Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.006
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nature ; 619(7968): 102-111, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37258676

RESUMO

The stability and resilience of the Earth system and human well-being are inseparably linked1-3, yet their interdependencies are generally under-recognized; consequently, they are often treated independently4,5. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice)4. The stricter of the safe or just boundaries sets the integrated safe and just ESB. Our findings show that justice considerations constrain the integrated ESBs more than safety considerations for climate and atmospheric aerosol loading. Seven of eight globally quantified safe and just ESBs and at least two regional safe and just ESBs in over half of global land area are already exceeded. We propose that our assessment provides a quantitative foundation for safeguarding the global commons for all people now and into the future.


Assuntos
Mudança Climática , Planeta Terra , Justiça Ambiental , Internacionalidade , Segurança , Humanos , Aerossóis/metabolismo , Clima , Água/metabolismo , Nutrientes/metabolismo , Segurança/legislação & jurisprudência , Segurança/normas
2.
PLoS Pathog ; 20(7): e1012338, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39008527

RESUMO

Recently published near full-length KSHV genomes from a Cameroon Kaposi sarcoma case-control study showed strong evidence of viral recombination and mixed infections, but no sequence variations associated with disease. Using the same methodology, an additional 102 KSHV genomes from 76 individuals with KSHV-associated diseases have been sequenced. Diagnoses comprise all KSHV-associated diseases (KAD): Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated large cell lymphoma (KSHV-LCL), a type of multicentric Castleman disease (KSHV-MCD), and KSHV inflammatory cytokine syndrome (KICS). Participants originated from 22 different countries, providing the opportunity to obtain new near full-length sequences of a wide diversity of KSHV genomes. These include near full-length sequence of genomes with KSHV K1 subtypes A, B, C, and F as well as subtype E, for which no full sequence was previously available. High levels of recombination were observed. Fourteen individuals (18%) showed evidence of infection with multiple KSHV variants (from two to four unique genomes). Twenty-six comparisons of sequences, obtained from various sampling sites including PBMC, tissue biopsies, oral fluids, and effusions in the same participants, identified near complete genome conservation between different biological compartments. Polymorphisms were identified in coding and non-coding regions, including indels in the K3 and K15 genes and sequence inversions here reported for the first time. One such polymorphism in KSHV ORF46, specific to the KSHV K1 subtype E2, encoded a mutation in the leucine loop extension of the uracil DNA glycosylase that results in alteration of biochemical functions of this protein. This confirms that KSHV sequence variations can have functional consequences warranting further investigation. This study represents the largest and most diverse analysis of KSHV genome sequences to date among individuals with KAD and provides important new information on global KSHV genomics.


Assuntos
Genoma Viral , Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/genética , Sarcoma de Kaposi/virologia , Sarcoma de Kaposi/genética , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Polimorfismo Genético , Idoso , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/virologia , Etnicidade/genética , Hiperplasia do Linfonodo Gigante/virologia , Hiperplasia do Linfonodo Gigante/genética , Filogenia
3.
Proc Natl Acad Sci U S A ; 120(9): e2214996120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36802419

RESUMO

Neurons throughout the primate inferior temporal (IT) cortex respond selectively to visual images of faces and other complex objects. The response magnitude of neurons to a given image often depends on the size at which the image is presented, usually on a flat display at a fixed distance. While such size sensitivity might simply reflect the angular subtense of retinal image stimulation in degrees, one unexplored possibility is that it tracks the real-world geometry of physical objects, such as their size and distance to the observer in centimeters. This distinction bears fundamentally on the nature of object representation in IT and on the scope of visual operations supported by the ventral visual pathway. To address this question, we assessed the response dependency of neurons in the macaque anterior fundus (AF) face patch to the angular versus physical size of faces. We employed a macaque avatar to stereoscopically render three-dimensional (3D) photorealistic faces at multiple sizes and distances, including a subset of size/distance combinations designed to cast the same size retinal image projection. We found that most AF neurons were modulated principally by the 3D physical size of the face rather than its two-dimensional (2D) angular size on the retina. Further, most neurons responded strongest to extremely large and small faces, rather than to those of normal size. Together, these findings reveal a graded encoding of physical size among face patch neurons, providing evidence that category-selective regions of the primate ventral visual pathway participate in a geometric analysis of real-world objects.


Assuntos
Macaca , Lobo Temporal , Animais , Lobo Temporal/fisiologia , Neurônios/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Mapeamento Encefálico
4.
Genes Dev ; 32(21-22): 1443-1458, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30366904

RESUMO

Bcl9 and Pygopus (Pygo) are obligate Wnt/ß-catenin cofactors in Drosophila, yet their contribution to Wnt signaling during vertebrate development remains unresolved. Combining zebrafish and mouse genetics, we document a conserved, ß-catenin-associated function for BCL9 and Pygo proteins during vertebrate heart development. Disrupting the ß-catenin-BCL9-Pygo complex results in a broadly maintained canonical Wnt response yet perturbs heart development and proper expression of key cardiac regulators. Our work highlights BCL9 and Pygo as selective ß-catenin cofactors in a subset of canonical Wnt responses during vertebrate development. Moreover, our results implicate alterations in BCL9 and BCL9L in human congenital heart defects.


Assuntos
Cardiopatias Congênitas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Fatores de Transcrição/genética , Via de Sinalização Wnt , Proteínas de Peixe-Zebra/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Coração/embriologia , Camundongos , Mutação , Miocárdio/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , beta Catenina/metabolismo
5.
EMBO J ; 40(10): e106785, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33934382

RESUMO

The interplay between extrinsic signaling and downstream gene networks controls the establishment of cell identity during development and its maintenance in adult life. Advances in next-generation sequencing and single-cell technologies have revealed additional layers of complexity in cell identity. Here, we review our current understanding of transcription factor (TF) networks as key determinants of cell identity. We discuss the concept of the core regulatory circuit as a set of TFs and interacting factors that together define the gene expression profile of the cell. We propose the core regulatory circuit as a comprehensive conceptual framework for defining cellular identity and discuss its connections to cell function in different contexts.


Assuntos
Medicina Regenerativa/métodos , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
J Cell Sci ; 136(6)2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36846872

RESUMO

Multidirectional or disturbed flow promotes endothelial dysfunction and is associated with early atherogenesis. Here we investigated the role of Wnt signalling in flow-mediated endothelial dysfunction. The expression of Frizzled-4 was higher in cultured human aortic endothelial cells (ECs) exposed to disturbed flow compared to that seen for undisturbed flow, obtained using an orbital shaker. Increased expression was also detected in regions of the porcine aortic arch exposed to disturbed flow. The increased Frizzled-4 expression in cultured ECs was abrogated following knockdown of R-spondin-3. Disturbed flow also increased the nuclear localisation and activation of ß-catenin, an effect that was dependent on Frizzled-4 and R-spondin-3. Inhibition of ß-catenin using the small-molecule inhibitor iCRT5 or knockdown of Frizzled-4 or R-spondin-3 resulted in reduced expression of pro-inflammatory genes in ECs exposed to disturbed flow, as did inhibition of WNT5A signalling. Inhibition of the canonical Wnt pathway had no effect. Inhibition of ß-catenin also reduced endothelial paracellular permeability; this was associated with altered junctional and focal adhesion organisation and cytoskeletal remodelling. These data suggest the presence of an atypical Frizzled-4-ß-catenin pathway that promotes endothelial dysfunction in response to disturbed flow.


Assuntos
Células Endoteliais , beta Catenina , Animais , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Células Endoteliais/metabolismo , Inflamação/metabolismo , Permeabilidade , Suínos , Via de Sinalização Wnt , Receptores Frizzled/metabolismo
7.
Development ; 149(4)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35175330

RESUMO

In-depth investigation of any developmental process in plants requires knowledge of both the underpinning molecular networks and how they directly determine patterns of cell division and expansion over time. Floral meristems (FMs) produce floral organs, after which they undergo floral meristem termination (FMT); precise control of organ initiation and FMT is crucial to the reproductive success of any flowering plant. Using live confocal imaging, we characterized developmental dynamics during floral organ primordia initiation and FMT in Aquilegia coerulea (Ranunculaceae). Our results uncover distinct patterns of primordium initiation between stamens and staminodes compared with carpels, and provide insight into the process of FMT, which is discernable based on cell division dynamics that precede carpel initiation. To our knowledge, this is the first quantitative live imaging of meristem development in a system with numerous whorls of floral organs, as well as an apocarpous gynoecium. This study provides crucial information for our understanding of how the spatial-temporal regulation of floral meristem behavior is achieved in both evolutionary and developmental contexts. This article has an associated 'The people behind the papers' interview.


Assuntos
Aquilegia/metabolismo , Meristema/metabolismo , Microscopia de Fluorescência , Aquilegia/crescimento & desenvolvimento , Flores/anatomia & histologia , Flores/crescimento & desenvolvimento , Flores/metabolismo , Processamento de Imagem Assistida por Computador , Proteínas de Plantas/metabolismo
8.
Nature ; 570(7759): 83-86, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31168104

RESUMO

There is a supermassive black hole of mass 4 × 106 solar masses at the centre of the Milky Way1,2. A large reservoir of hot (107 kelvin) and cooler (102 to 104 kelvin) gas surrounds it within a few parsecs3. Although constraints on the amount of hot gas in the accretion zone of the black hole-that is, within 105 Schwarzschild radii (0.04 parsecs)-have been provided by X-ray observations4-6, the mass in cooler gas has been unconstrained. One possible way this cooler gas could be detected is by its emission in hydrogen recombination spectral lines7,8. Here we report imaging of a 104-kelvin ionized gas disk within 2 × 104 Schwarzschild radii, using the 1.3-millimetre recombination line H30α. This emission line is double-peaked, with full velocity linewidth of about 2,200 kilometres per second. The emission is centred on the radio source Sagittarius A*, but the redshifted side is displaced 0.11 arcsec (0.004 parsecs at a distance of 8 kiloparsecs) to the northeast and the blueshifted side is displaced a similar distance to the southwest. We interpret these observations in terms of a rotating disk of mass 10-5 to 10-4 solar masses and mean hydrogen density of about 105 to 106 per cubic centimetre, with the values being sensitive to the assumed geometry. The emission is stronger than expected, given the upper limit on the strength of the Brγ spectral line of hydrogen. We suggest that the H30α transition is enhanced by maser emission.

9.
Proc Natl Acad Sci U S A ; 119(40): e2204071119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36179046

RESUMO

Many tumors express meiotic genes that could potentially drive somatic chromosome instability. While germline cohesin subunits SMC1B, STAG3, and REC8 are widely expressed in many cancers, messenger RNA and protein for RAD21L subunit are expressed at very low levels. To elucidate the potential of meiotic cohesins to contribute to genome instability, their expression was investigated in human cell lines, predominately in DLD-1. While the induction of the REC8 complex resulted in a mild mitotic phenotype, the expression of the RAD21L complex produced an arrested but viable cell pool, thus providing a source of DNA damage, mitotic chromosome missegregation, sporadic polyteny, and altered gene expression. We also found that genomic binding profiles of ectopically expressed meiotic cohesin complexes were reminiscent of their corresponding specific binding patterns in testis. Furthermore, meiotic cohesins were found to localize to the same sites as BORIS/CTCFL, rather than CTCF sites normally associated with the somatic cohesin complex. These findings highlight the existence of a germline epigenomic memory that is conserved in cells that normally do not express meiotic genes. Our results reveal a mechanism of action by unduly expressed meiotic cohesins that potentially links them to aneuploidy and chromosomal mutations in affected cells.


Assuntos
Expressão Ectópica do Gene , Neoplasias , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Instabilidade Cromossômica/genética , Proteínas Cromossômicas não Histona , Segregação de Cromossomos , Proteínas de Ligação a DNA/metabolismo , Humanos , Masculino , Meiose/genética , Neoplasias/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , RNA Mensageiro , Coesinas
10.
Genesis ; 62(4): e23612, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39054872

RESUMO

The SRY HMG box transcription factor Sox21 plays multiple critical roles in neurogenesis, with its function dependent on concentration and developmental stage. In the allotetraploid Xenopus laevis, there are two homeologs of sox21, namely sox21.S and sox21.L. Previous studies focused on Sox21.S, but its amino acid sequence is divergent, lacking conserved poly-A stretches and bearing more similarity with ancestral homologs. In contrast, Sox21.L shares higher sequence similarity with mouse and chick Sox21. To determine if Sox21.S and Sox21.L have distinct functions, we conducted gain and loss-of-function studies in Xenopus embryos. Our studies revealed that Sox21.S and Sox21.L are functionally redundant, but Sox21.L is more effective at driving changes than Sox21.S. These results also support our earlier findings in ectodermal explants, demonstrating that Sox21 function is dose-dependent. While Sox21 is necessary for primary neuron formation, high levels prevent their formation. Strikingly, these proteins autoregulate, with high levels of Sox21.L reducing sox21.S and sox21.L mRNA levels, and decreased Sox21.S promoting increased expression of sox21.L. Our findings shed light on the intricate concentration-dependent roles of Sox21 homeologs in Xenopus neurogenesis.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Neurogênese , Proteínas de Xenopus , Xenopus laevis , Animais , Neurogênese/genética , Xenopus laevis/genética , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Neurônios/metabolismo , Fatores de Transcrição SOXB2/genética , Fatores de Transcrição SOXB2/metabolismo
11.
J Neurosci ; 43(50): 8744-8755, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-37857485

RESUMO

Mammalian target of rapamycin (mTOR) pathway has emerged as a key molecular mechanism underlying memory processes. Although mTOR inhibition is known to block memory processes, it remains elusive whether and how an enhancement of mTOR signaling may improve memory processes. Here we found in male mice that the administration of VO-OHpic, an inhibitor of the phosphatase and tensin homolog (PTEN) that negatively modulates AKT-mTOR pathway, enhanced auditory fear memory for days and weeks, while it left short-term memory unchanged. Memory enhancement was associated with a long-lasting increase in immature-type dendritic spines of pyramidal neurons into the auditory cortex. The persistence of spine remodeling over time arose by the interplay between PTEN inhibition and memory processes, as VO-OHpic induced only a transient immature spine growth in the somatosensory cortex, a region not involved in long-term auditory memory. Both the potentiation of fear memories and increase in immature spines were hampered by rapamycin, a selective inhibitor of mTORC1. These data revealed that memory can be potentiated over time by the administration of a selective PTEN inhibitor. In addition to disclosing new information on the cellular mechanisms underlying long-term memory maintenance, our study provides new insights on the molecular processes that aid enhancing memories over time.SIGNIFICANCE STATEMENT The neuronal mechanisms that may help improve the maintenance of long-term memories are still elusive. The inhibition of mammalian-target of rapamycin (mTOR) signaling shows that this pathway plays a crucial role in synaptic plasticity and memory formation. However, whether its activation may strengthen long-term memory storage is unclear. We assessed the consequences of positive modulation of AKT-mTOR pathway obtained by VO-OHpic administration, a phosphatase and tensin homolog inhibitor, on memory retention and underlying synaptic modifications. We found that mTOR activation greatly enhanced memory maintenance for weeks by producing a long-lasting increase of immature-type dendritic spines in pyramidal neurons of the auditory cortex. These results offer new insights on the cellular and molecular mechanisms that can aid enhancing memories over time.


Assuntos
Córtex Auditivo , Proteínas Proto-Oncogênicas c-akt , Masculino , Camundongos , Animais , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Córtex Auditivo/metabolismo , Espinhas Dendríticas/metabolismo , Tensinas/metabolismo , Memória de Longo Prazo/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Memória de Curto Prazo/fisiologia , Sirolimo/farmacologia , Medo/fisiologia , Monoéster Fosfórico Hidrolases/metabolismo , Mamíferos
12.
Am J Physiol Endocrinol Metab ; 326(1): E50-E60, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38019084

RESUMO

The 5' adenosine monophosphate-activated protein kinase (AMPK) is an important skeletal muscle regulator implicated as a possible therapeutic target to ameliorate the local undesired deconditioning of disuse atrophy. However, the muscle-specific role of AMPK in regulating muscle function, fibrosis, and transcriptional reprogramming during physical disuse is unknown. The purpose of this study was to determine how the absence of both catalytic subunits of AMPK in skeletal muscle influences muscle force production, collagen deposition, and the transcriptional landscape. We generated skeletal muscle-specific tamoxifen-inducible AMPKα1/α2 knockout (AMPKα-/-) mice that underwent 14 days of hindlimb unloading (HU) or remained ambulatory for 14 days (AMB). We found that AMPKα-/- during ambulatory conditions altered body weight and myofiber size, decreased muscle function, depleted glycogen stores and TBC1 domain family member 1 (TBC1D1) phosphorylation, increased collagen deposition, and altered transcriptional pathways. Primarily, pathways related to cellular senescence and mitochondrial biogenesis and function were influenced by the absence of AMPKα. The effects of AMPKα-/- persisted, but were not worsened, following hindlimb unloading. Together, we report that AMPKα is necessary to maintain skeletal muscle quality.NEW & NOTEWORTHY We determined that skeletal muscle-specific AMPKα knockout (KO) mice display functional, fibrotic, and transcriptional alterations before and during muscle disuse atrophy. We also observed that AMPKα KO drives muscle fibrosis and pathways related to cellular senescence that continues during the hindlimb unloading period.


Assuntos
Proteínas Quinases Ativadas por AMP , Transtornos Musculares Atróficos , Animais , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Colágeno/metabolismo , Fibrose , Glicogênio/metabolismo , Elevação dos Membros Posteriores/fisiologia , Camundongos Knockout , Debilidade Muscular/genética , Debilidade Muscular/metabolismo , Debilidade Muscular/patologia , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Transtornos Musculares Atróficos/genética , Transtornos Musculares Atróficos/metabolismo
13.
Cancer ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078647

RESUMO

BACKGROUND: Ruxolitinib (RUX) is a JAK1/2 inhibitor approved for the therapy of myelofibrosis (MF) based on clinical trials including only intermediate2-high risk (INT2/HIGH) patients. However, RUX is commonly used in intermediate-1 (INT1) patients, with scarce information on responses and outcome. METHODS: The authors investigated the benefit of RUX in 1055 MF patients, included in the "RUX-MF" retrospective study. RESULTS: At baseline (BL), 595 (56.2%) patients were at INT1-risk according to DIPSS (PMF) or MYSEC-PM (SMF). The spleen was palpable at <5 cm, between 5 and 10 cm, and >10 cm below costal margin in 5.9%, 47.4%, and 39.7% of patients, respectively; 300 (54.1%) were highly symptomatic (total symptom score ≥20). High-molecular-risk (HMR) mutations (IDH1/2, ASXL-1, SRSF2, EZH2, U2AF1Q157) were detected in 77/167 patients. A total of 101 (19.2%) patients had ≥1 cytopenia (Hb < 10 g/dL: n.36; PLT <100 x 109/L: n = 43; white blood cells <4 x 109/L: n = 40). After 6 months on RUX, IWG-MRT-defined spleen and symptoms response rates were 26.8% and 67.9%, respectively. In univariate analysis, predictors of SR at 6 months were no HMR mutations odds ratio [OR], 2.0, p = .05], no cytopenia (OR, 2.10; p = .01), and blasts <1% (OR, 1.91; p = .01). In multivariate analysis, absence of HMR maintained a significant association (OR, 2.1 [1.12-3.76]; p = .01). CONCLUSIONS: In INT1 patients, responses were more frequent and durable, whereas toxicity rates were lower compared to INT2/high-risk patients. Presence of HMR mutations, cytopenia, and peripheral blasts identified less-responsive INT1 patients, who may benefit for alternative therapeutic strategies.

14.
Cancer ; 130(8): 1270-1280, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38153814

RESUMO

BACKGROUND: Anemia is frequently present in patients with myelofibrosis (MF), and it may be exacerbated by treatment with the JAK2-inhibitor ruxolitinib (RUX). Recently, a relevant blast phase (BP) incidence has been reported in anemic MF patients unexposed to RUX. METHODS: The authors investigated the incidence of BP in 886 RUX-treated MF patients, included in the "RUX-MF" retrospective study. RESULTS: The BP incidence rate ratio (IRR) was 3.74 per 100 patient-years (3.74 %p-y). At therapy start, Common Terminology Criteria for Adverse Events grade 3-4 anemia (hemoglobin [Hb] <8 g/dL) and severe sex/severity-adjusted anemia (Hb <8/<9 g/dL in women/men) were present in 22.5% and 25% patients, respectively. IRR of BP was 2.34 in patients with no baseline anemia and reached respectively 4.22, 4.89, and 4.93 %p-y in patients with grade 1, 2, and 3-4 anemia. Considering the sex/severity-adjusted Hb thresholds, IRR of BP was 2.85, 4.97, and 4.89 %p-y in patients with mild/no anemia, moderate, and severe anemia. Transfusion-dependent patients had the highest IRR (5.03 %p-y). Progression-free survival at 5 years was 70%, 52%, 43%, and 27% in patients with no, grade 1, 2, and 3-4 anemia, respectively (p < .001). At 6 months, 260 of 289 patients with no baseline anemia were receiving ruxolitinib, and 9.2% had developed a grade 3-4 anemia. By 6-month landmark analysis, BP-free survival was significantly worse in patients acquiring grade 3-4 anemia (69.3% vs. 88.1% at 5 years, p < .001). CONCLUSIONS: This study highlights that anemia correlates with an increased risk of evolution into BP, both when present at baseline and when acquired during RUX monotherapy. Innovative anemia therapies and disease-modifying agents are warranted in these patients.


Assuntos
Anemia , Mielofibrose Primária , Pirazóis , Pirimidinas , Masculino , Humanos , Feminino , Mielofibrose Primária/tratamento farmacológico , Crise Blástica , Resultado do Tratamento , Incidência , Estudos Retrospectivos , Nitrilas , Anemia/induzido quimicamente , Anemia/epidemiologia , Hemoglobinas
15.
Gastroenterology ; 164(5): 752-765, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36804602

RESUMO

Pancreatic cancer usually results in poor survival with limited options for treatment, as most affected individuals present with advanced disease. Early detection of preinvasive pancreatic neoplasia and identifying molecular therapeutic targets provide opportunities for extending survival. Although screening for pancreatic cancer is currently not recommended for the general population, emerging evidence indicates that pancreatic surveillance can improve outcomes for individuals in certain high-risk groups. Changes in the epidemiology of pancreatic cancer, experience from pancreatic surveillance, and discovery of novel biomarkers provide a roadmap for new strategies for pancreatic cancer risk assessment, early detection, and prevention.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pancreáticas , Humanos , Detecção Precoce de Câncer/métodos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/prevenção & controle , Medição de Risco , Pâncreas , Fatores de Risco , Neoplasias Pancreáticas
16.
Anal Chem ; 96(2): 615-619, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38165272

RESUMO

STD NMR spectroscopy is a powerful ligand-observed NMR tool for screening and characterizing the interactions of small molecules and low molecular weight fragments with a given macromolecule, identifying the main intermolecular contacts in the bound state. It is also a powerful analytical technique for the accurate determination of protein-ligand dissociation constants (KD) of medium-to-weak affinity, of interest in the pharmaceutical industry. However, accurate KD determination and epitope mapping requires a long series of experiments at increasing saturation times to carry out a full analysis using the so-called STD NMR build-up curve approach and apply the "initial slopes approximation". Here, we have developed a new protocol to bypass this important limitation, which allows us to obtain initial slopes by using just two saturation times and, hence, to very quickly determine precise protein-ligand dissociation constants by STD NMR.


Assuntos
Imageamento por Ressonância Magnética , Proteínas , Ligantes , Proteínas/química , Espectroscopia de Ressonância Magnética/métodos , Mapeamento de Epitopos , Ligação Proteica
17.
Curr Genet ; 70(1): 1, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353733

RESUMO

GATA family transcription factors (GATA-TFs) are metalloproteins that regulate many metabolic pathways. These conserved proteins recognize the consensus sequence (A/T)GATA(A/G) in the promoter regions of many genes and regulate their transcription in response to environmental signals. Currently, the study of GATA-TFs is of increasing interest. GATA genes and their proteins are most actively studied in vascular plants and fungi. Based on the results of numerous studies, it has been shown that GATA factors regulate the metabolic pathways of nitrogen and carbon, and also play a major role in the processes induced by light and circadian rhythms. In algae, GATA-TFs remain poorly studied, and information about them is scattered. In this work, all known data on GATA-TFs in the unicellular green alga Chlamydomonas reinhardtii has been collected and systematized. The genome of this alga contains 12 GATA coding genes. Using the phylogenetic analysis, we identified three classes of GATA factors in C. reinhardtii according to the structure of the zinc finger domain and showed their difference from the classification of GATA factors developed on vascular plants.


Assuntos
Chlamydomonas reinhardtii , Chlamydomonas reinhardtii/genética , Filogenia , Carbono , Ritmo Circadiano , Fatores de Transcrição GATA/genética
18.
Photosynth Res ; 159(2-3): 97-114, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37093504

RESUMO

Flavodiiron proteins Flv1/Flv3 accept electrons from photosystem (PS) I. In this work we investigated light adaptation mechanisms of Flv1-deficient mutant of Synechocystis PCC 6803, incapable to form the Flv1/Flv3 heterodimer. First seconds of dark-light transition were studied by parallel measurements of light-induced changes in chlorophyll fluorescence, P700 redox transformations, fluorescence emission at 77 K, and OCP-dependent fluorescence quenching. During the period of Calvin cycle activation upon dark-light transition, the linear electron transport (LET) in wild type is supported by the Flv1/Flv3 heterodimer, whereas in Δflv1 mutant activation of LET upon illumination is preceded by cyclic electron flow that maintains State 2. The State 2-State 1 transition and Orange Carotenoid Protein (OCP)-dependent non-photochemical quenching occur independently of each other, begin in about 10 s after the illumination of the cells and are accompanied by a short-term re-reduction of the PSI reaction center (P700+). ApcD is important for the State 2-State 1 transition in the Δflv1 mutant, but S-M rise in chlorophyll fluorescence was not completely inhibited in Δflv1/ΔapcD mutant. LET in Δflv1 mutant starts earlier than the S-M rise in chlorophyll fluorescence, and the oxidation of plastoquinol (PQH2) pool promotes the activation of PSII, transient re-reduction of P700+ and transition to State 1. An attempt to induce state transition in the wild type under high intensity light using methyl viologen, highly oxidizing P700 and PQH2, was unsuccessful, showing that oxidation of intersystem electron-transport carriers might be insufficient for the induction of State 2-State 1 transition in wild type of Synechocystis under high light.


Assuntos
Synechocystis , Transporte de Elétrons , Synechocystis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Mutação , Oxirredução , Complexo de Proteína do Fotossistema I/genética , Complexo de Proteína do Fotossistema I/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo
19.
Cardiovasc Diabetol ; 23(1): 98, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38493287

RESUMO

BACKGROUND: Telomere Length (TL), a marker of cellular aging, holds promise as a biomarker to elucidate the molecular mechanism of diabetes. This study aimed to investigate whether shorter telomeres are associated with a higher risk of type 2 diabetes mellitus (T2DM) incidence in patients with coronary heart disease; and to determine whether the most suitable dietary patterns, particularly a Mediterranean diet or a low-fat diet, can mitigate the development of diabetes in these patients after a follow-up period of five years. METHODS: The CORonary Diet Intervention with Olive oil and cardiovascular PREVention study (CORDIOPREV study) was a single-centre, randomised clinical trial done at the Reina Sofia University Hospital in Córdoba, Spain. Patients with established coronary heart disease (aged 20-75 years) were randomly assigned in a 1:1 ratio by the Andalusian School of Public Health to receive two healthy diets. Clinical investigators were masked to treatment assignment; participants were not. Quantitative-PCR was used to assess TL measurements. FINDINGS: 1002 patients (59.5 ± 8.7 years and 82.5% men) were enrolled into Mediterranean diet (n = 502) or a low-fat diet (n = 500) groups. In this analysis, we included all 462 patients who did not have T2DM at baseline. Among them, 107 patients developed T2DM after a median of 60 months. Cox regression analyses showed that patients at risk of short telomeres (TL < percentile 20th) are more likely to experience T2DM than those at no risk of short telomeres (HR 1.65, p-value 0.023). In terms of diet, patients at high risk of short telomeres had a higher risk of T2DM incidence after consuming a low-fat diet compared to patients at no risk of short telomeres (HR 2.43, 95CI% 1.26 to 4.69, p-value 0.008), while no differences were observed in the Mediterranean diet group. CONCLUSION: Patients with shorter TL presented a higher risk of developing T2DM. This association could be mitigated with a specific dietary pattern, in our case a Mediterranean diet, to prevent T2DM in patients with coronary heart disease. TRIAL REGISTRATION: Clinicaltrials.gov number NCT00924937.


Assuntos
Doenças Cardiovasculares , Doença das Coronárias , Diabetes Mellitus Tipo 2 , Dieta Mediterrânea , Feminino , Humanos , Masculino , Biomarcadores , Doenças Cardiovasculares/epidemiologia , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia , Doença das Coronárias/genética , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Telômero , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso
20.
J Exp Bot ; 75(7): 1800-1822, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38109712

RESUMO

The Ranunculales are a hyperdiverse lineage in many aspects of their phenotype, including growth habit, floral and leaf morphology, reproductive mode, and specialized metabolism. Many Ranunculales species, such as opium poppy and goldenseal, have a high medicinal value. In addition, the order includes a large number of commercially important ornamental plants, such as columbines and larkspurs. The phylogenetic position of the order with respect to monocots and core eudicots and the diversity within this lineage make the Ranunculales an excellent group for studying evolutionary processes by comparative studies. Lately, the phylogeny of Ranunculales was revised, and genetic and genomic resources were developed for many species, allowing comparative analyses at the molecular scale. Here, we review the literature on the resources for genetic manipulation and genome sequencing, the recent phylogeny reconstruction of this order, and its fossil record. Further, we explain their habitat range and delve into the diversity in their floral morphology, focusing on perianth organ identity, floral symmetry, occurrences of spurs and nectaries, sexual and pollination systems, and fruit and dehiscence types. The Ranunculales order offers a wealth of opportunities for scientific exploration across various disciplines and scales, to gain novel insights into plant biology for researchers and plant enthusiasts alike.


Assuntos
Flores , Ranunculales , Filogenia , Evolução Biológica , Folhas de Planta/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA