Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 328
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Plant Cell ; 34(11): 4495-4515, 2022 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-35972376

RESUMEN

Cold tolerance at the booting (CTB) stage is a major factor limiting rice (Oryza sativa L.) productivity and geographical distribution. A few cold-tolerance genes have been identified, but they either need to be overexpressed to result in CTB or cause yield penalties, limiting their utility for breeding. Here, we characterize the function of the cold-induced transcription factor WRKY53 in rice. The wrky53 mutant displays increased CTB, as determined by higher seed setting. Low temperature is associated with lower gibberellin (GA) contents in anthers in the wild type but not in the wrky53 mutant, which accumulates slightly more GA in its anthers. WRKY53 directly binds to the promoters of GA biosynthesis genes and transcriptionally represses them in anthers. In addition, we uncover a possible mechanism by which GA regulates male fertility: SLENDER RICE1 (SLR1) interacts with and sequesters two critical transcription factors for tapetum development, UNDEVELOPED TAPETUM1 (UDT1), and TAPETUM DEGENERATION RETARDATION (TDR), and GA alleviates the sequestration by SLR1, thus allowing UDT1 and TDR to activate transcription. Finally, knocking out WRKY53 in diverse varieties increases cold tolerance without a yield penalty, leading to a higher yield in rice subjected to cold stress. Together, these findings provide a target for improving CTB in rice.


Asunto(s)
Oryza , Oryza/metabolismo , Giberelinas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genes de Plantas , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
2.
J Am Chem Soc ; 146(20): 14260-14266, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38714344

RESUMEN

The electrochemical CO2 reduction reaction by copper-based catalysts features a promising approach to generate value-added multicarbon (C2+) products. However, due to the unfavored formation of oxygenate intermediates on the catalyst surface, the selectivity of C2+ alcohols like ethanol remains unsatisfactory compared to that of ethylene. The bifurcation point (i.e., the CH2═CHO* intermediate adsorbed on Cu via a Cu-O-C linkage) is critical to the C2+ product selectivity, whereas the subsequent cleavage of the Cu-O or the O-C bond determines the ethanol or ethylene pathway. Inspired by the hard-soft acid-base theory, in this work, we demonstrate an electron delocalization tuning strategy of the Cu catalyst by a nitrene surface functionalization approach, which allows weakening and cleaving of the Cu-O bond of the adsorbed CH2═CHO*, as well as accelerating hydrogenation of the C═C bond along the ethanol pathway. As a result, the nitrene-functionalized Cu catalyst exhibited a much-enhanced ethanol Faradaic efficiency of 45% with a peak partial current density of 406 mA·cm-2, substantially exceeding that of unmodified Cu or amide-functionalized Cu. When assembled in a membrane electrode assembly electrolyzer, the catalyst presented a stable CO2-to-ethanol conversion for >300 h at an industrial current density of 400 mA·cm-2.

3.
Clin Oral Implants Res ; 35(7): 719-728, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38624226

RESUMEN

OBJECTS: This study aims to explore the etiology of peri-implantitis by comparing the metabolic profiles in peri-implant crevicular fluid (PICF) from patients with healthy implants (PH) and those with peri-implantitis (PI). MATERIALS AND METHODS: Fifty-six patients were enrolled in this cross-sectional study. PICF samples were collected and analyzed using both non-targeted and targeted metabolomics approaches. The relationship between metabolites and clinical indices including probing depth (PD), bleeding on probing (BOP), and marginal bone loss (MBL) was examined. Additionally, submucosal microbiota was collected and analyzed using 16S rRNA gene sequencing to elucidate the association between the metabolites and microbial communities. RESULTS: Significant differences in metabolic profiles were observed between the PH and PI groups, with 179 distinct metabolites identified. In the PI group, specific amino acids and fatty acids were significantly elevated compared to the PH group. Organic acids including succinic acid, fructose-6-phosphate, and glucose-6-phosphate were markedly higher in the PI group, showing positive correlations with mean PD, BOP, and MBL. Metabolites that increased in the PI group positively correlated with the presence of Porphyromonas and Treponema and negatively with Streptococcus and Haemophilus. CONCLUSIONS: This study establishes a clear association between metabolic compositions and peri-implant condition, highlighting enhanced metabolite activity in peri-implantitis. These findings open avenues for further research into metabolic mechanisms of peri-implantitis and their potential therapeutic implications.


Asunto(s)
Líquido del Surco Gingival , Periimplantitis , Humanos , Periimplantitis/metabolismo , Periimplantitis/microbiología , Líquido del Surco Gingival/microbiología , Líquido del Surco Gingival/metabolismo , Líquido del Surco Gingival/química , Masculino , Femenino , Estudios Transversales , Persona de Mediana Edad , Anciano , Metaboloma , Adulto , Microbiota
4.
BMC Geriatr ; 24(1): 415, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38730347

RESUMEN

BACKGROUND: Parkinson's disease (PD) is a slowly progressive neurodegenerating disease that may eventually lead to disabling condition and pose a threat to the health of aging populations. This study aimed to explore the association of two potential risk factors, selenium and cadmium, with the prognosis of Parkinson's disease as well as their interaction effect. METHODS: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 to 2015-2016 and National Death Index (NDI). Participants were classified as Parkinson's patients by self-reported anti-Parkinson medications usage. Cox regression models and restricted cubic spline models were applied to evaluate the association between PD mortality and selenium intake level as well as blood cadmium level. Subgroup analysis was also conducted to explore the interaction between them. RESULTS: A total of 184 individuals were included. In full adjusted cox regression model (adjusted for age, gender, race, hypertension, pesticide exposure, smoking status and caffeine intake), compared with participants with low selenium intake, those with normal selenium intake level were significantly associated with less risk of death (95%CI: 0.18-0.76, P = 0.005) while no significant association was found between low selenium intake group and high selenium group (95%CI: 0.16-1.20, P = 0.112). Restricted cubic spline model indicated a nonlinear relationship between selenium intake and PD mortality (P for nonlinearity = 0.050). The association between PD mortality and blood cadmium level was not significant (95%CI: 0.19-5.57, P = 0.112). However, the interaction term of selenium intake and blood cadmium showed significance in the cox model (P for interaction = 0.048). Subgroup analysis showed that the significant protective effect of selenium intake existed in populations with high blood cadmium but not in populations with low blood cadmium. CONCLUSION: Moderate increase of selenium intake had a protective effect on PD mortality especially in high blood cadmium populations.


Asunto(s)
Cadmio , Enfermedad de Parkinson , Selenio , Humanos , Cadmio/sangre , Masculino , Femenino , Enfermedad de Parkinson/sangre , Enfermedad de Parkinson/mortalidad , Selenio/sangre , Selenio/administración & dosificación , Estudios Retrospectivos , Anciano , Persona de Mediana Edad , Encuestas Nutricionales/métodos , Factores de Riesgo , Dieta , Causas de Muerte/tendencias , Estudios de Cohortes
5.
J Neurosci ; 42(4): 532-551, 2022 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-34848499

RESUMEN

Mutations in some cell adhesion molecules (CAMs) cause abnormal synapse formation and maturation, and serve as one of the potential mechanisms of autism spectrum disorders (ASDs). Recently, DSCAM (Down syndrome cell adhesion molecule) was found to be a high-risk gene for autism. However, it is still unclear how DSCAM contributes to ASD. Here, we show that DSCAM expression was downregulated following synapse maturation, and that DSCAM deficiency caused accelerated dendritic spine maturation during early postnatal development. Mechanistically, the extracellular domain of DSCAM interacts with neuroligin1 (NLGN1) to block the NLGN1-neurexin1ß (NRXN1ß) interaction. DSCAM extracellular domain was able to rescue spine overmaturation in DSCAM knockdown neurons. Precocious spines in DSCAM-deficient mice showed increased glutamatergic transmission in the developing cortex and induced autism-like behaviors, such as social novelty deficits and repetitive behaviors. Thus, DSCAM might be a repressor that prevents premature spine maturation and excessive glutamatergic transmission, and its deficiency could lead to autism-like behaviors. Our study provides new insight into the potential pathophysiological mechanisms of ASDs.SIGNIFICANCE STATEMENTDSCAM is not only associated with Down syndrome but is also a strong autism risk gene based on large-scale sequencing analysis. However, it remains unknown exactly how DSCAM contributes to autism. In mice, either neuron- and astrocyte-specific or pyramidal neuron-specific DSCAM deficiencies resulted in autism-like behaviors and enhanced spatial memory. In addition, DSCAM knockout or knockdown in pyramidal neurons led to increased dendritic spine maturation. Mechanistically, the extracellular domain of DSCAM binds to NLGN1 and inhibits NLGN1-NRXN1ß interaction, which can rescue abnormal spine maturation induced by DSCAM deficiency. Our research demonstrates that DSCAM negatively modulates spine maturation, and that DSCAM deficiency leads to excessive spine maturation and autism-like behaviors, thus providing new insight into a potential pathophysiological mechanism of autism.


Asunto(s)
Trastorno del Espectro Autista/metabolismo , Moléculas de Adhesión Celular/deficiencia , Espinas Dendríticas/metabolismo , Neurogénesis/fisiología , Corteza Somatosensorial/metabolismo , Animales , Trastorno del Espectro Autista/genética , Trastorno del Espectro Autista/patología , Células COS , Moléculas de Adhesión Celular/genética , Células Cultivadas , Chlorocebus aethiops , Espinas Dendríticas/patología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Técnicas de Cultivo de Órganos , Ratas , Ratas Sprague-Dawley , Corteza Somatosensorial/patología
6.
Mov Disord ; 38(3): 410-422, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36656044

RESUMEN

BACKGROUND: Current models of levodopa (L-dopa)-induced dyskinesia (LID) are obtained by treating dopamine-depleted animals with L-dopa. However, patients with LID receive combination therapies that often include dopamine agonists. OBJECTIVE: Using 6-hydroxydopamine-lesioned rats as a model, we aimed to establish whether an adjunct treatment with the D2/3 agonist ropinirole impacts on patterns of LID-related neuroplasticity and drug responses. METHODS: Different regimens of L-dopa monotreatment and L-dopa-ropinirole cotreatment were compared using measures of hypokinesia and dyskinesia. Striatal expression of ∆FosB and angiogenesis markers were studied immunohistochemically. Antidyskinetic effects of different drug categories were investigated in parallel groups of rats receiving either L-dopa monotreatment or L-dopa combined with ropinirole. RESULTS: We defined chronic regimens of L-dopa monotreatment and L-dopa-ropinirole cotreatment inducing overall similar abnormal involuntary movement scores. Compared with the monotreatment group, animals receiving the L-dopa-ropinirole combination exhibited an overall lower striatal expression of ∆FosB with a distinctive compartmental distribution. The expression of angiogenesis markers and blood-brain barrier hyperpermeability was markedly reduced after L-dopa-ropinirole cotreatment compared with L-dopa monotreatment. Moreover, significant group differences were detected upon examining the response to candidate antidyskinetic drugs. In particular, compounds modulating D1 receptor signaling had a stronger effect in the L-dopa-only group, whereas both amantadine and the selective NMDA antagonist MK801 produced a markedly larger antidyskinetic effect in L-dopa-ropinirole cotreated animals. CONCLUSIONS: Cotreatment with ropinirole altered LID-related neuroplasticity and pharmacological response profiles. The impact of adjuvant dopamine agonist treatment should be taken into consideration when investigating LID mechanisms and candidate interventions in both clinical and experimental settings. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Discinesia Inducida por Medicamentos , Levodopa , Ratas , Animales , Levodopa/uso terapéutico , Agonistas de Dopamina/farmacología , Agonistas de Dopamina/uso terapéutico , Antiparkinsonianos/uso terapéutico , Ratas Sprague-Dawley , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Oxidopamina , Modelos Animales de Enfermedad
7.
EMBO Rep ; 22(7): e52006, 2021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-34096155

RESUMEN

Tunneling nanotubes (TNTs) are actin-rich structures that connect two or more cells and mediate cargo exchange between spatially separated cells. TNTs transport signaling molecules, vesicles, organelles, and even pathogens. However, the molecular mechanisms regulating TNT formation remain unclear and little is known about the endogenous mechanisms suppressing TNT formation in lung cancer cells. Here, we report that MICAL2PV, a splicing isoform of the neuronal guidance gene MICAL2, is a novel TNT regulator that suppresses TNT formation and modulates mitochondrial distribution. MICAL2PV interacts with mitochondrial Rho GTPase Miro2 and regulates subcellular mitochondrial trafficking. Moreover, down-regulation of MICAL2PV enhances survival of cells treated with chemotherapeutical drugs. The monooxygenase (MO) domain of MICAL2PV is required for its activity to inhibit TNT formation by depolymerizing F-actin. Our data demonstrate a previously unrecognized function of MICAL2 in TNT formation and mitochondrial trafficking. Furthermore, our study uncovers a role of the MICAL2PV-Miro2 axis in mitochondrial trafficking, providing a mechanistic explanation for MICAL2PV activity in suppressing TNT formation and in modulating mitochondrial subcellular distribution.


Asunto(s)
Comunicación Celular , Nanotubos , Citoesqueleto de Actina , Actinas/genética , Humanos , Proteínas de Microfilamentos , Orgánulos , Oxidorreductasas
8.
Org Biomol Chem ; 21(40): 8089-8093, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37779504

RESUMEN

We report an efficient and sustainable electrocatalytic approach for the synthesis of 3,3-disubstituted 2-oxindoles bearing ester groups from readily accessible N-arylacrylamides and carbazates. The reaction proceeds through an electrochemical iron-catalyzed radical addition/cyclization sequence with a commercially available iron catalyst and carbazates as alkoxycarbonyl radical precursors. This mild and operationally simple method transforms a wide range of structurally diverse N-arylacrylamides into oxindole derivatives in good yields and can be smoothly scaled up for the preparation of synthetically valuable oxindoles that are key intermediates for the synthesis of natural products.

9.
Chem Rev ; 121(17): 10469-10558, 2021 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-34254782

RESUMEN

Nucleic acids, including deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are natural biopolymers composed of nucleotides that store, transmit, and express genetic information. Overexpressed or underexpressed as well as mutated nucleic acids have been implicated in many diseases. Therefore, nucleic acid tests (NATs) are extremely important. Inspired by intracellular DNA replication and RNA transcription, in vitro NATs have been extensively developed to improve the detection specificity, sensitivity, and simplicity. The principles of NATs can be in general classified into three categories: nucleic acid hybridization, thermal-cycle or isothermal amplification, and signal amplification. Driven by pressing needs in clinical diagnosis and prevention of infectious diseases, NATs have evolved to be a rapidly advancing field. During the past ten years, an explosive increase of research interest in both basic research and clinical translation has been witnessed. In this review, we aim to provide comprehensive coverage of the progress to analyze nucleic acids, use nucleic acids as recognition probes, construct detection devices based on nucleic acids, and utilize nucleic acids in clinical diagnosis and other important fields. We also discuss the new frontiers in the field and the challenges to be addressed.


Asunto(s)
Enfermedades Transmisibles/diagnóstico , ADN/análisis , Técnicas de Amplificación de Ácido Nucleico , Sondas de Ácido Nucleico , ARN/análisis , Animales , Enfermedades Transmisibles/microbiología , Enfermedades Transmisibles/virología , Humanos , Sondas de Ácido Nucleico/análisis
10.
Philos Trans A Math Phys Eng Sci ; 381(2260): 20220384, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37742710

RESUMEN

For the fatigue reliability analysis of aeroengine blade-disc systems, the traditional direct integral modelling methods or separate independent modelling methods will lead to low computational efficiency or accuracy. In this work, a physics-informed ensemble learning (PIEL) method is proposed, i.e. firstly, based on the physical characteristics of blade-disc systems, the complex multi-component reliability analysis is split into a series of single-component reliability analyses; moreover, the PIEL model is established by introducing the mapping of multiple constitutive responses and the multi-material physical characteristics into the ensemble learning; finally, the PIEL-based system reliability framework is established by quantifying the failure correlation with the Copula function. The reliability analysis of a typical aeroengine high-pressure turbine blade-disc system is regarded as an example to verify the effectiveness of the proposed method. Compared with the direct Monte Carlo, support vector regression, neural network, ensemble learning and physics-informed neural network, the proposed method exhibits the highest computing accuracy and efficiency, and is validated to be an efficient method for the reliability analysis of blade-disc systems. The current work can provide a novel insight for physics-informed modelling and fatigue reliability analyses. This article is part of the theme issue 'Physics-informed machine learning and its structural integrity applications (Part 1)'.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA