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1.
Nature ; 618(7966): 712-715, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37286602

RESUMEN

The most massive and shortest-lived stars dominate the chemical evolution of the pre-galactic era. On the basis of numerical simulations, it has long been speculated that the mass of such first-generation stars was up to several hundred solar masses1-4. The very massive first-generation stars with a mass range from 140 to 260 solar masses are predicted to enrich the early interstellar medium through pair-instability supernovae (PISNe)5. Decades of observational efforts, however, have not been able to uniquely identify the imprints of such very massive stars on the most metal-poor stars in the Milky Way6,7. Here we report the chemical composition of a very metal-poor (VMP) star with extremely low sodium and cobalt abundances. The sodium with respect to iron in this star is more than two orders of magnitude lower than that of the Sun. This star exhibits very large abundance variance between the odd- and even-charge-number elements, such as sodium/magnesium and cobalt/nickel. Such peculiar odd-even effect, along with deficiencies of sodium and α elements, are consistent with the prediction of primordial pair-instability supernova (PISN) from stars more massive than 140 solar masses. This provides a clear chemical signature indicating the existence of very massive stars in the early universe.

2.
Development ; 151(14)2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39036998

RESUMEN

We present a new set of computational tools that enable accurate and widely applicable 3D segmentation of nuclei in various 3D digital organs. We have developed an approach for ground truth generation and iterative training of 3D nuclear segmentation models, which we applied to popular CellPose, PlantSeg and StarDist algorithms. We provide two high-quality models trained on plant nuclei that enable 3D segmentation of nuclei in datasets obtained from fixed or live samples, acquired from different plant and animal tissues, and stained with various nuclear stains or fluorescent protein-based nuclear reporters. We also share a diverse high-quality training dataset of about 10,000 nuclei. Furthermore, we advanced the MorphoGraphX analysis and visualization software by, among other things, providing a method for linking 3D segmented nuclei to their surrounding cells in 3D digital organs. We found that the nuclear-to-cell volume ratio varies between different ovule tissues and during the development of a tissue. Finally, we extended the PlantSeg 3D segmentation pipeline with a proofreading tool that uses 3D segmented nuclei as seeds to correct cell segmentation errors in difficult-to-segment tissues.


Asunto(s)
Núcleo Celular , Aprendizaje Profundo , Imagenología Tridimensional , Programas Informáticos , Núcleo Celular/metabolismo , Imagenología Tridimensional/métodos , Animales , Algoritmos , Arabidopsis , Procesamiento de Imagen Asistido por Computador/métodos
3.
PLoS Genet ; 20(9): e1011393, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39264939

RESUMEN

Holometabolous insects undergo morphological remodeling from larvae to pupae and to adults with typical changes in the cuticle; however, the mechanism is unclear. Using the lepidopteran agricultural insect Helicoverpa armigera, cotton bollworm, as a model, we revealed that the transcription factor RUNT-like (encoded by Runt-like) regulates the development of the pupal cuticle via promoting a pupal cuticle protein gene (HaPcp) expression. The HaPcp was highly expressed in the epidermis and wing during metamorphosis and was found being involved in pupal cuticle development by RNA interference (RNAi) analysis in larvae. Runt-like was also strongly upregulated in the epidermis and wing during metamorphosis. Knockdown of Runt-like produced similar phenomena, a failure of abdomen yellow envelope and wing formation, to those following HaPcp knockdown. The insect molting hormone 20-hydroxyecdysonen (20E) upregulated HaPcp transcription via RUNT-like. 20E upregulated Runt-like transcription via nuclear receptor EcR and the transcription factor FOXO. Together, RUNT-like and HaPCP are involved in pupal cuticle development during metamorphosis under 20E regulation.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Proteínas de Insectos , Mariposas Nocturnas , Animales , Ecdisterona/metabolismo , Epidermis/metabolismo , Epidermis/crecimiento & desarrollo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Larva/crecimiento & desarrollo , Larva/genética , Larva/metabolismo , Metamorfosis Biológica , Muda/genética , Mariposas Nocturnas/crecimiento & desarrollo , Mariposas Nocturnas/genética , Mariposas Nocturnas/metabolismo , Pupa/crecimiento & desarrollo , Pupa/genética , Pupa/metabolismo , Interferencia de ARN , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Alas de Animales/crecimiento & desarrollo , Alas de Animales/metabolismo
4.
Circ Res ; 135(8): 806-821, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39229723

RESUMEN

BACKGROUND: Cardiac hypertrophy and its associated remodeling are among the leading causes of heart failure. Lysine crotonylation is a recently discovered posttranslational modification whose role in cardiac hypertrophy remains largely unknown. NAE1 (NEDD8 [neural precursor cell expressed developmentally downregulated protein 8]-activating enzyme E1 regulatory subunit) is mainly involved in the neddylation modification of protein targets. However, the function of crotonylated NAE1 has not been defined. This study aims to elucidate the effects and mechanisms of NAE1 crotonylation on cardiac hypertrophy. METHODS: Crotonylation levels were detected in both human and mouse subjects with cardiac hypertrophy through immunoprecipitation and Western blot assays. Tandem mass tag (TMT)-labeled quantitative lysine crotonylome analysis was performed to identify the crotonylated proteins in a mouse cardiac hypertrophic model induced by transverse aortic constriction. We generated NAE1 knock-in mice carrying a crotonylation-defective K238R (lysine to arginine mutation at site 238) mutation (NAE1 K238R) and NAE1 knock-in mice expressing a crotonylation-mimicking K238Q (lysine to glutamine mutation at site 238) mutation (NAE1 K238Q) to assess the functional role of crotonylation of NAE1 at K238 in pathological cardiac hypertrophy. Furthermore, we combined coimmunoprecipitation, mass spectrometry, and dot blot analysis that was followed by multiple molecular biological methodologies to identify the target GSN (gelsolin) and corresponding molecular events contributing to the function of NAE1 K238 (lysine residue at site 238) crotonylation. RESULTS: The crotonylation level of NAE1 was increased in mice and patients with cardiac hypertrophy. Quantitative crotonylomics analysis revealed that K238 was the main crotonylation site of NAE1. Loss of K238 crotonylation in NAE1 K238R knock-in mice attenuated cardiac hypertrophy and restored the heart function, while hypercrotonylation mimic in NAE1 K238Q knock-in mice significantly enhanced transverse aortic constriction-induced pathological hypertrophic response, leading to impaired cardiac structure and function. The recombinant adenoviral vector carrying NAE1 K238R mutant attenuated, while the K238Q mutant aggravated Ang II (angiotensin II)-induced hypertrophy. Mechanistically, we identified GSN as a direct target of NAE1. K238 crotonylation of NAE1 promoted GSN neddylation and, thus, enhanced its protein stability and expression. NAE1 crotonylation-dependent increase of GSN promoted actin-severing activity, which resulted in adverse cytoskeletal remodeling and progression of pathological hypertrophy. CONCLUSIONS: Our findings provide new insights into the previously unrecognized role of crotonylation on nonhistone proteins during cardiac hypertrophy. We found that K238 crotonylation of NAE1 plays an essential role in mediating cardiac hypertrophy through GSN neddylation, which provides potential novel therapeutic targets for pathological hypertrophy and cardiac remodeling.


Asunto(s)
Cardiomegalia , Animales , Humanos , Cardiomegalia/metabolismo , Cardiomegalia/patología , Cardiomegalia/genética , Ratones , Masculino , Procesamiento Proteico-Postraduccional , Ratones Endogámicos C57BL , Enzimas Activadoras de Ubiquitina/metabolismo , Enzimas Activadoras de Ubiquitina/genética , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratones Transgénicos , Proteína NEDD8/metabolismo , Proteína NEDD8/genética , Células HEK293
5.
Mol Cell ; 72(6): 999-1012.e6, 2018 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-30449722

RESUMEN

Double-stranded RNA (dsRNA) is a potent proinflammatory signature of viral infection. Long cytosolic dsRNA is recognized by MDA5. The cooperative assembly of MDA5 into helical filaments on dsRNA nucleates the assembly of a multiprotein type I interferon signaling platform. Here, we determined cryoelectron microscopy (cryo-EM) structures of MDA5-dsRNA filaments with different helical twists and bound nucleotide analogs at resolutions sufficient to build and refine atomic models. The structures identify the filament-forming interfaces, which encode the dsRNA binding cooperativity and length specificity of MDA5. The predominantly hydrophobic interface contacts confer flexibility, reflected in the variable helical twist within filaments. Mutation of filament-forming residues can result in loss or gain of signaling activity. Each MDA5 molecule spans 14 or 15 RNA base pairs, depending on the twist. Variations in twist also correlate with variations in the occupancy and type of nucleotide in the active site, providing insights on how ATP hydrolysis contributes to MDA5-dsRNA recognition.


Asunto(s)
Adenosina Trifosfato/metabolismo , Microscopía por Crioelectrón , Helicasa Inducida por Interferón IFIH1/ultraestructura , ARN Bicatenario/ultraestructura , Células HEK293 , Humanos , Hidrólisis , Interacciones Hidrofóbicas e Hidrofílicas , Helicasa Inducida por Interferón IFIH1/genética , Helicasa Inducida por Interferón IFIH1/metabolismo , Interferón beta/genética , Interferón beta/metabolismo , Simulación del Acoplamiento Molecular , Mutación , Conformación de Ácido Nucleico , Conformación Proteica , ARN Bicatenario/metabolismo , Transducción de Señal , Relación Estructura-Actividad
6.
Proc Natl Acad Sci U S A ; 120(1): e2213437120, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36580587

RESUMEN

ABCG2 is an ATP-binding cassette (ABC) transporter that extrudes a wide range of xenobiotics and drugs from the cell and contributes to multidrug resistance in cancer cells. Following our recent structural characterization of topotecan-bound ABCG2, here, we present cryo-EM structures of ABCG2 under turnover conditions in complex with a special modulator and slow substrate, tariquidar, in nanodiscs. The structures reveal that similar to topotecan, tariquidar induces two distinct ABCG2 conformations under turnover conditions (turnover-1 and turnover-2). µs-scale molecular dynamics simulations of drug-bound and apo ABCG2 in native-like lipid bilayers, in both topotecan- and tariquidar-bound states, characterize the ligand size as a major determinant of its binding stability. The simulations highlight direct lipid-drug interactions for the smaller topotecan, which exhibits a highly dynamic binding mode. In contrast, the larger tariquidar occupies most of the available volume in the binding pocket, thus leaving little space for lipids to enter the cavity and interact with it. Similarly, when simulating ABCG2 in the apo inward-open state, we also observe spontaneous penetration of phospholipids into the binding cavity. The captured phospholipid diffusion pathway into ABCG2 offers a putative general path to recruit any hydrophobic/amphiphilic substrates directly from the membrane. Our simulations also reveal that ABCG2 rejects cholesterol as a substrate, which is omnipresent in plasma membranes that contain ABCG2. At the same time, cholesterol is found to prohibit the penetration of phospholipids into ABCG2. These molecular findings have direct functional ramifications on ABCG2's function as a transporter.


Asunto(s)
Resistencia a Múltiples Medicamentos , Topotecan , Ligandos , Transportadoras de Casetes de Unión a ATP/metabolismo , Fosfolípidos , Colesterol , Resistencia a Antineoplásicos
7.
Proc Natl Acad Sci U S A ; 120(15): e2218673120, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37014854

RESUMEN

High- (and medium-) entropy alloys have emerged as potentially suitable structural materials for nuclear applications, particularly as they appear to show promising irradiation resistance. Recent studies have provided evidence of the presence of local chemical order (LCO) as a salient feature of these complex concentrated solid-solution alloys. However, the influence of such LCO on their irradiation response has remained uncertain thus far. In this work, we combine ion irradiation experiments with large-scale atomistic simulations to reveal that the presence of chemical short-range order, developed as an early stage of LCO, slows down the formation and evolution of point defects in the equiatomic medium-entropy alloy CrCoNi during irradiation. In particular, the irradiation-induced vacancies and interstitials exhibit a smaller difference in their mobility, arising from a stronger effect of LCO in localizing interstitial diffusion. This effect promotes their recombination as the LCO serves to tune the migration energy barriers of these point defects, thereby delaying the initiation of damage. These findings imply that local chemical ordering may provide a variable in the design space to enhance the resistance of multi-principal element alloys to irradiation damage.

8.
Proc Natl Acad Sci U S A ; 120(15): e2220608120, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37018199

RESUMEN

A precise modulation of heterogeneous catalysts in structural and surface properties promises the development of more sustainable advanced oxidation water purification technologies. However, while catalysts with superior decontamination activity and selectivity are already achievable, maintaining a long-term service life of such materials remains challenging. Here, we propose a crystallinity engineering strategy to break the activity-stability tradeoff of metal oxides in Fenton-like catalysis. The amorphous/crystalline cobalt-manganese spinel oxide (A/C-CoMnOx) provided highly active, hydroxyl group-rich surface, with moderate peroxymonosulfate (PMS)-binding affinity and charge transfer energy and strong pollutant adsorption, to trigger concerted radical and nonradical reactions for efficient pollutant mineralization, thereby alleviating the catalyst passivation by oxidation intermediate accumulation. Meanwhile, the surface-confined reactions, benefited from the enhanced adsorption of pollutants at A/C interface, rendered the A/C-CoMnOx/PMS system ultrahigh PMS utilization efficiency (82.2%) and unprecedented decontamination activity (rate constant of 1.48 min-1) surpassing almost all the state-of-the-art heterogeneous Fenton-like catalysts. The superior cyclic stability and environmental robustness of the system for real water treatment was also demonstrated. Our work unveils a critical role of material crystallinity in modulating the Fenton-like catalytic activity and pathways of metal oxides, which fundamentally improves our understanding of the structure-activity-selectivity relationships of heterogeneous catalysts and may inspire material design for more sustainable water purification application and beyond.

9.
Plant J ; 120(3): 1079-1093, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39312631

RESUMEN

In plants, RNA silencing constitutes a strong defense against viral infection, which viruses counteract with RNA-silencing suppressors (RSSs). Understanding the interactions between viral RSSs and host factors is crucial for elucidating the molecular arms race between viruses and host plants. We report that the helicase motif (Hel) of the replicase encoded by apple stem grooving virus (ASGV)-the main virus affecting pear trees in China-is an RSS that can inhibit both local and systemic RNA silencing, possibly by binding double-stranded (ds) siRNA. The transcription factor related to ABSCISIC ACID INSENSITIVE3/VIVIPAROUS1 from pear (PbRAV1) enters the cytoplasm and binds Hel through its C terminus, thereby attenuating its RSS activity by reducing its binding affinity to 21- and 24-nt ds siRNA, and suppressing ASGV infection. PbRAV1 can also target p24, an RSS encoded by grapevine leafroll-associated virus 2 (GLRaV-2), with similar negative effects on p24's suppressive function and inhibition of GLRaV-2 infection. Moreover, like the positive role of the PbRAV1 homolog from grapevine (VvRAV1) in p24's previously reported RSS activity, ASGV Hel can also hijack VvRAV1 and employ the protein to sequester 21-nt ds siRNA, thereby enhancing its own RSS activity and promoting ASGV infection. Furthermore, PbRAV1 neither interacts with CP, an RSS encoded by grapevine inner necrosis virus, nor has any obvious effect on CP's RSS activity. Our results identify an RSS encoded by ASGV and demonstrate that PbRAV1, representing a novel type of RAV transcription factor, plays a defensive role against viral infection by targeting viral RSSs.


Asunto(s)
Enfermedades de las Plantas , Proteínas de Plantas , Pyrus , Interferencia de ARN , Factores de Transcripción , Pyrus/virología , Pyrus/genética , Pyrus/metabolismo , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Virales/metabolismo , Proteínas Virales/genética , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , ARN Viral/genética , ARN Viral/metabolismo , Virus de Plantas/fisiología , Virus de Plantas/genética
10.
Nature ; 570(7761): 358-362, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31217599

RESUMEN

The ability to manipulate the twisting topology of van der Waals structures offers a new degree of freedom through which to tailor their electrical and optical properties. The twist angle strongly affects the electronic states, excitons and phonons of the twisted structures through interlayer coupling, giving rise to exotic optical, electric and spintronic behaviours1-5. In twisted bilayer graphene, at certain twist angles, long-range periodicity associated with moiré patterns introduces flat electronic bands and highly localized electronic states, resulting in Mott insulating behaviour and superconductivity3,4. Theoretical studies suggest that these twist-induced phenomena are common to layered materials such as transition-metal dichalcogenides and black phosphorus6,7. Twisted van der Waals structures are usually created using a transfer-stacking method, but this method cannot be used for materials with relatively strong interlayer binding. Facile bottom-up growth methods could provide an alternative means to create twisted van der Waals structures. Here we demonstrate that the Eshelby twist, which is associated with a screw dislocation (a chiral topological defect), can drive the formation of such structures on scales ranging from the nanoscale to the mesoscale. In the synthesis, axial screw dislocations are first introduced into nanowires growing along the stacking direction, yielding van der Waals nanostructures with continuous twisting in which the total twist rates are defined by the radii of the nanowires. Further radial growth of those twisted nanowires that are attached to the substrate leads to an increase in elastic energy, as the total twist rate is fixed by the substrate. The stored elastic energy can be reduced by accommodating the fixed twist rate in a series of discrete jumps. This yields mesoscale twisting structures consisting of a helical assembly of nanoplates demarcated by atomically sharp interfaces with a range of twist angles. We further show that the twisting topology can be tailored by controlling the radial size of the structure.

