Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.623
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Cell ; 182(1): 226-244.e17, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32649875

RESUMO

Lung cancer in East Asia is characterized by a high percentage of never-smokers, early onset and predominant EGFR mutations. To illuminate the molecular phenotype of this demographically distinct disease, we performed a deep comprehensive proteogenomic study on a prospectively collected cohort in Taiwan, representing early stage, predominantly female, non-smoking lung adenocarcinoma. Integrated genomic, proteomic, and phosphoproteomic analysis delineated the demographically distinct molecular attributes and hallmarks of tumor progression. Mutational signature analysis revealed age- and gender-related mutagenesis mechanisms, characterized by high prevalence of APOBEC mutational signature in younger females and over-representation of environmental carcinogen-like mutational signatures in older females. A proteomics-informed classification distinguished the clinical characteristics of early stage patients with EGFR mutations. Furthermore, integrated protein network analysis revealed the cellular remodeling underpinning clinical trajectories and nominated candidate biomarkers for patient stratification and therapeutic intervention. This multi-omic molecular architecture may help develop strategies for management of early stage never-smoker lung adenocarcinoma.


Assuntos
Progressão da Doença , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteogenômica , Fumar/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinógenos/toxicidade , Estudos de Coortes , Citosina Desaminase/metabolismo , Ásia Oriental , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Genoma Humano , Humanos , Metaloproteinases da Matriz/metabolismo , Mutação/genética , Análise de Componente Principal
2.
Cell ; 179(6): 1409-1423.e17, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31778655

RESUMO

The evolution of flight in feathered dinosaurs and early birds over millions of years required flight feathers whose architecture features hierarchical branches. While barb-based feather forms were investigated, feather shafts and vanes are understudied. Here, we take a multi-disciplinary approach to study their molecular control and bio-architectural organizations. In rachidial ridges, epidermal progenitors generate cortex and medullary keratinocytes, guided by Bmp and transforming growth factor ß (TGF-ß) signaling that convert rachides into adaptable bilayer composite beams. In barb ridges, epidermal progenitors generate cylindrical, plate-, or hooklet-shaped barbule cells that form fluffy branches or pennaceous vanes, mediated by asymmetric cell junction and keratin expression. Transcriptome analyses and functional studies show anterior-posterior Wnt2b signaling within the dermal papilla controls barbule cell fates with spatiotemporal collinearity. Quantitative bio-physical analyses of feathers from birds with different flight characteristics and feathers in Burmese amber reveal how multi-dimensional functionality can be achieved and may inspire future composite material designs. VIDEO ABSTRACT.


Assuntos
Adaptação Fisiológica , Plumas/anatomia & histologia , Plumas/fisiologia , Voo Animal/fisiologia , Animais , Evolução Biológica , Aves/anatomia & histologia , Moléculas de Adesão Celular/metabolismo , Citoesqueleto/metabolismo , Derme/anatomia & histologia , Células-Tronco/citologia , Fatores de Tempo , Transcriptoma/genética , Via de Sinalização Wnt/genética
3.
Annu Rev Biochem ; 82: 497-530, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23746261

RESUMO

Isoprenoids are a class of natural products with more than 55,000 members. All isoprenoids are constructed from two precursors, isopentenyl diphosphate and its isomer dimethylallyl diphosphate. Two of the most important discoveries in isoprenoid biosynthetic studies in recent years are the elucidation of a second isoprenoid biosynthetic pathway [the methylerythritol phosphate (MEP) pathway] and a modified mevalonic acid (MVA) pathway. In this review, we summarize mechanistic insights on the MEP pathway enzymes. Because many isoprenoids have important biological activities, the need to produce them in sufficient quantities for downstream research efforts or commercial application is apparent. Recent advances in both MVA and MEP pathway-based synthetic biology are also illustrated by reviewing the landmark work of artemisinic acid and taxadien-5α-ol production through microbial fermentations.


Assuntos
Vias Biossintéticas/fisiologia , Eritritol/metabolismo , Hemiterpenos/biossíntese , Terpenos/metabolismo , Catálise , Humanos , Compostos Organofosforados
4.
Proc Natl Acad Sci U S A ; 121(4): e2314396121, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38236736

RESUMO

In our quest to leverage the capabilities of the emerging single-atom catalysts (SACs) for wastewater purification, we confronted fundamental challenges related to electron scarcity and instability. Through meticulous theoretical calculations, we identified optimal placements for nitrogen vacancies (Nv) and iron (Fe) single-atom sites, uncovering a dual-site approach that significantly amplified visible-light absorption and charge transfer dynamics. Informed by these computational insights, we cleverly integrated Nv into the catalyst design to boost electron density around iron atoms, yielding a potent and flexible photoactivator for benign peracetic acid. This exceptional catalyst exhibited remarkable stability and effectively degraded various organic contaminants over 20 cycles with self-cleaning properties. Specifically, the Nv sites captured electrons, enabling their swift transfer to adjacent Fe sites under visible light irradiation. This mechanism accelerated the reduction of the formed "peracetic acid-catalyst" intermediate. Theoretical calculations were used to elucidate the synergistic interplay of dual mechanisms, illuminating increased adsorption and activation of reactive molecules. Furthermore, electron reduction pathways on the conduction band were elaborately explored, unveiling the production of reactive species that enhanced photocatalytic processes. A six-flux model and associated parameters were also applied to precisely optimize the photocatalytic process, providing invaluable insights for future photocatalyst design. Overall, this study offers a molecule-level insight into the rational design of robust SACs in a photo-Fenton-like system, with promising implications for wastewater treatment and other high-value applications.

5.
N Engl J Med ; 388(8): 683-693, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36812432

RESUMO

BACKGROUND: Unilateral focused ultrasound ablation of the internal segment of globus pallidus has reduced motor symptoms of Parkinson's disease in open-label studies. METHODS: We randomly assigned, in a 3:1 ratio, patients with Parkinson's disease and dyskinesias or motor fluctuations and motor impairment in the off-medication state to undergo either focused ultrasound ablation opposite the most symptomatic side of the body or a sham procedure. The primary outcome was a response at 3 months, defined as a decrease of at least 3 points from baseline either in the score on the Movement Disorders Society-Unified Parkinson's Disease Rating Scale, part III (MDS-UPDRS III), for the treated side in the off-medication state or in the score on the Unified Dyskinesia Rating Scale (UDysRS) in the on-medication state. Secondary outcomes included changes from baseline to month 3 in the scores on various parts of the MDS-UPDRS. After the 3-month blinded phase, an open-label phase lasted until 12 months. RESULTS: Of 94 patients, 69 were assigned to undergo ultrasound ablation (active treatment) and 25 to undergo the sham procedure (control); 65 patients and 22 patients, respectively, completed the primary-outcome assessment. In the active-treatment group, 45 patients (69%) had a response, as compared with 7 (32%) in the control group (difference, 37 percentage points; 95% confidence interval, 15 to 60; P = 0.003). Of the patients in the active-treatment group who had a response, 19 met the MDS-UPDRS III criterion only, 8 met the UDysRS criterion only, and 18 met both criteria. Results for secondary outcomes were generally in the same direction as those for the primary outcome. Of the 39 patients in the active-treatment group who had had a response at 3 months and who were assessed at 12 months, 30 continued to have a response. Pallidotomy-related adverse events in the active-treatment group included dysarthria, gait disturbance, loss of taste, visual disturbance, and facial weakness. CONCLUSIONS: Unilateral pallidal ultrasound ablation resulted in a higher percentage of patients who had improved motor function or reduced dyskinesia than a sham procedure over a period of 3 months but was associated with adverse events. Longer and larger trials are required to determine the effect and safety of this technique in persons with Parkinson's disease. (Funded by Insightec; ClinicalTrials.gov number, NCT03319485.).


Assuntos
Globo Pálido , Ablação por Ultrassom Focalizado de Alta Intensidade , Doença de Parkinson , Humanos , Discinesias/etiologia , Discinesias/cirurgia , Globo Pálido/cirurgia , Doença de Parkinson/complicações , Doença de Parkinson/cirurgia , Resultado do Tratamento
6.
Mol Cell ; 69(2): 279-291.e5, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29351847

RESUMO

Sustained energy starvation leads to activation of AMP-activated protein kinase (AMPK), which coordinates energy status with numerous cellular processes including metabolism, protein synthesis, and autophagy. Here, we report that AMPK phosphorylates the histone methyltransferase EZH2 at T311 to disrupt the interaction between EZH2 and SUZ12, another core component of the polycomb repressive complex 2 (PRC2), leading to attenuated PRC2-dependent methylation of histone H3 at Lys27. As such, PRC2 target genes, many of which are known tumor suppressors, were upregulated upon T311-EZH2 phosphorylation, which suppressed tumor cell growth both in cell culture and mouse xenografts. Pathologically, immunohistochemical analyses uncovered a positive correlation between AMPK activity and pT311-EZH2, and higher pT311-EZH2 correlates with better survival in both ovarian and breast cancer patients. Our finding suggests that AMPK agonists might be promising sensitizers for EZH2-targeting cancer therapies.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Animais , Carcinogênese/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/fisiologia , Epigênese Genética , Feminino , Histonas/metabolismo , Humanos , Camundongos , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Ovarianas/metabolismo , Fosforilação , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Fatores de Transcrição , Regulação para Cima
7.
Mol Cell ; 71(4): 606-620.e7, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-30118680

RESUMO

Metformin has been reported to possess antitumor activity and maintain high cytotoxic T lymphocyte (CTL) immune surveillance. However, the functions and detailed mechanisms of metformin's role in cancer immunity are not fully understood. Here, we show that metformin increases CTL activity by reducing the stability and membrane localization of programmed death ligand-1 (PD-L1). Furthermore, we discover that AMP-activated protein kinase (AMPK) activated by metformin directly phosphorylates S195 of PD-L1. S195 phosphorylation induces abnormal PD-L1 glycosylation, resulting in its ER accumulation and ER-associated protein degradation (ERAD). Consistently, tumor tissues from metformin-treated breast cancer patients exhibit reduced PD-L1 levels with AMPK activation. Blocking the inhibitory signal of PD-L1 by metformin enhances CTL activity against cancer cells. Our findings identify a new regulatory mechanism of PD-L1 expression through the ERAD pathway and suggest that the metformin-CTLA4 blockade combination has the potential to increase the efficacy of immunotherapy.


Assuntos
Antineoplásicos/farmacologia , Antígeno B7-H1/genética , Antígeno CTLA-4/genética , Regulação Neoplásica da Expressão Gênica , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/imunologia , Animais , Antígeno B7-H1/imunologia , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Feminino , Glicosilação , Humanos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/imunologia , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos NOD , Fosforilação , Serina/metabolismo , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia
8.
Nucleic Acids Res ; 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39119895

RESUMO

High-quality primer design is essential for the success of all polymerase chain reaction (PCR)-based experiments. We previously developed a thermodynamics-based gene-specific quantitative PCR (qPCR) primer database for 147 organisms, which has been used extensively in gene expression studies. However, the number of organisms and the imperfection of function in the database limits its potential applications. Here, we improved the functionality of qPrimerDB to create a more comprehensive primer resource. Specifically, we (i) developed an improved primer design tool, qPrimer, building upon the previous qPrimerDB pipeline, to enhance the efficiency and simplicity of genome-scale qPCR primer design; (ii) pre-computed qPCR primer resources from 1 308 genomes of 1172 organisms and (iii) introduced a complete system for identifying, designing, checking, marking, and submitting qPCR primers. qPrimerDB 2.0 is freely available at https://qprimerdb.biodb.org. The qPrimer source code is available at https://github.com/swu1019lab/qPrimer.

9.
Plant Physiol ; 195(3): 1925-1940, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38427921

RESUMO

Leaf senescence is a vital aspect of plant physiology and stress responses and is induced by endogenous factors and environmental cues. The plant-specific NAC (NAM, ATAF1/2, CUC2) transcription factor family influences growth, development, and stress responses in Arabidopsis (Arabidopsis thaliana) and other species. However, the roles of NACs in tobacco (Nicotiana tabacum) leaf senescence are still unclear. Here, we report that NtNAC56 regulates leaf senescence in tobacco. Transgenic plants overexpressing NtNAC56 (NtNAC56-OE) showed induction of senescence-related genes and exhibited early senescence and lower chlorophyll content compared to wild-type (WT) plants and the Ntnac56-19 mutant. In addition, root development and seed germination were inhibited in the NtNAC56-OE lines. Transmission electron microscopy observations accompanied by physiological and biochemical assays revealed that NtNAC56 overexpression triggers chloroplast degradation and reactive oxygen species accumulation in tobacco leaves. Transcriptome analysis demonstrated that NtNAC56 activates leaf senescence-related genes and jasmonic acid (JA) biosynthesis pathway genes. In addition, the JA content of NtNAC56-OE plants was higher than in WT plants, and JA treatment induced NtNAC56 expression. We performed DNA affinity purification sequencing to identify direct targets of NtNAC56, among which we focused on LIPOXYGENASE 5 (NtLOX5), a key gene in JA biosynthesis. A dual-luciferase reporter assay and a yeast one-hybrid assay confirmed that NtNAC56 directly binds to the TTTCTT motif in the NtLOX5 promoter. Our results reveal a mechanism whereby NtNAC56 regulates JA-induced leaf senescence in tobacco and provide a strategy for genetically manipulating leaf senescence and plant growth.


Assuntos
Ciclopentanos , Regulação da Expressão Gênica de Plantas , Nicotiana , Oxilipinas , Folhas de Planta , Proteínas de Plantas , Senescência Vegetal , Plantas Geneticamente Modificadas , Fatores de Transcrição , Nicotiana/genética , Nicotiana/fisiologia , Nicotiana/efeitos dos fármacos , Nicotiana/crescimento & desenvolvimento , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Folhas de Planta/metabolismo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Senescência Vegetal/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Clorofila/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Regiões Promotoras Genéticas/genética
10.
Nucleic Acids Res ; 51(9): 4223-4236, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-36484109

RESUMO

Rpc31 is a subunit in the TFIIE-related Rpc82/34/31 heterotrimeric subcomplex of Saccharomyces cerevisiae RNA polymerase III (pol III). Structural analyses of pol III have indicated that the N-terminal region of Rpc31 anchors on Rpc82 and further interacts with the polymerase core and stalk subcomplex. However, structural and functional information for the C-terminal region of Rpc31 is sparse. We conducted a mutational analysis on Rpc31, which uncovered a functional peptide adjacent to the highly conserved Asp-Glu-rich acidic C-terminus. This C-terminal peptide region, termed 'pre-acidic', is important for optimal cell growth, tRNA synthesis, and stable association of Rpc31 in the pre-initiation complex (PIC). Our site-directed photo-cross-linking to map protein interactions within the PIC reveal that this pre-acidic region specifically targets Rpc34 during transcription initiation, but also interacts with the DNA entry surface in free pol III. Thus, we have uncovered a switchable Rpc31 C-terminal region that functions in an initiation-specific protein interaction for pol III transcription.


Assuntos
RNA Polimerase III , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Iniciação da Transcrição Genética , Ligação Proteica , Domínios Proteicos , RNA Polimerase III/química , RNA Polimerase III/metabolismo , RNA de Transferência/biossíntese , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA