle form. The decoration of Pt single atoms onto TiO2 yields a remarkable current density of 5.89 mA cm-2 at 1.23 VRHE, surpassing bare TiO2 (or Pt nanoparticle decorated TiO2) by 2.52 times. Notably, this enhancement remains consistent over a wide pH range. By accompanying theoretical work, we assign this significant enhancement to an improved charge transfer and separation efficiency along with accelerated kinetics in the oxygen evolution reaction facilitated by the presence of Pt single atoms on the TiO2 surface.
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We report the synthesis, crystal structure, and physical properties of a novel ternary compound, Th2Cu4As5. The material crystallizes in a tetragonal structure with lattice parameters a = 4.0639(3) Å and c = 24.8221(17) Å. Its structure can be described as an alternating stacking of fluorite-type Th2As2 layers with antifluorite-type double-layered Cu4As3 slabs. The measurement of electrical resistivity, magnetic susceptibility, and specific heat reveals that Th2Cu4As5 undergoes bulk superconducting transition at 4.2 K. Additionally, all these physical quantities exhibit anomalies at 48 K, accompanied by a sign change in the Hall coefficient, suggesting a charge-density-wave-like (CDW) phase transition. Drawing from both experimental data and band calculations, we propose that the superconducting and CDW-like phase transitions are, respectively, associated with the Cu4As3 slabs and the As plane in the Th2As2 layers.
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Ubiquitin-specific peptidase 15 (USP15), a critical deubiquitinating enzyme, has been demonstrated to improve substrate stabilization by hydrolyzing the bond between the substrate and ubiquitin, and is implicated in multiple carcinogenic processes. Prompted by the information cited from The Cancer Genome Atlas (TCGA) database and the Cancer Proteogenomic Data Analysis Site (cProSite), USP15 is selectively overexpressed in clear cell renal cell carcinoma (ccRCC) samples. We aimed to investigate the function of USP15 on ccRCC malignant features, which was emphasized in its deubiquitination of SHC adaptor protein 1 (SHC1). The overexpression of USP15 promoted the capacity of proliferation, migration, and invasion in ccRCC CAKI1 and 769-P cells, and these malignant biological properties were diminished by USP15 deletion in 786-O cells. USP15 accelerated tumor growth and lung metastasis in vivo. In addition, deubiquitinase USP15 was further identified as a new protector for SHC1 from degradation by the ubiquitination pathway, the post-translational modification. In sequence, transcription factor activating enhancer binding protein 4 (TFAP4) was shown to be partly responsible for USP15 expression at the level of transcription, as manifested by the chromatin immunoprecipitation and pull-down assay. Based on the in vitro and in vivo data, we postulate that USP15 regulated by TFAP4 transcriptionally deteriorates ccRCC malignant biological properties via stabilizing SHC1 by deubiquitination.
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Carcinoma de Células Renais , Proliferação de Células , Neoplasias Renais , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Proteases Específicas de Ubiquitina , Ubiquitinação , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/genética , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/genética , Linhagem Celular Tumoral , Animais , Proteases Específicas de Ubiquitina/metabolismo , Proteases Específicas de Ubiquitina/genética , Camundongos , Proliferação de Células/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Camundongos Nus , MasculinoRESUMO
BACKGROUND & AIMS: Endoplasmic reticulum (ER) stress of hepatocytes plays a causative role in non-alcoholic fatty liver disease (NAFLD). Reduced expression of hepatic nuclear factor 4α (HNF4α) is a critical event in the pathogenesis of NAFLD and other liver diseases. Whether ER stress regulates HNF4α expression remains unknown. The aim of this study was to delineate the machinery of HNF4α protein degradation and explore a therapeutic strategy based on protecting HNF4α stability during NAFLD progression. METHODS: Correlation of HNF4α and tribbles homologue 3 (TRIB3), an ER stress sensor, was evaluated in human and mouse NAFLD tissues. RNA-sequencing, mass spectrometry analysis, co-immunoprecipitation, in vivo and in vitro ubiquitination assays were used to elucidate the mechanisms of TRIB3-mediated HNF4α degradation. Molecular docking and co-immunoprecipitation analyses were performed to identify a cell-penetrating peptide that ablates the TRIB3-HNF4α interaction. RESULTS: TRIB3 directly interacts with HNF4α and mediates ER stress-induced HNF4α degradation. TRIB3 recruits tripartite motif containing 8 (TRIM8) to form an E3 ligase complex that catalyzes K48-linked polyubiquitination of HNF4α on lysine 470. Abrogating the degradation of HNF4α attenuated the effect of TRIB3 on a diet-induced NAFLD model. Moreover, the TRIB3 gain-of-function variant p.Q84R is associated with NAFLD progression in patients, and induces lower HNF4α levels and more severe hepatic steatosis in mice. Importantly, disrupting the TRIB3-HNF4α interaction using a cell-penetrating peptide restores HNF4α levels and ameliorates NAFLD progression in mice. CONCLUSIONS: Our findings unravel the machinery of HNF4α protein degradation and indicate that targeting TRIB3-TRIM8 E3 complex-mediated HNF4α polyubiquitination may be an ideal strategy for NAFLD therapy. IMPACT AND IMPLICATIONS: Reduced expression of hepatic nuclear factor 4α (HNF4α) is a critical event in the pathogenesis of NAFLD and other liver diseases. However, the mechanism of HNF4α protein degradation remains unknown. Herein, we reveal that TRIB3-TRIM8 E3 ligase complex is responsible for HNF4α degradation during NAFLD. Inhibiting the TRIB3-HNF4α interaction effectively stabilized HNF4α protein levels and transcription factor activity in the liver and ameliorated TRIB3-mediated NAFLD progression. Our findings demonstrate that disturbing the TRIM8-TRIB3-HNF4α interaction may provide a novel approach to treat NAFLD and even other liver diseases by stabilizing the HNF4α protein.
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Peptídeos Penetradores de Células , Hepatopatia Gordurosa não Alcoólica , Proteínas Serina-Treonina Quinases , Animais , Humanos , Camundongos , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Peptídeos Penetradores de Células/metabolismo , Fígado/patologia , Simulação de Acoplamento Molecular , Proteínas do Tecido Nervoso , Hepatopatia Gordurosa não Alcoólica/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Proteomics analysis of mass-limited samples has become increasingly important for understanding biological systems in physiologically relevant contexts such as patient samples, multicellular organoids, spheroids, and single cells. However, relatively low sensitivity in top-down proteomics methods makes their application to mass-limited samples challenging. Capillary electrophoresis (CE) has emerged as an ideal separation method for mass-limited samples due to its high separation resolution, ultralow detection limit, and minimal sample volume requirements. Recently, we developed "spray-capillary", an electrospray ionization (ESI)-assisted device, that is capable of quantitative ultralow-volume sampling (e.g., pL-nL level). Here, we developed a spray-capillary-CE-MS platform for ultrasensitive top-down proteomics analysis of intact proteins in mass-limited complex biological samples. Specifically, to improve the sensitivity of the spray-capillary platform, we incorporated a polyethylenimine (PEI)-coated capillary and optimized the spray-capillary inner diameter. Under optimized conditions, we successfully detected over 200 proteoforms from 50 pg of E. coli lysate. To our knowledge, the spray-capillary CE-MS platform developed here represents one of the most sensitive detection methods for top-down proteomics. Furthermore, in a proof-of-principle experiment, we detected 261 ± 65 and 174 ± 45 intact proteoforms from fewer than 50 HeLa and OVCAR-8 cells, respectively, by coupling nanodroplet-based sample preparation with our optimized CE-MS platform. Overall, our results demonstrate the capability of the modified spray-capillary CE-MS platform to perform top-down proteomics analysis on picogram amounts of samples. This advancement presents the possibility of meaningful top-down proteomics analysis of mass-limited samples down to the level of single mammalian cells.
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Eletroforese Capilar , Proteômica , Eletroforese Capilar/métodos , Proteômica/métodos , Humanos , Escherichia coli/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas/métodosRESUMO
G-quadruplex structures within the nuclear genome (nG4) is an important regulatory factor, while the function of G4 in the mitochondrial genome (mtG4) still needs to be explored, especially in human sperms. To gain a better understanding of the relationship between mtG4 and mitochondrial function, it is crucial to develop excellent probes that can selectively visualize and track mtG4 in both somatic cells and sperms. Herein, based on our previous research on purine frameworks, we attempted for the first time to extend the conjugated structure from the C-8 site of purine skeleton and discovered that the purine derivative modified by the C-8 aldehyde group is an ideal platform for constructing near-infrared probes with extremely large Stokes shift (>220 nm). Compared with the compound substituted with methylpyridine (PAP), the molecule substituted with methylthiazole orange (PATO) showed better G4 recognition ability, including longer emission (â¼720 nm), more significant fluorescent enhancement (â¼67-fold), lower background, and excellent photostability. PATO exhibited a sensitive response to mtG4 variation in both somatic cells and human sperms. Most importantly, PATO helped us to discover that mtG4 was significantly increased in cells with mitochondrial respiratory chain damage caused by complex I inhibitors (6-OHDA and rotenone), as well as in human sperms that suffer from oxidative stress. Altogether, our study not only provides a novel ideal molecular platform for constructing high-performance probes but also develops an effective tool for studying the relationship between mtG4 and mitochondrial function in both somatic cells and human sperms.
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Corantes Fluorescentes , Purinas , Humanos , Purinas/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Doenças Mitocondriais/metabolismo , Regulação para Cima , Genoma Mitocondrial , Quadruplex G , Mitocôndrias/metabolismo , Raios Infravermelhos , Células HeLaRESUMO
OBJECTIVE: The aim of this study is to evaluate the clinicopathological features and prognostic significance of HER2 low, fibrotic focus (FF), and tumor-infiltrating lymphocytes (TILs) in patients with HER2-negative breast cancer. METHODS: We retrospectively reviewed the data of 293 patients with HER2-negative, stage I-II, invasive breast cancer of non-specific types. The HER2-negative cases were classified into HER2 low and HER2 0. Digital analysis of hematoxylin-eosin stained whole slide images was used to evaluate the FF expression. TILs were also evaluated using the Whole Slide Image. Furthermore, the association between HER2 low, FF, and TILs as well as their prognostic significance were analyzed. RESULTS: The study cohort included 178 cases (60.8%) with HER2 low and 115 cases (39.2%) with HER2 0. Older age, lower Nottingham histological grade (NHG), estrogen receptor (ER) positivity, progesterone receptor (PR) positivity, and hormone receptor (HR) positivity were all associated with HER2 low. FF was correlated with older age, intermediate and low NHG, vascular invasion, HR positivity, HER2 low status, high Ki67 expression, and low TILs. Univariate survival analysis showed that FF was significantly associated with shorter progression-free survival (PFS). Stratified analysis indicated that in the HR-negative and HR-positive groups, HER2 status and TILs did not affect PFS. DFS was longer in patients without FF compared to those with FF in the HR-positive (hazard ratio [HR] = 0.313) and HER2 low (HR = 0.272) groups. DFS was also significantly longer in patients without FF compared to those with FF in the HR-negative (HR = 0.069) and HER2 0 groups (HR = 0.129). CONCLUSION: The results indicated that the HER2 low status and the TILs expression did not impact prognosis. However, patients with FF exhibited distinct biological characteristics and prognostic significance, particularly in the HR-negative and HER2 0 groups. This provides a rationale for accurate diagnosis and treatment of HER2-negative breast cancer.
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Neoplasias da Mama , Humanos , Feminino , Prognóstico , Estudos Retrospectivos , Receptor ErbB-2/metabolismo , Linfócitos do Interstício Tumoral , Intervalo Livre de DoençaRESUMO
Mass spectrometry-based metabolomics approaches can enable detection and quantification of many thousands of metabolite features simultaneously. However, compound identification and reliable quantification are greatly complicated owing to the chemical complexity and dynamic range of the metabolome. Simultaneous quantification of many metabolites within complex mixtures can additionally be complicated by ion suppression, fragmentation and the presence of isomers. Here we present guidelines covering sample preparation, replication and randomization, quantification, recovery and recombination, ion suppression and peak misidentification, as a means to enable high-quality reporting of liquid chromatography- and gas chromatography-mass spectrometry-based metabolomics-derived data.