11.
Plant J ; 115(2): 317-334, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37009643

RESUMEN

Frequent herbicide use selects for herbicide resistance in weeds. Cytochrome P450s are important detoxification enzymes responsible for herbicide resistance in plants. We identified and characterized a candidate P450 gene (BsCYP81Q32) from the problematic weed Beckmannia syzigachne to test whether it conferred metabolic resistance to the acetolactate synthase-inhibiting herbicides mesosulfuron-methyl, bispyribac-sodium, and pyriminobac-methyl. Transgenic rice overexpressing BsCYP81Q32 was resistant to the three herbicides. Equally, rice overexpressing the rice ortholog gene OsCYP81Q32 was more resistant to mesosulfuron-methyl. Conversely, an OsCYP81Q32 gene knockout generated using CRISPR/Cas9 enhanced mesosulfuron-methyl sensitivity in rice. Overexpression of the BsCYP81Q32 gene resulted in enhanced mesosulfuron-methyl metabolism in transgenic rice seedlings via O-demethylation. The major metabolite, demethylated mesosulfuron-methyl, was chemically synthesized and displayed reduced herbicidal effect in plants. Moreover, a transcription factor (BsTGAL6) was identified and shown to bind a key region in the BsCYP81Q32 promoter for gene activation. Inhibition of BsTGAL6 expression by salicylic acid treatment in B. syzigachne plants reduced BsCYP81Q32 expression and consequently changed the whole plant response to mesosulfuron-methyl. Sequence polymorphisms in an important region of the BsTGAL6 promoter may explain the higher expression of BsTGAL6 in resistant versus susceptible B. syzigachne plants. Collectively, the present study reveals the evolution of an herbicide-metabolizing and resistance-endowing P450 and its transcription regulation in an economically important weedy plant species.


Asunto(s)
Acetolactato Sintasa , Herbicidas , Oryza , Acetolactato Sintasa/genética , Poaceae/genética , Compuestos de Sulfonilurea/farmacología , Oryza/genética , Oryza/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Herbicidas/farmacología , Resistencia a los Herbicidas/genética
12.
Plant Biotechnol J ; 2024 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-39466674

RESUMEN

Populations of Polypogon fugax have developed resistance to many acetyl-CoA carboxylase (ACCase)-inhibiting herbicides. This resistance threats the effectiveness and sustainability of herbicide use. In our previous research, a field P. fugax population exhibited GST-based metabolic resistance to the widely used ACCase-inhibiting herbicide quizalofop-p-ethyl. Here, in this current study, we identified and characterized two GST genes (named as PfGSTF2 and PfGSTF58) that showed higher expression levels in the resistant than the susceptible population. Transgenic rice calli overexpressing PfGSTF2, but not PfGSTF58, became resistant to quizalofop-p-ethyl and haloxyfop-R-methyl. This reflects similar cross-resistance pattern to what was observed in the resistant P. fugax population. Transgenic rice seedlings overexpressing PfGSTF2 also exhibited resistance to quizalofop-p-ethyl. In contrast, CRISPR/Cas9 knockout of the orthologue gene in rice seedlings increased their sensitivity to quizalofop-p-ethyl. LC-MS analysis of in vitro herbicide metabolism by Escherichia coli-expressed recombinant PfGSTF2 revealed that quizalofop (but not haloxyfop) was detoxified at the ether bond, generating the GSH-quizalofop conjugate and a propanoic acid derivative with greatly reduced herbicidal activity. Equally, these two metabolites accumulated at higher levels in the resistant population than the susceptible population. In addition, both recombinant PfGSTF2 and PfGSTF58 can attenuate cytotoxicity by reactive oxygen species (ROS), suggesting a role in plant defence against ROS generated by herbicides. Furthermore, the GST inhibitor (NBD-Cl) reversed resistance in the resistant population, and PfGSTF2 (but not PfGSTF58) responded to NBD-Cl inhibition. All these suggest that PfGSTF2 plays a significant role in the evolution of quizalofop resistance through enhanced herbicide metabolism in P. fugax.

13.
J Virol ; 97(10): e0093823, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37792003

RESUMEN

IMPORTANCE: Human norovirus (HuNoV) is highly infectious and can result in severe illnesses in the elderly and children. So far, there is no effective antiviral drug to treat HuNoV infection, and thus, the development of HuNoV vaccines is urgent. However, NoV evolves rapidly, and currently, at least 10 genogroups with numerous genotypes have been found. The genetic diversity of NoV and the lack of cross-protection between different genotypes pose challenges to the development of broadly protective vaccines. In this study, guided by structural alignment between GI.1 and GII.4 HuNoV VP1 proteins, several chimeric-type virus-like particles (VLPs) were designed through surface-exposed loop grafting. Mouse immunization studies show that two of the designed chimeric VLPs induced cross-immunity against both GI.1 and GII.4 HuNoVs. To our knowledge, this is the first designed chimeric VLPs that can induce cross-immune activities across different genogroups of HuNoV, which provides valuable strategies for the development of cross-reactive HuNoV vaccines.


Asunto(s)
Infecciones por Caliciviridae , Epítopos , Genotipo , Norovirus , Vacunas Virales , Virión , Animales , Humanos , Ratones , Infecciones por Caliciviridae/inmunología , Infecciones por Caliciviridae/prevención & control , Infecciones por Caliciviridae/virología , Epítopos/química , Epítopos/genética , Epítopos/inmunología , Inmunización , Norovirus/química , Norovirus/clasificación , Norovirus/genética , Norovirus/inmunología , Vacunas Virales/química , Vacunas Virales/genética , Vacunas Virales/inmunología , Quimera/genética , Quimera/inmunología , Proteínas de la Cápside/química , Proteínas de la Cápside/genética , Proteínas de la Cápside/inmunología , Virión/química , Virión/genética , Virión/inmunología
14.
Plant Cell Environ ; 2024 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-39412187

RESUMEN

Actin depolymerizing factors (ADFs), like other actin-binding proteins (ABPs), are modified by phosphorylation to regulate the dynamics of the actin filaments, thereby functioning in various processes throughout the plant lifecycle. In this study, we found that the Arabidopsis thaliana cytoplasmic kinase AGC1.7 interacts with ADF7 in vitro and in vivo. AGC1.7 phosphorylates ADF7 at its Ser-6, Ser-103 and Ser-104 residues in vitro, while replacing these residues with alanine promotes ADF7-mediated actin depolymerization in vitro. Expression of the phosphorylation-mimetic mutant protein ADF7S6/103/104D driven by the pollen-specific LAT52 promoter fully rescues the defects in germination rate, silique length and seeds per silique in both adf7-2 and agc1.5 agc1.7 (agcdm) mutants. Our data establish a model whereby AGC1.7-mediated ADF7 phosphorylation plays an important role in pollen germination and pollen tube growth.

15.
Plant Cell Environ ; 47(8): 3030-3045, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38644762

RESUMEN

The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN-FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss-of-function of CARK3 in overexpressing GFP-D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell-free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin-mediated plant growth and development.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/enzimología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fosforilación , Ácidos Indolacéticos/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Citosol/metabolismo , Ácido Abscísico/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas Quinasas/metabolismo , Proteínas Quinasas/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Plantas Modificadas Genéticamente
16.
Plant Cell ; 33(4): 1229-1251, 2021 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-33693903

RESUMEN

Flowers are the core reproductive structures and key distinguishing features of angiosperms. Flower opening to expose stamens and gynoecia is important in cases where pollinators much be attracted to promote cross-pollination, which can enhance reproductive success and species preservation. The floral opening process is accompanied by the coordinated movement of various floral organs, particularly petals. However, the mechanisms underlying petal movement and flower opening are not well understood. Here, we integrated anatomical, physiological, and molecular approaches to determine the petal movement regulatory network using rose (Rosa hybrida) as a model. We found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), a homeodomain transcription factor (TF) gene, is a direct target of ETHYLENE INSENSITIVE3, a TF that functions downstream of ethylene signaling. RhPMP1 expression was upregulated by ethylene and specifically activated endoreduplication of parenchyma cells on the adaxial side of the petal (ADSP) base by inducing the expression of RhAPC3b, a gene encoding the core subunit of the Anaphase-Promoting Complex. Cell expansion of the parenchyma on the ADSP base was subsequently enhanced, thus resulting in asymmetric growth of the petal base, leading to the typical epinastic movement of petals and flower opening. These findings provide insights into the pathway regulating petal movement and associated flower-opening mechanisms.�.


Asunto(s)
Etilenos/metabolismo , Flores/crecimiento & desarrollo , Rosa/crecimiento & desarrollo , Ciclopropanos/farmacología , Etilenos/farmacología , Flores/efectos de los fármacos , Flores/genética , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas , Silenciador del Gen , Células Vegetales/fisiología , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Rosa/efectos de los fármacos , Rosa/genética , Rosa/metabolismo
17.
BMC Cancer ; 24(1): 1272, 2024 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-39397012

RESUMEN

Ovarian cancer is the fifth most prevalent cancer in women. Chemotherapy is a major treatment option for patients with advanced ovarian cancer (OC). Quinoline-2-thione and its derivatives are potential candidates for tumor therapy. In this study, we investigated the anticancer activity of the quinoline-2-thione derivative KA3D against ovarian cancer. The effect of KA3D on the viability of ovarian cancer cells was evaluated using MTT assay, and its effects on apoptosis and the cell cycle were detected using flow cytometry. Western blotting was performed to identify apoptosis-and cell cycle-related proteins altered by KA3D treatment. A xenograft model was used to verify the inhibitory effect of KA3D in vivo. H&E staining, biochemical indicator detection, and blood cell counts were used to observe the toxicity and side effects of KA3D. KA3D treatment impeded cell viability, induced apoptosis, and impeded the G2 phase of the cell cycle in ovarian cancer cells. Mechanistically, we found that KA3D enhanced the expression of proapoptotic molecules such as BAX and Caspase 3, while antiapoptotic proteins such as BCL2 were inhibited. The G0/G1 phase-related protein cyclin D1 was reduced and the G2 phase-related protein cyclin B1 was upregulated. In vivo, KA3D displayed potent anticancer activity, with no apparent toxicity in BABLC/c nude mice bearing SKOV3 cells. KA3D demonstrated remarkable chemotherapeutic drug efficacy in terms of significant cancer suppression in vitro and in vivo with low toxicity.


Asunto(s)
Antineoplásicos , Apoptosis , Neoplasias Ováricas , Quinolinas , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Animales , Femenino , Ratones , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Neoplasias Ováricas/metabolismo , Apoptosis/efectos de los fármacos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Quinolinas/farmacología , Quinolinas/uso terapéutico , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ratones Desnudos , Tionas/farmacología , Ciclo Celular/efectos de los fármacos , Ratones Endogámicos BALB C
18.
Int Arch Allergy Immunol ; 185(2): 124-132, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37913762

RESUMEN

INTRODUCTION: The incidence of allergic rhinitis (AR) is increasing year by year, and the pathogenesis is complex, in which diet may play an important role. The role of polyunsaturated fatty acids (PUFAs) in AR is still controversial. Previous studies have looked at the effects of PUFA during pregnancy, childhood, and adolescence. In this study, we aimed to determine the association between dietary intake of PUFA and AR in adults. METHODS: We used the NHANES database from 2005 to 2006 to include a total of 4,211 adult subjects. We collected dietary PUFA intake data and information on AR. Logistic regression and restricted cubic spline models were constructed to examine the association between PUFA intake and AR in adults. The t test was used to compare daily PUFA intakes in patients with and without AR. RESULTS: In the fully adjusted model (OR: 1.016; 95% CI: 1.003; 1.028), PUFA intake was positively correlated with allergic symptoms, hay fever, and AR in adults (p < 0.05). In addition, daily PUFA intake was significantly higher in people with allergic symptoms, hay fever, and AR than in people without the disease (p < 0.01). CONCLUSIONS: Our results suggest a positive association between dietary PUFA intake and AR in adults to a certain extent. Future studies on dietary PUFA dose will provide new strategies for the prevention and treatment of allergic diseases such as AR related to non-pharmaceutical interventions.


Asunto(s)
Rinitis Alérgica Estacional , Rinitis Alérgica , Adulto , Embarazo , Femenino , Adolescente , Humanos , Niño , Estudios Transversales , Encuestas Nutricionales , Dieta , Rinitis Alérgica/epidemiología , Ácidos Grasos Insaturados
19.
Ann Hematol ; 103(1): 163-174, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37817010

RESUMEN

The present study aimed to investigate the clinical features, prognosis, and treatment of advanced-stage non-nasal type extranodal natural killer/T-cell lymphoma (ENKTCL). This real-world study retrospectively reviewed 56 newly diagnosed advanced-stage non-nasal type ENKTCL patients from two large-scale Chinese cancer centers in the last 10-15 years and screened 139 newly diagnosed advanced-stage nasal type ENKTCLs admitted during the same period for comparison. The non-nasal type ENKTCLs exhibited significantly higher Ki-67 expression levels compared to nasal type disease (P = 0.011). With a median follow-up duration of 75.03 months, the non-nasal group showed slightly inferior survival outcomes without statistically significant differences compared to the nasal group (median overall survival (OS): 14.57 vs. 21.53 months, 5-year OS: 28.0% vs. 38.5%, P = 0.120). Eastern Cooperative Oncology Group (ECOG) score ≥ 2 (hazard ratio (HR) = 2.18, P = 0.039) and lactic dehydrogenase (LDH) elevation (HR = 2.44, P = 0.012) were significantly correlated with worse OS in the non-nasal group. First-line gemcitabine-based chemotherapy regimens showed a trend toward slightly improved efficacy and survival outcomes compared to non-gemcitabine-based ones in the present cohort of non-nasal ENKTCLs (objective response rate: 91.7% vs. 63.6%, P = 0.144; complete response rate: 50.0% vs. 33.3%, P = 0.502; median progression-free survival: 10.43 vs. 3.40 months, P = 0.106; median OS: 25.13 vs. 9.30 months, P = 0.125), which requires further validation in larger sample size studies. Advanced-stage non-nasal type patients could achieve comparable prognosis with nasal cases after rational therapy. The modified nomogram-revised index (including age, ECOG score, and LDH) and modified international prognostic index (including age, ECOG score, LDH, and number of extranodal involvement) functioned effectively for prognostic stratification in non-nasal type ENKTCLs.


Asunto(s)
Linfoma Extranodal de Células NK-T , Linfoma de Células T , Humanos , Pronóstico , Estudios Retrospectivos , Modelos de Riesgos Proporcionales , Células Asesinas Naturales/patología , Linfoma de Células T/patología , Linfoma Extranodal de Células NK-T/diagnóstico , Linfoma Extranodal de Células NK-T/tratamiento farmacológico , Estadificación de Neoplasias
20.
Ann Hematol ; 103(8): 3061-3069, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38805037

RESUMEN

In this prospective, multicenter, Phase 2 clinical trial (NCT02987244), patients with peripheral T-cell lymphomas (PTCLs) who had responded to first-line chemotherapy with cyclophosphamide, doxorubicin or epirubicin, vincristine or vindesine, etoposide, and prednisone (Chi-CHOEP) were treated by autologous stem cell transplantation (ASCT) or with chidamide maintenance or observation. A total of 85 patients received one of the following interventions: ASCT (n = 15), chidamide maintenance (n = 44), and observation (n = 26). estimated 3 PFS and OS rates were 85.6%, 80.8%, and 49.4% (P = 0.001). The two-year OS rates were 85.6%, 80.8%, and 69.0% (P = 0.075).The ASCT and chidamide maintenance groups had significantly better progression-free survival (PFS) than the observation group (P = 0.001, and P = 0.01, respectively). The overall survival (OS) differed significantly between the chidamide maintenance group and the observation group ( P = 0.041). The multivariate and propensity score matching analyses for PFS revealed better outcomes in the subjects in the chidamide maintenance than observation groups (P = 0.02). The ASCT and chidamide maintenance groups had significant survival advantages over the observation group. In the post-remission stage of the untreated PTCL patients, single-agent chidamide maintenance demonstrated superior PFS and better OS than observation. Our findings highlight the potential benefit of chidamide in this patient subset, warranting further investigation through larger prospective trials. Clinical trial registration: clinicaltrial.gov, NCT02987244. Registered 8 December 2016, http://www.clinicaltrials.gov/ct2/show/NCT02987244 .


Asunto(s)
Aminopiridinas , Protocolos de Quimioterapia Combinada Antineoplásica , Benzamidas , Trasplante de Células Madre Hematopoyéticas , Linfoma de Células T Periférico , Humanos , Linfoma de Células T Periférico/terapia , Linfoma de Células T Periférico/mortalidad , Linfoma de Células T Periférico/tratamiento farmacológico , Masculino , Femenino , Adulto , Persona de Mediana Edad , Aminopiridinas/uso terapéutico , Benzamidas/uso terapéutico , Estudios Prospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , China/epidemiología , Trasplante Autólogo , Anciano , Tasa de Supervivencia , Adulto Joven , Quimioterapia de Mantención , Autoinjertos , Inducción de Remisión , Adolescente
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