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1.
Nature ; 613(7943): 298-302, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36631652

RESUMEN

Bed load sediment transport, in which wind or water flowing over a bed of sediment causes grains to roll or hop along the bed, is a critically important mechanism in contexts ranging from river restoration1 to planetary exploration2. Despite its widespread occurrence, predictions of bed load sediment flux are notoriously imprecise3,4. Many studies have focused on grain size variability5 as a source of uncertainty, but few have investigated the role of grain shape, even though shape has long been suspected to influence transport rates6. Here we show that grain shape can modify bed load transport rates by an amount comparable to the scatter in many sediment transport datasets4,7,8. We develop a theory that accounts for grain shape effects on fluid drag and granular friction and predicts that the onset and efficiency of transport depend on the coefficients of drag and bulk friction of the transported grains. Laboratory experiments confirm these predictions and reveal that the effect of grain shape on sediment transport can be difficult to intuit from the appearance of grains. We propose a shape-corrected sediment transport law that collapses our experimental measurements. Our results enable greater accuracy in predictions of sediment transport and help reconcile theories developed for spherical particles with the behaviour of natural sediment grains.

2.
EMBO J ; 42(2): e111673, 2023 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-36514940

RESUMEN

Adenosine N6-methylation (m6A) and N6,2'-O-dimethylation (m6Am) are regulatory modifications of eukaryotic mRNAs. m6Am formation is catalyzed by the methyl transferase phosphorylated CTD-interacting factor 1 (PCIF1); however, the pathophysiological functions of this RNA modification and PCIF1 in cancers are unclear. Here, we show that PCIF1 expression is upregulated in colorectal cancer (CRC) and negatively correlates with patient survival. CRISPR/Cas9-mediated depletion of PCIF1 in human CRC cells leads to loss of cell migration, invasion, and colony formation in vitro and loss of tumor growth in athymic mice. Pcif1 knockout in murine CRC cells inhibits tumor growth in immunocompetent mice and enhances the effects of anti-PD-1 antibody treatment by decreasing intratumoral TGF-ß levels and increasing intratumoral IFN-γ, TNF-α levels, and tumor-infiltrating natural killer cells. We further show that PCIF1 modulates CRC growth and response to anti-PD-1 in a context-dependent mechanism with PCIF1 directly targeting FOS, IFITM3, and STAT1 via m6Am modifications. PCIF1 stabilizes FOS mRNA, which in turn leads to FOS-dependent TGF-ß regulation and tumor growth. While during immunotherapy, Pcif1-Fos-TGF-ß, as well as Pcif1-Stat1/Ifitm3-IFN-γ axes, contributes to the resistance of anti-PD-1 therapy. Collectively, our findings reveal a role of PCIF1 in promoting CRC tumorigenesis and resistance to anti-PD-1 therapy, supporting that the combination of PCIF1 inhibition with anti-PD-1 treatment is a potential therapeutic strategy to enhance CRC response to immunotherapy. Finally, we developed a lipid nanoparticles (LNPs) and chemically modified small interfering RNAs (CMsiRNAs)-based strategy to silence PCIF1 in vivo and found that this treatment significantly reduced tumor growth in mice. Our results therefore provide a proof-of-concept for tumor growth suppression using LNP-CMsiRNA to silence target genes in cancer.


Asunto(s)
Neoplasias Colorrectales , Inmunoterapia , Animales , Humanos , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Proteínas de la Membrana/metabolismo , Metilación , Proteínas Nucleares/metabolismo , ARN Mensajero/genética , Proteínas de Unión al ARN/metabolismo , Factor de Crecimiento Transformador beta/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(41): e2407820121, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39356671

RESUMEN

Protein acetylation is a common and reversible posttranslational modification tightly governed by protein acetyltransferases and deacetylases crucial for various biological processes in both eukaryotes and prokaryotes. Although recent studies have characterized many acetyltransferases in diverse bacterial species, only a few protein deacetylases have been identified in prokaryotes, perhaps in part due to their limited sequence homology. In this study, we identified YkuR, encoded by smu_318, as a unique protein deacetylase in Streptococcus mutans. Through protein acetylome analysis, we demonstrated that the deletion of ykuR significantly upregulated protein acetylation levels, affecting key enzymes in translation processes and metabolic pathways, including starch and sucrose metabolism, glycolysis/gluconeogenesis, and biofilm formation. In particular, YkuR modulated extracellular polysaccharide synthesis and biofilm formation through the direct deacetylation of glucosyltransferases (Gtfs) in the presence of NAD+. Intriguingly, YkuR can be acetylated in a nonenzymatic manner, which then negatively regulated its deacetylase activity, suggesting the presence of a self-regulatory mechanism. Moreover, in vivo studies further demonstrated that the deletion of ykuR attenuated the cariogenicity of S. mutans in the rat caries model, substantiating its involvement in the pathogenesis of dental caries. Therefore, our study revealed a unique regulatory mechanism mediated by YkuR through protein deacetylation that regulates the physiology and pathogenicity of S. mutans.


Asunto(s)
Proteínas Bacterianas , Biopelículas , Caries Dental , Streptococcus mutans , Streptococcus mutans/enzimología , Streptococcus mutans/genética , Streptococcus mutans/metabolismo , Animales , Caries Dental/microbiología , Biopelículas/crecimiento & desarrollo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Acetilación , Ratas , Glucosiltransferasas/metabolismo , Glucosiltransferasas/genética , Procesamiento Proteico-Postraduccional , Regulación Bacteriana de la Expresión Génica
4.
Brief Bioinform ; 25(3)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38711371

RESUMEN

T-cell receptor (TCR) recognition of antigens is fundamental to the adaptive immune response. With the expansion of experimental techniques, a substantial database of matched TCR-antigen pairs has emerged, presenting opportunities for computational prediction models. However, accurately forecasting the binding affinities of unseen antigen-TCR pairs remains a major challenge. Here, we present convolutional-self-attention TCR (CATCR), a novel framework tailored to enhance the prediction of epitope and TCR interactions. Our approach utilizes convolutional neural networks to extract peptide features from residue contact matrices, as generated by OpenFold, and a transformer to encode segment-based coded sequences. We introduce CATCR-D, a discriminator that can assess binding by analyzing the structural and sequence features of epitopes and CDR3-ß regions. Additionally, the framework comprises CATCR-G, a generative module designed for CDR3-ß sequences, which applies the pretrained encoder to deduce epitope characteristics and a transformer decoder for predicting matching CDR3-ß sequences. CATCR-D achieved an AUROC of 0.89 on previously unseen epitope-TCR pairs and outperformed four benchmark models by a margin of 17.4%. CATCR-G has demonstrated high precision, recall and F1 scores, surpassing 95% in bidirectional encoder representations from transformers score assessments. Our results indicate that CATCR is an effective tool for predicting unseen epitope-TCR interactions. Incorporating structural insights enhances our understanding of the general rules governing TCR-epitope recognition significantly. The ability to predict TCRs for novel epitopes using structural and sequence information is promising, and broadening the repository of experimental TCR-epitope data could further improve the precision of epitope-TCR binding predictions.


Asunto(s)
Receptores de Antígenos de Linfocitos T , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Humanos , Epítopos/química , Epítopos/inmunología , Biología Computacional/métodos , Redes Neurales de la Computación , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/química , Antígenos/química , Antígenos/inmunología , Secuencia de Aminoácidos
5.
PLoS Pathog ; 20(4): e1012147, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38620039

RESUMEN

Post-transcriptional regulation by small RNAs and post-translational modifications (PTM) such as lysine acetylation play fundamental roles in physiological circuits, offering rapid responses to environmental signals with low energy consumption. Yet, the interplay between these regulatory systems remains underexplored. Here, we unveil the cross-talk between sRNAs and lysine acetylation in Streptococcus mutans, a primary cariogenic pathogen known for its potent acidogenic virulence. Through systematic overexpression of sRNAs in S. mutans, we identified sRNA SmsR1 as a critical player in modulating acidogenicity, a key cariogenic virulence feature in S. mutans. Furthermore, combined with the analysis of predicted target mRNA and transcriptome results, potential target genes were identified and experimentally verified. A direct interaction between SmsR1 and 5'-UTR region of pdhC gene was determined by in vitro binding assays. Importantly, we found that overexpression of SmsR1 reduced the expression of pdhC mRNA and increased the intracellular concentration of acetyl-CoA, resulting in global changes in protein acetylation levels. This was verified by acetyl-proteomics in S. mutans, along with an increase in acetylation level and decreased activity of LDH. Our study unravels a novel regulatory paradigm where sRNA bridges post-transcriptional regulation with post-translational modification, underscoring bacterial adeptness in fine-tuning responses to environmental stress.


Asunto(s)
Proteínas Bacterianas , Regulación Bacteriana de la Expresión Génica , Procesamiento Proteico-Postraduccional , Streptococcus mutans , Animales , Acetilación , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Caries Dental/microbiología , Caries Dental/metabolismo , ARN Bacteriano/metabolismo , ARN Bacteriano/genética , ARN Pequeño no Traducido/metabolismo , ARN Pequeño no Traducido/genética , Streptococcus mutans/metabolismo , Streptococcus mutans/genética , Streptococcus mutans/patogenicidad , Virulencia , Femenino , Ratas
6.
Proc Natl Acad Sci U S A ; 120(36): e2301954120, 2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37639595

RESUMEN

Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. Studies of how permafrost responded historically during Earth's past warm periods are helpful in exploring potential future permafrost behavior and to evaluate the uncertainty of future permafrost change projections. Here, we combine a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near-surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere during the mid-Pliocene warm period (mPWP, ~3.264 to 3.025 Ma). This period shares similarities with the projected future climate. Constrained by proxy-based surface air temperature records, our simulations demonstrate that near-surface permafrost was highly spatially restricted during the mPWP and was 93 ± 3% smaller than the preindustrial extent. Near-surface permafrost was present only in the eastern Siberian uplands, Canadian high Arctic Archipelago, and northernmost Greenland. The simulations are similar to near-surface permafrost changes projected for the end of this century under the SSP5-8.5 scenario and provide a perspective on the potential permafrost behavior that may be expected in a warmer world.

7.
Cereb Cortex ; 34(2)2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38216525

RESUMEN

Observational studies have reported that osteoporosis is associated with cortical changes in the brain. However, the inherent limitations of observational studies pose challenges in eliminating confounding factors and establishing causal relationships. And previous observational studies have not reported changes in specific brain regions. By employing Mendelian randomization, we have been able to infer a causal relationship between osteoporosis and a reduction in the surficial area (SA) of the brain cortical. This effect is partially mediated by vascular calcification. We found that osteoporosis significantly decreased the SA of global brain cortical (ß = -1587.62 mm2, 95%CI: -2645.94 mm2 to -529.32 mm2, P = 0.003) as well as the paracentral gyrus without global weighted (ß = - 19.42 mm2, 95%CI: -28.90 mm2 to -9.95 mm2, P = 5.85 × 10-5). Furthermore, we estimated that 42.25% and 47.21% of the aforementioned effects are mediated through vascular calcification, respectively. Osteoporosis leads to a reduction in the SA of the brain cortical, suggesting the presence of the bone-brain axis. Vascular calcification plays a role in mediating this process to a certain extent. These findings establish a theoretical foundation for further investigations into the intricate interplay between bone, blood vessels, and the brain.


Asunto(s)
Osteoporosis , Calcificación Vascular , Humanos , Análisis de la Aleatorización Mendeliana , Encéfalo/diagnóstico por imagen , Osteoporosis/diagnóstico por imagen , Osteoporosis/genética , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple
8.
Apoptosis ; 29(5-6): 757-767, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38358580

RESUMEN

Autophagy has emerged as an important process of cell metabolism. With continuous in-depth research on autophagy, TFEB has been a key transcription factor regulating autophagy levels in recent years. Studies have established that TFEB regulates autophagy and apoptosis in various diseases. However, the relationship between TFEB and the pathogenesis of endometriosis remains unclear. This study aimed to investigate the effect of TFEB on the mechanism of endometriosis progression. The results showed that TFEB and autophagy-related protein LC3 are highly expressed in ectopic endometrium of patients with endometriosis, overexpression of TFEB in cultured human endometrial stromal cells (HESCs) by lentivirus not only promoted autophagy but also inhibited apoptosis. In addition, the migration and invasion ability of HESCs were enhanced by TFEB overexpression. Furthermore, inhibiting autophagy with specific inhibitors can attenuate migration and invasion of HESCs induced by TFEB. The rat models of endometriosis show that TFEB knockdown can suppress lesion growth in vivo. Our results suggest that autophagy may be involved in the progression mechanism of endometriosis, and the mechanism of autophagy disorder in endometriosis is probably related to TFEB. TFEB may be a key molecule in promoting endometriosis.


Asunto(s)
Apoptosis , Autofagia , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Movimiento Celular , Endometriosis , Endometrio , Adulto , Animales , Femenino , Humanos , Ratas , Apoptosis/genética , Autofagia/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Movimiento Celular/genética , Endometriosis/metabolismo , Endometriosis/patología , Endometriosis/genética , Endometrio/metabolismo , Endometrio/patología , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Ratas Sprague-Dawley , Células del Estroma/metabolismo , Células del Estroma/patología
9.
EMBO J ; 39(21): e106057, 2020 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-32944968

RESUMEN

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2 and has spread across the globe. SARS-CoV-2 is a highly infectious virus with no vaccine or antiviral therapy available to control the pandemic; therefore, it is crucial to understand the mechanisms of viral pathogenesis and the host immune responses to SARS-CoV-2. SARS-CoV-2 is a new member of the betacoronavirus genus like other closely related viruses including SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). Both SARS-CoV and MERS-CoV have caused serious outbreaks and epidemics in the past eighteen years. Here, we report that one of the interferon-stimulated genes (ISGs), cholesterol 25-hydroxylase (CH25H), is induced by SARS-CoV-2 infection in vitro and in COVID-19-infected patients. CH25H converts cholesterol to 25-hydrocholesterol (25HC) and 25HC shows broad anti-coronavirus activity by blocking membrane fusion. Furthermore, 25HC inhibits USA-WA1/2020 SARS-CoV-2 infection in lung epithelial cells and viral entry in human lung organoids. Mechanistically, 25HC inhibits viral membrane fusion by activating the ER-localized acyl-CoA:cholesterol acyltransferase (ACAT) which leads to the depletion of accessible cholesterol from the plasma membrane. Altogether, our results shed light on a potentially broad antiviral mechanism by 25HC through depleting accessible cholesterol on the plasma membrane to suppress virus-cell fusion. Since 25HC is a natural product with no known toxicity at effective concentrations, it provides a potential therapeutic candidate for COVID-19 and emerging viral diseases in the future.


Asunto(s)
Antivirales/farmacología , Betacoronavirus/efectos de los fármacos , Colesterol/metabolismo , Infecciones por Coronavirus/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Mucosa Respiratoria/virología , Esteroide Hidroxilasas/farmacología , Internalización del Virus/efectos de los fármacos , Acetil-CoA C-Acetiltransferasa/metabolismo , Animales , COVID-19 , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Chlorocebus aethiops , Activación Enzimática/efectos de los fármacos , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/efectos de los fármacos , Organoides/virología , Pandemias , Mucosa Respiratoria/efectos de los fármacos , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/efectos de los fármacos , SARS-CoV-2 , Células Vero , Tratamiento Farmacológico de COVID-19
10.
Anal Chem ; 96(8): 3535-3543, 2024 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-38353024

RESUMEN

Currently, in situ monitoring of the adenosine triphosphate (ATP) level in lysosomes is critical to understand their involvement in various biological processes, but it remains difficult due to the interferences of limited targeting and low resolution of fluorescent probes. Herein, we report a classic Mn(II) probe (FX2-MnCl2) with near-infrared (NIR) nonlinear (NLO) properties, accompanied by three-four photon transition and fivefold fluorescence enhancement in the presence of ATP. FX2-MnCl2 combines with ATP through dual recognition sites of diethoxy and manganese ions to reflect slightly fluorescence lifetime change. Through the synergy of multiphoton fluorescence imaging (MP-FI) and multiphoton fluorescence lifetime imaging microscopy (MP-FLIM), it is further demonstrated that FX2-MnCl2 displays lysosome-specific targeting behavior, which can monitor lysosome-related ATP migration under NIR laser light. This work provides a novel multiphoton transformation fluorescence complex, which might be a potential candidate as a simple and straightforward biomarker of lysosome ATP in vitro for clinical diagnosis.


Asunto(s)
Colorantes Fluorescentes , Lisosomas , Microscopía Fluorescente/métodos , Imagen Óptica , Fotones , Microscopía de Fluorescencia por Excitación Multifotónica/métodos
11.
PLoS Pathog ; 18(5): e1010505, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35503798

RESUMEN

The Hippo signaling pathway, which is historically considered as a dominator of organ development and homeostasis has recently been implicated as an immune regulator. However, its role in host defense against influenza A virus (IAV) has not been widely investigated. Here, we found that IAV could activate the Hippo effectors Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) through physical binding of the IAV non-structural protein 1 (NS1) with C-terminal domain of YAP/TAZ, facilitating their nuclear location. Meanwhile, YAP/TAZ downregulated the expression of pro-inflammatory and anti-viral cytokines against IAV infection, therefore benefiting virus replication and host cell apoptosis. A mouse model of IAV infection further demonstrated Yap deficiency protected mice against IAV infection, relieving lung injury. Mechanistically, YAP/TAZ blocked anti-viral innate immune signaling via downregulation of Toll-like receptor 3 (TLR3) expression. YAP directly bound to the putative TEADs binding site on the promoter region of TLR3. The elimination of acetylated histone H3 occupancy in the TLR3 promoter resulted in its transcriptional silence. Moreover, treatment of Trichostatin A, a histone deacetylases (HDACs) inhibitor or disruption of HDAC4/6 reversed the inhibition of TLR3 expression by YAP/TAZ, suggesting HDAC4/6 mediated the suppression function of YAP/TAZ. Taken together, we uncovered a novel immunomodulatory mechanism employed by IAV, where YAP/TAZ antagonize TLR3-mediated innate immunity.


Asunto(s)
Virus de la Influenza A , Receptor Toll-Like 3 , Proteínas no Estructurales Virales/metabolismo , Animales , Inmunidad Innata , Virus de la Influenza A/metabolismo , Ratones , Transducción de Señal , Factores de Transcripción/metabolismo
12.
Appl Environ Microbiol ; 90(2): e0187123, 2024 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-38299814

RESUMEN

Dental caries is the most common chronic infectious disease around the world and disproportionately affects the marginalized socioeconomic group. Streptococcus mutans, considered a primary etiological agent of caries, depends on the coordinated physiological response to tolerate the oxidative stress generated by commensal species within dental plaque, which is a critical aspect of its pathogenicity. Here, we identified and characterized a novel tetracycline repressor family regulator, SMU_1361c, which appears to be acquired by the bacteria via horizontal gene transfer. Surprisingly, smu_1361c functions as a negative transcriptional regulator to regulate gene expression outside its operon and is involved in the oxidative stress response of S. mutans. The smu_1361c overexpression strain UA159/pDL278-1361c was more susceptible to oxidative stress and less competitive against hydrogen peroxide generated by commensal species Streptococcus gordonii and Streptococcus sanguinis. Transcriptomics analysis revealed that smu_1361c overexpression resulted in the significant downregulation of 22 genes, mainly belonging to three gene clusters responsible for the oxidative stress response. The conversed DNA binding motif of SMU_1361c was determined by electrophoretic mobility shift and DNase I footprinting assay with purified SMU_1361c protein; therefore, smu_1361c is directly involved in gene transcription related to the oxidative stress response. Crucially, our finding provides a new understanding of how S. mutans deals with the oxidative stress that is required for pathogenesis and will facilitate the development of new and improved therapeutic approaches for dental caries.IMPORTANCEStreptococcus mutans is the major organism associated with the development of dental caries, which globally is the most common chronic disease. To persist and survive in biofilms, S. mutans must compete with commensal species that occupy the same ecological niche. Here, we uncover a novel molecular mechanism of how tetracycline repressor family regulator smu_1361c is involved in the oxidative stress response through transcriptomics analysis, electrophoretic mobility shift assay, and DNase I footprinting assay. Furthermore, we demonstrated that smu_1361c mediates S. mutans sensitivity to oxidative stress and competitiveness with commensal streptococci. Therefore, this study has revealed a previously unknown regulation between smu_1361c and genes outside its operon and demonstrated the importance of smu_1361c in the oxidative stress response and the fitness of S. mutans within the plaque biofilms, which can be exploited as a new therapy to modulate ecological homeostasis and prevent dental caries.


Asunto(s)
Caries Dental , Streptococcus mutans , Humanos , Streptococcus mutans/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biopelículas , Estrés Oxidativo , Tetraciclinas , Desoxirribonucleasa I/metabolismo
13.
New Phytol ; 241(2): 676-686, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37974482

RESUMEN

Marine phytoplankton can interchange trace metals in various biochemical functions, particularly under metal-limiting conditions. Here, we investigate the stimulating and toxicity effect of chromium (Cr) on a marine Chlorophyceae Osetreococcus tauri under Fe-replete and Fe-deficient conditions. We determined the growth, photosynthesis, and proteome expressions of Osetreococcus tauri cultured under different Cr and Fe concentrations. In Fe-replete conditions, the presence of Cr(VI) stimulated significantly the growth rate and the maximum yield of photochemistry of photosystem II (Fv /Fm ) of the phytoplankton, while the functional absorption cross-section of photosystem II (σPSII ) did not change. Minor additions of Cr(VI) partially rescued phytoplankton growth under Fe-limited conditions. Proteomic analysis of this alga grown in Fe-replete normal and Fe-replete with Cr addition media (10 µM Cr) showed that the presence of Cr significantly decreased the expression of phosphate-transporting proteins and photosynthetic proteins, while increasing the expression of proteins related to carbon assimilation. Cr can stimulate the growth and photosynthesis of O. tauri, but the effects are dependent on both the Cr(VI) concentration and the availability of Fe. The proteomic results further suggest that Cr(VI) addition might significantly increase starch production and carbon fixation.


Asunto(s)
Complejo de Proteína del Fotosistema II , Proteómica , Complejo de Proteína del Fotosistema II/metabolismo , Cromo/toxicidad , Cromo/metabolismo , Fotosíntesis , Fitoplancton/metabolismo , Proteoma/metabolismo
14.
New Phytol ; 244(2): 635-653, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39183373

RESUMEN

The integrity of wheat (Triticum aestivum) production is increasingly jeopardized by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), particularly amid the vicissitudes of climate change. Here, we delineated the role of a wheat transcription factor, TaNAC1, which precipitates cellular apoptosis and fortifies resistance against Bgt. Utilizing BiFC, co-immunoprecipitation, protein quantification, luciferase report assays, we determined that cytoplasmic TaNAC1-7A undergoes phosphorylation at the S184/S258 sites by TaCDPK20, facilitating its nuclear translocation. This migration appears to prime further phosphorylation by TaMPK1, thereby enhancing transcriptional regulatory activity. Notably, the apoptotic activity of phosphorylated TaNAC1-7A is negatively modulated by the nuclear protein phosphatase PP2Ac. Furthermore, activation of TaNAC1 phosphorylation initiates transcription of downstream genes TaSec1a and TaCAMTA4, through binding to the C[T/G]T[N7]A[A/C]G nucleic acid motif. Suppression of TaNAC1, TaCDPK20, and TaMPK1 in wheat compromises its resistance to Bgt strain E09, whereas overexpression of TaNAC1 and silencing of PP2Ac markedly elevate resistance levels. Our results reveal the pivotal role of TaNAC1 in basal resistance which is mediated by its effects on homotypic fusion, vacuolar protein sorting, and the expression of defense-related genes. The findings highlight the potential through targeting TaNAC1 and its regulators as a strategy for improving wheat's resistance to fungal pathogens.


Asunto(s)
Ascomicetos , Regulación de la Expresión Génica de las Plantas , Enfermedades de las Plantas , Proteínas de Plantas , Triticum , Apoptosis , Ascomicetos/fisiología , Núcleo Celular/metabolismo , Resistencia a la Enfermedad/genética , Fosforilación , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Unión Proteica , Proteína Fosfatasa 2/metabolismo , Proteína Fosfatasa 2/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Triticum/microbiología , Triticum/genética
15.
J Exp Bot ; 75(5): 1465-1478, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-37952108

RESUMEN

Powdery mildew fungi are obligate biotrophic pathogens that only invade plant epidermal cells. There are two epidermal surfaces in every plant leaf: the adaxial (upper) side and the abaxial (lower) side. While both leaf surfaces can be susceptible to adapted powdery mildew fungi in many plant species, there have been observations of leaf abaxial immunity in some plant species including Arabidopsis. The genetic basis of such leaf abaxial immunity remains unknown. In this study, we tested a series of Arabidopsis mutants defective in one or more known defense pathways with the adapted powdery mildew isolate Golovinomyces cichoracearum UCSC1. We found that leaf abaxial immunity was significantly compromised in mutants impaired for both the EDS1/PAD4- and PEN2/PEN3-dependent defenses. Consistently, expression of EDS1-yellow fluorescent protein and PEN2-green fluorescent protein fusions from their respective native promoters in the respective eds1-2 and pen2-1 mutant backgrounds was higher in the abaxial epidermal cells than in the adaxial epidermal cells. Altogether, our results indicate that leaf abaxial immunity against powdery mildew in Arabidopsis is at least partially due to enhanced EDS1/PAD4- and PEN2/PEN3-dependent defenses. Such transcriptionally pre-programmed defense mechanisms may underlie leaf abaxial immunity in other plant species such as hemp and may be exploited for engineering adaxial immunity against powdery mildew fungi in crop plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regiones Promotoras Genéticas , Hojas de la Planta/metabolismo , Mecanismos de Defensa , Enfermedades de las Plantas/microbiología
16.
Toxicol Appl Pharmacol ; 490: 117020, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38969211

RESUMEN

This study explored the effects of 1, 2-bis (2,4, 6-tribromophenoxy) ethane (BTBPE) and bis (2-ethylhexyl) tetrabromophthalate (TBPH) on serum metabolites and lipids in male Sprague-Dawley (SD) rats. Rats were orally gavaged 250 mg/kg bw of BTBPE and 500 mg/kg bw of TBPH for 28 consecutive days. Serum samples were collected for metabolomics and lipidomics analysis. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to explore changes in rat metabolic patterns. Least absolute shrinkage and selection operator (LASSO) regression models were established using serum levels of total thyroxine (TT4), free thyroxine (FT4), and rats' grouping information as variables to screen for robust differential substances. SuperPred was the database to obtain potential targets. The metabolomics and lipidomics results showed that BTBPE and TBPH had an impact on rat metabolic patterns, affecting pathways such as vitamin B6 synthesis. For BTBPE treatment, pyridoxal and ceramide (Cer) 24:0;4O were selected as differential substances related to thyroid hormones. For TBPH treatment, dehydroascorbic acid, acylcarnitine (CAR) 19:0, and diglyceride (DG) 38:4 were selected as differential substances related to thyroid hormones. Serotonin 2c receptor and cyclooxygenase-2 were chosen as potential targets of BTBPE and TBPH, respectively. In conclusion, this study found that BTBPE and TBPH impacted the metabolism of rats, and this effect may be related to changes in thyroid function.


Asunto(s)
Metabolómica , Ácidos Ftálicos , Ratas Sprague-Dawley , Animales , Masculino , Ratas , Ácidos Ftálicos/toxicidad , Tiroxina/sangre , Lipidómica , Lípidos/sangre , Metabolismo de los Lípidos/efectos de los fármacos
17.
Psychol Sci ; 35(1): 55-71, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38175943

RESUMEN

We often use cues from our environment when we get stuck searching our memories, but prior research has failed to show benefits of cuing with other, randomly selected list items during memory search. What accounts for this discrepancy? We proposed that cues' content critically determines their effectiveness and sought to select the right cues by building a computational model of how cues affect memory search. Participants (N = 195 young adults from the United States) recalled significantly more items when receiving our model's best (vs. worst) cue. Our model provides an account of why some cues better aid recall: Effective cues activate contexts most similar to the remaining items' contexts, facilitating recall in an unsearched area of memory. We discuss our contributions in relation to prominent theories about the effect of external cues.


Asunto(s)
Señales (Psicología) , Recuerdo Mental , Adulto Joven , Humanos , Recuerdo Mental/fisiología
18.
Horm Metab Res ; 56(3): 193-196, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37402397

RESUMEN

Ferroptosis is an iron-dependent death mode mediated by the aggregation of lipid peroxides and lipid-reactive oxygen species. It is characterized by iron-dependent lipid peroxide accumulation accompanied by oxidoreductase deficiency. Pancreatic beta cell dysfunction and insulin resistance are two major causes of type 2 diabetes mellitus (T2DM). Iron accumulation and metabolism may play a role in the development of T2DM. The molecular mechanism of ß cell apoptosis and iron death in T2DM were reviewed. In addition, we discuss recent insights on the relationship between the trace element iron and apoptosis of ß cells in T2DM.


Asunto(s)
Diabetes Mellitus Tipo 2 , Ferroptosis , Humanos , Vitamina D , Vitaminas , Transducción de Señal , Hierro , Peróxidos Lipídicos , Especies Reactivas de Oxígeno
19.
Mol Cell Probes ; : 101987, 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39413935

RESUMEN

Thyroid cancer (TC) is the most common malignant tumor of the head and neck. As a common epigenetic modification in mRNAs, N6-methyladenosine (m6A) modification plays critical roles in biological process of cancers. However, m6A methyltransferase methyltransferase-like 14 (METTL14)-mediated m6A modification and its potential regulatory mechanisms in TC are not fully elucidated. In our study, we observed that METTL14 was decreased in TC tissues and cells. And upregulation of METTL14 induced apoptotic cell death and hampered cell proliferation, epithelial mesenchymal transition (EMT) and tumor growth in vitro and in vivo. Mechanistically, METTL14 increased the expression of suppressor of cytokine signaling 3 (SOCS3) through m6A methylation modification, and knockdown of SOCS3 reversed the inhibitory effect of overexpressing METTL14 on TC tumorigenesis. In addition, METTL14-mediated m6A modification of SOCS3 inactivated the janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway, and in the METTL14-overexpressing TC cells, silencing SOCS3-induced upregulation of cell proliferation, EMT and suppression of apoptosis was reversed by JAK2/STAT3 inhibitor AG490 and WP1066. Together, we indicated that METTL14/m6A/SOCS3/ JAK2/STAT3 axis play an important role in the progression of TC.

20.
Inorg Chem ; 63(33): 15398-15408, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39096309

RESUMEN

Steering selectivity in photocatalytic conversion of CO2, especially toward deep reduction products, is vital to energy and environmental goals yet remains a great challenge. In this work, we demonstrate a facet-dependent photocatalytic selective reduction of CO2 to CH4 in Cu-doped TiO2 catalysts exposed with different facets synthesized by a topological transformation from MIL-125 (Ti) precursors. The optimized round cake-like Cu/TiO2 photocatalyst mainly exposed with the (001) facet exhibited a high photocatalytic CO2 reduction performance with a CH4 yield of 40.36 µmol g-1 h-1 with a selectivity of 94.1%, which are significantly higher than those of TiO2 (001) (4.70 µmol g-1 h-1 and 52.6%, respectively), Cu/TiO2 (001 + 101) (18.95 µmol g-1 h-1 and 69.6%, respectively), and Cu/TiO2 (101) (14.73 µmol g-1 h-1 and 78.9%, respectively). The results of experimental and theoretical calculations demonstrate that the Cu doping dominating the promoted separation and migration efficiencies of photogenerated charges and the preferential adsorption on (001) facets synergistically contribute to the selective reduction of CO2 to CH4. This work highlights the significance of synergy between facet engineering and ion doping in the design of high-performance photocatalysts with respect to selective reduction of CO2 to multielectron products.

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