Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 865
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Plant Cell ; 36(4): 881-898, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-37941457

RESUMEN

Double fertilization in many flowering plants (angiosperms) often occurs during the hot summer season, but the mechanisms that enable angiosperms to adapt specifically to high temperatures are largely unknown. The actin cytoskeleton is essential for pollen germination and the polarized growth of pollen tubes, yet how this process responds to high temperatures remains unclear. Here, we reveal that the high thermal stability of 11 Arabidopsis (Arabidopsis thaliana) actin-depolymerizing factors (ADFs) is significantly different: ADFs that specifically accumulate in tip-growing cells (pollen and root hairs) exhibit high thermal stability. Through ancestral protein reconstruction, we found that subclass II ADFs (expressed specifically in pollen) have undergone a dynamic wave-like evolution of the retention, loss, and regeneration of thermostable sites. Additionally, the sites of AtADF7 with high thermal stability are conserved in ADFs specific to angiosperm pollen. Moreover, the high thermal stability of ADFs is required to regulate actin dynamics and turnover at high temperatures to promote pollen germination. Collectively, these findings suggest strategies for the adaptation of sexual reproduction to high temperature in angiosperms at the cell biology level.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Factores Despolimerizantes de la Actina/metabolismo , Actinas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Temperatura , Germinación/genética , Arabidopsis/metabolismo , Polen/metabolismo , Tubo Polínico
2.
Proc Natl Acad Sci U S A ; 121(29): e2323040121, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38985761

RESUMEN

Stomata in leaves regulate gas (carbon dioxide and water vapor) exchange and water transpiration between plants and the atmosphere. SLow Anion Channel 1 (SLAC1) mediates anion efflux from guard cells and plays a crucial role in controlling stomatal aperture. It serves as a central hub for multiple signaling pathways in response to environmental stimuli, with its activity regulated through phosphorylation via various plant protein kinases. However, the molecular mechanism underlying SLAC1 phosphoactivation has remained elusive. Through a combination of protein sequence analyses, AlphaFold-based modeling and electrophysiological studies, we unveiled that the highly conserved motifs on the N- and C-terminal segments of SLAC1 form a cytosolic regulatory domain (CRD) that interacts with the transmembrane domain(TMD), thereby maintaining the channel in an autoinhibited state. Mutations in these conserved motifs destabilize the CRD, releasing autoinhibition in SLAC1 and enabling its transition into an activated state. Our further studies demonstrated that SLAC1 activation undergoes an autoinhibition-release process and subsequent structural changes in the pore helices. These findings provide mechanistic insights into the activation mechanism of SLAC1 and shed light on understanding how SLAC1 controls stomatal closure in response to environmental stimuli.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Estomas de Plantas , Transducción de Señal , Fosforilación , Estomas de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Dominios Proteicos , Mutación
3.
J Cell Sci ; 136(9)2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-37039099

RESUMEN

The width of cisternal structures in the endoplasmic reticulum (ER) is maintained by the ER-resident protein Climp63 (also known as CKAP4). Self-association of the Climp63 luminal domain (LD), even though moderate, plays a key role in shaping ER sheets. However, the molecular basis of luminal spacing remains elusive. Here, we analyzed the homotypic interactions of the Climp63 LD using deep learning-predicted structures. The LD is highly α-helical, with a flexible leading helix followed by a five-helix bundle (5HB). Charge-based trans associations were formed between the tip of the 5HB and the C-terminus of the LD, consistent with generating a width of ∼50 nm for ER sheets. The leading helix of the LD was dispensable for homotypic interactions but packing of the 5HB regulated self-association. The density of Climp63, likely reflecting the strength of cis interactions, influenced the ER width, which was maintained by trans interactions. These results indicate that a general principle in maintaining membrane tethering is multi-modular self-association.


Asunto(s)
Retículo Endoplásmico , Retículo Endoplásmico/metabolismo
4.
Plant Cell ; 34(10): 3718-3736, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-35861414

RESUMEN

Pollen tube guidance regulates the growth direction and ovule targeting of pollen tubes in pistils, which is crucial for the completion of sexual reproduction in flowering plants. The Arabidopsis (Arabidopsis thaliana) pollen-specific receptor kinase (PRK) family members PRK3 and PRK6 are specifically tip-localized and essential for pollen tube growth and guidance. However, the mechanisms controlling the polar localization of PRKs at the pollen tube tip are unclear. The Arabidopsis P4-ATPase ALA3 helps establish the polar localization of apical phosphatidylserine (PS) in pollen tubes. Here, we discovered that loss of ALA3 function caused pollen tube defects in growth and ovule targeting and significantly affected the polar localization pattern of PRK3 and PRK6. Both PRK3 and PRK6 contain two polybasic clusters in the intracellular juxtamembrane domain, and they bound to PS in vitro. PRK3 and PRK6 with polybasic cluster mutations showed reduced or abolished binding to PS and altered polar localization patterns, and they failed to effectively complement the pollen tube-related phenotypes of prk mutants. These results suggest that ALA3 influences the precise localization of PRK3, PRK6, and other PRKs by regulating the distribution of PS, which plays a key role in regulating pollen tube growth and guidance.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Adenosina Trifosfatasas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fosfatidilserinas/metabolismo , Fosfolípidos/metabolismo , Tubo Polínico , Proteínas Serina-Treonina Quinasas
5.
Nature ; 572(7769): 341-346, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31367039

RESUMEN

Salinity is detrimental to plant growth, crop production and food security worldwide. Excess salt triggers increases in cytosolic Ca2+ concentration, which activate Ca2+-binding proteins and upregulate the Na+/H+ antiporter in order to remove Na+. Salt-induced increases in Ca2+ have long been thought to be involved in the detection of salt stress, but the molecular components of the sensing machinery remain unknown. Here, using Ca2+-imaging-based forward genetic screens, we isolated the Arabidopsis thaliana mutant monocation-induced [Ca2+]i increases 1 (moca1), and identified MOCA1 as a glucuronosyltransferase for glycosyl inositol phosphorylceramide (GIPC) sphingolipids in the plasma membrane. MOCA1 is required for salt-induced depolarization of the cell-surface potential, Ca2+ spikes and waves, Na+/H+ antiporter activation, and regulation of growth. Na+ binds to GIPCs to gate Ca2+ influx channels. This salt-sensing mechanism might imply that plasma-membrane lipids are involved in adaption to various environmental salt levels, and could be used to improve salt resistance in crops.


Asunto(s)
Arabidopsis/citología , Arabidopsis/metabolismo , Señalización del Calcio , Calcio/metabolismo , Glicoesfingolípidos/metabolismo , Células Vegetales/metabolismo , Cloruro de Sodio/metabolismo , Arabidopsis/genética , Glucuronosiltransferasa/genética , Glucuronosiltransferasa/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Mutación , Estrés Salino/genética , Estrés Salino/fisiología , Cloruro de Sodio/farmacología , Intercambiadores de Sodio-Hidrógeno/metabolismo
6.
BMC Genomics ; 25(1): 485, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755540

RESUMEN

BACKGROUND: Indigenous chickens were developed through a combination of natural and artificial selection; essentially, changes in genomes led to the formation of these modern breeds via admixture events. However, their confusing genetic backgrounds include a genomic footprint regulating complex traits, which is not conducive to modern animal breeding. RESULTS: To better evaluate the candidate regions under domestication in indigenous chickens, we considered both runs of homozygosity (ROHs) and selective signatures in 13 indigenous chickens. The genomes of Silkie feather chickens presented the highest heterozygosity, whereas the highest inbreeding status and ROH number were found in Luhua chickens. Short ROH (< 1 Mb), were the principal type in all chickens. A total of 291 ROH islands were detected, and QTLdb mapping results indicated that body weight and carcass traits were the most important traits. An ROH on chromosome 2 covering VSTM2A gene was detected in 12 populations. Combined analysis with the Tajima's D index revealed that 18 genes (e.g., VSTM2A, BBOX1, and RYR2) were under selection and covered by ROH islands. Transcriptional analysis results showed that RYR2 and BBOX1 were specifically expressed in the heart and muscle tissue, respectively. CONCLUSION: Based on genome-wide scanning for ROH and selective signatures, we evaluated the genomic characteristics and detected significant candidate genes covered by ROH islands and selective signatures. The findings in this study facilitated the understanding of genetic diversity and provided valuable insights for chicken breeding and conservation strategies.


Asunto(s)
Pollos , Domesticación , Homocigoto , Animales , Pollos/genética , Selección Genética , Sitios de Carácter Cuantitativo , Genoma , Genómica/métodos , Polimorfismo de Nucleótido Simple
7.
Funct Integr Genomics ; 24(3): 79, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38653845

RESUMEN

Coronaviruses have been identified as pathogens of gastrointestinal and respiratory diseases in humans and various animal species. In recent years, the global spread of new coronaviruses has had profound influences for global public health and economies worldwide. As highly pathogenic zoonotic viruses, coronaviruses have become the focus of current research. Porcine Deltacoronavirus (PDCoV), an enterovirus belonging to the family of coronaviruses, has emerged on a global scale in the past decade and significantly influenced the swine industry. Moreover, PDCoV infects not only pigs but also other species, including humans, chickens and cattles, exhibiting a broad host tropism. This emphasizes the need for in-depth studies on coronaviruses to mitigate their potential threats. In this review, we provided a comprehensive summary of the current studies on PDCoV. We first reviewed the epidemiological investigations on the global prevalence and distribution of PDCoV. Then, we delved into the studies on the pathogenesis of PDCoV to understand the mechanisms how the virus impacts its hosts. Furthermore, we also presented some exploration studies on the immune evasion mechanisms of the virus to enhance the understanding of host-virus interactions. Despite current limitations in vaccine development for PDCoV, we highlighted the inhibitory effects observed with certain substances, which offers a potential direction for future research endeavors. In conclusion, this review summarized the scientific findings in epidemiology, pathogenesis, immune evasion mechanisms and vaccine development of PDCoV. The ongoing exploration of potential vaccine candidates and the insights gained from inhibitory substances have provided a solid foundation for future vaccine development to prevent and control diseases associated with PDCoV.


Asunto(s)
Infecciones por Coronavirus , Deltacoronavirus , Evasión Inmune , Enfermedades de los Porcinos , Vacunas Virales , Animales , Porcinos , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Infecciones por Coronavirus/epidemiología , Deltacoronavirus/patogenicidad , Deltacoronavirus/inmunología , Deltacoronavirus/genética , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/epidemiología , Vacunas Virales/inmunología , Desarrollo de Vacunas , Humanos
8.
Anal Chem ; 96(8): 3329-3334, 2024 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-38366976

RESUMEN

Simultaneous detection of the concentration variations of microRNA-221 (miRNA-221) and PTEN mRNA molecules in the PI3K/AKT signaling pathway is of significance to elucidate cancer cell migration and invasion, which is useful for cancer diagnosis and therapy. In this work, we show the biodegradable MnO2 nanosheet-assisted and target-triggered DNAzyme recycling signal amplification cascaded approach for the specific detection of the PI3K/AKT signaling pathway in live cells via simultaneous and sensitive monitoring of the variation of intracellular miRNA-221 and PTEN mRNA. Our nanoprobes enable highly sensitive and multiplexed sensing of miRNA-221 and PTEN mRNA with low detection limits of 23.6 and 0.59 pM in vitro, respectively, due to the signal amplification cascades. Importantly, the nanoprobes can be readily delivered into cancer cells and the MnO2 nanosheets can be degraded by intracellular glutathione to release the Mn2+ cofactors to trigger multiple DNAzyme recycling cycles to show highly enhanced fluorescence at different wavelengths to realize sensitive and multiplexed imaging of PTEN mRNA and miRNA-221 for detecting the PI3K/AKT signaling pathway. Moreover, the regulation of PTEN mRNA expression by miRNA-221 upon stimulation by various drugs can also be verified by our method, indicating its promising potentials for both disease diagnosis and drug screening.


Asunto(s)
ADN Catalítico , MicroARNs , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , ADN Catalítico/metabolismo , ARN Mensajero/genética , Compuestos de Manganeso , Óxidos , Transducción de Señal , Proliferación Celular
9.
Small ; 20(25): e2311056, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38377262

RESUMEN

The poor efficiency and low immunogenicity of photodynamic therapy (PDT), and the immunosuppressive tumor microenvironment (ITM) lead to tumor recurrence and metastasis. In this work, TCPP-TER-Zn@RSV nanosheets (TZR NSs) that co-assembled from the endoplasmic reticulum (ER)-targeting photosensitizer TCPP-TER-Zn nanosheets (TZ NSs for short) and the autophagy promoting and indoleamine-(2, 3)-dioxygenase (IDO) inhibitor-like resveratrol (RSV) are fabricated to enhance antitumor PDT. TZR NSs exhibit improved therapeutic efficiency and amplified immunogenic cancer cell death (ICD) by ER targeting PDT and ER autophagy promotion. TZR NSs reversed the ITM with an increase of CD8+ T cells and reduce of immunosuppressive Foxp3 regulatory T cells, which effectively burst antitumor immunity thus clearing residual tumor cells. The ER-targeting TZR NSs developed in this paper presents a simple but valuable reference for high-efficiency tumor photodynamic immunotherapy.


Asunto(s)
Autofagia , Retículo Endoplásmico , Inmunoterapia , Fotoquimioterapia , Microambiente Tumoral , Microambiente Tumoral/efectos de los fármacos , Fotoquimioterapia/métodos , Inmunoterapia/métodos , Autofagia/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Animales , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/uso terapéutico , Nanoestructuras/química , Humanos , Línea Celular Tumoral , Ratones
10.
Brief Bioinform ; 23(1)2022 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-34505138

RESUMEN

After experiencing the COVID-19 pandemic, it is widely acknowledged that a rapid drug repurposing method is highly needed. A series of useful drug repurposing tools have been developed based on data-driven modeling and network pharmacology. Based on the disease module, we identified several hub proteins that play important roles in the onset and development of the COVID-19, which are potential targets for repositioning approved drugs. Moreover, different network distance metrics were applied to quantify the relationship between drug targets and COVID-19 disease targets in the protein-protein-interaction (PPI) network and predict COVID-19 therapeutic effects of bioactive herbal ingredients and chemicals. Furthermore, the tentative mechanisms of candidates were illustrated through molecular docking and gene enrichment analysis. We obtained 15 chemical and 15 herbal ingredient candidates and found that different drugs may play different roles in the process of virus invasion and the onset and development of the COVID-19 disease. Given pandemic outbreaks, our method has an undeniable immense advantage in the feasibility analysis of drug repurposing or drug screening, especially in the analysis of herbal ingredients.


Asunto(s)
Antivirales/química , Tratamiento Farmacológico de COVID-19 , Reposicionamiento de Medicamentos , Medicamentos Herbarios Chinos/química , Simulación del Acoplamiento Molecular , Pandemias , SARS-CoV-2 , Antivirales/uso terapéutico , COVID-19/epidemiología , Medicamentos Herbarios Chinos/uso terapéutico , Humanos
11.
Appl Environ Microbiol ; 90(4): e0174323, 2024 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-38470180

RESUMEN

Soil and rhizosphere bacteria act as a rich source of secondary metabolites, effectively fighting against a diverse array of pathogens. Certain Pseudomonas species harbor biosynthetic gene clusters for producing both pyoluteorin and 2,4-diacetylphloroglucinol (2,4-DAPG), which are polyketides that exhibit highly similar antimicrobial spectrum against bacteria and fungi or oomycete. A complex cross talk exists between pyoluteorin and 2,4-DAPG biosynthesis, and production of 2,4-DAPG was strongly repressed by pyoluteorin, yet the underlying mechanism is still elusive. In this study, we find that the TetR family transcription factor PhlH is involved in the cross talk between pyoluteorin and 2,4-DAPG biosynthesis. PhlH binds to a palindromic sequence within the promoter of phlG (PphlG), which encodes a C-C bond hydrolase responsible for degrading 2,4-DAPG. As a signaling molecule, pyoluteorin disrupts the PhlH-PphlG complex by binding to PhlH, leading to decreased levels of 2,4-DAPG. Proteomics data suggest that pyoluteorin regulates multiple physiological processes including fatty acid biosynthesis and transportation of taurine, siderophore, and amino acids. Our work not only reveals a novel mechanism of cross talk between pyoluteorin and 2,4-DAPG biosynthesis, but also highlights pyoluteorin's role as a messenger in the complex communication network of Pseudomonas.IMPORTANCEAntibiosis serves as a crucial defense mechanism for microbes against invasive bacteria and resource competition. These bacteria typically orchestrate the production of multiple antibiotics in a coordinated fashion, wherein the synthesis of one antibiotic inhibits the generation of another. This strategic coordination allows the bacterium to focus its resources on producing the most advantageous antibiotic under specific circumstances. However, the underlying mechanisms of distinct antibiotic production in bacterial cells remain largely elusive. In this study, we reveal that the TetR family transcription factor PhlH detects the secondary metabolite pyoluteorin and mediates the cross talk between pyoluteorin and 2,4-DAPG biosynthesis in the biocontrol strain Pseudomonas protegens Pf-5. These findings hold promise for future research, potentially informing the manipulation of these systems to enhance the effectiveness of biocontrol agents.


Asunto(s)
Fenoles , Floroglucinol/análogos & derivados , Pseudomonas fluorescens , Pirroles , Factores de Transcripción , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación Bacteriana de la Expresión Génica , Pseudomonas/metabolismo , Antibacterianos/farmacología , Pseudomonas fluorescens/genética
12.
J Med Virol ; 96(4): e29577, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38572977

RESUMEN

Uncovering the immune response to an inactivated SARS-CoV-2 vaccine (In-Vac) and natural infection is crucial for comprehending COVID-19 immunology. Here we conducted an integrated analysis of single-cell RNA sequencing (scRNA-seq) data from serial peripheral blood mononuclear cell (PBMC) samples derived from 12 individuals receiving In-Vac compared with those from COVID-19 patients. Our study reveals that In-Vac induces subtle immunological changes in PBMC, including cell proportions and transcriptomes, compared with profound changes for natural infection. In-Vac modestly upregulates IFN-α but downregulates NF-κB pathways, while natural infection triggers hyperactive IFN-α and NF-κB pathways. Both In-Vac and natural infection alter T/B cell receptor repertoires, but COVID-19 has more significant change in preferential VJ gene, indicating a vigorous immune response. Our study reveals distinct patterns of cellular communications, including a selective activation of IL-15RA/IL-15 receptor pathway after In-Vac boost, suggesting its potential role in enhancing In-Vac-induced immunity. Collectively, our study illuminates multifaceted immune responses to In-Vac and natural infection, providing insights for optimizing SARS-CoV-2 vaccine efficacy.


Asunto(s)
COVID-19 , Humanos , COVID-19/prevención & control , Vacunas contra la COVID-19 , Leucocitos Mononucleares , FN-kappa B , SARS-CoV-2 , Vacunas de Productos Inactivados , Inmunidad , Análisis de Secuencia de ARN , Anticuerpos Antivirales
13.
Ann Surg Oncol ; 31(8): 5011-5020, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38520581

RESUMEN

BACKGROUND: Noninvasively and accurately predicting subcarinal lymph node metastasis (SLNM) for patients with non-small cell lung cancer (NSCLC) remains challenging. This study was designed to develop and validate a tumor and subcarinal lymph nodes (tumor-SLNs) dual-region computed tomography (CT) radiomics model for predicting SLNM in NSCLC. METHODS: This retrospective study included NSCLC patients who underwent lung resection and SLNs dissection between January 2017 and December 2020. The radiomic features of the tumor and SLNs were extracted from preoperative CT, respectively. Ninety machine learning (ML) models were developed based on tumor region, SLNs region, and tumor-SLNs dual-region. The model performance was assessed by the area under the curve (AUC) and validated internally by fivefold cross-validation. RESULTS: In total, 202 patients were included in this study. ML models based on dual-region radiomics showed good performance for SLNM prediction, with a median AUC of 0.794 (range, 0.686-0.880), which was superior to those of models based on tumor region (median AUC, 0.746; range, 0.630-0.811) and SLNs region (median AUC, 0.700; range, 0.610-0.842). The ML model, which is developed by using the naive Bayes algorithm and dual-region features, had the highest AUC of 0.880 (range of cross-validation, 0.825-0.937) among all ML models. The optimal logistic regression model was inferior to the optimal ML model for predicting SLNM, with an AUC of 0.727. CONCLUSIONS: The CT radiomics showed the potential for accurately predicting SLNM in NSCLC patients. The ML model with dual-region radiomic features has better performance than the logistic regression or single-region models.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Metástasis Linfática , Aprendizaje Automático , Tomografía Computarizada por Rayos X , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Carcinoma de Pulmón de Células no Pequeñas/secundario , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/cirugía , Masculino , Femenino , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Persona de Mediana Edad , Anciano , Estudios de Seguimiento , Pronóstico , Adulto , Ganglios Linfáticos/patología , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/cirugía , Anciano de 80 o más Años , Escisión del Ganglio Linfático , Neumonectomía , Radiómica
14.
J Neurol Neurosurg Psychiatry ; 95(10): 902-911, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-38503484

RESUMEN

BACKGROUND: This study aimed to investigate the efficacy of circuits-based paired associative stimulation (PAS) in adults with amnestic mild cognitive impairment (aMCI). METHODS: We conducted a parallel-group, randomised, controlled clinical trial. Initially, a cohort of healthy subjects was recruited to establish the cortical-hippocampal circuits by tracking white matter fibre connections using diffusion tensor imaging. Subsequently, patients diagnosed with aMCI, matched for age and education, were randomly allocated in a 1:1 ratio to undergo a 2-week intervention, either circuit-based PAS or sham PAS. Additionally, we explored the relationship between changes in cognitive performance and the functional connectivity (FC) of cortical-hippocampal circuits. RESULTS: FCs between hippocampus and precuneus and between hippocampus and superior frontal gyrus (orbital part) were most closely associated with the Auditory Verbal Learning Test (AVLT)_N5 score in 42 aMCI patients, thus designated as target circuits. The AVLT_N5 score improved from 2.43 (1.43) to 5.29 (1.98) in the circuit-based PAS group, compared with 2.52 (1.44) to 3.86 (2.39) in the sham PAS group (p=0.003; Cohen's d=0.97). A significant decrease was noted in FC between the left hippocampus and left precuneus in the circuit-based PAS group from baseline to postintervention (p=0.013). Using a generalised linear model, significant group×FC interaction effects for the improvements in AVLT_N5 scores were found within the circuit-based PAS group (B=3.4, p=0.017). CONCLUSIONS: Circuit-based PAS effectively enhances long-term delayed recall in adults diagnosed with aMCI, which includes individuals aged 50-80 years. This enhancement is potentially linked to the decreased functional connectivity between the left hippocampus and left precuneus. TRIAL REGISTRATION NUMBER: ChiCTR2100053315; Chinese Clinical Trial Registry.


Asunto(s)
Amnesia , Disfunción Cognitiva , Hipocampo , Recuerdo Mental , Humanos , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/terapia , Masculino , Femenino , Anciano , Hipocampo/diagnóstico por imagen , Hipocampo/fisiopatología , Recuerdo Mental/fisiología , Amnesia/fisiopatología , Amnesia/diagnóstico por imagen , Amnesia/terapia , Imagen de Difusión Tensora , Persona de Mediana Edad , Pruebas Neuropsicológicas
15.
Cerebellum ; 23(5): 1867-1881, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38472628

RESUMEN

Responding to burst stimulation of parallel fibers (PFs), cerebellar Purkinje neurons (PNs) generate a convolved synaptic response displaying a fast excitatory postsynaptic current (EPSCFast) followed by a slow EPSC (EPSCSlow). The latter is companied with a rise of intracellular Ca2+ and critical for motor coordination. The genesis of EPSCSlow in PNs results from activation of metabotropic type 1 glutamate receptor (mGluR1), oligomerization of stromal interaction molecule 1 (STIM1) on the membrane of endoplasmic reticulum (ER) and opening of transient receptor potential canonical 3 (TRPC3) channels on the plasma membrane. Neuronal nitric oxide synthase (nNOS) is abundantly expressed in PFs and granule neurons (GNs), catalyzing the production of nitric oxide (NO) hence regulating PF-PN synaptic function. We recently found that nNOS/NO regulates the morphological development of PNs through mGluR1-regulated Ca2+-dependent mechanism. This study investigated the role of nNOS/NO in regulating EPSCSlow. Electrophysiological analyses showed that EPSCSlow in cerebellar slices of nNOS knockout (nNOS-/-) mice was significantly larger than that in wildtype (WT) mice. Activation of mGluR1 in cultured PNs from nNOS-/- mice evoked larger TRPC3-channel mediated currents and intracellular Ca2+ rise than that in PNs from WT mice. In addition, nNOS inhibitor and NO-donor increased and decreased, respectively, the TRPC3-current and Ca2+ rise in PNs. Moreover, the NO-donor effectively decreased TRPC3 currents in HEK293 cells expressing WT STIM1, but not cells expressing a STIM1 with cysteine mutants. These novel findings indicate that nNOS/NO inhibits TRPC3-containig channel mediated cation influx during EPSCSlow, at least in part, by S-nitrosylation of STIM1.


Asunto(s)
Cerebelo , Potenciales Postsinápticos Excitadores , Óxido Nítrico Sintasa de Tipo I , Células de Purkinje , Molécula de Interacción Estromal 1 , Canales Catiónicos TRPC , Animales , Humanos , Ratones , Cerebelo/metabolismo , Cerebelo/citología , Potenciales Postsinápticos Excitadores/fisiología , Células HEK293 , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Óxido Nítrico Sintasa de Tipo I/genética , Células de Purkinje/metabolismo , Células de Purkinje/fisiología , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/genética , Molécula de Interacción Estromal 1/metabolismo , Molécula de Interacción Estromal 1/genética , Canales Catiónicos TRPC/metabolismo , Canales Catiónicos TRPC/genética
16.
Langmuir ; 40(31): 16538-16548, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39041610

RESUMEN

The theory of heat conduction paths has been widely recognized and widely studied in the research about the thermal conductivity of thermal conductive polymer composites at present. Encapsulating polymer pellets with thermally conductive fillers and processing them into thermally conductive polymer composites is a simple and effective method for constructing heat conduction paths. It is meaningful to investigate the related heat conduction mechanism of this method. Otherwise, this approach can significantly preserve the performance of the polymer substrate, making it highly valuable for practical material applications. In this work, polyethylene-octene elastomer (POE) pellets were encapsulated with thermal conductive fillers by physical absorption. Subsequently, the composite films containing heat conduction paths were fabricated using the encapsulated POE pellets through a heating press. Alumina (Al2O3), boron nitride (BN), and alumina/boron nitride hybrid (Al2O3/BN) fillers were used to prepare Al2O3@POE, BN@POE, and BN/Al2O3@POE composite films to investigate the influence of filler shapes on heat conduction path construction. The influence of the constitute and density of heat conduction paths on the thermal conductivity of composite films was analyzed by infrared thermal imaging, finite element analysis, and thermal resistance theory in detail. Owing to the reserved good adhesion and flexibility of the POE substrate, the composite films could be directly used as thermal interface materials for chip cooling, which presented a good heat dissipation effect. Furthermore, a series of integrated composite materials were prepared by the combination of encapsulated pellets with various functional films (copper foil, aluminum foil, and graphite sheet) through a one-pot heating press, exhibiting a good electromagnetic shielding effect. The performance of the composites and the corresponding preparation method demonstrate the strong significance of this research for practical applications.

17.
Analyst ; 149(2): 451-456, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38099654

RESUMEN

The aberrant expression of microRNAs (miRs) in cells is closely linked to the initiation and progression of various diseases. Sensitive monitoring of their level is hence vital for biomedical research and disease diagnosis. Herein, a highly sensitive and non-label fluorescence sensor based on multiple recycling signal amplification cascades is constructed for the detection of miR-21 in human sera. The presence of miR-21 initiates the primer-fueled target recycling process for the generation of many primer/hairpin templates for the subsequent auto-cycling primer extension (APE) amplification cycles, which result in the formation of lots of long-stem hairpins. The enzyme-based cleavage of such hairpins via polymerization/excision cycles further leads to the generation of abundant G-quadruplex strands, which associate with the thioflavin T (ThT) dye to emit remarkably magnified fluorescence for detecting miR-21 in the range of 1 pM-100 nM with a 0.32 pM detection limit without labeling the probes. Besides, the proposed assay can selectively discriminate miR-21 against other control molecules and realize the sensing of low levels of miR-21 in diluted sera. With features of high sensitivity via the triplex signal amplification cycles and simplicity in a non-label homogeneous manner, our miR sensing protocol can be a robust means for detecting various nucleic acids for the early diagnosis of diseases.


Asunto(s)
Técnicas Biosensibles , G-Cuádruplex , MicroARNs , Humanos , MicroARNs/genética , Límite de Detección , Espectrometría de Fluorescencia/métodos , Técnicas Biosensibles/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos
18.
BMC Infect Dis ; 24(1): 1111, 2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39375610

RESUMEN

BACKGROUND: Quality assessment of the prevalence and distribution of human papillomavirus (HPV) genotypes could support additional targeted HPV vaccinations. However, the characteristics of HPV infection in Wuhan city are limited in the past decade. We aimed to assess the epidemiology of HPV infection among women and provide a reference for the prevention and treatment of cervical cancer in this region. METHODS: A retrospective study employing 105,679 women attending Wuhan Medical and Health Center for Women and Children for cervical cancer screening from January 2015 to December 2022 was conducted. The HPV genotype was detected by polymerase chain reaction (PCR) and diversion hybridization. The overall incidence and age-specific type distribution of HPV infection and the relationship between HPV infection and cervical cytology were analyzed. RESULTS: The overall HPV infection rate was 16.87% in Wuhan city, and the prevalence rates of high-risk, low-risk and mixed high- and low-risk HPV infections were 13.64%, 1.77% and 1.46%, respectively. The five most prevalent genotypes were HPV52 (4.24%), HPV58 (2.42%), HPV16 (2.34%), HPV53 (1.87%), and HPV39 (1.66%). The prevalence of HPV in women exhibited a "two-peak" pattern, the peaks of which were observed in the < 21 years group (37.4%) and the 61-65 years group (41.72%). Logistic regression analysis revealed no significant difference in the rate of high-grade lesion positivity between single and multiple high-risk HPV infections. Among patients with a high-grade squamous intraepithelial lesion+ (HSIL+) ThinPrep cytologic test (TCT) diagnosis, HPV58 was the most common type, followed by HPV52, HPV16, HPV39 and HPV53. CONCLUSIONS: HPV types 52, 58, 16, 53, and 39 were the most common types in the general female population in Wuhan, and the prevalence of HPV infection varied among different age groups. This study provides a comprehensive overview of the epidemiological characteristics of HPV infection in women, which could support the development of targeted prevention and control strategies for cervical cancer in the region.


Asunto(s)
Genotipo , Papillomaviridae , Infecciones por Papillomavirus , Humanos , Femenino , China/epidemiología , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Adulto , Persona de Mediana Edad , Estudios Retrospectivos , Prevalencia , Adulto Joven , Papillomaviridae/genética , Papillomaviridae/clasificación , Papillomaviridae/aislamiento & purificación , Anciano , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología , Incidencia , Adolescente
19.
Anal Bioanal Chem ; 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39482386

RESUMEN

ß-Lactoglobulin (ß-Lg) is a prevalent allergenic protein found in most dairy products, which poses great food safety risks for individuals with allergies, especially for infants. Sensitive and effective detection methods for such allergens are essential to reduce the risk of allergies in daily life. Herein, a fluorescent aptamer bioassay based on a dual and cyclic bidirectional strand displacement means is developed for the sensitive detection of ß-Lg in infant rice porridge and milk. The aptamer in the duplex DNA probe binds ß-Lg to release the assistance strand to further hybridize with two hairpins, which triggers the initiation of two cyclic amplification cycles through the polymerization, displacement, and nicking of the strands under the action of DNA polymerase and endonuclease restriction enzymes. The amplification cycles lead to the unfolding of many fluorescently quenched signal probes to exhibit substantially enhanced fluorescence recovery for detecting ß-Lg. The assay can realize detection of ß-Lg in concentrations as low as 4.41 pM within the range of 0.01 to 10 nM. Furthermore, our sensing method has the capability to discriminate ß-Lg from other proteins with high selectivity, resulting in low levels of ß-Lg detection in rice porridge and milk samples, demonstrating promising potentials of the developed sensing method for monitoring various food allergens.

20.
Macromol Rapid Commun ; 45(14): e2400064, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38594967

RESUMEN

Polyethylene (PE), a highly prevalent non-biodegradable polymer in the field of plastics, presents a waste management issue. To alleviate this issue, bio-based PE (bio-PE), derived from renewable resources like corn and sugarcane, offers an environmentally friendly alternative. This review discusses various production methods of bio-PE, including fermentation, gasification, and catalytic conversion of biomass. Interestingly, the bio-PE production volumes and market are expanding due to the growing environmental concerns and regulatory pressures. Additionally, the production of PE and bio-PE biocomposites using agricultural waste as filler materials, highlights the growing demand for sustainable alternatives to conventional plastics. According to previous studies, addition of ≈50% defibrillated corn and abaca fibers into bio-PE matrix and a compatibilizer, results in the highest Young's modulus of 4.61 and 5.81 GPa, respectively. These biocomposites have potential applications in automotive, building construction, and furniture industries. Moreover, the advancement made in abiotic and biotic degradation of PE and PE biocomposites is elucidated to address their environmental impacts. Finally, the paper concludes with insights into the opportunities, challenges, and future perspectives in the sustainable production and utilization of PE and bio-PE biocomposites. In summary, production of PE and bio-PE biocomposites can contribute to a cleaner and sustainable future.


Asunto(s)
Polietileno , Polietileno/química , Biomasa , Fermentación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA