Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 428
Filtrar
2.
Nat Commun ; 15(1): 4999, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38866834

RESUMEN

Cryptophytes are ancestral photosynthetic organisms evolved from red algae through secondary endosymbiosis. They have developed alloxanthin-chlorophyll a/c2-binding proteins (ACPs) as light-harvesting complexes (LHCs). The distinctive properties of cryptophytes contribute to efficient oxygenic photosynthesis and underscore the evolutionary relationships of red-lineage plastids. Here we present the cryo-electron microscopy structure of the Photosystem II (PSII)-ACPII supercomplex from the cryptophyte Chroomonas placoidea. The structure includes a PSII dimer and twelve ACPII monomers forming four linear trimers. These trimers structurally resemble red algae LHCs and cryptophyte ACPI trimers that associate with Photosystem I (PSI), suggesting their close evolutionary links. We also determine a Chl a-binding subunit, Psb-γ, essential for stabilizing PSII-ACPII association. Furthermore, computational calculation provides insights into the excitation energy transfer pathways. Our study lays a solid structural foundation for understanding the light-energy capture and transfer in cryptophyte PSII-ACPII, evolutionary variations in PSII-LHCII, and the origin of red-lineage LHCIIs.


Asunto(s)
Microscopía por Crioelectrón , Criptófitas , Complejos de Proteína Captadores de Luz , Complejo de Proteína del Fotosistema II , Complejo de Proteína del Fotosistema II/metabolismo , Complejo de Proteína del Fotosistema II/química , Complejos de Proteína Captadores de Luz/metabolismo , Complejos de Proteína Captadores de Luz/química , Criptófitas/metabolismo , Fotosíntesis , Modelos Moleculares , Transferencia de Energía , Complejo de Proteína del Fotosistema I/metabolismo , Complejo de Proteína del Fotosistema I/química , Clorofila A/metabolismo , Clorofila A/química
3.
J Phys Chem Lett ; 15(25): 6662-6667, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38889366

RESUMEN

Lithium hydride (LiH), a saline hydride with a hydrogen density of 12.6 wt %, is highly thermostable, which hinders its extensive application in hydrogen storage. In this study, we demonstrate a distinct photodecomposition of LiH under ambient conditions. Ultraviolet-visible (UV-vis) illumination induces hydrogen release and creates surface hydrogen vacancies on LiH. The subsequent H- migration enables hydrogen desorption and the accumulation of vacancies at the subsurface, resulting in the generation of metallic Li clusters. Rehydrogenation, on the contrary, can be charged under UV-vis illumination in 1 bar H2. Such phenomena show that the thermodynamic and kinetic limits in the re/dehydrogenation of LiH can be broken under illumination, which allows hydrogen storage over the LiH surface at temperatures ∼600 K lower than those of the corresponding thermal process. This work provides new insights into the interaction of semiconducting hydrides and photons and opens an avenue for the development and optimization of materials for hydrogen storage and related photodriven reactions.

4.
Front Cardiovasc Med ; 11: 1383567, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38720919

RESUMEN

Background: Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) combined with resistant hypertension (RH) have a high risk of developing primary aldosteronism (PA). This study investigated the aldosterone-renin ratio (ARR), plasma aldosterone concentration (PAC), and plasma renin activity (PRA) to determine the optimal cutoff values for PA diagnosis in patients with OSAHS combined with RH. Methods: Patients diagnosed with moderate and severe OSAHS combined with RH were recruited from the inpatient clinic of the Department of Endocrinology at Ji'an Central Hospital between October 2020 and April 2023. The included patients were divided into PA and no-PA groups. Diagnostic accuracy measures were calculated for each group, and receiver operating characteristic (ROC) curves were generated. Results: A total of 241 patients were included, of which 103 had positive ARR screening results in the diagnostic accuracy analysis and 66 were diagnosed with PA. PAC and ARR showed moderate predictive capacity for PA, with area under the curve (AUC) values of 0.66 [95% confidence interval (CI): 0.55-0.77] and 0.72 (95% CI: 0.63-0.82), respectively, while PRA exhibited a limited predictive capacity (AUC = 0.51, 95% CI: 0.40-0.63). Using 45 as the optimal cutoff value for ARR, the sensitivity was 86% and the specificity was 52%. The optimal cutoff value for PAC was 17, with a sensitivity of 78% and a specificity of 55%. Notably, in patients with severe OSAHS, ARR at screening demonstrated significant predictive value for PA, with an AUC of 0.84 (95% CI: 0.72-0.96), a sensitivity of 85%, and a specificity of 76%. Conversely, in patients with moderate OSAHS, only ARR demonstrated significant predictive value for PA diagnosis, while PAC did not demonstrate notable diagnostic value. Conclusion: ARR and PAC are initial screening tools for PA, facilitating early detection, particularly in low-resource settings. In patients with OSAHS and RH, the ARR and PAC thresholds for PA diagnosis may require more stringent adjustment.

5.
Heliyon ; 10(9): e30791, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38765160

RESUMEN

To investigate the dynamic changes in dry matter accumulation in maize after anthesis, we established a logistic model to describe grain filling characteristics (GFC), and analyzed differences between spring and summer maize, and the influence of meteorological factors. The results showed that the logistic model accurately simulated the dynamic changes in grain growth. For spring maize, the fitted hundred-grain weight at maturity was closely related to the average grain filling rate until maturity, days of the active grain filling period, time of the maximum grain filling rate, and duration of the rapid increase in grain weight. For summer maize, it was closely related to the time of the maximum grain filling rate, days of active grain filling period, duration of gradual grain weight, and the rapidly increasing period. The filling characteristics of spring and summer maize differed because of the different meteorological conditions and biological characteristics. The grain filling duration of spring maize was longer than that of summer maize. The maximum grain filling rate of spring maize occurred later than that of summer maize. Temperature and precipitation were the main meteorological factors affecting the hundred-grain weight of spring maize, whereas temperature was the main factor affecting summer maize. The response of spring maize GFC to meteorological factors was more complex than that of summer maize. These results are important for the development of appropriate strategies for improving maize productivity in China.

6.
ACS Appl Mater Interfaces ; 16(20): 26500-26511, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38739095

RESUMEN

In this study, we propose and implement a deep neural network framework based on multitask learning aimed at simplifying the forward modeling and inverse design process of photonic devices integrating active metasurfaces. We demonstrate and validate our approach by constructing a continuously tunable bandpass filter that is effective in the midwave infrared region. The key to this filter is the combination of a metasurface and Fabry-Perot (F-P) cavity structure of the tunable phase-change material Ge2Sb2Se4Te (GSST) and the precise control of the crystallinity of the GSST by a silicon-based heater. With the help of a deep learning framework, we are able to independently model the crystallinity and geometric parameters of the filter to maximize the use of GSST tuning for bandpass filtering. Our model discusses the self-attention mechanism and the effect of noise and compares several existing popular algorithms, and the results show that a multitask deep learning strategy can better assist the on-demand reverse design of photonic structures with phase change materials. This opens up new possibilities for personalization and functional extension of optical devices.

7.
Mol Biol Rep ; 51(1): 506, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622341

RESUMEN

BACKGROUND: Atrial Fibrillation (AF), a prevalent arrhythmic condition, is intricately associated with atrial fibrosis, a major pathological contributor. Central to the development of atrial fibrosis is myocardial inflammation. This study focuses on Atrial Natriuretic Peptide (ANP) and its role in mitigating atrial fibrosis, aiming to elucidate the specific mechanisms by which ANP exerts its effects, with an emphasis on fibroblast dynamics. METHODS AND RESULTS: The study involved forty Sprague-Dawley rats, divided into four groups: control, Angiotensin II (Ang II), Ang II + ANP, and ANP only. The administration of 1 µg/kg/min Ang II was given to Ang II and Ang II + ANP groups, while both Ang II + ANP and ANP groups received 0.1 µg/kg/min ANP intravenously for a duration of 14 days. Cardiac fibroblasts were used for in vitro validation of the proposed mechanisms. The study observed that rats in the Ang II and Ang II + ANP groups showed an increase in blood pressure and a decrease in body weight, more pronounced in the Ang II group. Diastolic dysfunction, a characteristic of the Ang II group, was alleviated by ANP. Additionally, ANP significantly reduced Ang II-induced atrial fibrosis, myofibroblast proliferation, collagen overexpression, macrophage infiltration, and the elevated expression of Interleukin 6 (IL-6) and Tenascin-C (TN-C). Transcriptomic sequencing indicated enhanced PI3K/Akt signaling in the Ang II group. Furthermore, in vitro studies showed that ANP, along with the PI3K inhibitor LY294002, effectively reduced PI3K/Akt pathway activation and the expression of TN-C, collagen-I, and collagen-III, which were induced by Ang II. CONCLUSIONS: The study demonstrates ANP's potential in inhibiting myocardial inflammation and reducing atrial fibrosis. Notably, ANP's effect in countering atrial fibrosis seems to be mediated through the suppression of the Ang II-induced PI3K/Akt-Tenascin-C signaling pathway. These insights enhance our understanding of AF pathogenesis and position ANP as a potential therapeutic agent for treating atrial fibrosis.


Asunto(s)
Fibrilación Atrial , Factor Natriurético Atrial , Ratas , Animales , Ratas Sprague-Dawley , Factor Natriurético Atrial/farmacología , Factor Natriurético Atrial/metabolismo , Proteínas Proto-Oncogénicas c-akt , Fosfatidilinositol 3-Quinasas , Tenascina , Fibrilación Atrial/tratamiento farmacológico , Angiotensina II/farmacología , Inflamación/tratamiento farmacológico , Colágeno , Fibrosis
8.
Front Plant Sci ; 15: 1373081, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38576786

RESUMEN

The brown planthopper (BPH) is the most destructive insect pest that threatens rice production globally. Developing rice varieties incorporating BPH-resistant genes has proven to be an effective control measure against BPH. In this study, we assessed the resistance of a core collection consisting of 502 rice germplasms by evaluating resistance scores, weight gain rates and honeydew excretions. A total of 117 rice varieties (23.31%) exhibited resistance to BPH. Genome-wide association studies (GWAS) were performed on both the entire panel of 502 rice varieties and its subspecies, and 6 loci were significantly associated with resistance scores (P value < 1.0e-8). Within these loci, we identified eight candidate genes encoding receptor-like protein kinase (RLK), nucleotide-binding and leucine-rich repeat (NB-LRR), or LRR proteins. Two loci had not been detected in previous study and were entirely novel. Furthermore, we evaluated the predictive ability of genomic selection for resistance to BPH. The results revealed that the highest prediction accuracy for BPH resistance reached 0.633. As expected, the prediction accuracy increased progressively with an increasing number of SNPs, and a total of 6.7K SNPs displayed comparable accuracy to 268K SNPs. Among various statistical models tested, the random forest model exhibited superior predictive accuracy. Moreover, increasing the size of training population improved prediction accuracy; however, there was no significant difference in prediction accuracy between a training population size of 737 and 1179. Additionally, when there existed close genetic relatedness between the training and validation populations, higher prediction accuracies were observed compared to scenarios when they were genetically distant. These findings provide valuable resistance candidate genes and germplasm resources and are crucial for the application of genomic selection for breeding durable BPH-resistant rice varieties.

10.
ChemSusChem ; : e202400221, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38656613

RESUMEN

Alkali and alkaline earth metal amides are a type of functional materials for hydrogen storage, thermal energy storage, ion conduction, and chemical transformations such as ammonia synthesis and decomposition. The thermal chemistry of lithium amide (LiNH2), as a simple but representative alkali or alkaline earth metal amide, has been well studied previously encouraged by its potentials in hydrogen storage. In comparison, little is known about the interaction of plasma and LiNH2. Herein, we report that the plasma treatment of LiNH2 in an Ar flow under ambient temperature and pressure gives rise to distinctly different reaction products and reaction pathway from that of the thermal process. We found that plasma treatment of LiNH2 leads to the formation of Li colloids, N2, and H2 as observed by UV-vis absorption, EPR, and gas products analysis. Inspired by this very unique interaction between plasma and LiNH2, a chemical loop for ammonia decomposition to N2 and H2 mediated by LiNH2 was proposed and demonstrated.

11.
J Card Fail ; 30(6): 853-856, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38513886

RESUMEN

BACKGROUND: It is common for clinicians to use the pulmonary artery diastolic pressure (PADP) as a surrogate for the pulmonary capillary wedge pressure (PCWP). Here, we determine the validity of this relationship in patients with various phenotypes of cardiogenic shock (CS). METHODS AND RESULTS: In this analysis of the Critical Care Cardiology Trials Network registry, we identified 1225 people admitted with CS who received pulmonary artery catheters. Linear regression, Bland-Altman and receiver operator characteristic analyses were performed to determine the strength of the association between PADP and PCWP in patients with left-, right-, biventricular, and other non-myocardia phenotypes of CS (eg, arrhythmia, valvular stenosis, tamponade). There was a moderately strong correlation between PADP and PCWP in the total population (r = 0.64, n = 1225) and in each CS phenotype, except for right ventricular CS, for which the correlation was weak (r = 0.43, n = 71). Additionally, we found that a PADP ≥ 24 mmHg can be used to infer a PCWP ≥ 18 mmHg with ≥ 90% confidence in all but the right ventricular CS phenotype. CONCLUSIONS: This analysis validates the practice of using PADP as a surrogate for PCWP in most patients with CS; however, it should generally be avoided in cases of right ventricular-predominant CS.


Asunto(s)
Arteria Pulmonar , Presión Esfenoidal Pulmonar , Sistema de Registros , Choque Cardiogénico , Humanos , Presión Esfenoidal Pulmonar/fisiología , Masculino , Femenino , Choque Cardiogénico/fisiopatología , Persona de Mediana Edad , Anciano , Arteria Pulmonar/fisiopatología , Diástole
12.
Sensors (Basel) ; 24(6)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38544011

RESUMEN

When mining deep coal seams with thin bedrock and thick alluvium, the collapse and fracture of thin bedrock layers may cause geological disasters, such as water inrush and sand inrush of the mining face. Comprehensively obtaining the response data of coal mining and reasonably analyzing the failure characteristics of overlying strata are helpful in guiding safe production. In this study, the caving zone heights of overlying strata are obtained by field detection during layered mining. Then, the caving zone heights during the once-full-height mining are evaluated by theoretical analysis. Further, the force and failure characteristics of coal-rock structures under different mining conditions are compared by the simulation detection and analysis. Finally, the results of on-site observation, theoretical analysis, and simulation detection are compared and discussed, and an optimized mining technology is proposed to ensure safe mining. The research shows the caving zone heights of on-site and simulation detections are, respectively, 14.65 m and 13.5 m during bottom-layer mining, which is larger than the caving zone heights of the top-layer coal mining. During once-full-height mining, the maximum caving zone height of simulation detection is 21 m, which is in between two standard results. For the mechanical responses of an aquiclude clay layer under thick loose alluvium, the maximum disturbance displacement of clay aquiclude is 5.8 m during layered mining, which is slightly larger than the disturbance displacement of once full-height mining; however, the maximum stress of the clay layer is 25 MPa during once-full-height mining, which is larger than the maximum stress of clay layer during layered mining. For the clay aquiclude failure, the clay layer during layered mining is in the deflection deformation area, and there is no obvious fracture structure to inrush the water and sand of thick loose alluvium; however, the clay layer during once-full-height mining is prone to produce obvious fracture structure. Therefore, the layered mining technology can effectively reduce and prevent the water/sand inrush disaster of mining working face.

13.
Nat Commun ; 15(1): 2392, 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-38493166

RESUMEN

Symbiodinium are the photosynthetic endosymbionts for corals and play a vital role in supplying their coral hosts with photosynthetic products, forming the nutritional foundation for high-yield coral reef ecosystems. Here, we determine the cryo-electron microscopy structure of Symbiodinium photosystem I (PSI) supercomplex with a PSI core composed of 13 subunits including 2 previously unidentified subunits, PsaT and PsaU, as well as 13 peridinin-Chl a/c-binding light-harvesting antenna proteins (AcpPCIs). The PSI-AcpPCI supercomplex exhibits distinctive structural features compared to their red lineage counterparts, including extended termini of PsaD/E/I/J/L/M/R and AcpPCI-1/3/5/7/8/11 subunits, conformational changes in the surface loops of PsaA and PsaB subunits, facilitating the association between the PSI core and peripheral antennae. Structural analysis and computational calculation of excitation energy transfer rates unravel specific pigment networks in Symbiodinium PSI-AcpPCI for efficient excitation energy transfer. Overall, this study provides a structural basis for deciphering the mechanisms governing light harvesting and energy transfer in Symbiodinium PSI-AcpPCI supercomplexes adapted to their symbiotic ecosystem, as well as insights into the evolutionary diversity of PSI-LHCI among various photosynthetic organisms.


Asunto(s)
Complejos de Proteína Captadores de Luz , Complejo de Proteína del Fotosistema I , Complejo de Proteína del Fotosistema I/metabolismo , Complejos de Proteína Captadores de Luz/metabolismo , Ecosistema , Microscopía por Crioelectrón , Fotosíntesis
14.
Cancer Res ; 84(11): 1781-1798, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38507720

RESUMEN

Inflammatory breast cancer (IBC) is a highly aggressive subtype of breast cancer characterized by rapidly arising diffuse erythema and edema. Genomic studies have not identified consistent alterations and mechanisms that differentiate IBC from non-IBC tumors, suggesting that the microenvironment could be a potential driver of IBC phenotypes. Here, using single-cell RNA sequencing, multiplex staining, and serum analysis in patients with IBC, we identified enrichment of a subgroup of luminal progenitor (LP) cells containing high expression of the neurotropic cytokine pleiotrophin (PTN) in IBC tumors. PTN secreted by the LP cells promoted angiogenesis by directly interacting with the NRP1 receptor on endothelial tip cells located in both IBC tumors and the affected skin. NRP1 activation in tip cells led to recruitment of immature perivascular cells in the affected skin of IBC, which are correlated with increased angiogenesis and IBC metastasis. Together, these findings reveal a role for cross-talk between LPs, endothelial tip cells, and immature perivascular cells via PTN-NRP1 axis in the pathogenesis of IBC, which could lead to improved strategies for treating IBC. SIGNIFICANCE: Nonmalignant luminal progenitor cells expressing pleiotrophin promote angiogenesis by activating NRP1 and induce a prometastatic tumor microenvironment in inflammatory breast cancer, providing potential therapeutic targets for this aggressive breast cancer subtype.


Asunto(s)
Proteínas Portadoras , Citocinas , Neoplasias Inflamatorias de la Mama , Neovascularización Patológica , Microambiente Tumoral , Humanos , Femenino , Citocinas/metabolismo , Proteínas Portadoras/metabolismo , Proteínas Portadoras/genética , Animales , Ratones , Neovascularización Patológica/patología , Neovascularización Patológica/metabolismo , Neoplasias Inflamatorias de la Mama/patología , Neoplasias Inflamatorias de la Mama/metabolismo , Neoplasias Inflamatorias de la Mama/genética , Neuropilina-1/metabolismo , Neuropilina-1/genética , Línea Celular Tumoral , Células Madre Neoplásicas/patología , Células Madre Neoplásicas/metabolismo , Metástasis de la Neoplasia , Angiogénesis
15.
J Hepatol ; 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38508240

RESUMEN

BACKGROUND & AIMS: Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer and is highly lethal. Clonorchis sinensis (C. sinensis) infection is an important risk factor for iCCA. Here we investigated the clinical impact and underlying molecular characteristics of C. sinensis infection-related iCCA. METHODS: We performed single-cell RNA sequencing, whole-exome sequencing, RNA sequencing, metabolomics and spatial transcriptomics in 251 patients with iCCA from three medical centers. Alterations in metabolism and the immune microenvironment of C. sinensis-related iCCAs were validated through an in vitro co-culture system and in a mouse model of iCCA. RESULTS: We revealed that C. sinensis infection was significantly associated with iCCA patients' overall survival and response to immunotherapy. Fatty acid biosynthesis and the expression of fatty acid synthase (FASN), a key enzyme catalyzing long-chain fatty acid synthesis, were significantly enriched in C. sinensis-related iCCAs. iCCA cell lines treated with excretory/secretory products of C. sinensis displayed elevated FASN and free fatty acids. The metabolic alteration of tumor cells was closely correlated with the enrichment of tumor-associated macrophage (TAM)-like macrophages and the impaired function of T cells, which led to formation of an immunosuppressive microenvironment and tumor progression. Spatial transcriptomics analysis revealed that malignant cells were in closer juxtaposition with TAM-like macrophages in C. sinensis-related iCCAs than non-C. sinensis-related iCCAs. Importantly, treatment with a FASN inhibitor significantly reversed the immunosuppressive microenvironment and enhanced anti-PD-1 efficacy in iCCA mouse models treated with excretory/secretory products from C. sinensis. CONCLUSIONS: We provide novel insights into metabolic alterations and the immune microenvironment in C. sinensis infection-related iCCAs. We also demonstrate that the combination of a FASN inhibitor with immunotherapy could be a promising strategy for the treatment of C. sinensis-related iCCAs. IMPACT AND IMPLICATIONS: Clonorchis sinensis (C. sinensis)-infected patients with intrahepatic cholangiocarcinoma (iCCA) have a worse prognosis and response to immunotherapy than non-C. sinensis-infected patients with iCCA. The underlying molecular characteristics of C. sinensis infection-related iCCAs remain unclear. Herein, we demonstrate that upregulation of FASN (fatty acid synthase) and free fatty acids in C. sinensis-related iCCAs leads to formation of an immunosuppressive microenvironment and tumor progression. Thus, administration of FASN inhibitors could significantly reverse the immunosuppressive microenvironment and further enhance the efficacy of anti-PD-1 against C. sinensis-related iCCAs.

16.
Ann Rheum Dis ; 83(5): 576-588, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38302261

RESUMEN

OBJECTIVES: B10 and B10pro cells suppress immune responses via secreting interleukin (IL)-10. However, their regulators and underlying mechanisms, especially in human autoimmune diseases, are elusive. This study aimed to address these questions in rheumatoid arthritis (RA), one of the most common highly disabling autoimmune diseases. METHODS: The frequencies and functions of B10 and B10pro cells in healthy individuals and patients with RA were first analysed. The effects of proinflammatory cytokines, particularly tumour necrosis factor (TNF)-α on the quantity, stability and pathogenic phenotype of these cells, were then assessed in patients with RA before and after anti-TNF therapy. The underlying mechanisms were further investigated by scRNA-seq database reanalysis, transcriptome sequencing, TNF-α-/- and B cell-specific SHIP-1-/- mouse disease model studies. RESULTS: TNF-α was a key determinant for B10 cells. TNF-α elicited the proinflammatory feature of B10 and B10pro cells by downregulating IL-10, and upregulating interferon-γ and IL-17A. In patients with RA, B10 and B10pro cells were impaired with exacerbated proinflammatory phenotype, while anti-TNF therapy potently restored their frequencies and immunosuppressive functions, consistent with the increased B10 cells in TNF-α-/- mice. Mechanistically, TNF-α diminished B10 and B10pro cells by inhibiting their glycolysis and proliferation. TNF-α also regulated the phosphatidylinositol phosphate signalling of B10 and B10pro cells and dampened the expression of SHIP-1, a dominant phosphatidylinositol phosphatase regulator of these cells. CONCLUSIONS: TNF-α provoked the proinflammatory phenotype of B10 and B10pro cells by disturbing SHIP-1 in RA, contributing to the disease development. Reinstating the immunosuppressive property of B10 and B10pro cells might represent novel therapeutic approaches for RA.


Asunto(s)
Artritis Reumatoide , Enfermedades Autoinmunes , Linfocitos B Reguladores , Factor de Necrosis Tumoral alfa , Animales , Humanos , Ratones , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Enfermedades Autoinmunes/metabolismo , Linfocitos B Reguladores/metabolismo , Fenotipo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatasas/genética , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatasas/metabolismo , Inhibidores del Factor de Necrosis Tumoral/uso terapéutico , Factor de Necrosis Tumoral alfa/metabolismo
17.
Sci Adv ; 10(6): eadk2285, 2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38324694

RESUMEN

Physiologically, FoxA1 plays a key role in liver differentiation and development, and pathologically exhibits an oncogenic role in prostate and breast cancers. However, its role and upstream regulation in liver tumorigenesis remain unclear. Here, we demonstrate that FoxA1 acts as a tumor suppressor in liver cancer. Using a CRISPR-based kinome screening approach, noncanonical inflammatory kinase IKBKE has been identified to inhibit FoxA1 transcriptional activity. Notably, IKBKE directly binds to and phosphorylates FoxA1 to reduce its complex formation and DNA interaction, leading to elevated hepatocellular malignancies. Nonphosphorylated mimic Foxa1 knock-in mice markedly delay liver tumorigenesis in hydrodynamic transfection murine models, while phospho-mimic Foxa1 knock-in phenocopy Foxa1 knockout mice to exhibit developmental defects and liver inflammation. Notably, Ikbke knockout delays diethylnitrosamine (DEN)-induced mouse liver tumor development. Together, our findings not only reveal FoxA1 as a bona fide substrate and negative nuclear effector of IKBKE in hepatocellular carcinioma (HCC) but also provide a promising strategy to target IKBEK for HCC therapy.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Masculino , Ratones , Carcinogénesis/genética , Carcinogénesis/patología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Factor Nuclear 3-alfa del Hepatocito/genética , Factor Nuclear 3-alfa del Hepatocito/metabolismo , Neoplasias Hepáticas/patología , Ratones Noqueados
18.
Nat Chem ; 16(3): 373-379, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38228852

RESUMEN

Photon-driven chemical processes are usually mediated by oxides, nitrides and sulfides whose photo-conversion efficiency is limited by charge carrier recombination. Here we show that lithium hydride undergoes photolysis upon ultraviolet illumination to yield long-lived photon-generated electrons residing in hydrogen vacancies, known as F centres. We demonstrate that photon-driven dehydrogenation and dark rehydrogenation over lithium hydride can be fulfilled reversibly at room temperature, which is about 600 K lower than the corresponding thermal process. As light-driven F centre generation could provide an alternative approach to charge carrier separation to favour chemical transformations that are kinetically or thermodynamically challenging, we show that light-activated lithium hydride cleaves the N≡N triple bond to form a N-H bond under mild conditions. Co-feeding a N2/H2 mixture with low H2 partial pressure leads to photocatalytic ammonia formation at near ambient conditions. This work provides insights into the development of advanced materials and processes for light harvesting and conversion.

19.
Gut ; 73(7): 1156-1168, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38191266

RESUMEN

OBJECTIVE: Whether and how the PI3K-AKT pathway, a central node of metabolic homeostasis, is responsible for high-fat-induced non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) remain a mystery. Characterisation of AKT regulation in this setting will provide new strategies to combat HCC. DESIGN: Metabolite library screening disclosed that palmitic acid (PA) could activate AKT. In vivo and in vitro palmitoylation assay were employed to detect AKT palmitoylation. Diverse cell and mouse models, including generation of AKT1C77S and AKT1C224S knock-in cells, Zdhhc17 and Zdhhc24 knockout mice and Akt1C224S knock-in mice were employed. Human liver tissues from patients with NASH and HCC, hydrodynamic transfection mouse model, high-fat/high-cholesterol diet (HFHCD)-induced NASH/HCC mouse model and high-fat and methionine/choline-deficient diet (HFMCD)-induced NASH mouse model were also further explored for our mechanism studies. RESULTS: By screening a metabolite library, PA has been defined to activate AKT by promoting its palmitoyl modification, an essential step for growth factor-induced AKT activation. Biologically, a high-fat diet could promote AKT kinase activity, thereby promoting NASH and liver cancer. Mechanistically, palmitoyl binding anchors AKT to the cell membrane in a PIP3-independent manner, in part by preventing AKT from assembling into an inactive polymer. The palmitoyltransferases ZDHHC17/24 were characterised to palmitoylate AKT to exert oncogenic effects. Interestingly, the anti-obesity drug orlistat or specific penetrating peptides can effectively attenuate AKT palmitoylation and activation by restricting PA synthesis or repressing AKT modification, respectively, thereby antagonising liver tumorigenesis. CONCLUSIONS: Our findings elucidate a novel fine-tuned regulation of AKT by PA-ZDHHC17/24-mediated palmitoylation, and highlight tumour therapeutic strategies by taking PA-restricted diets, limiting PA synthesis, or directly targeting AKT palmitoylation.


Asunto(s)
Carcinoma Hepatocelular , Dieta Alta en Grasa , Lipoilación , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Proteínas Proto-Oncogénicas c-akt , Animales , Proteínas Proto-Oncogénicas c-akt/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/etiología , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/etiología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/patología , Humanos , Ácido Palmítico/metabolismo , Carcinogénesis/metabolismo , Ratones Noqueados , Modelos Animales de Enfermedad , Masculino , Transducción de Señal
20.
Adv Sci (Weinh) ; 11(13): e2307850, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38240457

RESUMEN

Kidney fibrosis is a common fate of chronic kidney diseases (CKDs), eventually leading to renal dysfunction. Yet, no effective treatment for this pathological process has been achieved. During the bioassay-guided chemical investigation of the medicinal plant Wikstroemia chamaedaphne, a daphne diterpenoid, daphnepedunin A (DA), is characterized as a promising anti-renal fibrotic lead. DA shows significant anti-kidney fibrosis effects in cultured renal fibroblasts and unilateral ureteral obstructed mice, being more potent than the clinical trial drug pirfenidone. Leveraging the thermal proteome profiling strategy, cell division cycle 42 (Cdc42) is identified as the direct target of DA. Mechanistically, DA targets to reduce Cdc42 activity and down-regulates its downstream phospho-protein kinase Cζ(p-PKCζ)/phospho-glycogen synthase kinase-3ß (p-GSK-3ß), thereby promoting ß-catenin Ser33/37/Thr41 phosphorylation and ubiquitin-dependent proteolysis to block classical pro-fibrotic ß-catenin signaling. These findings suggest that Cdc42 is a promising therapeutic target for kidney fibrosis, and highlight DA as a potent Cdc42 inhibitor for combating CKDs.


Asunto(s)
Diterpenos , Enfermedades Renales , Proteína de Unión al GTP cdc42 , Animales , Ratones , beta Catenina/efectos de los fármacos , beta Catenina/metabolismo , Fibrosis/tratamiento farmacológico , Glucógeno Sintasa Quinasa 3 beta/efectos de los fármacos , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Riñón/metabolismo , Enfermedades Renales/tratamiento farmacológico , Wikstroemia/química , Diterpenos/farmacología , Proteína de Unión al GTP cdc42/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA