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1.
Nature ; 618(7966): 687-697, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37344649

RESUMO

Light and sound are the most ubiquitous forms of waves, associated with a variety of phenomena and physical effects such as rainbows and echoes. Light and sound, both categorized as classical waves, have lately been brought into unexpected connections with exotic topological phases of matter. We are currently witnessing the onset of a second wave of active research into this topic. The past decade has been marked by fundamental advances comprising two-dimensional quantum Hall insulators and quantum spin and valley Hall insulators, whose topological properties are characterized using linear band topology. Here, going beyond these conventional topological systems, we focus on the latest frontiers, including non-Hermitian, nonlinear and non-Abelian topology as well as topological defects, for which the characterization of the topological features goes beyond the standard band-topology language. In addition to an overview of the current state of the art, we also survey future research directions for valuable applications.

2.
FASEB J ; 38(13): e23780, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38948938

RESUMO

Aerobic training (AT), an effective form of cardiac rehabilitation, has been shown to be beneficial for cardiac repair and remodeling after myocardial infarction (MI). The p300/CBP-associated factor (PCAF) is one of the most important lysine acetyltransferases and is involved in various biological processes. However, the role of PCAF in AT and AT-mediated cardiac remodeling post-MI has not been determined. Here, we found that the PCAF protein level was significantly increased after MI, while AT blocked the increase in PCAF. AT markedly improved cardiac remodeling in mice after MI by reducing endoplasmic reticulum stress (ERS). In vivo, similar to AT, pharmacological inhibition of PCAF by Embelin improved cardiac recovery and attenuated ERS in MI mice. Furthermore, we observed that both IGF-1, a simulated exercise environment, and Embelin protected from H2O2-induced cardiomyocyte injury, while PCAF overexpression by viruses or the sirtuin inhibitor nicotinamide eliminated the protective effect of IGF-1 in H9C2 cells. Thus, our data indicate that maintaining low PCAF levels plays an essential role in AT-mediated cardiac protection, and PCAF inhibition represents a promising therapeutic target for attenuating cardiac remodeling after MI.


Assuntos
Infarto do Miocárdio , Condicionamento Físico Animal , Remodelação Ventricular , Fatores de Transcrição de p300-CBP , Animais , Fatores de Transcrição de p300-CBP/metabolismo , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Camundongos , Remodelação Ventricular/efeitos dos fármacos , Remodelação Ventricular/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos
3.
J Immunol ; 211(5): 836-843, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37466391

RESUMO

Our previous studies identified a population of stem cell-like proliferating myeloid cells within inflamed tissues that could serve as a reservoir for tissue macrophages to adopt different activation states depending on the microenvironment. By lineage-tracing cells derived from CX3CR1+ precursors in mice during infection and profiling by single-cell RNA sequencing, in this study, we identify a cluster of BIRC5+ myeloid cells that expanded in the liver during chronic infection with either the parasite Schistosoma mansoni or the bacterial pathogen Staphylococcus aureus. In the absence of tissue-damaging toxins, S. aureus infection does not elicit these BIRC5+ cells. Moreover, deletion of BIRC5 from CX3CR1-expressing cells results in improved survival during S. aureus infection. Hence the combination of single-cell RNA sequencing and genetic fate-mapping CX3CR1+ cells revealed a toxin-dependent pathogenic role for BIRC5 in myeloid cells during S. aureus infection.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Camundongos , Animais , Células Mieloides/patologia , Análise de Célula Única , Infecções Estafilocócicas/microbiologia
4.
Proc Natl Acad Sci U S A ; 119(31): e2123017119, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35881802

RESUMO

Staphylococcus aureus is an opportunistic pathogen and chief among bloodstream-infecting bacteria. S. aureus produces an array of human-specific virulence factors that may contribute to immune suppression. Here, we defined the response of primary human phagocytes following infection with S. aureus using RNA-sequencing (RNA-Seq). We found that the overall transcriptional response to S. aureus was weak both in the number of genes and in the magnitude of response. Using an ex vivo bacteremia model with fresh human blood, we uncovered that infection with S. aureus resulted in the down-regulation of genes related to innate immune response and cytokine and chemokine signaling. This muted transcriptional response was conserved across diverse S. aureus clones but absent in blood exposed to heat-killed S. aureus or blood infected with the less virulent staphylococcal species Staphylococcus epidermidis. Notably, this signature was also present in patients with S. aureus bacteremia. We identified the master regulator S. aureus exoprotein expression (SaeRS) and the SaeRS-regulated pore-forming toxins as key mediators of the transcriptional suppression. The S. aureus-mediated suppression of chemokine and cytokine transcription was reflected by circulating protein levels in the plasma. Wild-type S. aureus elicited a soluble milieu that was restrictive in the recruitment of human neutrophils compared with strains lacking saeRS. Thus, S. aureus blunts the inflammatory response resulting in impaired neutrophil recruitment, which could promote the survival of the pathogen during invasive infection.


Assuntos
Interações Hospedeiro-Patógeno , Neutrófilos , Infecções Estafilocócicas , Staphylococcus aureus , Bacteriemia/imunologia , Bacteriemia/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Citocinas/metabolismo , Regulação Bacteriana da Expressão Gênica , Interações Hospedeiro-Patógeno/imunologia , Humanos , Neutrófilos/imunologia , Neutrófilos/microbiologia , Proteínas Citotóxicas Formadoras de Poros/genética , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Staphylococcus epidermidis/patogenicidade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Nano Lett ; 24(18): 5521-5528, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38662651

RESUMO

Exploring multiple states based on the domain wall (DW) position has garnered increased attention for in-memory computing applications, particularly focusing on the utilization of spin-orbit torque (SOT) to drive DW motion. However, devices relying on the DW position require efficient DW pinning. Here, we achieve granular magnetization switching by incorporating an HfOx insertion layer between the Co/Ti interface. This corresponds to a transition in the switching model from the DW motion to DW nucleation. Compared to the conventional Pt/Co/Ti structure, incorporation of the HfOx layer results in an enhanced SOT efficiency and a lower switching current density. We also realized stable multistate storage and synaptic plasticity by applying pulse current in the Pt/Co/HfOx/Ti device. The simulation of artificial neural networks (ANN) based on the device can perform digital recognition tasks with an accuracy rate of 91%. These results identify that DW nucleation with a Pt/Co/HfOx/Ti based device has potential applications in multistate storage and ANN.

6.
J Am Chem Soc ; 146(33): 23212-23220, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39084600

RESUMO

Analyzing the molecular structure-photophysical property correlations of metal nanoclusters to accomplish function-oriented photocatalysis could be challenging. Here, the selective heteroatom alloying has been exploited to a Au15 nanocluster, making up a structure-correlated nanocluster series, including homogold Au15, bimetallic AgxAu15-x and CuxAu15-x, trimetallic AgxCuyAu15-x-y, and tetrametallic Pt1AgxCuyAu15-x-y. Their structure-dependent photophysical properties were investigated due to the atomically precise structures of these nanoclusters. Cu-alloyed CuxAu15-x showed intense phosphorescence and the highest singlet oxygen production efficiency. Moreover, the generation of 1O2 species from excited nanoclusters enabled CuxAu15-x as a suitable catalyst for efficient photocatalytic oxidation of silyl enol ethers to produce α,ß-unsaturated carbonyl compounds. The generality and applicability of the CuxAu15-x catalysts toward different photocatalytic oxidations were assessed. Overall, this study presents an intriguing Au15-based cluster series enabling an atomic-level understanding of structure-photophysical property correlations, which hopefully provides guidance for the fabrication of cluster-based catalysts with customized photocatalytic performance.

7.
Curr Issues Mol Biol ; 46(3): 2701-2712, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38534786

RESUMO

Inflammation and collagen-degrading enzymes' overexpression promote collagen decomposition, which affects the structural integrity of the extracellular matrix. The polysaccharide and peptide extracts of the green alga Caulerpa microphysa (C. microphysa) have been proven to have anti-inflammatory, wound healing, and antioxidant effects in vivo and in vitro. However, the biological properties of the non-water-soluble components of C. microphysa are still unknown. In the present study, we demonstrated the higher effective anti-inflammatory functions of C. microphysa ethyl acetate (EA) extract than water extract up to 16-30% in LPS-induced HaCaT cells, including reducing the production of interleukin (IL)-1ß, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Furthermore, the excellent collagen homeostasis effects from C. microphysa were proven by suppressing the matrix metalloproteinase-1 (MMP-1) secretion, enhancing type 1 procollagen and collagen expressions dose-dependently in WS1 cells. Moreover, using UHPLC-QTOF-MS analysis, four terpenoids, siphonaxanthin, caulerpenyne, caulerpal A, and caulerpal B, were identified and may be involved in the superior collagen homeostasis and anti-inflammatory effects of the C. microphysa EA extract.

8.
Eur J Neurosci ; 59(8): 2016-2028, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382896

RESUMO

The aim of this work was to analyse the effect of tandem repetitions in exon III of the DRD4 gene on the features of human decision-making in a model of choosing tourist attractions by adult residents of China. The study included 380 subjects: 162 (42.6%) men and 218 (57.4%) women. The mean age of the subjects was 31.7 ± 3.32 years. As a result of the survey of subjects, 5 groups of motivations for choosing tourist attractions were identified, and the frequency of their use, including the identified combinations, was determined. Using the genotyping method, the frequency of DRD4 subtypes among the subjects was determined, and their relationship with the indicated attraction selection groups was studied. It has been established that there is a significant dependence of the frequency of choosing the attractors 'relaxation', 'desire for novelty' and 'self-realization' and their combinations on the frequency of occurrence of the DRD4 2R, 4R and 5R+ subtypes in the study groups. A conclusion was made about the possible mechanism of the influence of manifestations of DRD4 subtypes on the choice of tourist attractors by implementing the neurophysiological influence of the genome on reducing the sensitivity of brain receptors to dopamine, which stimulates behaviours that compensate for the need for additional emotional influences. This work complements the existing knowledge about the impact of human innate properties on the characteristics of his behaviour and possible patterns of influence of human genotype variability on decision-making and suggests further possible directions of research in this area.


Assuntos
Repetições Minissatélites , Receptores de Dopamina D4 , Masculino , Adulto , Humanos , Feminino , Receptores de Dopamina D4/genética , Genótipo , Éxons , Emoções
9.
Biochem Biophys Res Commun ; 725: 150260, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-38878760

RESUMO

This study introduces an innovative brain-targeted drug delivery system, RVG-Exo/CBD, utilizing rabies virus glycoprotein (RVG)-engineered exosomes for encapsulating cannabidiol (CBD). The novel delivery system was meticulously characterized, confirming the maintenance of exosomal integrity, size, and successful drug encapsulation with a high drug loading rate of 83.0 %. Evaluation of the RVG-Exo/CBD's brain-targeting capability demonstrated superior distribution and retention in brain tissue compared to unmodified exosomes, primarily validated through in vivo fluorescence imaging. The efficacy of this delivery system was assessed using a behavioral sensitization model in mice, where RVG-Exo/CBD notably suppressed methamphetamine-induced hyperactivity more effectively than CBD alone, indicating a reduction in effective dose and enhanced bioavailability. Overall, the RVG-Exo/CBD system emerges as a promising strategy for enhancing the therapeutic efficacy and safety of CBD, particularly for neurological applications, highlighting its potential for addressing the limitations associated with traditional CBD administration in clinical settings.


Assuntos
Encéfalo , Canabidiol , Canabidiol/administração & dosagem , Canabidiol/química , Canabidiol/farmacologia , Animais , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Camundongos , Masculino , Glicoproteínas/química , Glicoproteínas/metabolismo , Glicoproteínas/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Fragmentos de Peptídeos , Proteínas Virais
10.
Biochem Biophys Res Commun ; 710: 149883, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38588611

RESUMO

Congenital heart diseases are the most common birth defects around the world. Emerging evidence suggests that mitochondrial homeostasis is required for normal heart development. In mitochondria, a series of molecular chaperones including heat shock protein 60 (HSP60) are engaged in assisting the import and folding of mitochondrial proteins. However, it remains largely obscure whether and how these mitochondrial chaperones regulate cardiac development. Here, we generated a cardiac-specific Hspd1 deletion mouse model by αMHC-Cre and investigated the role of HSP60 in cardiac development. We observed that deletion of HSP60 in embryonic cardiomyocytes resulted in abnormal heart development and embryonic lethality, characterized by reduced cardiac cell proliferation and thinner ventricular walls, highlighting an essential role of cardiac HSP60 in embryonic heart development and survival. Our results also demonstrated that HSP60 deficiency caused significant downregulation of mitochondrial ETC subunits and induced mitochondrial stress. Analysis of gene expression revealed that P21 that negatively regulates cell proliferation is significantly upregulated in HSP60 knockout hearts. Moreover, HSP60 deficiency induced activation of eIF2α-ATF4 pathway, further indicating the underlying mitochondrial stress in cardiomyocytes after HSP60 deletion. Taken together, our study demonstrated that regular function of mitochondrial chaperones is pivotal for maintaining normal mitochondrial homeostasis and embryonic heart development.


Assuntos
Chaperonina 60 , Cardiopatias Congênitas , Animais , Camundongos , Chaperonina 60/genética , Chaperonina 60/metabolismo , Cardiopatias Congênitas/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Miócitos Cardíacos/metabolismo
11.
Chembiochem ; 25(3): e202300678, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38015421

RESUMO

Using myoglobin (Mb) as a model protein, we herein developed a facial approach to modifying the heme active site. A cavity was first generated in the heme distal site by F46 C mutation, and the thiol group of Cys46 was then used for covalently linked to exogenous ligands, 1H-1,2,4-triazole-3-thiol and 1-(4-hydroxyphenyl)-1H-pyrrole-2,5-dione. The engineered proteins, termed F46C-triazole Mb and F46C-phenol Mb, respectively, were characterized by X-ray crystallography, spectroscopic and stopped-flow kinetic studies. The results showed that both the heme coordination state and the protein function such as H2 O2 activation and peroxidase activity could be efficiently regulated, which suggests that this approach might be generally applied to the design of functional heme proteins.


Assuntos
Heme , Mioglobina , Mioglobina/química , Mioglobina/genética , Mioglobina/metabolismo , Domínio Catalítico , Heme/química , Cinética , Conformação Proteica , Compostos de Sulfidrila
12.
Basic Res Cardiol ; 119(1): 57-74, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38151579

RESUMO

Cardiac sympathetic overactivation is a critical driver in the progression of acute myocardial infarction (AMI). The left middle cervical ganglion (LMCG) is an important extracardiac sympathetic ganglion. However, the regulatory effects of LMCG on AMI have not yet been fully documented. In the present study, we detected that the LMCG was innervated by abundant sympathetic components and exerted an excitatory effect on the cardiac sympathetic nervous system in response to stimulation. In canine models of AMI, targeted ablation of LMCG reduced the sympathetic indexes of heart rate variability and serum norepinephrine, resulting in suppressed cardiac sympathetic activity. Moreover, LMCG ablation could improve ventricular electrophysiological stability, evidenced by the prolonged ventricular effective refractory period, elevated action potential duration, increased ventricular fibrillation threshold, and enhanced connexin43 expression, consequently showing antiarrhythmic effects. Additionally, compared with the control group, myocardial infarction size, circulating cardiac troponin I, and myocardial apoptosis were significantly reduced, accompanied by preserved cardiac function in canines subjected to LMCG ablation. Finally, we performed the left stellate ganglion (LSG) ablation and compared its effects with LMCG destruction. The results indicated that LMCG ablation prevented ventricular electrophysiological instability, cardiac sympathetic activation, and AMI-induced ventricular arrhythmias with similar efficiency as LSG denervation. In conclusion, this study demonstrated that LMCG ablation suppressed cardiac sympathetic activity, stabilized ventricular electrophysiological properties and mitigated cardiomyocyte death, resultantly preventing ischemia-induced ventricular arrhythmias, myocardial injury, and cardiac dysfunction. Neuromodulation therapy targeting LMCG represented a promising strategy for the treatment of AMI.


Assuntos
Infarto do Miocárdio , Animais , Cães , Arritmias Cardíacas , Coração/inervação , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/prevenção & controle , Gânglios Simpáticos/metabolismo
13.
Rev Cardiovasc Med ; 25(5): 159, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-39076475

RESUMO

Atrial septal defect (ASD) is the third most common type of structural congenital heart defect. Patent foramen ovale (PFO) is an anatomical anomaly in up to 25% of the general population. With the innovation of occlusion devices and improvement of transcatheter techniques, percutaneous closure has become a first-line therapeutic alternative for treatment of ASD and PFO. During the past few decades, the development of biodegradable occlusion devices has become a promising direction for transcatheter closure of ASD/PFO due to their biodegradability and improved biocompatibility. The purpose of this review is to comprehensively summarize biodegradable ASD/PFO occlusion devices, regarding device design, materials, biodegradability, and evaluation of animal or clinical experiments (if available). The current challenges and the research direction for the development of biodegradable occluders for congenital heart defects are also discussed.

14.
Opt Lett ; 49(18): 5200-5203, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39270267

RESUMO

We analyze the role of the energy flow coefficient in beam shifts and develop the theory of the angle spectrum method to calculate the beam shifts of polarized beam reflection and transmission. By applying the self-consistency between the law of conservation of momentum and the angular Goos-Hänchen (GH) shift, we prove the necessity of the correcting energy flow coefficient of the transmitted light fields. For the air-glass interface, we find that the influence of the energy flow coefficient on the angular GH shift is very pronounced in the case of close grazing.

15.
Circ Res ; 130(10): 1586-1600, 2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35437018

RESUMO

BACKGROUND: Pathological cardiac hypertrophy is one of the leading causes of heart failure with highly complicated pathogeneses. The E3 ligase TRIM16 (tripartite motif-containing protein 16) has been recognized as a pivotal regulator to control cell survival, immune response, and oxidativestress. However, the role of Trim16 in cardiac hypertrophy is unknown. METHODS: We generated cardiac-specific knockout mice and adeno-associated virus serotype 9-Trim16 mice to evaluate the function of Trim16 in pathological myocardial hypertrophy. The direct effect of TRIM16 on cardiomyocyte enlargement was examined using an adenovirus system. Furthermore, we combined RNA-sequencing and interactome analysis that was followed by multiple molecular biological methodologies to identify the direct target and corresponding molecular events contributing to TRIM16 function. RESULTS: We found an intimate correlation of Trim16 expression with hypertrophy-related heart failure in both human and mouse. Our functional investigations and unbiased transcriptomic analyses clearly demonstrated that Trim16 deficiency markedly exacerbated cardiomyocyte enlargement in vitro and in transverse aortic constriction-induced cardiac hypertrophy mouse model, whereas Trim16 overexpression attenuated cardiac hypertrophy and remodeling. Mechanistically, Prdx1 (peroxiredoxin 1) is an essential target of Trim16 in cardiac hypertrophy. We found that Trim16 interacts with Prdx1 and inhibits its phosphorylation, leading to a robust enhancement of its downstream Nrf2 (nuclear factor-erythroid 2-related factor 2) pathway to block cardiac hypertrophy. Trim16-blocked Prdx1 phosphorylation was largely dependent on a direct interaction between Trim16 and Src and the resultant Src ubiquitinational degradation. Notably, Prdx1 knockdown largely abolished the anti-hypertrophic effects of Trim16 overexpression. CONCLUSIONS: Our findings provide the first evidence supporting Trim16 as a novel suppressor of pathological cardiac hypertrophy and indicate that targeting the Trim16-Prdx1 axis represents a promising therapeutic strategy for hypertrophy-related heart failure.


Assuntos
Cardiomegalia , Insuficiência Cardíaca , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Animais , Cardiomegalia/metabolismo , Modelos Animais de Doenças , Insuficiência Cardíaca/metabolismo , Camundongos , Camundongos Knockout , Miócitos Cardíacos/metabolismo , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genética
16.
J Org Chem ; 89(18): 13608-13622, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39235899

RESUMO

The utilization of photogenerated carbene species to perform N-H insertion reactions has attracted considerable attention in the past few years. In this Article, we disclose a visible-light-promoted N-H insertion of 3-aminomethylated maleimides with aryl diazoacetates under sole blue LED irradiation. Continuous flow reactor technology was exploited to improve the reaction efficiency. By simply varying the reaction conditions, the formed N-H insertion products could be selectively transferred to bioimportant octahydropyrrolo[3,4-c]pyrroles and E-selective trisubstituted olefins.

17.
Inorg Chem ; 63(35): 16274-16283, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39154358

RESUMO

Different types of electron transfers (ETs) underlie the versatile use of various solid viologen-derived compounds, which is still insufficiently understood and difficult to control. Here, we demonstrate an effective strategy for modulating the key ET process in crystalline metalloviologen compounds (MVCs). By adjusting the coordinated transition metal ions bearing different electronic structures (e.g., d5, d7, d10), three MVCs (i.e., Mn-1, Co-2, and Cd-3) with highly consistent coordination environments have been synthesized successfully. Surprisingly, whether the photochromism (energy-induced ET mechanism) or the specific analyte recognition (molecule-induced ET mechanism), compound Cd-3 exhibits obvious photochromic behavior and differential dimethylamine detection. Combined detailed structural analysis with theoretical calculations, such unique ion-dependent properties, were correlated to the fine modulation of the electron density of the bipyridinium cores by metal ions. Additionally, thanks to the delicate recognition of dimethylamine vapor, a convenient test strip Cd-3-PAN was prepared as a sensitive biogenic amine sensor for evaluating the real-time freshness of seafood.

18.
Nanotechnology ; 35(36)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38861984

RESUMO

Electric field control of spin-orbit torque (SOT) exhibits promising potential in advanced spintronic devices through interfacial modulation. In this work, we investigate the influence of electric field and interfacial oxidation on SOT efficiency in annealed Ta/CoFeB/HfOxheterostructures. By varying annealing temperatures, the damping-like SOT efficiency reaches its peak at the annealing temperature of 320 °C, with an 80% field-free magnetization switching ratio induced by SOT having been demonstrated. This enhancement is ascribed to the annealing-induced modulation of oxygen ion migration at the CoFeB/HfOxinterface. By applying voltages across the Ta/CoFeB/HfOxheterostructures, which drives the O2‒migration across the interface, a reversible, bipolar, and non-volatile modulation of SOT efficiency was observed. The collective influence of annealing temperature and electric field effects on SOT carried out in this work provides an effective approach into facilitating the optimization and control of SOT in spintronic devices.

19.
J Biochem Mol Toxicol ; 38(1): e23602, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38053484

RESUMO

Flavonoids, which contain a benzo-γ-pyrone (C6-C3-C6) skeleton, have been reported to exhibit effective antioxidant ability. This study aimed to compare the antioxidant activities of 7,8-dihydroxyflavone (7,8-DHF) and 7-hydroxyflavone (7-HF) in H2 O2 , lipopolysaccharide (LPS), or tert-butyl hydroperoxide (t-BHP)-induced RAW264.7 cells, respectively. The antioxidant capacities of 7,8-DHF and 7-HF were firstly evaluated by 2,2-azinobis-3-ethyl-benzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Then, reactive oxygen species (ROS), super oxide dismutase (SOD), and malondialdehyde (MDA) productions in H2 O2 , LPS, or t-BHP-induced RAW264.7 cells were tested and compared, respectively. Finally, the antioxidant mechanisms of 7-HF and 7,8-DHF were initially investigated by western blot. Our results showed that 7,8-DHF possessed stronger free-radical scavenging capacity than 7-HF. Both 7,8-DHF and 7-HF suppressed MDA production and ROS accumulation, improved the activity of SOD in H2 O2 , LPS, or t-BHP-induced RAW264.7 cells, respectively. And 7,8-DHF exerted a better antioxidant effect than 7-HF, especially in t-BHP-induced oxidative stress. Mechanically, 7,8-DHF prevented the activation of poly ADP-ribosepolymerase and caspase-3, meanwhile markedly upregulated the expression of HO-1 protein in t-BHP-induced oxidative stress. These results suggested that 7,8-DHF might serve as a potential pharmaceutical drug against oxidative stress injury.


Assuntos
Antioxidantes , Flavonas , Inibidores de Poli(ADP-Ribose) Polimerases , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Caspase 3/metabolismo , Lipopolissacarídeos/toxicidade , Estresse Oxidativo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Animais , Camundongos
20.
Bioorg Chem ; 143: 106986, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37995641

RESUMO

Photodynamic therapy (PDT) has emerged as a highly efficacious therapeutic modality for malignant tumors owing to its non-invasive property and minimal adverse effects. However, the pervasive hypoxic microenvironment within tumors significantly compromises the efficacy of oxygen-dependent PDT, posing a formidable challenge to the advancement of high-efficiency PDT. Here, we developed a nanostructured photosensitizer (PS) assembled by cationic and anionic zinc phthalocyanines to load oxygen-throttling drug atovaquone (ATO), which was subsequently coated with polydopamine to obtain the final product ATO/ZnPc-CA@DA. ATO/ZnPc-CA@DA exhibited excellent stability, particularly in the blood milieu. Interestingly, the acidic microenvironment can trigger drug release from ATO/ZnPc-CA@DA, leading to a significant enhancement in fluorescence and an augmented generation of reactive oxygen species (ROS). ATO/ZnPc-CA@DA can induce synergistic cytotoxicity of PS and ATO, and significantly enhance the killing ability against tumor cells under hypoxic conditions. The mechanism underlying cytotoxicity of ATO/ZnPc-CA@DA was demonstrated to be associated with augmented cell apoptosis, disruption of mitochondrial membrane potential, diminished ATP production, heightened intracellular ROS generation, and reduced intracellular oxygen consumption. The animal experiments indicated that ATO/ZnPc-CA@DA possessed enhanced tumor targeting capability, along with a reduction in PS distribution within normal organs. Furthermore, ATO/ZnPc-CA@DA exhibited enhanced inhibitory effect on tumor growth and caused aggravated damage to tumor tissue. The construction strategy of nanostructured PS and the synergistic antitumor principle of combined oxygen-throttling drugs can be applied to other PSs, thereby advancing the development of photodynamic antitumor therapy and promoting the clinical translation.


Assuntos
Nanopartículas , Compostos Organometálicos , Fotoquimioterapia , Animais , Fotoquimioterapia/métodos , Espécies Reativas de Oxigênio/metabolismo , Preparações de Ação Retardada , Linhagem Celular Tumoral , Fluorescência , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Isoindóis , Oxigênio , Compostos Organometálicos/farmacologia
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