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1.
Cell ; 187(4): 897-913.e18, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38280374

RESUMEN

Canonically, the complement system is known for its rapid response to remove microbes in the bloodstream. However, relatively little is known about a functioning complement system on intestinal mucosal surfaces. Herein, we report the local synthesis of complement component 3 (C3) in the gut, primarily by stromal cells. C3 is expressed upon commensal colonization and is regulated by the composition of the microbiota in healthy humans and mice, leading to an individual host's specific luminal C3 levels. The absence of membrane attack complex (MAC) components in the gut ensures that C3 deposition does not result in the lysis of commensals. Pathogen infection triggers the immune system to recruit neutrophils to the infection site for pathogen clearance. Basal C3 levels directly correlate with protection against enteric infection. Our study reveals the gut complement system as an innate immune mechanism acting as a vigilant sentinel that combats pathogens and spares commensals.


Asunto(s)
Complemento C3 , Mucosa Intestinal , Microbiota , Animales , Humanos , Ratones , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Neutrófilos , Complemento C3/metabolismo , Células del Estroma/metabolismo
2.
Cell ; 181(7): 1533-1546.e13, 2020 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-32631492

RESUMEN

The gut microbiome is the resident microbial community of the gastrointestinal tract. This community is highly diverse, but how microbial diversity confers resistance or susceptibility to intestinal pathogens is poorly understood. Using transplantation of human microbiomes into several animal models of infection, we show that key microbiome species shape the chemical environment of the gut through the activity of the enzyme bile salt hydrolase. The activity of this enzyme reduced colonization by the major human diarrheal pathogen Vibrio cholerae by degrading the bile salt taurocholate that activates the expression of virulence genes. The absence of these functions and species permits increased infection loads on a personal microbiome-specific basis. These findings suggest new targets for individualized preventative strategies of V. cholerae infection through modulating the structure and function of the gut microbiome.


Asunto(s)
Cólera/metabolismo , Susceptibilidad a Enfermedades/microbiología , Microbioma Gastrointestinal/fisiología , Adulto , Animales , Ácidos y Sales Biliares , Cólera/microbiología , Modelos Animales de Enfermedad , Trasplante de Microbiota Fecal/métodos , Femenino , Interacciones Huésped-Patógeno/fisiología , Humanos , Hidrolasas/análisis , Masculino , Ratones , Ratones Endogámicos C57BL , Microbiota , Ácido Taurocólico/metabolismo , Vibrio cholerae/patogenicidad , Vibrio cholerae/fisiología , Virulencia
3.
Nature ; 627(8002): 189-195, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38355798

RESUMEN

Phagocyte NADPH oxidase, a protein complex with a core made up of NOX2 and p22 subunits, is responsible for transferring electrons from intracellular NADPH to extracellular oxygen1. This process generates superoxide anions that are vital for killing pathogens1. The activation of phagocyte NADPH oxidase requires membrane translocation and the binding of several cytosolic factors2. However, the exact mechanism by which cytosolic factors bind to and activate NOX2 is not well understood. Here we present the structure of the human NOX2-p22 complex activated by fragments of three cytosolic factors: p47, p67 and Rac1. The structure reveals that the p67-Rac1 complex clamps onto the dehydrogenase domain of NOX2 and induces its contraction, which stabilizes the binding of NADPH and results in a reduction of the distance between the NADPH-binding domain and the flavin adenine dinucleotide (FAD)-binding domain. Furthermore, the dehydrogenase domain docks onto the bottom of the transmembrane domain of NOX2, which reduces the distance between FAD and the inner haem. These structural rearrangements might facilitate the efficient transfer of electrons between the redox centres in NOX2 and lead to the activation of phagocyte NADPH oxidase.


Asunto(s)
NADPH Oxidasa 2 , Fagocitos , Humanos , Electrones , Activación Enzimática , Flavina-Adenina Dinucleótido/metabolismo , Hemo/química , Hemo/metabolismo , NADP/metabolismo , NADPH Oxidasa 2/química , NADPH Oxidasa 2/metabolismo , Fagocitos/enzimología , Dominios Proteicos , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo , Superóxidos/metabolismo , Unión Proteica
4.
Nature ; 626(8001): 999-1004, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38418915

RESUMEN

The advantage of 3D printing-that is, additive manufacturing (AM) of structural materials-has been severely compromised by their disappointing fatigue properties1,2. Commonly, poor fatigue properties appear to result from the presence of microvoids induced by current printing process procedures3,4. Accordingly, the question that we pose is whether the elimination of such microvoids can provide a feasible solution for marked enhancement of the fatigue resistance of void-free AM (Net-AM) alloys. Here we successfully rebuild an approximate void-free AM microstructure in Ti-6Al-4V titanium alloy by development of a Net-AM processing technique through an understanding of the asynchronism of phase transformation and grain growth. We identify the fatigue resistance of such AM microstructures and show that they lead to a high fatigue limit of around 1 GPa, exceeding the fatigue resistance of all AM and forged titanium alloys as well as that of other metallic materials. We confirm the high fatigue resistance of Net-AM microstructures and the potential advantages of AM processing in the production of structural components with maximum fatigue strength, which is beneficial for further application of AM technologies in engineering fields.

5.
Mol Cell ; 81(13): 2722-2735.e9, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34077757

RESUMEN

Lipid droplets are important for cancer cell growth and survival. However, the mechanism underlying the initiation of lipid droplet lipolysis is not well understood. We demonstrate here that glucose deprivation induces the binding of choline kinase (CHK) α2 to lipid droplets, which is sequentially mediated by AMPK-dependent CHKα2 S279 phosphorylation and KAT5-dependent CHKα2 K247 acetylation. Importantly, CHKα2 with altered catalytic domain conformation functions as a protein kinase and phosphorylates PLIN2 at Y232 and PLIN3 at Y251. The phosphorylated PLIN2/3 dissociate from lipid droplets and are degraded by Hsc70-mediated autophagy, thereby promoting lipid droplet lipolysis, fatty acid oxidation, and brain tumor growth. In addition, levels of CHKα2 S279 phosphorylation, CHKα2 K247 acetylation, and PLIN2/3 phosphorylation are positively correlated with one another in human glioblastoma specimens and are associated with poor prognosis in glioblastoma patients. These findings underscore the role of CHKα2 as a protein kinase in lipolysis and glioblastoma development.


Asunto(s)
Colina Quinasa/metabolismo , Glioblastoma/enzimología , Gotas Lipídicas/enzimología , Lipólisis , Proteínas de Neoplasias/metabolismo , Proteínas Quinasas/metabolismo , Acetilación , Línea Celular Tumoral , Colina Quinasa/genética , Glioblastoma/genética , Humanos , Proteínas de Neoplasias/genética , Proteínas Quinasas/genética
6.
Nature ; 601(7892): 280-284, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34880493

RESUMEN

Human sodium-glucose cotransporter 2 (hSGLT2) mediates the reabsorption of the majority of filtrated glucose in the kidney1. Pharmacological inhibition of hSGLT2 by oral small-molecule inhibitors, such as empagliflozin, leads to enhanced excretion of glucose and is widely used in the clinic to manage blood glucose levels for the treatment of type 2 diabetes1. Here we determined the cryogenic electron microscopy structure of the hSGLT2-MAP17 complex in the empagliflozin-bound state to an overall resolution of 2.95 Å. Our structure shows eukaryotic SGLT-specific structural features. MAP17 interacts with transmembrane helix 13 of hSGLT2. Empagliflozin occupies both the sugar-substrate-binding site and the external vestibule to lock hSGLT2 in an outward-open conformation, thus inhibiting the transport cycle. Our work provides a framework for understanding the mechanism of SLC5A family glucose transporters and also develops a foundation for the future rational design and optimization of new inhibitors targeting these transporters.


Asunto(s)
Inhibidores del Cotransportador de Sodio-Glucosa 2 , Transportador 2 de Sodio-Glucosa , Microscopía por Crioelectrón , Glucosa/metabolismo , Humanos , Transportador 2 de Sodio-Glucosa/química , Transportador 2 de Sodio-Glucosa/metabolismo , Transportador 2 de Sodio-Glucosa/ultraestructura , Inhibidores del Cotransportador de Sodio-Glucosa 2/química , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología
7.
Nature ; 606(7914): 550-556, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35545672

RESUMEN

Animals constantly receive various sensory stimuli, such as odours, sounds, light and touch, from the surrounding environment. These sensory inputs are essential for animals to search for food and avoid predators, but they also affect their physiological status, and may cause diseases such as cancer. Malignant gliomas-the most lethal form of brain tumour1-are known to intimately communicate with neurons at the cellular level2,3. However, it remains unclear whether external sensory stimuli can directly affect the development of malignant glioma under normal living conditions. Here we show that olfaction can directly regulate gliomagenesis. In an autochthonous mouse model that recapitulates adult gliomagenesis4-6 originating in oligodendrocyte precursor cells (OPCs), gliomas preferentially emerge in the olfactory bulb-the first relay of brain olfactory circuitry. Manipulating the activity of olfactory receptor neurons (ORNs) affects the development of glioma. Mechanistically, olfaction excites mitral and tufted (M/T) cells, which receive sensory information from ORNs and release insulin-like growth factor 1 (IGF1) in an activity-dependent manner. Specific knockout of Igf1 in M/T cells suppresses gliomagenesis. In addition, knocking out the IGF1 receptor in pre-cancerous mutant OPCs abolishes the ORN-activity-dependent mitogenic effects. Our findings establish a link between sensory experience and gliomagenesis through their corresponding sensory neuronal circuits.


Asunto(s)
Carcinogénesis , Glioma , Factor I del Crecimiento Similar a la Insulina , Neuronas Receptoras Olfatorias , Olfato , Animales , Glioma/metabolismo , Glioma/patología , Ratones , Vías Nerviosas , Bulbo Olfatorio/patología , Neuronas Receptoras Olfatorias/fisiología , Olfato/fisiología
8.
EMBO J ; 42(12): e112514, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-36946144

RESUMEN

Increasing evidence has shown that light exists in a diverse range of deep-sea environments. We unexpectedly found that blue light is necessary to produce excess zero-valent sulfur (ZVS) in Erythrobacter flavus 21-3, a bacterium that has been recently isolated from a deep-sea cold seep. E. flavus 21-3 is able to convert thiosulfate to ZVS using a novel thiosulfate oxidation pathway comprising a thiosulfate dehydrogenase (TsdA) and a thiosulfohydrolase (SoxB). Using proteomic, bacterial two-hybrid and heterologous expression assays, we found that the light-oxygen-voltage histidine kinase LOV-1477 responds to blue light and activates the diguanylate cyclase DGC-2902 to produce c-di-GMP. Subsequently, the PilZ domain-containing protein mPilZ-1753 binds to c-di-GMP and activates TsdA through direct interaction. Finally, Raman spectroscopy and gene knockout results verified that TsdA and two SoxB homologs cooperate to regulate ZVS production. As ZVS is an energy source for E. flavus 21-3, we propose that deep-sea blue light provides E. flavus 21-3 with a selective advantage in the cold seep, suggesting a previously unappreciated relationship between light-sensing pathways and sulfur metabolism in a deep-sea microorganism.


Asunto(s)
Proteómica , Tiosulfatos , Tiosulfatos/metabolismo , Bacterias/metabolismo , Oxidación-Reducción , Azufre/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo
9.
Nat Methods ; 20(6): 925-934, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37142767

RESUMEN

The fluorescent glutamate indicator iGluSnFR enables imaging of neurotransmission with genetic and molecular specificity. However, existing iGluSnFR variants exhibit low in vivo signal-to-noise ratios, saturating activation kinetics and exclusion from postsynaptic densities. Using a multiassay screen in bacteria, soluble protein and cultured neurons, we generated variants with improved signal-to-noise ratios and kinetics. We developed surface display constructs that improve iGluSnFR's nanoscopic localization to postsynapses. The resulting indicator iGluSnFR3 exhibits rapid nonsaturating activation kinetics and reports synaptic glutamate release with decreased saturation and increased specificity versus extrasynaptic signals in cultured neurons. Simultaneous imaging and electrophysiology at individual boutons in mouse visual cortex showed that iGluSnFR3 transients report single action potentials with high specificity. In vibrissal sensory cortex layer 4, we used iGluSnFR3 to characterize distinct patterns of touch-evoked feedforward input from thalamocortical boutons and both feedforward and recurrent input onto L4 cortical neuron dendritic spines.


Asunto(s)
Ácido Glutámico , Transmisión Sináptica , Ratones , Animales , Ácido Glutámico/metabolismo , Cinética , Neuronas/fisiología , Sinapsis/fisiología
10.
Mol Cell ; 70(2): 197-210.e7, 2018 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-29677490

RESUMEN

EGFR activates phosphatidylinositide 3-kinase (PI3K), but the mechanism underlying this activation is not completely understood. We demonstrated here that EGFR activation resulted in lysine acetyltransferase 5 (KAT5)-mediated K395 acetylation of the platelet isoform of phosphofructokinase 1 (PFKP) and subsequent translocation of PFKP to the plasma membrane, where the PFKP was phosphorylated at Y64 by EGFR. Phosphorylated PFKP binds to the N-terminal SH2 domain of p85α, which is distinct from binding of Gab1 to the C-terminal SH2 domain of p85α, and recruited p85α to the plasma membrane resulting in PI3K activation. PI3K-dependent AKT activation results in enhanced phosphofructokinase 2 (PFK2) phosphorylation and production of fructose-2,6-bisphosphate, which in turn promotes PFK1 activation. PFKP Y64 phosphorylation-enhanced PI3K/AKT-dependent PFK1 activation and GLUT1 expression promoted the Warburg effect, tumor cell proliferation, and brain tumorigenesis. These findings underscore the instrumental role of PFKP in PI3K activation and enhanced glycolysis through PI3K/AKT-dependent positive-feedback regulation.


Asunto(s)
Neoplasias Encefálicas/enzimología , Glioblastoma/enzimología , Glucólisis , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfofructoquinasa-1 Tipo C/metabolismo , Acetilación , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase Ia , Activación Enzimática , Receptores ErbB/genética , Receptores ErbB/metabolismo , Retroalimentación Fisiológica , Fructosadifosfatos/metabolismo , Glioblastoma/genética , Glioblastoma/patología , Transportador de Glucosa de Tipo 1/genética , Transportador de Glucosa de Tipo 1/metabolismo , Humanos , Lisina Acetiltransferasa 5/genética , Lisina Acetiltransferasa 5/metabolismo , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Fosfatidilinositol 3-Quinasas/genética , Fosfofructoquinasa-1 Tipo C/genética , Fosfofructoquinasa-2/genética , Fosfofructoquinasa-2/metabolismo , Fosforilación , Unión Proteica , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Dominios Homologos src
11.
Proc Natl Acad Sci U S A ; 120(37): e2302275120, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37669376

RESUMEN

Alerting for imminent earthquakes is particularly challenging due to the high nonlinearity and nonstationarity of geodynamical phenomena. In this study, based on spatiotemporal information (STI) transformation for high-dimensional real-time data, we developed a model-free framework, i.e., real-time spatiotemporal information transformation learning (RSIT), for extending the nonlinear and nonstationary time series. Specifically, by transforming high-dimensional information of the global navigation satellite system into one-dimensional dynamics via the STI strategy, RSIT efficiently utilizes two criteria of the transformed one-dimensional dynamics, i.e., unpredictability and instability. Such two criteria contemporaneously signal a potential critical transition of the geodynamical system, thereby providing early-warning signals of possible upcoming earthquakes. RSIT explores both the spatial and temporal dynamics of real-world data on the basis of a solid theoretical background in nonlinear dynamics and delay-embedding theory. The effectiveness of RSIT was demonstrated on geodynamical data of recent earthquakes from a number of regions across at least 4 y and through further comparison with existing methods.

12.
N Engl J Med ; 387(15): 1361-1372, 2022 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-36239644

RESUMEN

BACKGROUND: Data from trials investigating the effects and risks of endovascular thrombectomy for the treatment of stroke due to basilar-artery occlusion are limited. METHODS: We conducted a multicenter, prospective, randomized, controlled trial of endovascular thrombectomy for basilar-artery occlusion at 36 centers in China. Patients were assigned, in a 2:1 ratio, within 12 hours after the estimated time of basilar-artery occlusion to receive endovascular thrombectomy or best medical care (control). The primary outcome was good functional status, defined as a score of 0 to 3 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]), at 90 days. Secondary outcomes included a modified Rankin scale score of 0 to 2, distribution across the modified Rankin scale score categories, and quality of life. Safety outcomes included symptomatic intracranial hemorrhage at 24 to 72 hours, 90-day mortality, and procedural complications. RESULTS: Of the 507 patients who underwent screening, 340 were in the intention-to-treat population, with 226 assigned to the thrombectomy group and 114 to the control group. Intravenous thrombolysis was used in 31% of the patients in the thrombectomy group and in 34% of those in the control group. Good functional status at 90 days occurred in 104 patients (46%) in the thrombectomy group and in 26 (23%) in the control group (adjusted rate ratio, 2.06; 95% confidence interval [CI], 1.46 to 2.91, P<0.001). Symptomatic intracranial hemorrhage occurred in 12 patients (5%) in the thrombectomy group and in none in the control group. Results for the secondary clinical and imaging outcomes were generally in the same direction as those for the primary outcome. Mortality at 90 days was 37% in the thrombectomy group and 55% in the control group (adjusted risk ratio, 0.66; 95% CI, 0.52 to 0.82). Procedural complications occurred in 14% of the patients in the thrombectomy group, including one death due to arterial perforation. CONCLUSIONS: In a trial involving Chinese patients with basilar-artery occlusion, approximately one third of whom received intravenous thrombolysis, endovascular thrombectomy within 12 hours after stroke onset led to better functional outcomes at 90 days than best medical care but was associated with procedural complications and intracerebral hemorrhage. (Funded by the Program for Innovative Research Team of the First Affiliated Hospital of USTC and others; ATTENTION ClinicalTrials.gov number, NCT04751708.).


Asunto(s)
Arteriopatías Oclusivas , Arteria Basilar , Procedimientos Endovasculares , Accidente Cerebrovascular , Trombectomía , Humanos , Administración Intravenosa , Arteriopatías Oclusivas/complicaciones , Arteriopatías Oclusivas/tratamiento farmacológico , Arteriopatías Oclusivas/mortalidad , Arteriopatías Oclusivas/cirugía , Arteria Basilar/efectos de los fármacos , Arteria Basilar/cirugía , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/etiología , Isquemia Encefálica/cirugía , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/métodos , Fibrinolíticos/administración & dosificación , Fibrinolíticos/efectos adversos , Fibrinolíticos/uso terapéutico , Hemorragias Intracraneales/inducido químicamente , Hemorragias Intracraneales/etiología , Estudios Prospectivos , Calidad de Vida , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/cirugía , Trombectomía/efectos adversos , Trombectomía/métodos , Terapia Trombolítica/efectos adversos , Terapia Trombolítica/métodos , Resultado del Tratamiento , Recuperación de la Función
13.
Brief Bioinform ; 24(6)2023 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-37833841

RESUMEN

The critical point or pivotal threshold of cell transition occurs in early embryonic development when cell differentiation culminates in its transition to specific cell fates, at which the cell population undergoes an abrupt and qualitative shift. Revealing such critical points of cell transitions can track cellular heterogeneity and shed light on the molecular mechanisms of cell differentiation. However, precise detection of critical state transitions proves challenging when relying on single-cell RNA sequencing data due to their inherent sparsity, noise, and heterogeneity. In this study, diverging from conventional methods like differential gene analysis or static techniques that emphasize classification of cell types, an innovative computational approach, single-cell gene association entropy (SGAE), is designed for the analysis of single-cell RNA-seq data and utilizes gene association information to reveal critical states of cell transitions. More specifically, through the translation of gene expression data into local SGAE scores, the proposed SGAE can serve as an index to quantitatively assess the resilience and critical properties of genetic regulatory networks, consequently detecting the signal of cell transitions. Analyses of five single-cell datasets for embryonic development demonstrate that the SGAE method achieves better performance in facilitating the characterization of a critical phase transition compared with other existing methods. Moreover, the SGAE value can effectively discriminate cellular heterogeneity over time and performs well in the temporal clustering of cells. Besides, biological functional analysis also indicates the effectiveness of the proposed approach.


Asunto(s)
Desarrollo Embrionario , Redes Reguladoras de Genes , Entropía , Diferenciación Celular , Desarrollo Embrionario/genética , Perfilación de la Expresión Génica
14.
Brief Bioinform ; 24(2)2023 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-36705581

RESUMEN

Complex biological systems do not always develop smoothly but occasionally undergo a sharp transition; i.e. there exists a critical transition or tipping point at which a drastic qualitative shift occurs. Hunting for such a critical transition is important to prevent or delay the occurrence of catastrophic consequences, such as disease deterioration. However, the identification of the critical state for complex biological systems is still a challenging problem when using high-dimensional small sample data, especially where only a certain sample is available, which often leads to the failure of most traditional statistical approaches. In this study, a novel quantitative method, sample-perturbed network entropy (SPNE), is developed based on the sample-perturbed directed network to reveal the critical state of complex biological systems at the single-sample level. Specifically, the SPNE approach effectively quantifies the perturbation effect caused by a specific sample on the directed network in terms of network entropy and thus captures the criticality of biological systems. This model-free method was applied to both bulk and single-cell expression data. Our approach was validated by successfully detecting the early warning signals of the critical states for six real datasets, including four tumor datasets from The Cancer Genome Atlas (TCGA) and two single-cell datasets of cell differentiation. In addition, the functional analyses of signaling biomarkers demonstrated the effectiveness of the analytical and computational results.


Asunto(s)
Neoplasias , Humanos , Entropía , Progresión de la Enfermedad , Biomarcadores/metabolismo , Transducción de Señal
15.
Am J Pathol ; 194(1): 52-70, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37820926

RESUMEN

Loss of hepatocyte nuclear factor 4α (HNF4α) expression is frequently observed in end-stage liver disease and associated with loss of vital liver functions, thus increasing mortality. Loss of HNF4α expression is mediated by inflammatory cytokines, such as transforming growth factor (TGF)-ß. However, details of how HNF4α is suppressed are largely unknown to date. Herein, TGF-ß did not directly inhibit HNF4α but contributed to its transcriptional regulation by SMAD2/3 recruiting acetyltransferase CREB-binding protein/p300 to the HNF4α promoter. The recruitment of CREB-binding protein/p300 is indispensable for CCAAT/enhancer-binding protein α (C/EBPα) binding, another essential requirement for constitutive HNF4α expression in hepatocytes. Consistent with the in vitro observation, 67 of 98 patients with hepatic HNF4α expressed both phospho-SMAD2 and C/EBPα, whereas 22 patients without HNF4α expression lacked either phospho-SMAD2 or C/EBPα. In contrast to the observed induction of HNF4α, SMAD2/3 inhibited C/EBPα transcription. Long-term TGF-ß incubation resulted in C/EBPα depletion, which abrogated HNF4α expression. Intriguingly, SMAD2/3 inhibitory binding to the C/EBPα promoter was abolished by insulin. Two-thirds of patients without C/EBPα lacked membrane glucose transporter type 2 expression in hepatocytes, indicating insulin resistance. Taken together, these data indicate that hepatic insulin sensitivity is essential for hepatic HNF4α expression in the condition of inflammation.


Asunto(s)
Proteína de Unión a CREB , Insulina , Humanos , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Proteína de Unión a CREB/metabolismo , Factor Nuclear 4 del Hepatocito/genética , Factor Nuclear 4 del Hepatocito/metabolismo , Hepatocitos/metabolismo , Hígado/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Factor de Crecimiento Transformador beta/metabolismo
16.
Hepatology ; 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38377452

RESUMEN

BACKGROUND AND AIMS: Protein tyrosine sulfation (PTS) is a common posttranslational modification that regulates a variety of physiological and pathological processes. However, the role of PTS in cancer remains poorly understood. The goal of this study was to determine whether and how PTS plays a role in HCC progression. APPROACH AND RESULTS: By mass spectrometry and bioinformatics analysis, we identified SAV1 as a novel substrate of PTS in HCC. Oxidative stress upregulates the transcription of SLC35B2, a Golgi-resident transporter of sulfate donor 3'-phosphoadenosine 5'-phosphosulfate, leading to increased sulfation of SAV1. Sulfation of SAV1 disrupts the formation of the SAV1-MST1 complex, resulting in a decrease of MST1 phosphorylation and subsequent inactivation of Hippo signaling. These molecular events ultimately foster the growth of HCC cells both in vivo and in vitro. Moreover, SLC35B2 is a novel transcription target gene of the Hippo pathway, constituting a positive feedback loop that facilitates HCC progression under oxidative stress. CONCLUSIONS: Our findings reveal a regulatory mechanism of the SLC35B2/SAV1 sulfation axis in response to oxidative stress, highlighting its potential as a promising therapeutic target for HCC.

17.
Plant Physiol ; 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38917222

RESUMEN

Wheat (Triticum aestivum L.) is one of the most important crops worldwide and a major source of human Cd intake. Limiting grain Cd concentration (Gr_Cd_Conc) in wheat is necessary to ensure food safety. However, the genetic factors associated with Cd uptake, translocation, distribution, and Gr_Cd_Conc in wheat are poorly understood. Here, we mapped quantitative trait loci (QTL) for Gr_Cd_Conc and its related transport pathway using a recombinant inbred line (RIL_DT) population derived from two Polish wheat varieties (dwarf Polish wheat [DPW] and tall Polish wheat [TPW]). We identified 29 novel major QTLs for grain and tissue Cd concentration; 14 novel major QTLs for Cd uptake, translocation, and distribution; and 27 major QTLs for agronomic traits. We also analyzed the pleiotropy of these QTLs. Six novel QTLs (QGr_Cd_Conc-1A, QGr_Cd_Conc-3A, QGr_Cd_Conc-4B, QGr_Cd_Conc-5B, QGr_Cd_Conc-6A and QGr_Cd_Conc-7A) for Gr_Cd_Conc explained 8.16-17.02% of the phenotypic variation. QGr_Cd_Conc-3A, QGr_Cd_Conc-6A and QGr_Cd_Conc-7A pleiotropically regulated Cd transport; three other QTLs were organ-specific for Gr_Cd_Conc. We fine-mapped the locus of QGr_Cd_Conc-4B and identified the candidate gene as Cation/Ca exchanger 2 (TpCCX2-4B), which was differentially expressed in DPW and TPW. It encodes an endoplasmic reticulum membrane/plasma membrane-localized Cd efflux transporter in yeast. Overexpression of TpCCX2-4B reduced Gr_Cd_Conc in rice. The average Gr_Cd_Conc was significantly lower in TpCCX2-4BDPW genotypes than in TpCCX2-4BTPWgenotypes of the RIL_DT population and two other natural populations, based on a KASP marker derived from the different promoter sequences between TpCCX2-4BDPW and TpCCX2-4BTPW. Our study reveals the genetic mechanism of Cd accumulation in wheat and provides valuable resources for genetic improvement of low-Cd-accumulating wheat cultivars.

18.
Nature ; 574(7777): 206-210, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31514202

RESUMEN

Soluble guanylate cyclase (sGC) is the primary sensor of nitric oxide. It has a central role in nitric oxide signalling and has been implicated in many essential physiological processes and disease conditions. The binding of nitric oxide boosts the enzymatic activity of sGC. However, the mechanism by which nitric oxide activates the enzyme is unclear. Here we report the cryo-electron microscopy structures of the human sGCα1ß1 heterodimer in different functional states. These structures revealed that the transducer module bridges the nitric oxide sensor module and the catalytic module. Binding of nitric oxide to the ß1 haem-nitric oxide and oxygen binding (H-NOX) domain triggers the structural rearrangement of the sensor module and a conformational switch of the transducer module from bending to straightening. The resulting movement of the N termini of the catalytic domains drives structural changes within the catalytic module, which in turn boost the enzymatic activity of sGC.


Asunto(s)
Microscopía por Crioelectrón , Guanilil Ciclasa Soluble/metabolismo , Guanilil Ciclasa Soluble/ultraestructura , Animales , Disulfuros/química , Disulfuros/metabolismo , Drosophila melanogaster , Activación Enzimática , Células HEK293 , Hemo/metabolismo , Humanos , Hidrazinas/farmacología , Ratones , Modelos Moleculares , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/metabolismo , Oxígeno/metabolismo , Dominios Proteicos , Multimerización de Proteína , Guanilil Ciclasa Soluble/química , Guanilil Ciclasa Soluble/genética
19.
Mol Ther ; 32(4): 1144-1157, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38310354

RESUMEN

The potent immunomodulatory function of mesenchymal stem/stromal cells (MSCs) elicited by proinflammatory cytokines IFN-γ and TNF-α (IT) is critical to resolve inflammation and promote tissue repair. However, little is known about how the immunomodulatory capability of MSCs is related to their differentiation competency in the inflammatory microenvironment. In this study, we demonstrate that the adipocyte differentiation and immunomodulatory function of human adipose tissue-derived MSCs (MSC(AD)s) are mutually exclusive. Mitochondrial reactive oxygen species (mtROS), which promote adipocyte differentiation, were decreased in MSC(AD)s due to IT-induced upregulation of superoxide dismutase 2 (SOD2). Furthermore, knockdown of SOD2 led to enhanced adipogenic differentiation but reduced immunosuppression capability of MSC(AD)s. Interestingly, the adipogenic differentiation was associated with increased mitochondrial biogenesis and upregulation of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A/PGC-1α) expression. IT inhibited PGC-1α expression and decreased mitochondrial mass but promoted glycolysis in an SOD2-dependent manner. MSC(AD)s lacking SOD2 were compromised in their therapeutic efficacy in DSS-induced colitis in mice. Taken together, these findings indicate that the adipogenic differentiation and immunomodulation of MSC(AD)s may compete for resources in fulfilling the respective biosynthetic needs. Blocking of adipogenic differentiation by mitochondrial antioxidant may represent a novel strategy to enhance the immunosuppressive activity of MSCs in the inflammatory microenvironment.


Asunto(s)
Células Madre Mesenquimatosas , Superóxido Dismutasa , Ratones , Humanos , Animales , Diferenciación Celular , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Adipocitos , Células Madre Mesenquimatosas/metabolismo
20.
Nucleic Acids Res ; 51(2): e12, 2023 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-36477375

RESUMEN

The hub metabolite, nicotinamide adenine dinucleotide (NAD), can be used as an initiating nucleotide in RNA synthesis to result in NAD-capped RNAs (NAD-RNA). Since NAD has been heightened as one of the most essential modulators in aging and various age-related diseases, its attachment to RNA might indicate a yet-to-be discovered mechanism that impacts adult life-course. However, the unknown identity of NAD-linked RNAs in adult and aging tissues has hindered functional studies. Here, we introduce ONE-seq method to identify the RNA transcripts that contain NAD cap. ONE-seq has been optimized to use only one-step chemo-enzymatic biotinylation, followed by streptavidin capture and the nudix phosphohydrolase NudC-catalyzed elution, to specifically recover NAD-capped RNAs for epitranscriptome and gene-specific analyses. Using ONE-seq, we discover more than a thousand of previously unknown NAD-RNAs in the mouse liver and reveal epitranscriptome-wide dynamics of NAD-RNAs with age. ONE-seq empowers the identification of NAD-capped RNAs that are responsive to distinct physiological states, facilitating functional investigation into this modification.


Asunto(s)
NAD , Caperuzas de ARN , Animales , Ratones , NAD/genética , NAD/metabolismo , Nucleótidos , Monoéster Fosfórico Hidrolasas , Caperuzas de ARN/genética , Transcriptoma , Epigénesis Genética
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