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1.
Annu Rev Cell Dev Biol ; 34: 289-310, 2018 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-30134119

RESUMEN

A major challenge in developmental biology is unraveling the precise regulation of plant stem cell maintenance and the transition to a fully differentiated cell. In this review, we highlight major themes coordinating the acquisition of cell identity and subsequent differentiation in plants. Plant cells are immobile and establish position-dependent cell lineages that rely heavily on external cues. Central players are the hormones auxin and cytokinin, which balance cell division and differentiation during organogenesis. Transcription factors and miRNAs, many of which are mobile in plants, establish gene regulatory networks that communicate cell position and fate. Small peptide signaling also provides positional cues as new cell types emerge from stem cell division and progress through differentiation. These pathways recruit similar players for patterning different organs, emphasizing the modular nature of gene regulatory networks. Finally, we speculate on the outstanding questions in the field and discuss how they may be addressed by emerging technologies.


Asunto(s)
Diferenciación Celular/genética , División Celular/genética , Células Vegetales , Células Madre/citología , Linaje de la Célula/genética , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes/genética , Transducción de Señal/genética
2.
Cell ; 165(2): 269-71, 2016 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-27058660

RESUMEN

Endophytic fungi are found within the roots of healthy plants, but their function is poorly understood. In this issue, Hiruma et al. demonstrate that, under phosphate-limiting conditions, the endophytic fungus, Colletotrichum tofieldiae, provides growth-promoting and fitness benefits to Arabidopsis, but the plant must restrict fungal growth or risk pathogenesis.


Asunto(s)
Endófitos , Amigos , Arabidopsis/microbiología , Hongos , Raíces de Plantas
3.
Nature ; 626(7999): 611-616, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38297119

RESUMEN

Precise control of cell division is essential for proper patterning and growth during the development of multicellular organisms. Coordination of formative divisions that generate new tissue patterns with proliferative divisions that promote growth is poorly understood. SHORTROOT (SHR) and SCARECROW (SCR) are transcription factors that are required for formative divisions in the stem cell niche of Arabidopsis roots1,2. Here we show that levels of SHR and SCR early in the cell cycle determine the orientation of the division plane, resulting in either formative or proliferative cell division. We used 4D quantitative, long-term and frequent (every 15 min for up to 48 h) light sheet and confocal microscopy to probe the dynamics of SHR and SCR in tandem within single cells of living roots. Directly controlling their dynamics with an SHR induction system enabled us to challenge an existing bistable model3 of the SHR-SCR gene-regulatory network and to identify key features that are essential for rescue of formative divisions in shr mutants. SHR and SCR kinetics do not align with the expected behaviour of a bistable system, and only low transient levels, present early in the cell cycle, are required for formative divisions. These results reveal an uncharacterized mechanism by which developmental regulators directly coordinate patterning and growth.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ciclo Celular , Raíces de Plantas , Arabidopsis/citología , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ciclo Celular/genética , División Celular/genética , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/citología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Microscopía Confocal , Mutación
4.
Cell ; 153(2): 285-6, 2013 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-23582319

RESUMEN

Establishing polarized surfaces enables cells to carry out specialized tasks. In this issue, Lee et al. present a mechanism for cell polarization in which localized peroxidases are used to position the Casparian strip, a diffusion barrier deposited between endodermal cells in plant roots.

5.
N Engl J Med ; 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847460

RESUMEN

BACKGROUND: Dual agonism of glucagon receptor and glucagon-like peptide-1 (GLP-1) receptor may be more effective than GLP-1 receptor agonism alone for treating metabolic dysfunction-associated steatohepatitis (MASH). The efficacy and safety of survodutide (a dual agonist of glucagon receptor and GLP-1 receptor) in persons with MASH and liver fibrosis are unclear. METHODS: In this 48-week, phase 2 trial, we randomly assigned adults with biopsy-confirmed MASH and fibrosis stage F1 through F3 in a 1:1:1:1 ratio to receive once-weekly subcutaneous injections of survodutide at a dose of 2.4, 4.8, or 6.0 mg or placebo. The trial had two phases: a 24-week rapid-dose-escalation phase, followed by a 24-week maintenance phase. The primary end point was histologic improvement (reduction) in MASH with no worsening of fibrosis. Secondary end points included a decrease in liver fat content by at least 30% and biopsy-assessed improvement (reduction) in fibrosis by at least one stage. RESULTS: A total of 293 randomly assigned participants received at least one dose of survodutide or placebo. Improvement in MASH with no worsening of fibrosis occurred in 47% of the participants in the survodutide 2.4-mg group, 62% of those in the 4.8-mg group, and 43% of those in the 6.0-mg group, as compared with 14% of those in the placebo group (P<0.001 for the quadratic dose-response curve as best-fitting model). A decrease in liver fat content by at least 30% occurred in 63% of the participants in the survodutide 2.4-mg group, 67% of those in the 4.8-mg group, 57% of those in the 6.0-mg group, and 14% of those in the placebo group; improvement in fibrosis by at least one stage occurred in 34%, 36%, 34%, and 22%, respectively. Adverse events that were more frequent with survodutide than with placebo included nausea (66% vs. 23%), diarrhea (49% vs. 23%), and vomiting (41% vs. 4%); serious adverse events occurred in 8% with survodutide and 7% with placebo. CONCLUSIONS: Survodutide was superior to placebo with respect to improvement in MASH without worsening of fibrosis, warranting further investigation in phase 3 trials. (Funded by Boehringer Ingelheim; 1404-0043 ClinicalTrials.gov number, NCT04771273; EudraCT number, 2020-002723-11.).

6.
N Engl J Med ; 390(6): 497-509, 2024 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-38324483

RESUMEN

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a progressive liver disease with no approved treatment. Resmetirom is an oral, liver-directed, thyroid hormone receptor beta-selective agonist in development for the treatment of NASH with liver fibrosis. METHODS: We are conducting an ongoing phase 3 trial involving adults with biopsy-confirmed NASH and a fibrosis stage of F1B, F2, or F3 (stages range from F0 [no fibrosis] to F4 [cirrhosis]). Patients were randomly assigned in a 1:1:1 ratio to receive once-daily resmetirom at a dose of 80 mg or 100 mg or placebo. The two primary end points at week 52 were NASH resolution (including a reduction in the nonalcoholic fatty liver disease [NAFLD] activity score by ≥2 points; scores range from 0 to 8, with higher scores indicating more severe disease) with no worsening of fibrosis, and an improvement (reduction) in fibrosis by at least one stage with no worsening of the NAFLD activity score. RESULTS: Overall, 966 patients formed the primary analysis population (322 in the 80-mg resmetirom group, 323 in the 100-mg resmetirom group, and 321 in the placebo group). NASH resolution with no worsening of fibrosis was achieved in 25.9% of the patients in the 80-mg resmetirom group and 29.9% of those in the 100-mg resmetirom group, as compared with 9.7% of those in the placebo group (P<0.001 for both comparisons with placebo). Fibrosis improvement by at least one stage with no worsening of the NAFLD activity score was achieved in 24.2% of the patients in the 80-mg resmetirom group and 25.9% of those in the 100-mg resmetirom group, as compared with 14.2% of those in the placebo group (P<0.001 for both comparisons with placebo). The change in low-density lipoprotein cholesterol levels from baseline to week 24 was -13.6% in the 80-mg resmetirom group and -16.3% in the 100-mg resmetirom group, as compared with 0.1% in the placebo group (P<0.001 for both comparisons with placebo). Diarrhea and nausea were more frequent with resmetirom than with placebo. The incidence of serious adverse events was similar across trial groups: 10.9% in the 80-mg resmetirom group, 12.7% in the 100-mg resmetirom group, and 11.5% in the placebo group. CONCLUSIONS: Both the 80-mg dose and the 100-mg dose of resmetirom were superior to placebo with respect to NASH resolution and improvement in liver fibrosis by at least one stage. (Funded by Madrigal Pharmaceuticals; MAESTRO-NASH ClinicalTrials.gov number, NCT03900429.).


Asunto(s)
Cirrosis Hepática , Enfermedad del Hígado Graso no Alcohólico , Piridazinas , Uracilo , Adulto , Humanos , Método Doble Ciego , Hígado/diagnóstico por imagen , Hígado/efectos de los fármacos , Hígado/patología , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/etiología , Cirrosis Hepática/patología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/patología , Piridazinas/uso terapéutico , Resultado del Tratamiento , Uracilo/análogos & derivados , Receptores beta de Hormona Tiroidea/agonistas , Biopsia , Relación Dosis-Respuesta a Droga
7.
Cell ; 150(5): 1002-15, 2012 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-22921914

RESUMEN

In plants, where cells cannot migrate, asymmetric cell divisions (ACDs) must be confined to the appropriate spatial context. We investigate tissue-generating asymmetric divisions in a stem cell daughter within the Arabidopsis root. Spatial restriction of these divisions requires physical binding of the stem cell regulator SCARECROW (SCR) by the RETINOBLASTOMA-RELATED (RBR) protein. In the stem cell niche, SCR activity is counteracted by phosphorylation of RBR through a cyclinD6;1-CDK complex. This cyclin is itself under transcriptional control of SCR and its partner SHORT ROOT (SHR), creating a robust bistable circuit with either high or low SHR-SCR complex activity. Auxin biases this circuit by promoting CYCD6;1 transcription. Mathematical modeling shows that ACDs are only switched on after integration of radial and longitudinal information, determined by SHR and auxin distribution, respectively. Coupling of cell-cycle progression to protein degradation resets the circuit, resulting in a "flip flop" that constrains asymmetric cell division to the stem cell region.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citología , Arabidopsis/metabolismo , Raíces de Plantas/citología , Secuencia de Aminoácidos , División Celular Asimétrica , Ciclina D/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Ácidos Indolacéticos/metabolismo , Células del Mesófilo/metabolismo , Datos de Secuencia Molecular , Fosforilación , Raíces de Plantas/metabolismo , Alineación de Secuencia
8.
Blood ; 143(13): 1259-1268, 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38194690

RESUMEN

ABSTRACT: Amyloidogenic serum free light chains (sFLCs) drive disease progression in AL amyloidosis. Matrix-assisted laser desorption/ionization time of flight mass spectrometry-based FLC assay (FLC-MS) has greater sensitivity than conventional sFLC assays allowing for the detection of serological residual disease. We report the utility of FLC-MS in a large series of patients with AL amyloidosis assessing the impact of FLC-MS negativity after treatment on overall survival (OS) and organ response rates. Serum samples were analyzed using FLC-MS at diagnosis and at 6 and 12 months after treatment. The impact of FLC-MS negativity over standard hematologic responses on survival and organ response was assessed. A total of 487 patients were included; 290 (59%) and 349 (71.5%) had cardiac and renal involvement, respectively. There was 100% concordance between the light chain (LC) fibril type and LC isotype identified by FLC-MS. At 6 and 12 months, 81 (16.6%) and 101 (20.7%) were FLC-MS negative. Of those achieving a conventional hematologic complete response (CR) at 6 and 12 months, 45 (27.7%) and 64 (39%) were FLC-MS negative. At 12 months, median OS for CR + FLC-MS negative was not reached vs 108 months in CR + FLC-MS positive (P = .024). At 12 months, 70% of patients with FLC-MS negativity (vs 50% FLC-MS positive) achieved a cardiac response (P = .015). In a multivariate analysis, FLC-MS negativity at 12 months was an independent predictor of better outcomes. FLC-MS can detect persistent monoclonal light chains in a significant proportion of patients in a conventional hematologic CR. FLC-MS assessment promises to be a new standard for response assessment in AL amyloidosis.


Asunto(s)
Amiloidosis , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Humanos , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/diagnóstico , Amiloidosis/diagnóstico , Cadenas Ligeras de Inmunoglobulina , Respuesta Patológica Completa , Progresión de la Enfermedad
9.
Nature ; 577(7788): 85-88, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31801996

RESUMEN

The stem cell niche and the size of the root meristem in plants are maintained by intercellular interactions and signalling networks involving a peptide hormone, root meristem growth factor 1 (RGF1)1. Understanding how RGF1 regulates the development of the root meristem is essential for understanding stem cell function. Although five receptors for RGF1 have been identified2-4, the downstream signalling mechanism remains unknown. Here we report a series of signalling events that follow RGF1 activity. We find that the RGF1-receptor pathway controls the distribution of reactive oxygen species (ROS) along the developmental zones of the Arabidopsis root. We identify a previously uncharacterized transcription factor, RGF1-INDUCIBLE TRANSCRIPTION FACTOR 1 (RITF1), that has a central role in mediating RGF1 signalling. Manipulating RITF1 expression leads to the redistribution of ROS along the root developmental zones. Changes in ROS distribution in turn enhance the stability of the PLETHORA2 protein, a master regulator of root stem cells. Our results thus clearly depict a signalling cascade that is initiated by RGF1, linking this peptide to mechanisms that regulate ROS.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Meristema/metabolismo , Péptidos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Meristema/genética , Meristema/crecimiento & desarrollo , Péptidos/genética
10.
Nature ; 580(7801): 87-92, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32238927

RESUMEN

Southern Ocean ecosystems are under pressure from resource exploitation and climate change1,2. Mitigation requires the identification and protection of Areas of Ecological Significance (AESs), which have so far not been determined at the ocean-basin scale. Here, using assemblage-level tracking of marine predators, we identify AESs for this globally important region and assess current threats and protection levels. Integration of more than 4,000 tracks from 17 bird and mammal species reveals AESs around sub-Antarctic islands in the Atlantic and Indian Oceans and over the Antarctic continental shelf. Fishing pressure is disproportionately concentrated inside AESs, and climate change over the next century is predicted to impose pressure on these areas, particularly around the Antarctic continent. At present, 7.1% of the ocean south of 40°S is under formal protection, including 29% of the total AESs. The establishment and regular revision of networks of protection that encompass AESs are needed to provide long-term mitigation of growing pressures on Southern Ocean ecosystems.


Asunto(s)
Sistemas de Identificación Animal , Organismos Acuáticos/fisiología , Cambio Climático/estadística & datos numéricos , Conservación de los Recursos Naturales/métodos , Ecosistema , Océanos y Mares , Conducta Predatoria , Animales , Regiones Antárticas , Biodiversidad , Aves , Peces , Cadena Alimentaria , Cubierta de Hielo , Mamíferos , Dinámica Poblacional
11.
Proc Natl Acad Sci U S A ; 120(40): e2310488120, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37748054

RESUMEN

Cognitive scientists treat verification as a computation in which descriptions that match the relevant situation are true, but otherwise false. The claim is controversial: The logician Gödel and the physicist Penrose have argued that human verifications are not computable. In contrast, the theory of mental models treats verification as computable, but the two truth values of standard logics, true and false, as insufficient. Three online experiments (n = 208) examined participants' verifications of disjunctive assertions about a location of an individual or a journey, such as: 'You arrived at Exeter or Perth'. The results showed that their verifications depended on observation of a match with one of the locations but also on the status of other locations (Experiment 1). Likewise, when they reached one destination and the alternative one was impossible, their use of the truth value: could be true and could be false increased (Experiment 2). And, when they reached one destination and the only alternative one was possible, they used the truth value, true and it couldn't have been false, and when the alternative one was impossible, they used the truth value: true but it could have been false (Experiment 3). These truth values and those for falsity embody counterfactuals. We implemented a computer program that constructs models of disjunctions, represents possible destinations, and verifies the disjunctions using the truth values in our experiments. Whether an awareness of a verification's outcome is computable remains an open question.


Asunto(s)
Médicos , Humanos , Programas Informáticos
12.
Proc Natl Acad Sci U S A ; 120(4): e2215418120, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36669114

RESUMEN

Naturally occurring metamorphic proteins have the ability to interconvert from one folded state to another through either a limited set of mutations or by way of a change in the local environment. Here, we show in a designed system that it is possible to switch reversibly between two of the most common monomeric folds employing only temperature changes. We demonstrate that a latent 3α state can be unmasked from an α/ß-plait topology with a single V90T amino acid substitution, populating both forms simultaneously. The equilibrium between these two states exhibits temperature dependence, such that the 3α state is predominant (>90%) at 5 °C, while the α/ß-plait fold is the major species (>90%) at 30 °C. We describe the structure and dynamics of these topologies, how mutational changes affect the temperature dependence, and the energetics and kinetics of interconversion. Additionally, we demonstrate how ligand-binding function can be tightly regulated by large amplitude changes in protein structure over a relatively narrow temperature range that is relevant to biology. The 3α/αß switch thus represents a potentially useful approach for designing proteins that alter their fold topologies in response to environmental triggers. It may also serve as a model for computational studies of temperature-dependent protein stability and fold switching.


Asunto(s)
Pliegue de Proteína , Proteínas , Temperatura , Proteínas/química , Mutación , Sustitución de Aminoácidos
13.
Proc Natl Acad Sci U S A ; 120(44): e2307593120, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37871223

RESUMEN

Chronic lymphocytic leukemia (CLL) is one of the most diagnosed forms of leukemia worldwide and it is usually classified into two forms: indolent and aggressive. These two forms are characterized by distinct molecular features that drive different responses to treatment and clinical outcomes. In this context, a better understanding of the molecular landscape of the CLL forms may potentially lead to the development of new drugs or the identification of novel biomarkers. Human endogenous retroviruses (HERVs) are a class of transposable elements that have been associated with the development of different human cancers, including different forms of leukemias. However, no studies about HERVs in CLL have ever been reported so far. Here, we present the first locus-specific profiling of HERV expression in both the aggressive and indolent forms of CLL. Our analyses revealed several dysregulations in HERV expression occurring in CLL and some of them were specific for either the aggressive or indolent form of CLL. Such results were also validated by analyzing an external cohort of CLL patients and by RT-qPCR. Moreover, in silico analyses have shown relevant signaling pathways associated with them suggesting a potential involvement of the dysregulated HERVs in these pathways and consequently in CLL development.


Asunto(s)
Retrovirus Endógenos , Leucemia Linfocítica Crónica de Células B , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Retrovirus Endógenos/genética , Biomarcadores
14.
Proc Natl Acad Sci U S A ; 120(4): e2210632120, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36669117

RESUMEN

Plant cells are surrounded by a cell wall and do not migrate, which makes the regulation of cell division orientation crucial for development. Regulatory mechanisms controlling cell division orientation may have contributed to the evolution of body organization in land plants. The GRAS family of transcription factors was transferred horizontally from soil bacteria to an algal common ancestor of land plants. SHORTROOT (SHR) and SCARECROW (SCR) genes in this family regulate formative periclinal cell divisions in the roots of flowering plants, but their roles in nonflowering plants and their evolution have not been studied in relation to body organization. Here, we show that SHR cell autonomously inhibits formative periclinal cell divisions indispensable for leaf vein formation in the moss Physcomitrium patens, and SHR expression is positively and negatively regulated by SCR and the GRAS member LATERAL SUPPRESSOR, respectively. While precursor cells of a leaf vein lacking SHR usually follow the geometry rule of dividing along the division plane with the minimum surface area, SHR overrides this rule and forces cells to divide nonpericlinally. Together, these results imply that these bacterially derived GRAS transcription factors were involved in the establishment of the genetic regulatory networks modulating cell division orientation in the common ancestor of land plants and were later adapted to function in flowering plant and moss lineages for their specific body organizations.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , División Celular/genética , Raíces de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas
15.
Circulation ; 149(15): 1157-1168, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38328945

RESUMEN

BACKGROUND: The extent of myocardial bone tracer uptake with technetium pyrophosphate, hydroxymethylene diphosphonate, and 3,3-diphosphono-1,2-propanodicarboxylate in transthyretin amyloid cardiomyopathy (ATTR-CM) might reflect cardiac amyloid burden and be associated with outcome. METHODS: Consecutive patients with ATTR-CM who underwent diagnostic bone tracer scintigraphy with acquisition of whole-body planar and cardiac single-photon emission computed tomography (SPECT) images from the National Amyloidosis Centre and 4 Italian centers were included. Cardiac uptake was defined according to the Perugini classification: 0=absent cardiac uptake; 1=mild uptake less than bone; 2=moderate uptake equal to bone; and 3=high uptake greater than bone. Extent of right ventricular (RV) uptake was defined as focal (basal segment of the RV free wall only) or diffuse (extending beyond basal segment) on the basis of SPECT imaging. The primary outcome was all-cause mortality. RESULTS: Among 1422 patients with ATTR-CM, RV uptake accompanying left ventricular uptake was identified by SPECT imaging in 100% of cases at diagnosis. Median follow-up in the whole cohort was 34 months (interquartile range, 21 to 50 months), and 494 patients died. By Kaplan-Meier analysis, diffuse RV uptake on SPECT imaging (n=936) was associated with higher all-cause mortality compared with focal (n=486) RV uptake (77.9% versus 22.1%; P<0.001), whereas Perugini grade was not associated with survival (P=0.27 in grade 2 versus grade 3). On multivariable analysis, after adjustment for age at diagnosis (hazard ratio [HR], 1.03 [95% CI, 1.02-1.04]; P<0.001), presence of the p.(V142I) TTR variant (HR, 1.42 [95% CI, 1.20-1.81]; P=0.004), National Amyloidosis Centre stage (each category, P<0.001), stroke volume index (HR, 0.99 [95% CI, 0.97-0.99]; P=0.043), E/e' (HR, 1.02 [95% CI, 1.007-1.03]; P=0.004), right atrial area index (HR, 1.05 [95% CI, 1.02-1.08]; P=0.001), and left ventricular global longitudinal strain (HR, 1.06 [95% CI, 1.03-1.09]; P<0.001), diffuse RV uptake on SPECT imaging (HR, 1.60 [95% CI, 1.26-2.04]; P<0.001) remained an independent predictor of all-cause mortality. The prognostic value of diffuse RV uptake was maintained across each National Amyloidosis Centre stage and in both wild-type and hereditary ATTR-CM (P<0.001 and P=0.02, respectively). CONCLUSIONS: Diffuse RV uptake of bone tracer on SPECT imaging is associated with poor outcomes in patients with ATTR-CM and is an independent prognostic marker at diagnosis.


Asunto(s)
Cardiomiopatías , Humanos , Cardiomiopatías/diagnóstico , Prealbúmina/genética , Pronóstico , Tomografía Computarizada de Emisión de Fotón Único
16.
Development ; 149(6)2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35285482

RESUMEN

Understanding the development of tissues, organs and entire organisms through the lens of single-cell genomics has revolutionized developmental biology. Although single-cell transcriptomics has been pioneered in animal systems, from an experimental perspective, plant development holds some distinct advantages: cells do not migrate in relation to one another, and new organ formation (of leaves, roots, flowers, etc.) continues post-embryonically from persistent stem cell populations known as meristems. For a time, plant studies lagged behind animal or cell culture-based, single-cell approaches, largely owing to the difficulty in dissociating plant cells from their rigid cell walls. Recent intensive development of single-cell and single-nucleus isolation techniques across plant species has opened up a wide range of experimental approaches. This has produced a rapidly expanding diversity of information across tissue types and species, concomitant with the creative development of methods. In this brief Spotlight, we highlight some of the technical developments and how they have led to profiling single-cell genomics in various plant organs. We also emphasize the contribution of single-cell genomics in revealing developmental trajectories among different cell types within plant organs. Furthermore, we present efforts toward comparative analysis of tissues and organs at a single-cell level. Single-cell genomics is beginning to generate comprehensive information relating to how plant organs emerge from stem cell populations.


Asunto(s)
Desarrollo de la Planta , Plantas , Animales , Flores , Regulación de la Expresión Génica de las Plantas , Genómica/métodos , Meristema/genética , Raíces de Plantas
17.
Hepatology ; 79(2): 502-523, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37540183

RESUMEN

BACKGROUND AND AIMS: Fatty liver disease is a major public health threat due to its very high prevalence and related morbidity and mortality. Focused and dedicated interventions are urgently needed to target disease prevention, treatment, and care. APPROACH AND RESULTS: We developed an aligned, prioritized action agenda for the global fatty liver disease community of practice. Following a Delphi methodology over 2 rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the action priorities using Qualtrics XM, indicating agreement using a 4-point Likert-scale and providing written feedback. Priorities were revised between rounds, and in R2, panelists also ranked the priorities within 6 domains: epidemiology, treatment and care, models of care, education and awareness, patient and community perspectives, and leadership and public health policy. The consensus fatty liver disease action agenda encompasses 29 priorities. In R2, the mean percentage of "agree" responses was 82.4%, with all individual priorities having at least a super-majority of agreement (> 66.7% "agree"). The highest-ranked action priorities included collaboration between liver specialists and primary care doctors on early diagnosis, action to address the needs of people living with multiple morbidities, and the incorporation of fatty liver disease into relevant non-communicable disease strategies and guidance. CONCLUSIONS: This consensus-driven multidisciplinary fatty liver disease action agenda developed by care providers, clinical researchers, and public health and policy experts provides a path to reduce the prevalence of fatty liver disease and improve health outcomes. To implement this agenda, concerted efforts will be needed at the global, regional, and national levels.


Asunto(s)
Atención a la Salud , Hepatopatías , Humanos
18.
Nat Chem Biol ; 19(11): 1331-1341, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37365405

RESUMEN

Brassinosteroids (BRs) are steroidal phytohormones that are essential for plant growth, development and adaptation to environmental stresses. BRs act in a dose-dependent manner and do not travel over long distances; hence, BR homeostasis maintenance is critical for their function. Biosynthesis of bioactive BRs relies on the cell-to-cell movement of hormone precursors. However, the mechanism of the short-distance BR transport is unknown, and its contribution to the control of endogenous BR levels remains unexplored. Here we demonstrate that plasmodesmata (PD) mediate the passage of BRs between neighboring cells. Intracellular BR content, in turn, is capable of modulating PD permeability to optimize its own mobility, thereby manipulating BR biosynthesis and signaling. Our work uncovers a thus far unknown mode of steroid transport in eukaryotes and exposes an additional layer of BR homeostasis regulation in plants.


Asunto(s)
Proteínas de Arabidopsis , Brasinoesteroides , Plasmodesmos/metabolismo , Reguladores del Crecimiento de las Plantas , Plantas/metabolismo , Hormonas , Regulación de la Expresión Génica de las Plantas , Proteínas de Arabidopsis/metabolismo
19.
Cell ; 143(4): 606-16, 2010 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-21074051

RESUMEN

The balance between cellular proliferation and differentiation is a key aspect of development in multicellular organisms. Using high-resolution expression data from the Arabidopsis root, we identified a transcription factor, UPBEAT1 (UPB1), that regulates this balance. Genomewide expression profiling coupled with ChIP-chip analysis revealed that UPB1 directly regulates the expression of a set of peroxidases that modulate the balance of reactive oxygen species (ROS) between the zones of cell proliferation and the zone of cell elongation where differentiation begins. Disruption of UPB1 activity alters this ROS balance, leading to a delay in the onset of differentiation. Modulation of either ROS balance or peroxidase activity through chemical reagents affects the onset of differentiation in a manner consistent with the postulated UPB1 function. This pathway functions independently of auxin and cytokinin plant hormonal signaling. Comparison to ROS-regulated growth control in animals suggests that a similar mechanism is used in plants and animals.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citología , Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/citología , Especies Reactivas de Oxígeno/metabolismo , Arabidopsis/genética , Diferenciación Celular , Proliferación Celular , Perfilación de la Expresión Génica , Raíces de Plantas/genética
20.
Proc Natl Acad Sci U S A ; 119(24): e2122389119, 2022 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-35666875

RESUMEN

Childhood growth faltering remains unacceptably high in sub-Saharan Africa. Rural communities dependent on household food production with limited off-farm income or liquid assets to bridge seasonal food availability are especially vulnerable. A cross-sectional survey in Siaya County, Kenya identified 23.5 and 4.8% of children under 5 y of age as stunted and wasted, respectively, using height-for-age Z (HAZ) scores to detect stunting and weight-for-height Z (WHZ) scores for wasting. Although these households are classified as living in poverty or extreme poverty with very limited off-farm income, households commonly have on-farm resources that could be developed to improve nutrition. While 95% of these households have chickens and consumption of eggs was shown to increase childhood growth by an average of 5%, the average flock size is small and constrained by high mortality due to infectious disease. We hypothesized that interventions to relieve this constraint would translate into household decisions influencing the diets and growth of children. Here, we show that vaccination of chickens against Newcastle disease has a causal impact on children's consumption of animal source foods rich in protein and micronutrients relative to a high-carbohydrate, grain-based diet. Children in treatment households (chicken vaccination) showed overall increases in scores for both HAZ and WHZ relative to control households, benefiting both girls and boys. The findings demonstrate the impact of directing interventions at common on-farm assets managed by women in rural communities and support programs to enhance productivity at the household level.


Asunto(s)
Pollos , Dieta , Trastornos del Crecimiento , Estado Nutricional , Vacunación , Animales , Desarrollo Infantil , Preescolar , Toma de Decisiones , Trastornos del Crecimiento/epidemiología , Trastornos del Crecimiento/prevención & control , Humanos , Lactante , Kenia/epidemiología , Población Rural , Vacunación/veterinaria
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