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1.
Immunity ; 52(5): 767-781.e6, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32277911

RESUMEN

The enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA in infected and malignant cells and catalyzes the formation of 2'3'cGMP-AMP (cGAMP), which in turn triggers interferon (IFN) production via the STING pathway. Here, we examined the contribution of anion channels to cGAMP transfer and anti-viral defense. A candidate screen revealed that inhibition of volume-regulated anion channels (VRACs) increased propagation of the DNA virus HSV-1 but not the RNA virus VSV. Chemical blockade or genetic ablation of LRRC8A/SWELL1, a VRAC subunit, resulted in defective IFN responses to HSV-1. Biochemical and electrophysiological analyses revealed that LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane. Enhancing VRAC activity by hypotonic cell swelling, cisplatin, GTPγS, or the cytokines TNF or interleukin-1 increased STING-dependent IFN response to extracellular but not intracellular cGAMP. Lrrc8e-/- mice exhibited impaired IFN responses and compromised immunity to HSV-1. Our findings suggest that cell-to-cell transmission of cGAMP via LRRC8/VRAC channels is central to effective anti-viral immunity.


Asunto(s)
Fibroblastos/inmunología , Interferones/inmunología , Proteínas de la Membrana/inmunología , Nucleótidos Cíclicos/inmunología , Canales Aniónicos Dependientes del Voltaje/inmunología , Animales , Antivirales/inmunología , Antivirales/metabolismo , Efecto Espectador , Línea Celular , Células Cultivadas , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Fibroblastos/citología , Fibroblastos/metabolismo , Células HeLa , Herpes Simple/inmunología , Herpes Simple/virología , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 1/fisiología , Humanos , Interferones/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Nucleótidos Cíclicos/metabolismo , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/inmunología , Nucleotidiltransferasas/metabolismo , Canales Aniónicos Dependientes del Voltaje/metabolismo
2.
Mol Cell ; 73(5): 1015-1027.e7, 2019 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-30711376

RESUMEN

TCRs recognize cognate pMHCs to initiate T cell signaling and adaptive immunity. Mechanical force strengthens TCR-pMHC interactions to elicit agonist-specific catch bonds to trigger TCR signaling, but the underlying dynamic structural mechanism is unclear. We combined steered molecular dynamics (SMD) simulation, single-molecule biophysical approaches, and functional assays to collectively demonstrate that mechanical force induces conformational changes in pMHCs to enhance pre-existing contacts and activates new interactions at the TCR-pMHC binding interface to resist bond dissociation under force, resulting in TCR-pMHC catch bonds and T cell activation. Intriguingly, cancer-associated somatic mutations in HLA-A2 that may restrict these conformational changes suppressed TCR-pMHC catch bonds. Structural analysis also indicated that HLA polymorphism might alter the equilibrium of these conformational changes. Our findings not only reveal critical roles of force-induced conformational changes in pMHCs for activating TCR-pMHC catch bonds but also have implications for T cell-based immunotherapy.


Asunto(s)
Inmunidad Adaptativa , Antígeno HLA-A2/inmunología , Mecanotransducción Celular , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T/inmunología , Animales , Células HEK293 , Antígeno HLA-A2/química , Antígeno HLA-A2/genética , Antígeno HLA-A2/metabolismo , Humanos , Hibridomas , Ratones Endogámicos C57BL , Ratones Transgénicos , Simulación de Dinámica Molecular , Mutación , Unión Proteica , Conformación Proteica , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Imagen Individual de Molécula/métodos , Relación Estructura-Actividad , Linfocitos T/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(34): e2402262121, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39145931

RESUMEN

Homologous recombination (HR) is essential for the maintenance of genome stability. During HR, Replication Protein A (RPA) rapidly coats the 3'-tailed single-strand DNA (ssDNA) generated by end resection. Then, the ssDNA-bound RPA must be timely replaced by Rad51 recombinase to form Rad51 nucleoprotein filaments that drive homology search and HR repair. How cells regulate Rad51 assembly dynamics and coordinate RPA and Rad51 actions to ensure proper HR remains poorly understood. Here, we identified that Rtt105, a Ty1 transposon regulator, acts to stimulate Rad51 assembly and orchestrate RPA and Rad51 actions during HR. We found that Rtt105 interacts with Rad51 in vitro and in vivo and restrains the adenosine 5' triphosphate (ATP) hydrolysis activity of Rad51. We showed that Rtt105 directly stimulates dynamic Rad51-ssDNA assembly, strand exchange, and D-loop formation in vitro. Notably, we found that Rtt105 physically regulates the binding of Rad51 and RPA to ssDNA via different motifs and that both regulations are necessary and epistatic in promoting Rad51 nucleation, strand exchange, and HR repair. Consequently, disrupting either of the interactions impaired HR and conferred DNA damage sensitivity, underscoring the importance of Rtt105 in orchestrating the actions of Rad51 and RPA. Our work reveals additional layers of mechanisms regulating Rad51 filament dynamics and the coordination of HR.


Asunto(s)
ADN de Cadena Simple , Recombinasa Rad51 , Reparación del ADN por Recombinación , Proteína de Replicación A , Proteínas de Saccharomyces cerevisiae , Recombinasa Rad51/metabolismo , Proteína de Replicación A/metabolismo , Proteína de Replicación A/genética , ADN de Cadena Simple/metabolismo , ADN de Cadena Simple/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Unión Proteica
4.
PLoS Pathog ; 20(7): e1012376, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39008531

RESUMEN

Antimicrobial resistance is an ongoing "one health" challenge of global concern. The acyl-ACP synthetase (termed AasS) of the zoonotic pathogen Vibrio harveyi recycles exogenous fatty acid (eFA), bypassing the requirement of type II fatty acid synthesis (FAS II), a druggable pathway. A growing body of bacterial AasS-type isoenzymes compromises the clinical efficacy of FAS II-directed antimicrobials, like cerulenin. Very recently, an acyl adenylate mimic, C10-AMS, was proposed as a lead compound against AasS activity. However, the underlying mechanism remains poorly understood. Here we present two high-resolution cryo-EM structures of AasS liganded with C10-AMS inhibitor (2.33 Å) and C10-AMP intermediate (2.19 Å) in addition to its apo form (2.53 Å). Apart from our measurements for C10-AMS' Ki value of around 0.6 µM, structural and functional analyses explained how this inhibitor interacts with AasS enzyme. Unlike an open state of AasS, ready for C10-AMP formation, a closed conformation is trapped by the C10-AMS inhibitor. Tight binding of C10-AMS blocks fatty acyl substrate entry, and therefore inhibits AasS action. Additionally, this intermediate analog C10-AMS appears to be a mixed-type AasS inhibitor. In summary, our results provide the proof of principle that inhibiting salvage of eFA by AasS reverses the FAS II bypass. This facilitates the development of next-generation anti-bacterial therapeutics, esp. the dual therapy consisting of C10-AMS scaffold derivatives combined with certain FAS II inhibitors.


Asunto(s)
Ácidos Grasos , Vibrio , Ácidos Grasos/metabolismo , Ácidos Grasos/química , Vibrio/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Antibacterianos/farmacología , Microscopía por Crioelectrón , Coenzima A Ligasas/metabolismo , Coenzima A Ligasas/antagonistas & inhibidores , Acido Graso Sintasa Tipo II/metabolismo , Acido Graso Sintasa Tipo II/antagonistas & inhibidores
5.
Nature ; 586(7831): 801-806, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33057191

RESUMEN

The strand-exchange reaction is central to homologous recombination. It is catalysed by the RecA family of ATPases, which form a helical filament with single-stranded DNA (ssDNA) and ATP. This filament binds to a donor double-stranded DNA (dsDNA) to form synaptic filaments, which search for homology and then catalyse the exchange of the complementary strand, forming either a new heteroduplex or-if homology is limited-a D-loop1,2. How synaptic filaments form, search for homology and catalyse strand exchange is poorly understood. Here we report the cryo-electron microscopy analysis of synaptic mini-filaments with both non-complementary and partially complementary dsDNA, and structures of RecA-D-loop complexes containing a 10- or a 12-base-pair heteroduplex. The C-terminal domain of RecA binds to dsDNA and directs it to the RecA L2 loop, which inserts into and opens up the duplex. The opening propagates through RecA sequestering the homologous strand at a secondary DNA-binding site, which frees the complementary strand to sample pairing with the ssDNA. At each RecA step, there is a roughly 20% probability that duplex opening will terminate and the as-yet-unopened dsDNA portion will bind to another C-terminal domain. Homology suppresses this process, through the cooperation of heteroduplex pairing with the binding of ssDNA to the secondary site, to extend dsDNA opening. This mechanism locally limits the length of ssDNA sampled for pairing if homology is not encountered, and could allow for the formation of multiple, widely separated synapses on the donor dsDNA, which would increase the likelihood of encountering homology. These findings provide key mechanistic insights into homologous recombination.


Asunto(s)
Microscopía por Crioelectrón , ADN de Cadena Simple/química , ADN de Cadena Simple/metabolismo , Proteínas de Unión al ADN/metabolismo , ADN/química , ADN/metabolismo , Proteínas de Escherichia coli/metabolismo , Conformación de Ácido Nucleico , Rec A Recombinasas/metabolismo , Secuencia de Bases , Sitios de Unión , Escherichia coli/enzimología , Recombinación Homóloga , Modelos Moleculares
6.
Proc Natl Acad Sci U S A ; 120(2): e2217493120, 2023 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-36598938

RESUMEN

In response to DNA damage, bacterial RecA protein forms filaments with the assistance of DinI protein. The RecA filaments stimulate the autocleavage of LexA, the repressor of more than 50 SOS genes, and activate the SOS response. During the late phase of SOS response, the RecA filaments stimulate the autocleavage of UmuD and λ repressor CI, leading to mutagenic repair and lytic cycle, respectively. Here, we determined the cryo-electron microscopy structures of Escherichia coli RecA filaments in complex with DinI, LexA, UmuD, and λCI by helical reconstruction. The structures reveal that LexA and UmuD dimers bind in the filament groove and cleave in an intramolecular and an intermolecular manner, respectively, while λCI binds deeply in the filament groove as a monomer. Despite their distinct folds and oligomeric states, all RecA filament binders recognize the same conserved protein features in the filament groove. The SOS response in bacteria can lead to mutagenesis and antimicrobial resistance, and our study paves the way for rational drug design targeting the bacterial SOS response.


Asunto(s)
Proteínas de Escherichia coli , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Respuesta SOS en Genética , Microscopía por Crioelectrón , ADN Polimerasa Dirigida por ADN/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Rec A Recombinasas/metabolismo
7.
Proc Natl Acad Sci U S A ; 119(19): e2119990119, 2022 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-35522713

RESUMEN

Over the years it has been established that SIN1, a key component of mTORC2, could interact with Ras family small GTPases through its Ras-binding domain (RBD). The physical association of Ras and SIN1/mTORC2 could potentially affect both mTORC2 and Ras-ERK pathways. To decipher the precise molecular mechanism of this interaction, we determined the high-resolution structures of HRas/KRas-SIN1 RBD complexes, showing the detailed interaction interface. Mutation of critical interface residues abolished Ras-SIN1 interaction and in SIN1 knockout cells we demonstrated that Ras-SIN1 association promotes SGK1 activity but inhibits insulin-induced ERK activation. With structural comparison and competition fluorescence resonance energy transfer (FRET) assays we showed that HRas-SIN1 RBD association is much weaker than HRas-Raf1 RBD but is slightly stronger than HRas-PI3K RBD interaction, providing a possible explanation for the different outcome of insulin or EGF stimulation. We also found that SIN1 isoform lacking the PH domain binds stronger to Ras than other longer isoforms and the PH domain appears to have an inhibitory effect on Ras-SIN1 binding. In addition, we uncovered a Ras dimerization interface that could be critical for Ras oligomerization. Our results advance our understanding of Ras-SIN1 association and crosstalk between growth factor-stimulated pathways.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Transducción de Señal , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proliferación Celular , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas ras/metabolismo
8.
Proc Natl Acad Sci U S A ; 119(31): e2205469119, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35895684

RESUMEN

T regulatory (Treg) cells are essential for self-tolerance whereas they are detrimental for dampening the host anti-tumor immunity. How Treg cells adapt to environmental signals to orchestrate their homeostasis and functions remains poorly understood. Here, we identified that transcription factor EB (TFEB) is induced by host nutrition deprivation or interleukin (IL)-2 in CD4+ T cells. The loss of TFEB in Treg cells leads to reduced Treg accumulation and impaired Treg function in mouse models of cancer and autoimmune disease. TFEB intrinsically regulates genes involved in Treg cell differentiation and mitochondria function while it suppresses expression of proinflammatory cytokines independently of its established roles in autophagy. This coordinated action is required for mitochondria integrity and appropriate lipid metabolism in Treg cells. These findings identify TFEB as a critical regulator for orchestrating Treg generation and function, which may contribute to the adaptive responses of T cells to local environmental cues.


Asunto(s)
Adaptación Fisiológica , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Mitocondrias , Neoplasias , Linfocitos T Reguladores , Adaptación Fisiológica/genética , Adaptación Fisiológica/fisiología , Animales , Enfermedades Autoinmunes/inmunología , Autofagia/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/fisiología , Modelos Animales de Enfermedad , Interleucina-2/metabolismo , Ratones , Mitocondrias/genética , Mitocondrias/metabolismo , Neoplasias/inmunología , Linfocitos T Reguladores/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Artículo en Inglés | MEDLINE | ID: mdl-38864769

RESUMEN

Sex differences are recognized in pulmonary hypertension, however the progression of disease with regards to vascular lesion formation and circulating cytokines/chemokines is unknown. To determine whether vascular lesion formation, changes in hemodynamics and alterations in circulating chemokines/cytokines differ between male and female. We used a progressive model of PAH, SU/Hx and analyzed cohorts of male and female rats at timepoints suggested to indicate worsening disease. Our analysis included echocardiograpy for hemodynamics, morphometry, immunofluoresecence and chemokine/cytokine analysis of plasma at each time point in both sexes. We found that male rats had significantly increased Fulton index compared to females at each time point as well as increased medial artery thickening at 8-weeks PAH. Further, females exhibit fewer obliterative vascular lesions than males at our latest time point. Our data also show increased IL-4, GM-CSF, IL-10, and MIP-1 that are not observed in females, while females have increased RANTES and CXCL-10 not found in males. Males also have increased infiltrating macrophages in vascular lesions as compared to females. We found that development of progressive PAH in hemodynamics, morphology and chemokine/cytokine circulation differ significantly between males and females. These data suggest a macrophage driven pathology in males, while there may be T-cell protection from vascular damage in female PAH.

10.
J Cell Biochem ; 125(1): 115-126, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38079224

RESUMEN

Asperosaponin VI (ASA VI) is a bioactive triterpenoid saponin extracted from Diptychus roots, of Diptyl, and has previously shown protective functions in rheumatoid arthritis and sepsis. This study investigates the effects and molecular mechanisms of ASA VI on skeletal muscle regeneration in a cardiotoxin (CTX)-induced skeletal muscle injury mouse model. Mice were subjected to CTX-induced injury in the tibialis anterior and C2C12 myotubes were treated with CTX. Muscle fiber histology was analyzed at 7 and 14 days postinjury. Apoptosis and autophagy-related protein expression were evaluated t s by Western blot, and muscle regeneration markers were quantified by quantitative polymerase chain reaction. Docking studies, cell viability assessments, and glycogen synthase kinase-3ß (GSK-3ß) activation analyses were performed to elucidate the mechanism. ASA VI was observed to improve muscle interstitial fibrosis, remodeling, and performance in CTX-treated mice, thereby increased skeletal muscle size, weight, and locomotion. Furthermore, ASA VI modulated the expression of apoptosis and autophagy-related proteins through GSK-3ß inhibition and activated the transcription of regeneration genes. Our results suggest that ASA VI mitigates skeletal muscle injury by modulating apoptosis and autophagy via GSK-3ß signaling and promotes regeneration, thus presenting a probable therapeutic agent for skeletal muscle injury.


Asunto(s)
Músculo Esquelético , Saponinas , Ratones , Animales , Glucógeno Sintasa Quinasa 3 beta/genética , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Músculo Esquelético/metabolismo , Apoptosis , Saponinas/farmacología
11.
Artículo en Inglés | MEDLINE | ID: mdl-39076085

RESUMEN

P. aeruginosa utilizes a type 3 secretion system to intoxicate host cells with the nucleotidyl cyclase ExoY. After activation by its host cell cofactor, filamentous actin, ExoY produces purine and pyrimidine cyclic nucleotides, including cAMP, cGMP, and cUMP. ExoY-generated cyclic nucleotides promote inter-endothelial gap formation, impair motility, and arrest cell growth. The disruptive activities of cAMP and cGMP during P. aeruginosa infection are established; however, little is known about the function of cUMP. Here, we tested the hypothesis that cUMP contributes to endothelial cell barrier disruption during P. aeruginosa infection. Utilizing a membrane permeable cUMP analog, cUMP-AM, we revealed that during infection with catalytically inactive ExoY, cUMP promotes inter-endothelial gap formation in cultured PMVECs and contributes to increased filtration coefficient in the isolated perfused lung. These findings indicate that cUMP contributes to endothelial permeability during P. aeruginosa lung infection.

12.
Prostate ; 84(9): 807-813, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38558009

RESUMEN

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common condition, yet it is challenging for the average BPH patient to find credible and accurate information about BPH. Our goal is to evaluate and compare the accuracy and reproducibility of large language models (LLMs), including ChatGPT-3.5, ChatGPT-4, and the New Bing Chat in responding to a BPH frequently asked questions (FAQs) questionnaire. METHODS: A total of 45 questions related to BPH were categorized into basic and professional knowledge. Three LLM-ChatGPT-3.5, ChatGPT-4, and New Bing Chat-were utilized to generate responses to these questions. Responses were graded as comprehensive, correct but inadequate, mixed with incorrect/outdated data, or completely incorrect. Reproducibility was assessed by generating two responses for each question. All responses were reviewed and judged by experienced urologists. RESULTS: All three LLMs exhibited high accuracy in generating responses to questions, with accuracy rates ranging from 86.7% to 100%. However, there was no statistically significant difference in response accuracy among the three (p > 0.017 for all comparisons). Additionally, the accuracy of the LLMs' responses to the basic knowledge questions was roughly equivalent to that of the specialized knowledge questions, showing a difference of less than 3.5% (GPT-3.5: 90% vs. 86.7%; GPT-4: 96.7% vs. 95.6%; New Bing: 96.7% vs. 93.3%). Furthermore, all three LLMs demonstrated high reproducibility, with rates ranging from 93.3% to 97.8%. CONCLUSIONS: ChatGPT-3.5, ChatGPT-4, and New Bing Chat offer accurate and reproducible responses to BPH-related questions, establishing them as valuable resources for enhancing health literacy and supporting BPH patients in conjunction with healthcare professionals.


Asunto(s)
Hiperplasia Prostática , Humanos , Hiperplasia Prostática/diagnóstico , Masculino , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Lenguaje , Educación del Paciente como Asunto/métodos
13.
Int J Obes (Lond) ; 48(2): 218-223, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37891401

RESUMEN

OBJECTIVE: The prospective association between vitamin D and obstructive sleep apnea (OSA) remains uncertain. We aimed to assess the association between serum 25-hydroxyvitamin D (25(OH)D), a major circulating form of vitamin D, and new-onset OSA, and examine the modifying effect of obesity. MATERIALS AND METHODS: This prospective cohort study included 444,975 participants from UK Biobank without prior OSA. The primary outcome was new-onset OSA. RESULTS: During a median follow-up duration of 12.0 years, 6051 (1.4%) participants occurred new-onset OSA. Overall, there was an inverse relation of serum 25(OH)D concentrations with the risk of new-onset OSA (per SD increment, HR, 0.92; 95%CI: 0.89-0.95). In the analysis of the interactions of serum 25(OH)D with the combination of BMI (<25, 25- < 30, and ≥30 kg/m2) and waist circumference (WC) (<90 and ≥90 cm) categories on new-onset OSA, the significantly inverse association of serum 25(OH)D and new-onset OSA was mainly found in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm (BMI 25-30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.90; 95%CI: 0.84-0.95; BMI ≥ 30 kg/m2 and WC ≥ 90 cm: per SD increment, HR, 0.85; 95%CI: 0.81-0.88), but not in other four groups with BMI < 25 kg/m2 or WC < 90 cm (P -interaction = 0.004). CONCLUSIONS: There was an inverse relation of serum 25(OH)D with the risk of new-onset OSA in participants with both BMI ≥ 25 kg/m2 and WC ≥ 90 cm. Our findings suggest the importance of maintaining a higher serum 25(OH)D concentration for primary prevention of OSA in a population with obesity.


Asunto(s)
Apnea Obstructiva del Sueño , Vitamina D , Humanos , Estudios Prospectivos , Obesidad/complicaciones , Obesidad/epidemiología , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/epidemiología , Vitaminas , Índice de Masa Corporal
14.
FASEB J ; 37(7): e23042, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37358817

RESUMEN

Patients who recover from hospital-acquired pneumonia exhibit a high incidence of end-organ dysfunction following hospital discharge, including cognitive deficits. We have previously demonstrated that pneumonia induces the production and release of cytotoxic oligomeric tau from pulmonary endothelial cells, and these tau oligomers can enter the circulation and may be a cause of long-term morbidities. Endothelial-derived oligomeric tau is hyperphosphorylated during infection. The purpose of these studies was to determine whether Ser-214 phosphorylation of tau is a necessary stimulus for generation of cytotoxic tau variants. The results of these studies demonstrate that Ser-214 phosphorylation is critical for the cytotoxic properties of infection-induced oligomeric tau. In the lung, Ser-214 phosphorylated tau contributes to disruption of the alveolar-capillary barrier, resulting in increased permeability. However, in the brain, both the Ser-214 phosphorylated tau and the mutant Ser-214-Ala tau, which cannot be phosphorylated, disrupted hippocampal long-term potentiation suggesting that inhibition of long-term potentiation was relatively insensitive to the phosphorylation status of Ser-214. Nonetheless, phosphorylation of tau is essential to its cytotoxicity since global dephosphorylation of the infection-induced cytotoxic tau variants rescued long-term potentiation. Collectively, these data demonstrate that multiple forms of oligomeric tau are generated during infectious pneumonia, with different forms of oligomeric tau being responsible for dysfunction of distinct end-organs during pneumonia.


Asunto(s)
Antineoplásicos , Neumonía , Humanos , Fosforilación , Proteínas tau/genética , Proteínas tau/metabolismo , Células Endoteliales/metabolismo , Pulmón/metabolismo
15.
Langmuir ; 40(10): 5378-5390, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38421604

RESUMEN

Montmorillonite (Mt) is a hydrophilic clay mineral with a generally high cationic exchange capacity and a remarkable swellability in water. Yet the application of Mt in cosmetics, paints, polymer nanocomposites, drug delivery systems, and tissue engineering are limited due to its unfavorable swelling and dispersion in alcohol/water mixtures. Improving the swellability and dispersibility of Mt in mixtures of ethanol and water remains challenging. Here, we showed that the swellability and dispersibility of Mt in ethanol/water could be significantly enhanced when lithium-Mt (Li-Mt) was intercalated by zwitterionic surfactant lauramidopropyl betaine (LPB). The binding mechanism of the LPB intercalate to Li-Mt originated from a combination of van der Waals forces, ion-dipole interaction, and electrostatic attraction. Due to the synergistic effect of Li+ and LPB, the comodified Mt (LPB-Li-Mt) exhibited excellent swellability, dispersibility, and rheological properties. The structure, morphology, zeta potential, dispersibility, and gel-forming performance of LPB-Li-Mt can be modulated by the concentrations of ethanol in ethanol/water mixtures. When the ethanol concentration increased to 75% v/v ethanol solution, the free swelling of LPB-Li-Mt remained above 80%. The results from X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray photoemission spectrometry, and small-angle X-ray scattering confirmed the full exfoliation of LPB-Li-Mt at 75% (v/v) ethanol solution. The formation of a stable colloidal LPB-Li-Mt dispersion in a mixture of ethanol/water might be derived from the association between water molecules and the Li+, the hydrophobic interaction, and the ion-dipole of ethanol with the LPB molecules. The findings provide a guide for improving dispersion and swelling of Mt and modified ones in water-miscible organic solvents.

16.
Mol Cell Biochem ; 479(4): 761-777, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37178376

RESUMEN

Saliva has emerged as a promising noninvasive biofluid for the diagnosis of oral and systemic diseases, including viral infections. During the coronavirus disease 2019 (COVID-19) pandemic, a growing number of studies focused on saliva-based detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Taking advantage of the WoS core collection (WoSCC) and CiteSpace, we retrieved 1021 articles related to saliva-based detection of SARS-CoV-2 and conducted a comprehensive bibliometric analysis. We analyzed countries, institutions, authors, cited authors, and cited journals to summarize their contribution and influence and analyzed keywords to explore research hotspots and trends. From 2020 to 2021, research focused on viral transmission via saliva and verification of saliva as a reliable specimen, whereas from 2021 to the present, the focus of research has switched to saliva-based biosensors for SARS-CoV-2 detection. By far, saliva has been verified as a reliable specimen for SARS-CoV-2 detection, although a standardized procedure for saliva sampling and processing is needed. Studies on saliva-based detection of SARS-CoV-2 will promote the development of saliva-based diagnostics and biosensors for viral detection. Collectively, our findings could provide valuable information to help scientists perceive the basic knowledge landscapes on saliva-based detection of SARS-CoV-2, the past and current research hotspots, and future opportunities.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiología , Saliva , Prueba de COVID-19 , Bibliometría
17.
Diabetes Obes Metab ; 26(9): 3597-3605, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38853714

RESUMEN

AIMS: To assess the relationship of longitudinal changes in fat mass (FM), lean mass (LM) and waist circumference (WC) with incident kidney outcomes in people with overweight/obesity and type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: A total of 3927 participants with baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 from the Look AHEAD (Action for Health in Diabetes) trial were included. The primary outcome was kidney outcomes, defined as a decrease in eGFR of at least 40% from baseline at follow-up visit, or end-stage kidney disease. RESULTS: During a median follow-up of 8.0 years, 450 kidney outcomes were documented after the first 1 year. In the intensive lifestyle intervention (ILI) group, reductions in FM (per 10% decrease, adjusted hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.69-0.94) and WC (per 10% decrease, adjusted HR 0.72, 95% CI 0.59-0.88) from baseline to 1-year follow-up were significantly associated with a lower risk of kidney outcomes. The change in LM was not significantly associated with risk of kidney outcomes (per 10% decrease, adjusted HR 0.78, 95% CI 0.58-1.06). In the diabetes support and education group (control group), no significant association was found between changes in body composition and kidney outcomes. Similar results were observed for the 4-year changes in body composition. CONCLUSIONS: In this post hoc analysis of the Look AHEAD trial, longitudinal declines in FM and WC were associated with a lower risk of kidney outcomes in the ILI group in participants with overweight/obesity and T2DM.


Asunto(s)
Composición Corporal , Diabetes Mellitus Tipo 2 , Tasa de Filtración Glomerular , Obesidad , Sobrepeso , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Masculino , Femenino , Persona de Mediana Edad , Obesidad/complicaciones , Obesidad/fisiopatología , Anciano , Sobrepeso/complicaciones , Sobrepeso/fisiopatología , Estudios Longitudinales , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/fisiopatología , Nefropatías Diabéticas/etiología , Circunferencia de la Cintura , Factores de Riesgo , Fallo Renal Crónico/terapia , Fallo Renal Crónico/fisiopatología , Fallo Renal Crónico/epidemiología , Estudios de Seguimiento
18.
Diabetes Obes Metab ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39161069

RESUMEN

AIM: To assess the association of intake of sugar-sweetened beverages (SSBs), artificially sweetened beverages (ASBs) and natural juices (NJs) with new-onset atrial fibrillation (AF) in people with prediabetes or diabetes. METHODS: A total of 31 433 participants with prediabetes and diabetes from the UK Biobank were included. Information on the intake of SSBs, ASBs and NJs was accessed by 24-hour dietary recalls from 2009 to 2012. The study outcome was new-onset AF. RESULTS: During a median follow-up of 12.0 years, 2470 (7.9%) AF cases were documented. Both the intake of SSBs (per 1 unit/day increment; adjusted hazard ratio [HR] = 1.11; 95% confidence interval [CI]: 1.04-1.18) and ASBs (per 1 unit/day increment; adjusted HR = 1.08; 95% CI: 1.02-1.14) were linearly and positively associated with new-onset AF, while NJ intake was not significantly associated with new-onset AF (per 1 unit/day increment; adjusted HR = 1.00; 95% CI: 0.93-1.08). Accordingly, compared with non-consumers, participants who consumed more than one unit per day of SSBs (adjusted HR = 1.30; 95% CI: 1.11-1.53) or ASBs (adjusted HR = 1.21; 95% CI:1.05-1.40) had an increased risk of AF. Substituting 1 unit/day of NJs for SSBs was associated with a 9% (adjusted HR = 0.91; 95% CI: 0.83-0.99) lower risk of new-onset AF, while replacing SSBs with ASBs was not significantly associated with new-onset AF (adjusted HR = 0.97; 95% CI: 0.89-1.06). CONCLUSIONS: Both the intake of SSBs and ASBs were linearly and positively associated with new-onset AF, while NJ intake did not show a significant association with AF in people with prediabetes or diabetes. Replacing an equivalent amount of SSB intake with NJs, but not ASBs, was associated with a lower risk of AF.

19.
BMC Gastroenterol ; 24(1): 129, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589828

RESUMEN

BACKGROUND: The HAP, Six-and-Twelve, Up to Seven, and ALBI scores have been substantiated as reliable prognostic markers in patients presenting with intermediate and advanced hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE) treatment. Given this premise, our research aims to assess the predictive efficacy of these models in patients with intermediate and advanced HCC receiving a combination of TACE and Apatinib. Additionally, we have conducted a meticulous comparative analysis of these four scoring systems to discern their respective predictive capacities and efficacies in combined therapy. METHODS: Performing a retrospective analysis on the clinical data from 200 patients with intermediate and advanced HCC, we studied those who received TACE combined with Apatinib at the First Affiliated Hospital of the University of Science and Technology of China between June 2018 and December 2022. To identify the factors affecting survival, the study performed univariate and multivariate Cox regression analyses, with calculations of four different scores: HAP, Six-and-Twelve, Up to Seven, and ALBI. Lastly, Harrell's C-index was employed to compare the prognostic abilities of these scores. RESULTS: Cox proportional hazards model results revealed that the ALBI score, presence of portal vein tumor thrombus (PVTT, )and tumor size are independent determinants of prognostic survival. The Kaplan-Meier analyses showed significant differences in survival rates among patients classified by the HAP, Six-and-Twelve, Up to Seven, and ALBI scoring methods. Of the evaluated systems, the HAP scoring demonstrated greater prognostic precision, with a Harrell's C-index of 0.742, surpassing the alternative models (P < 0.05). In addition, an analysis of the area under the AU-ROC curve confirms the remarkable superiority of the HAP score in predicting short-term survival outcomes. CONCLUSION: Our study confirms the predictive value of HAP, Six-and-Twelve, Up to Seven, and ALBI scores in intermediate to advanced Hepatocellular Carcinoma (HCC) patients receiving combined Transarterial Chemoembolization (TACE) and Apatinib therapy. Notably, the HAP model excels in predicting outcomes for this specific HCC subgroup.


Asunto(s)
Carcinoma Hepatocelular , Quimioembolización Terapéutica , Neoplasias Hepáticas , Piridinas , Humanos , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Quimioembolización Terapéutica/métodos , Estudios Retrospectivos , Pronóstico
20.
Exp Cell Res ; 424(2): 113506, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36764590

RESUMEN

After peripheral nerve injury, motor and sensory axons can regenerate, but the inaccurate reinnervation of the target leads to poor functional recovery. Schwann cells (SCs) express sensory and motor phenotypes associated with selective regeneration. Semaphorin 3A (Sema3A) is an axonal chemorepellent that plays an essential role in axon growth. SCs can secret Sema3A, and Sema3A presents a different expression pattern at the proximal and distal ends of injured sensory and motor nerves. Hence, in our study, the protein expression and secretion of Sema3A in sensory and motor SCs and the expression of its receptor Neuropilin-1 (Nrp1) in dorsal root ganglia (DRG) sensory neurons (SNs) and spinal cord motor neurons (MNs) were detected by Western blot and ELISA. The effect of Sema3A at different concentrations on neurite growth of sensory and motor neurons was observed by immunostaining. Also, by blocking the Nrp1 receptor on neurons, the effect of Sema3A on neurite growth was observed. Finally, we observed the neurite growth of sensory and motor neurons cocultured with Sema3A siRNA transfected SCs by immunostaining. The results suggested that the expression and secretion of Sema3A in sensory SCs are more significant than that in motor SCs, and the expression of its receptor Nrp1 in SNs is higher than in MNs. Sema3A could inhibit the neurite growth of sensory and motor neurons via Nrp1, and Sema3A has a more substantial effect on the neurite growth of SNs. These data provide evidence that SC-secreted Sema3A might play a role in selective regeneration by a preferential effect on SNs.


Asunto(s)
Axones , Semaforina-3A , Semaforina-3A/metabolismo , Axones/metabolismo , Neuronas Motoras/metabolismo , Médula Espinal/metabolismo , Ganglios Espinales/metabolismo , Neuropilina-1/genética , Neuropilina-1/metabolismo
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