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1.
Cell ; 184(3): 689-708.e20, 2021 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-33482083

RESUMEN

The most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is a GGGGCC repeat expansion in the C9orf72 gene. We developed a platform to interrogate the chromatin accessibility landscape and transcriptional program within neurons during degeneration. We provide evidence that neurons expressing the dipeptide repeat protein poly(proline-arginine), translated from the C9orf72 repeat expansion, activate a highly specific transcriptional program, exemplified by a single transcription factor, p53. Ablating p53 in mice completely rescued neurons from degeneration and markedly increased survival in a C9orf72 mouse model. p53 reduction also rescued axonal degeneration caused by poly(glycine-arginine), increased survival of C9orf72 ALS/FTD-patient-induced pluripotent stem cell (iPSC)-derived motor neurons, and mitigated neurodegeneration in a C9orf72 fly model. We show that p53 activates a downstream transcriptional program, including Puma, which drives neurodegeneration. These data demonstrate a neurodegenerative mechanism dynamically regulated through transcription-factor-binding events and provide a framework to apply chromatin accessibility and transcription program profiles to neurodegeneration.


Asunto(s)
Proteína C9orf72/metabolismo , Expansión de las Repeticiones de ADN/genética , Degeneración Nerviosa/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Axones/metabolismo , Proteína C9orf72/genética , Muerte Celular , Células Cultivadas , Corteza Cerebral/patología , Cromatina/metabolismo , Daño del ADN , Modelos Animales de Enfermedad , Drosophila , Ratones Endogámicos C57BL , Degeneración Nerviosa/patología , Estabilidad Proteica , Transcripción Genética , Proteínas Supresoras de Tumor/metabolismo
3.
PLoS Biol ; 21(3): e3002028, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36930682

RESUMEN

A major function of TAR DNA-binding protein-43 (TDP-43) is to repress the inclusion of cryptic exons during RNA splicing. One of these cryptic exons is in UNC13A, a genetic risk factor for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The accumulation of cryptic UNC13A in disease is heightened by the presence of a risk haplotype located within the cryptic exon itself. Here, we revealed that TDP-43 extreme N-terminus is important to repress UNC13A cryptic exon inclusion. Further, we found hnRNP L, hnRNP A1, and hnRNP A2B1 bind UNC13A RNA and repress cryptic exon inclusion, independently of TDP-43. Finally, higher levels of hnRNP L protein associate with lower burden of UNC13A cryptic RNA in ALS/FTD brains. Our findings suggest that while TDP-43 is the main repressor of UNC13A cryptic exon inclusion, other hnRNPs contribute to its regulation and may potentially function as disease modifiers.


Asunto(s)
Esclerosis Amiotrófica Lateral , Demencia Frontotemporal , Ribonucleoproteína Heterogénea-Nuclear Grupo L , Humanos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Exones/genética , Demencia Frontotemporal/genética , Ribonucleoproteínas Nucleares Heterogéneas/genética , ARN , Proteínas del Tejido Nervioso/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(48): e2210532119, 2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36409902

RESUMEN

A hexanucleotide repeat expansion in intron 1 of the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia, or c9ALS/FTD. The RNA transcribed from the expansion, r(G4C2)exp, causes various pathologies, including intron retention, aberrant translation that produces toxic dipeptide repeat proteins (DPRs), and sequestration of RNA-binding proteins (RBPs) in RNA foci. Here, we describe a small molecule that potently and selectively interacts with r(G4C2)exp and mitigates disease pathologies in spinal neurons differentiated from c9ALS patient-derived induced pluripotent stem cells (iPSCs) and in two c9ALS/FTD mouse models. These studies reveal a mode of action whereby a small molecule diminishes intron retention caused by the r(G4C2)exp and allows the liberated intron to be eliminated by the nuclear RNA exosome, a multi-subunit degradation complex. Our findings highlight the complexity of mechanisms available to RNA-binding small molecules to alleviate disease pathologies and establishes a pipeline for the design of brain penetrant small molecules targeting RNA with novel modes of action in vivo.


Asunto(s)
Exosomas , Demencia Frontotemporal , Animales , Ratones , Demencia Frontotemporal/metabolismo , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , ARN/genética , Exosomas/metabolismo , Barrera Hematoencefálica/metabolismo , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Encéfalo/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , ARN Nuclear
5.
Proc Natl Acad Sci U S A ; 119(49): e2123487119, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36454749

RESUMEN

Hexanucleotide G4C2 repeat expansions in the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Dipeptide repeat proteins (DPRs) generated by translation of repeat-containing RNAs show toxic effects in vivo as well as in vitro and are key targets for therapeutic intervention. We generated human antibodies that bind DPRs with high affinity and specificity. Anti-GA antibodies engaged extra- and intra-cellular poly-GA and reduced aggregate formation in a poly-GA overexpressing human cell line. However, antibody treatment in human neuronal cultures synthesizing exogenous poly-GA resulted in the formation of large extracellular immune complexes and did not affect accumulation of intracellular poly-GA aggregates. Treatment with antibodies was also shown to directly alter the morphological and biochemical properties of poly-GA and to shift poly-GA/antibody complexes to more rapidly sedimenting ones. These alterations were not observed with poly-GP and have important implications for accurate measurement of poly-GA levels including the need to evaluate all centrifugation fractions and disrupt the interaction between treatment antibodies and poly-GA by denaturation. Targeting poly-GA and poly-GP in two mouse models expressing G4C2 repeats by systemic antibody delivery for up to 16 mo was well-tolerated and led to measurable brain penetration of antibodies. Long-term treatment with anti-GA antibodies produced improvement in an open-field movement test in aged C9orf72450 mice. However, chronic administration of anti-GA antibodies in AAV-(G4C2)149 mice was associated with increased levels of poly-GA detected by immunoassay and did not significantly reduce poly-GA aggregates or alleviate disease progression in this model.


Asunto(s)
Genes Reguladores , Poli A , Animales , Humanos , Ratones , Complejo Antígeno-Anticuerpo , Proteína C9orf72/genética , Dipéptidos , Modelos Animales de Enfermedad
6.
New Phytol ; 241(5): 2059-2074, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38197218

RESUMEN

Thermo-sensitive genic male sterile (TGMS) lines are the core of two-line hybrid rice (Oryza sativa). However, elevated or unstable critical sterility-inducing temperatures (CSITs) of TGMS lines are bottlenecks that restrict the development of two-line hybrid rice. However, the genes and molecular mechanisms controlling CSIT remain unknown. Here, we report the CRITICAL STERILITY-INDUCING TEMPERATURE 2 (CSIT2) that encodes a really interesting new gene (RING) type E3 ligase, controlling the CSIT of thermo-sensitive male sterility 5 (tms5)-based TGMS lines through ribosome-associated protein quality control (RQC). CSIT2 binds to the large and small ribosomal subunits and ubiquitinates 80S ribosomes for dissociation, and may also ubiquitinate misfolded proteins for degradation. Mutation of CSIT2 inhibits the possible damage to ubiquitin system and protein translation, which allows more proteins such as catalases to accumulate for anther development and inhibits abnormal accumulation of reactive oxygen species (ROS) and premature programmed cell death (PCD) in anthers, partly rescuing male sterility and raised the CSIT of tms5-based TGMS lines. These findings reveal a mechanism controlling CSIT and provide a strategy for solving the elevated or unstable CSITs of tms5-based TGMS lines in two-line hybrid rice.


Asunto(s)
Infertilidad Masculina , Oryza , Masculino , Humanos , Temperatura , Oryza/genética , Ubiquitina , Ubiquitina-Proteína Ligasas/genética , Infertilidad Vegetal/genética
7.
Chemistry ; : e202401909, 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38972837

RESUMEN

Modulating the assembly pathway is an indispensable strategy for optimizing the performance of optical materials. However, implementing this strategy is nontrivial for metal nanocluster building blocks, due to the limited functional modification of nanoclusters and complexity of their emission mechanism. In this report, we demonstrate that a gold nanocluster modified by 4,6-diamino-2-pyrimidinethiol (DPT-AuNCs) self-assembles into two distinct aggregation structures in methanol (MeOH)/water mixed solvent, thus exhibiting pathway complexity. Kinetic studies show that DPT-AuNCs firstly assembles into non-luminescent nanofibers (kinetically controlled), which further transforms into strongly luminescent microflowers (thermodynamicallycontrolled). In-depth analysis of the assembly mechanism reveals that the transformation of aggregation structures involves the disassembly of nanofibers and a subsequent nucleation-growth process. Temperature-dependent photoluminescence (PL) spectroscopy and infrared (IR) measurements reveal that inter-cluster hydrogen bonding bridged by solvent molecules and C-H···π interaction are the key factors for emission enhancement. The photoluminescent property of DPT-AuNCs can be controlled by varying the cosolvent in water, enabling DPT-AuNCs to distinguish different kind of alcohols, particularly the isomerism n-propanol (NPA) and isopropanol (IPA). Additionally, he addition of seeds effectively regulate the assembly kinetics of DPT-AuNCs. This study advances our understanding of assembly pathways and improves the luminescent performance of nanoclusters (NCs).

8.
Biomacromolecules ; 25(5): 3190-3199, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38693753

RESUMEN

Intracellular bacteria in dormant states can escape the immune response and tolerate high-dose antibiotic treatment, leading to severe infections. To overcome this challenge, cascade-targeted nanoplatforms that can target macrophages and intracellular bacteria, exhibiting synergetic antibiotic/reactive oxygen species (ROS)/nitric oxide (NO)/immunotherapy, were developed. These nanoplatforms were fabricated by encapsulating trehalose (Tr) and vancomycin (Van) into phosphatidylserine (PS)-coated poly[(4-allylcarbamoylphenylboric acid)-ran-(arginine-methacrylamide)-ran-(N,N'-bisacryloylcystamine)] nanoparticles (PABS), denoted as PTVP. PS on PTVP simulates a signal of "eat me" to macrophages to promote cell uptake (the first-step targeting). After the uptake, the nanoplatform in the acidic phagolysosomes could release Tr, and the exposed phenylboronic acid on the nanoplatform could target bacteria (the second-step targeting). Nanoplatforms can release Van in response to infected intracellular overexpressed glutathione (GSH) and weak acid microenvironment. l-arginine (Arg) on the nanoplatforms could be catalyzed by upregulated inducible nitric oxide synthase (iNOS) in the infected macrophages to generate nitric oxide (NO). N,N'-Bisacryloylcystamine (BAC) on nanoplatforms could deplete GSH, allow the generation of ROS in macrophages, and then upregulate proinflammatory activity, leading to the reinforced antibacterial capacity. This nanoplatform possesses macrophage and bacteria-targeting antibiotic delivery, intracellular ROS, and NO generation, and pro-inflammatory activities (immunotherapy) provides a new strategy for eradicating intracellular bacterial infections.


Asunto(s)
Antibacterianos , Nanopartículas , Óxido Nítrico , Especies Reactivas de Oxígeno , Especies Reactivas de Oxígeno/metabolismo , Óxido Nítrico/metabolismo , Antibacterianos/farmacología , Antibacterianos/química , Ratones , Animales , Células RAW 264.7 , Nanopartículas/química , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/inmunología , Inmunoterapia/métodos , Vancomicina/farmacología , Vancomicina/química , Vancomicina/administración & dosificación , Infecciones Bacterianas/tratamiento farmacológico , Trehalosa/química , Trehalosa/farmacología
9.
Mol Biol Rep ; 51(1): 166, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38252343

RESUMEN

BACKGROUND: Genomic imprinting refers to expressing parent-specific genes in mammalian diploid cells. The NDN gene is maternally imprinted in humans and mice and correlates with the timing of puberty. This study aimed to investigate its imprinting status and its relationship with the onset of puberty in Dolang sheep. METHODS AND RESULTS: In this study, cloning and sequencing obtained the NDN gene cDNA sequence of 1082 bp of Dolang sheep, coding for 325 amino acids. Similarity analysis and phylogenetic tree showed that the NDN gene conformed to the law of speciation and was highly conserved among mammals. RT-qPCR results showed the highest expression of NDN mRNA was found in the hypothalamus at puberty, and the expression was significantly increased and then significantly decreased from prepuberty to postpuberty in the hypothalamus, pituitary, and ovary and oviduct. Based on expressed single nucleotide polymorphism (SNP), the NDN gene was expressed monoallelically in the tissues of adult and neonatal umbilical cords, and the expressed allele was paternally inherited. The NDN promoter region of 3400 bp was obtained by cloning and identified in monoallelic-expressing tissues (hypothalamus, ovary, spleen) as a differentially methylated region (DMR). CONCLUSION: These findings will enrich the number of imprinted genes in sheep and suggest that the NDN gene could be a candidate gene for studying puberty initiation in Dolang sheep.


Asunto(s)
Aminoácidos , Genes cdc , Animales , Femenino , Alelos , Clonación Molecular , Filogenia , Ovinos/genética
10.
Pestic Biochem Physiol ; 201: 105856, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38685238

RESUMEN

Plutella xylostella is an important pest showing resistance to various chemical pesticides, development of botanical pesticides is an effective strategy to resolve above problem and decrease utilization of chemical pesticides. Previous study showed that 2,3-dimethyl-6-(1-hydroxy)-pyrazine has significant repellent activity to P. xylostella adult which mainly effect to the olfactory system, however the molecular targets and mechanism are still unclear. Based on the RNA-Seq and RT-qPCR data, eight ORs (Odorant receptor) in P. xylostella were selected as candidate targets response to repellent activity of 2,3-dimethyl-6-(1-hydroxy)-pyrazine. Here, most of the ORs in P. xylostella were clustered into three branches, which showed similar functions such as recognition, feeding, and oviposition. PxylOR29, PxylOR31, and PxylOR46 were identified as the potential molecular targets based on the results of repellent activity and EAG response tests to the adults which have been injected with dsRNA, respectively. Additionally, the three ORs were higher expressed in antenna of P. xylostella, followed by those in the head segment. Furthermore, it was found that the bindings between these three ORs and 2,3-dimethyl-6-(1-hydroxy)-pyrazine mainly depend on the hydrophobic effect of active cavities, and the binding to PxylOR31 was more stabler and easier with an energy of -16.34 kcal/mol, together with the π-π T-shaped interaction at PHE195 site. These findings pave the way for the complete understanding of pyrazine repellent mechanisms.


Asunto(s)
Repelentes de Insectos , Mariposas Nocturnas , Pirazinas , Receptores Odorantes , Animales , Receptores Odorantes/metabolismo , Receptores Odorantes/genética , Pirazinas/farmacología , Repelentes de Insectos/farmacología , Mariposas Nocturnas/efectos de los fármacos , Mariposas Nocturnas/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética
11.
J Adv Nurs ; 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38712473

RESUMEN

AIMS: This study aims to investigate the epidemiological characteristics of COVID-19 infection among healthcare workers, including the severity, duration of infection, post-infection symptoms and related influencing factors. METHODS: A self-administered questionnaire was utilized to assess the post-infection status of primary healthcare workers in Jiangsu Province. The questionnaire collected information on demographic characteristics, lifestyle habits, post-infection clinical manifestations, work environment and recovery time of the respondents. Customized outcome events were selected as dependent variables and logistic regression models were employed to analyse the risk factors. Phi-coefficient was used to describe the relationship between post-infection symptoms. RESULTS: The analysis revealed that several factors, such as female, older age, obesity, previous medical history, exposure to high-risk environments and stress, were associated with a higher likelihood of experiencing more severe outcomes. On the other hand, vaccination and regular exercise were found to contribute to an earlier resolution of the infection. Among the post-infection symptoms, cough, malaise and muscle aches were the most frequently reported. Overall, there was a weak association among symptoms persisting beyond 14 days, with only cough and malaise, malaise and dizziness and headache showing a stronger correlation. CONCLUSION: The study findings indicate that the overall severity of the first wave of infection, following the complete lifting of restrictions in China, was low. The impact on primary healthcare workers was limited, and the post-infection symptoms exhibited similarity to those observed in other countries. It is important to highlight that these conclusions are specifically relevant to the population infected with the Omicron variant. IMPACTS: This study helps to grasp the impacts of the first wave of COVID-19 infections on healthcare workers in China after the national lockdown was lifted. PATIENTS: Primary healthcare workers in Jiangsu Province, including doctors, nurses, pharmacists and other personnel from primary healthcare units such as community health service centres and health centres.

12.
Drug Metab Dispos ; 51(6): 771-781, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36863865

RESUMEN

Icaritin (ICT) is a prenylflavonoid derivative that has been approved by National Medical Products Administration for the treatment of hepatocellular carcinoma. This study aims to evaluate the potential inhibitory effect of ICT against cytochrome P450 (CYP) enzymes and to elucidate the inactivation mechanisms. Results showed that ICT inactivated CYP2C9 in a time-, concentration-, and NADPH-dependent manner with Ki = 1.896 µM, Kinact = 0.02298 minutes-1, and Kinact/Ki = 12 minutes-1 mM-1, whereas the activities of other CYP isozymes was minimally affected. Additionally, the presence of CYP2C9 competitive inhibitor, sulfaphenazole, superoxide dismutase/catalase system, and GSH all protected CYP2C9 from ICT-induced activity loss. Moreover, the activity loss was neither recovered by washing the ICT-CYP2C9 preincubation mixture nor the addition of potassium ferricyanide. These results, collectively, implied the underlying inactivation mechanism involved the covalent binding of ICT to the apoprotein and/or the prosthetic heme of CYP2C9. Furthermore, an ICT-quinone methide (QM)-derived GSH adduct was identified, and human glutathione S-transferases (GST) isozymes GSTA1-1, GSTM1-1, and GSTP1-1 were shown to be substantially involved in the detoxification of ICT-QM. Interestingly, our systematic molecular modeling work predicted that ICT-QM was covalently bound to C216, a cysteine residue located in the F-G loop downstream of substrate recognition site (SRS) 2 in CYP2C9. The sequential molecular dynamics simulation confirmed the binding to C216 induced a conformational change in the active catalytic center of CYP2C9. Lastly, the potential risks of clinical drug-drug interactions triggered by ICT as a perpetrator were extrapolated. In summary, this work confirmed that ICT was an inactivator of CYP2C9. SIGNIFICANCE STATEMENT: This study is the first to report the time-dependent inhibition of CYP2C9 by icaritin (ICT) and the intrinsic molecular mechanism behind it. Experimental data indicated that the inactivation was via irreversible covalent binding of ICT-quinone methide to CYP2C9, while molecular modeling analysis provided additional evidence by predicting C216 as the key binding site which influenced the structural confirmation of CYP2C9's catalytic center. These findings suggest the potential of drug-drug interactions when ICT is co-administered with CYP2C9 substrates clinically.


Asunto(s)
Sistema Enzimático del Citocromo P-450 , Isoenzimas , Humanos , Citocromo P-450 CYP2C9 , Sistema Enzimático del Citocromo P-450/metabolismo
13.
Opt Lett ; 48(18): 4781-4784, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37707901

RESUMEN

Slow light devices have significant applications in memory, switching, and quantum optics. However, the design and fabrication of slow light devices with large tunable group delay are still challenging. Here, a graphene-based slow light device that can electrically modulate the group delay of terahertz (THz) waves is proposed and experimentally demonstrated. The unit cell of the device consists of a U-shaped metal resonator and an Ω-shaped metal resonator, with three graphene ribbons embedded between the two resonators. Under electrical stimuli, a relatively high amplitude modulation depth of 74% is achieved and the maximum transmission amplitude is as high as 0.7 at the transmission peak of 0.6 THz. Most importantly, the maximum group delay variation reaches 5 ps at 0.76 THz and the maximum group delay amplitude is as high as 8.8 ps. The experiment shows good agreement with simulation. This study paves a new way for developing novel switchable nanophotonic devices and slow light devices.

14.
Chem Res Toxicol ; 36(9): 1483-1494, 2023 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-37622730

RESUMEN

Genipin (GP) is the reactive aglycone of geniposide, the main component of traditional Chinese medicine Gardeniae Fructus (GF). The covalent binding of GP to cellular proteins is suspected to be responsible for GF-induced hepatotoxicity and inhibits drug-metabolizing enzyme activity, although the mechanisms remain to be clarified. In this study, the mechanisms of GP-induced human hepatic P450 inactivation were systemically investigated. Results showed that GP inhibited all tested P450 isoforms via distinct mechanisms. CYP2C19 was directly and irreversibly inactivated without time dependency. CYP1A2, CYP2C9, CYP2D6, and CYP3A4 T (testosterone as substrate) showed time-dependent and mixed-type inactivation, while CYP2B6, CYP2C8, and CYP3A4 M (midazolam as substrate) showed time-dependent and irreversible inactivation. For CYP3A4 inactivation, the kinact/KI values in the presence or absence of NADPH were 0.26 or 0.16 min-1 mM-1 for the M site and 0.62 or 0.27 min-1 mM-1 for the T site. Ketoconazole and glutathione (GSH) both attenuated CYP3A4 inactivation, suggesting an active site occupation- and reactive metabolite-mediated inactivation mechanism. Moreover, the in vitro and in vivo formation of a P450-dependent GP-S-GSH conjugate indicated the involvement of metabolic activation and thiol residues binding in GP-induced enzyme inactivation. Lastly, molecular docking analysis simulated potential binding sites and modes of GP association with CYP2C19 and CYP3A4. We propose that direct covalent binding and metabolic activation mediate GP-induced P450 inactivation and alert readers to potential risk factors for GP-related clinical drug-drug interactions.


Asunto(s)
Citocromo P-450 CYP3A , Gardenia , Humanos , Citocromo P-450 CYP2C19 , Simulación del Acoplamiento Molecular , Sistema Enzimático del Citocromo P-450
15.
Langmuir ; 39(37): 13316-13324, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37682809

RESUMEN

The construction of macroscopic chiral luminescent aggregates with well-defined structures not only contributes to the development of functional materials but also has significant implications for analyzing chiral transfer and amplification in biological systems and self-assembly systems. Meanwhile, achieving water-soluble chiral metal nanoclusters (NCs) with high photoluminescence (PL) intensity through a convenient method remains a challenge. Herein, we reported the enhanced luminescence of gold nanoclusters stabilized by D-/L-penicillamine (D-/L-AuNCs) induced by poly(allylamine hydrochloride) (PAH) through supramolecular self-assembly strategies. FT-IR spectra and zeta potential measurements revealed that supramolecular assembly was driven by the synergistic effect of hydrogen bonds and electrostatic interactions, which effectively limited the intramolecular vibration and rotation of the ligand and reduced nonradiative relaxation, thus improving the luminescence properties of nanoclusters. Interestingly, during the slow solvent evaporation process, chiral entanglement of assemblies was enhanced, forming macroscopic wheat-shaped superstructures. This study enriches the understanding of the self-assembly mechanism of nanoclusters and provides a pathway for constructing NC-based chiroptical materials.

16.
Nanotechnology ; 34(46)2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37549662

RESUMEN

Via first-principles computational modeling and calculations, we propose a new class of two-dimensional (2D) atomically thin crystals that contain metal-C3(MC3) moieties periodically distributed in a graphenic lattice, which we refer to as 2D graphitic metal carbides (g-MCs). Most g-MCs are dynamically stable as verified by the calculated phonon spectra. Our detailed chemical bonding analyzes reveal that the high stability of g-MCs can be attributed to a unique bonding feature, which manifests as the carbon-backbone-mediated metal-metal interactions. These analyzes provide new insights for understanding the stability of 2D materials. It is found that the calculated electronic band gaps and magnetic moments (per unit cell) of g-MCs can range from 0 to 1.30 eV and 0 to 4.40µB, respectively. Highly tunable electronic properties imply great potential of 2D g-MCs in various applications. As an example, we show that 2D g-MnC can be an excellent electrocatalyst towards CO2reductive reaction for the formation of formic acid with an exceptionally high loading of Mn atoms (∼43 wt%). We expect this work to simulate new experiments for fabrication and applications of g-MCs.

17.
J Nanobiotechnology ; 21(1): 364, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37794487

RESUMEN

The blood-spinal cord barrier (BSCB) is a physical barrier between the blood and the spinal cord parenchyma. Current evidence suggests that the disruption of BSCB integrity after spinal cord injury can lead to secondary injuries such as spinal cord edema and excessive inflammatory response. Regulatory T (Treg) cells are effective anti-inflammatory cells that can inhibit neuroinflammation after spinal cord injury, and their infiltration after spinal cord injury exhibits the same temporal and spatial characteristics as the automatic repair of BSCB. However, few studies have assessed the relationship between Treg cells and spinal cord injury, emphasizing BSCB integrity. This study explored whether Treg affects the recovery of BSCB after SCI and the underlying mechanism. We confirmed that spinal cord angiogenesis and Treg cell infiltration occurred simultaneously after SCI. Furthermore, we observed significant effects on BSCB repair and motor function in mice by Treg cell knockout and overexpression. Subsequently, we demonstrated the presence and function of exosomes in vitro. In addition, we found that Treg cell-derived exosomes encapsulated miR-2861, and miR-2861 regulated the expression of vascular tight junction (TJs) proteins. The luciferase reporter assay confirmed the negative regulation of IRAK1 by miR-2861, and a series of rescue experiments validated the biological function of IRAKI in regulating BSCB. In summary, we demonstrated that Treg cell-derived exosomes could package and deliver miR-2861 and regulate the expression of IRAK1 to affect BSCB integrity and motor function after SCI in mice, which provides novel insights for functional repair and limiting inflammation after SCI.


Asunto(s)
Exosomas , MicroARNs , Traumatismos de la Médula Espinal , Ratas , Ratones , Animales , Linfocitos T Reguladores/metabolismo , Recuperación de la Función , Exosomas/metabolismo , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/metabolismo , Barrera Hematoencefálica/metabolismo , MicroARNs/genética , MicroARNs/metabolismo
18.
Eur Spine J ; 32(11): 4045-4053, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37642775

RESUMEN

PURPOSE: We aimed to investigate the value of intraoperative multi-channel recording of somatosensory evoked potentials (SSEPs) in patients undergoing posterior instrumentation surgery with fusion. METHODS: This study included 176 patients with scoliosis who underwent posterior correction surgery from January 2019 to June 2020. Among them, 88 patients underwent routine SSEPs monitoring via single-channel (Cz'-Fpz) cortical recording (control group), while the remaining 88 patients underwent multi-channel (Cz'-Fpz and C3'-C4') SSEPs monitoring in the cortex. Chi-square and Fisher's exact tests were used to analyze the influence of age, spinal deformity classification, and Cobb angle on waveform differentiation and the success rate of SSEPs monitoring. RESULTS: Univariate analysis revealed that age, type of scoliosis, and Cobb angle exerted significant effects on the success rate of intraoperative SSEPs monitoring, and the SSEPs waveform differentiation rate was poorest among patients with congenital scoliosis. Intraoperative monitoring results indicated that the success rate of single-channel SSEPs monitoring was 90.9%, while that of multi-channel monitoring was 98.9% (P < 0.05). Among the intraoperative alarm cases, the incidence of adverse events after single-channel SSEPs monitoring was 66.7%, while the incidence of adverse events after multi-channel SSEPs monitoring was only 28.6%. CONCLUSION: Multi-channel cortical SSEPs monitoring can effectively and accurately evaluate the function of the posterior column of the spinal cord. Use of multi-channel SSEP monitoring may help to improve the success rate of monitoring and reduce the incidence of postoperative adverse events in patients with congenital scoliosis.


Asunto(s)
Escoliosis , Humanos , Potenciales Evocados Somatosensoriales/fisiología , Monitoreo Intraoperatorio/métodos , Médula Espinal , Procedimientos Neuroquirúrgicos/efectos adversos
19.
World J Surg Oncol ; 21(1): 42, 2023 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-36765340

RESUMEN

BACKGROUND: Hepatitis B virus (HBV) reactivation impact negatively the prognosis of patients with HBV-related hepatocellular carcinoma (HCC). This study aimed to observe the effect of antiviral therapy (AVT) on viral reactivation and long-term outcomes after percutaneous radiofrequency ablation (PRFA) for HBV-related HCC. METHODS: Data on 538 patients between 2009 and 2013 were reviewed. Propensity score matching (PSM) analysis was used to adjust for differences in baseline features between patients who received AVT (AVT group) and did not receive it (non-AVT group). Logistic regression was used to identify the independent factors for viral reactivation. The tumor recurrence and overall survival (OS) rates were analyzed using the Kaplan-Meier method. Recurrence patterns were also investigated. RESULTS: HBV reactivation developed in 10.8% (58/538) of patients after PRFA. AVT was associated independently with decreased viral reactivation (odd ratio: 0.061, 95% confidence interval: 0.018-0.200). In 215 pairs of patients obtained after PSM, the AVT group had lower 1-, 3-, and 5-year recurrence rates (24%, 55%, and 67% vs 33%, 75%, and 85%, respectively) and higher 1-, 3-, and 5-year OS rates (100%, 67%, and 59% vs 100%, 52%, and 42%, respectively) than non-AVT group (P < 0.001 for both). Additionally, the relapses in distant hepatic segments and the late recurrence after 2 years of PRFA were significantly reduced in the AVT group (78/215 vs 111/215 vs., P = 0.001; 39/109 vs. 61/91, P = 0.012, respectively). CONCLUSIONS: AVT reduced late and distal intrahepatic recurrence and improved OS in patients undergoing PRFA for HBV-related HCC by inhibiting viral reactivation.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ablación por Radiofrecuencia , Humanos , Carcinoma Hepatocelular/patología , Virus de la Hepatitis B/genética , Neoplasias Hepáticas/patología , Hepatectomía/efectos adversos , Recurrencia Local de Neoplasia/cirugía , Antivirales/uso terapéutico , ADN Viral , Estudios Retrospectivos
20.
Pestic Biochem Physiol ; 194: 105523, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37532335

RESUMEN

Diamondback moth (Plutella xylostella), a worldwide migratory pest that is developing strong resistance to various chemical insecticides. It has been determined that four natural pyrazines isolated from Allium tuberosum showed significant repellent activity to P. xylostella, but the molecular target still unknown. In the present study, a novel synthetic route for 2,3-dimethyl-6-(1-hydroxy)-pyrazine which has the most significant repellent activity with a purity of 90.60% was established. Simultaneously, the bioassay result declared that the repellent grade was IV at a dosage of 0.01 mg which was the same as to the published data. Transcriptomics analysis detected 1643 upregulated and 3837 downregulated genes in P. xylostella antennae following this pyrazine exposure. Then, 2142 differentially expressed genes were annotated using Gene Ontology and 2757 genes were annotated by Kyoto Encyclopedia of Genes and Genomes. Moreover, this procedure identified 84 odour perception-related genes, 58 odorant receptor (OR) genes including 57 conventional ORs and the odorant receptor co-receptor (Orco, atypical odorant receptor) gene, and 26 odorant-binding protein (OBP) genes. Based on quantitative real time PCR (RT-qPCR) and differential expression results, 9 OR genes including the Orco were cloned and characterised. In summary, this study provides important basis for the utilization of pyrazines as the main active ingredients or lead compounds to developing new botanical pesticides, which will reduce application of chemical pesticides and postpone the development of resistance.


Asunto(s)
Insecticidas , Mariposas Nocturnas , Receptores Odorantes , Animales , Receptores Odorantes/genética , Mariposas Nocturnas/genética , Insecticidas/farmacología , Perfilación de la Expresión Génica , Reacción en Cadena en Tiempo Real de la Polimerasa , Resistencia a los Insecticidas/genética , Larva
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