Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Commun ; 15(1): 4789, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918364

RESUMO

Two-dimensional freestanding membranes of materials, which can be transferred onto and make interfaces with any material, have attracted attention in the search for functional properties that can be utilized for next-generation nanoscale devices. We fabricated stable 1-nm-thick hafnia membranes exhibiting the metastable rhombohedral structure and out-of-plane ferroelectric polarizations as large as 13 µC/cm2. We also found that the rhombohedral phase transforms into another metastable orthorhombic phase without the ferroelectricity deteriorating as the thickness increases. Our results reveal the key role of the rhombohedral phase in the scale-free ferroelectricity in hafnia and also provide critical insights into the formation mechanism and phase stability of the metastable hafnia. Moreover, ultrathin hafnia membranes enable heterointerfaces and devices to be fabricated from structurally dissimilar materials beyond structural constrictions in conventional film-growth techniques.

2.
Ecotoxicol Environ Saf ; 279: 116458, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38759536

RESUMO

Heavy metals interact with each other in a coexisting manner to produce complex combined toxicity to organisms. At present, the toxic effects of chronic co-exposure to heavy metals hexavalent chromium [Cr(VI)] and divalent nickel [Ni(II)] on organisms are seldom studied and the related mechanisms are poorly understood. In this study, we explored the mechanism of the colon injury in mice caused by chronic exposure to Cr or/and Ni. The results showed that, compared with the control group, Cr or/and Ni chronic exposure affected the body weight of mice, and led to infiltration of inflammatory cells in the colon, decreased the number of goblet cells, fusion of intracellular mucus particles and damaged cell structure of intestinal epithelial. In the Cr or/and Ni exposure group, the activity of nitric oxide synthase (iNOS) increased, the expression levels of MUC2 were significantly down-regulated, and those of ZO-1 and Occludin were significantly up-regulated. Interestingly, factorial analysis revealed an interaction between Cr and Ni, which was manifested as antagonistic effects on iNOS activity, ZO-1 and MUC2 mRNA expression levels. Transcriptome sequencing further revealed that the expression of genes-related to inflammation, intestinal mucus and tight junctions changed obviously. Moreover, the relative contents of Cr(VI) and Ni(II) in the Cr, Ni and Cr+Ni groups all changed with in-vitro gastrointestinal (IVG)digestion, especially in the Cr+Ni group. Our results indicated that the chronic exposure to Cr or/and Ni can lead to damage to the mice colon, and the relative content changes of Cr(VI) and Ni(II) might be the main reason for the antagonistic effect of Cr+Ni exposure on the colon damage.


Assuntos
Cromo , Colo , Mucina-2 , Níquel , Animais , Cromo/toxicidade , Níquel/toxicidade , Camundongos , Colo/efeitos dos fármacos , Colo/patologia , Mucina-2/genética , Mucina-2/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Perfilação da Expressão Gênica , Masculino , Digestão/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/metabolismo , Proteína da Zônula de Oclusão-1/genética , Transcriptoma/efeitos dos fármacos , Ocludina/metabolismo , Ocludina/genética , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia
3.
Sci Total Environ ; 926: 171921, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38522525

RESUMO

Exposure to Cr and/or Ni can have widespread implications on the environment and health. However, the specific toxic effects of chronic Cr and Ni co-exposure on mice liver have not been reported. To ascertain the combined toxic effects of chronic Cr and Ni co-exposure on liver damage in mice, 80 6-week-old female C57BL/6 J mice were randomly divided into 4 groups: the Con group, Cr group (Cr+6 50 mg/L), Ni group (Ni+2 110 mg/L), and Cr + Ni group (Cr+6 50 mg/L + Ni+2 110 mg/L). The trial period lasted for 16 weeks. The results showed that Cr+6 and/or Ni+2 increased liver weight and liver index (P < 0.05) in mice, caused histological abnormality and ultrastructural damage, and micronutrients imbalance in mice liver. These findings serve as the basis for subsequent experiments. Compared with the individual exposure group, chronic Cr and Ni co-exposure resulted in decreased levels and activities of ALT, AST, MDA, T-AOC, and T-SOD (P < 0.05) in liver tissue, and decreased the mRNA expression levels of the TLR4/mTOR pathway related factors (TLR4, TRAM, TRIF, TBK-1, IRF-3, MyD88, IRAK-4, TRAF6, TAK-1, IKKß, NF-κB, IL-1ß, IL-6, TNFα, ULK1, Beclin 1, LC3) (P < 0.05) and decreased the protein expression levels of the factors (TLR4, MyD88, TRAF6, NF-κB p50, IL-6, TNFα, ULK1, LC3II/LC3I) (P < 0.05). Moreover, factorial analysis revealed the interaction between Cr and Ni, which was manifested as antagonistic effects on Cr concentration, Ni concentration, and TLR4, MyD88, NF-κB, mTOR, LC3, and p62 mRNA expression levels. In conclusion, the TLR4/mTOR pathway as a mechanism through which chronic Cr and Ni co-exposure induce liver inflammation and autophagy in mice, and there was an antagonistic effect between Cr and Ni. The above results provided a theoretical basis for understanding the underlying processes.


Assuntos
Autofagia , Cromo , Inflamação , Fígado , NF-kappa B , Níquel , Transdução de Sinais , Receptor 4 Toll-Like , Animais , Feminino , Camundongos , Inflamação/induzido quimicamente , Interleucina-6/metabolismo , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/metabolismo , RNA Mensageiro , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Cromo/metabolismo , Cromo/toxicidade , Níquel/metabolismo , Níquel/toxicidade
4.
Nat Commun ; 15(1): 1377, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355941

RESUMO

Injectable biomaterials have garnered increasing attention for their potential and beneficial applications in minimally invasive surgical procedures and tissue regeneration. Extracellular matrix (ECM) hydrogels and porous synthetic polymer microspheres can be prepared for injectable administration to achieve in situ tissue regeneration. However, the rapid degradation of ECM hydrogels and the poor injectability and biological inertness of most polymeric microspheres limit their pro-regenerative capabilities. Here, we develop a biomaterial system consisting of elastic porous poly(l-lactide-co-ε-caprolactone) (PLCL) microspheres mixed with ECM hydrogels as injectable composites with interleukin-4 (IL-4) and insulin-like growth factor-1 (IGF-1) dual-release functionality. The developed multifunctional composites have favorable injectability and biocompatibility, and regulate the behavior of macrophages and myogenic cells following injection into muscle tissue. The elicited promotive effects on tissue regeneration are evidenced by enhanced neomusle formation, vascularization, and neuralization at 2-months post-implantation in a male rat model of volumetric muscle loss. Our developed system provides a promising strategy for engineering bioactive injectable composites that demonstrates desirable properties for clinical use and holds translational potential for application as a minimally invasive and pro-regenerative implant material in multiple types of surgical procedures.


Assuntos
Materiais Biocompatíveis , Matriz Extracelular , Masculino , Ratos , Animais , Porosidade , Microesferas , Hidrogéis , Engenharia Tecidual/métodos
5.
Int J Biol Macromol ; 253(Pt 8): 127635, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37884239

RESUMO

Beclin1, also known as ATG6, has been shown to be closely related to coronavirus, however, the link between Beclin1 and nephropathogenic infectious bronchitis virus (NIBV) has been poorly investigated and there are no available antibodies specifically targeting the chicken Beclin1 protein. The study aimed to prepare and assay a polyclonal antibody to Beclin1, enabling a deeper understanding of the mechanism of action of Beclin1 in NIBV. In this study, we amplified the chicken Beclin1 target gene and constructed a recombinant plasmid using prokaryotic expression techniques, then obtained the recombinant target protein by induced expression. Finally, the serum is obtained by immunizing rabbits with the purified and concentrated protein. The results show that the antiserum potency of the ELISA assay was >1:204800. By western blotting and immunofluorescence, the antibodies we prepared specifically recognized the chicken Beclin1 protein, which is mainly found in the nucleus of trachea, lung, kidney, spleen and fabricant cells. NIBV infection significantly decreased the expression of Beclin1 in the trachea, but increased in others. We have successfully prepared specific rabbit anti-chicken Beclin1 polyclonal antibodies, and detected changes in tissues of diseased chickens infected with NIBV, laying the foundation for further studies on the role of Beclin1 in avian diseases.


Assuntos
Galinhas , Vírus da Bronquite Infecciosa , Animais , Coelhos , Vírus da Bronquite Infecciosa/genética , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Anticorpos , Rim/metabolismo , Western Blotting
6.
Front Genet ; 14: 1265137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37842645

RESUMO

Background: The pathogenic genes of colorectal cancer (CRC) have not yet been fully elucidated, and there is currently a lack of effective therapeutic targets. This study used bioinformatics methods to explore and experimentally validate the most valuable biomarkers for colorectal cancer and further investigate their potential as targets. Methods: We analyzed differentially expressed genes (DEGs) based on the Gene Expression Omnibus (GEO) dataset and screened out hub genes. ROC curve and univariate Cox analysis of The Cancer Genome Atlas (TCGA) dataset revealed the most diagnostically and prognostically valuable genes. Immunohistochemistry (IHC) experiments were then conducted to validate the expression level of these selected genes in colorectal cancer. Gene set enrichment analysis (GSEA) was performed to evaluate the enriched signaling pathways associated with the gene. Using the CIBERSORT algorithm in R software, we analyzed the immune infiltrating cell abundance in both high and low gene expression groups and examined the gene's correlation with immune cells and immune checkpoints. Additionally, we performed drug sensitivity analysis utilizing the DepMap database, and explored the correlation between gene expression levels and ferroptosis based on the The Cancer Genome Atlas dataset. Results: The study identified a total of 159 DEGs, including 7 hub genes: SPP1, MMP1, CXCL8, CXCL1, TIMP1, MMP3, and CXCL10. Further analysis revealed TIMP1 as the most valuable diagnostic and prognostic biomarker for colorectal cancer, with IHC experiments verifying its high expression. Additionally, GSEA results showed that the high TIMP1 expression group was involved in many cancer signaling pathways. Analysis of the TCGA database revealed a positive correlation between TIMP1 expression and infiltration of macrophages (M0, M1, M2) and neutrophils, as well as the expression of immune checkpoint genes, including CTLA-4 and HAVCR2. Drug sensitivity analysis, conducted using the DepMap database, revealed that colorectal cancer cell lines exhibiting elevated levels of TIMP1 expression were more responsive to certain drugs, such as CC-90003, Pitavastatin, Atuveciclib, and CT7001, compared to those with low levels of TIMP1. Furthermore, TIMP1 expression was positively correlated with that of ferroptosis-related genes, such as GPX4 and HSPA5. Conclusion: TIMP1 can be used as a biomarker for colorectal cancer and is associated with the immunological microenvironment, drug sensitivity, and ferroptosis inhibition in this disease.

7.
RSC Adv ; 13(15): 10254-10260, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37006349

RESUMO

The interface of perovskite heterostructures has been shown to exhibit various electronic and magnetic phases such as two-dimensional electron gas, magnetism, superconductivity, and electronic phase separation. These rich phases are expected due to the strong interplay between spin, charge, and orbital degree of freedom at the interface. In this work, the polar and nonpolar interfaces are designed in LaMnO3-based (LMO) superlattices to investigate the difference in magnetic and transport properties. For the polar interface in a LMO/SrMnO3 superlattice, a novel robust ferromagnetism, exchange bias effect, vertical magnetization shift, and metallic behaviors coexist due to the polar catastrophe, which results in a double exchange coupling effect in the interface. For the nonpolar interface in a LMO/LaNiO3 superlattice, only the ferromagnetism and exchange bias effect characteristics exist due to the polar continuous interface. This is attributed to the charge transfer between Mn3+ and Ni3+ ions at the interface. Therefore, transition metal oxides exhibit various novel physical properties due to the strong correlation of d electrons and the polar and nonpolar interfaces. Our observations may provide an approach to further tune the properties using the selected polar and nonpolar oxide interfaces.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34574719

RESUMO

Moral identity is associated with people's subjective well-being; however, little is known about how an individual with moral identity relates to one's subjective well-being. Based on the eudaimonic identity theory, the current study proposed that identity commitment quality is a critical mechanism that links moral identity (two dimensions: internalization and symbolization) and subjective well-being. We examined our hypotheses in 419 college students, who completed the Self-importance of Moral Identity Questionnaire, Satisfaction with Life Scale, Scale of Positive and Negative Experience, and Questionnaire for Eudaimonic Well-being. Results confirmed significant positive correlations among moral identity, identity commitment quality, and subjective well-being; findings also suggested that both the internalization and symbolization dimensions of moral identity predicted subjective well-being through identity commitment quality, and identity commitment quality fully mediated the pathway relationship between moral identity and subjective well-being. We discussed these findings with respect to implications and proposed research suggestions for future studies.


Assuntos
Princípios Morais , Estudantes , Humanos , Inquéritos e Questionários
9.
J Integr Med ; 14(3): 203-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27181127

RESUMO

OBJECTIVE: Celastrol has been established as a nuclear factor-κB (NF-κB) activation inhibitor; however, the exact mechanism behind this action is still unknown. Using text-mining technology, the authors predicted that interleukin-1 receptor-associated kinases (IRAKs) are potential celastrol targets, and hypothesized that targeting IRAKs might be one way that celastrol inhibits NF-κB. This is because IRAKs are key molecules for some crucial pathways to activate NF-κB (e.g., the interleukin-1 receptor (IL-1R)/Toll-like receptor (TLR) superfamily). METHODS: The human hepatocellular cell line (HepG2) treated with palmitic acid (PA) was used as a model for stimulating TLR4/NF-κB activation, in order to observe the potential effects of celastrol in IRAK regulation and NF-κB inhibition. The transfection of small interfering RNA was used for down-regulating TLR4, IRAK1 and IRAK4, and the Western blot method was used to detect changes in the protein expressions. RESULTS: The results showed that celastrol could effectively inhibit PA-caused TLR4-dependent NF-κB activation in the HepG2 cells; PA also activated IRAKs, which were inhibited by celastrol. Knocking down IRAKs abolished PA-caused NF-κB activation. CONCLUSION: The results for the first time show that targeting IRAKs is one way in which celastrol inhibits NF-κB activation.


Assuntos
Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Receptor 4 Toll-Like/antagonistas & inibidores , Triterpenos/farmacologia , Células Hep G2 , Humanos , NF-kappa B/metabolismo , Triterpenos Pentacíclicos , Fosforilação , Receptor 4 Toll-Like/fisiologia
10.
BMC Cancer ; 15: 873, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26552919

RESUMO

BACKGROUND: Celastrol is a novel anti-tumor agent. Ways to further enhance this effect of celastrol has attracted much research attention. METHODS AND RESULTS: Here, we report that celastrol treatment can elevate miR-223 in human breast cancer cell line MCF-7 and prostate cancer PC3. Down-regulating miR-223 could increase the number of viable cells, yet it further reduced viable cells in samples that were treated by celastrol; up-regulation of miR-223 displayed opposite effects. Celastrol's miR-223 induction might be due to NF-κB inhibition and transient mTOR activation: these two events occurred prior to miR-223 elevation in celastrol-treated cells. NF-κB inhibitor, like celastrol, could induce miR-223; the induction of miR-223 by NF-κB inhibitor or celastrol was reduced by the use of mTOR inhibitor. Finally and interestingly, miR-223 also could affect NF-κB and mTOR and the effects were different between cells treated or not treated with celastrol, thus providing an explanation for differing effects of miR-223 alteration on cellular viability in the presence of celastrol or not. CONCLUSIONS: For the first time, we disclose that celastrol could induce miR-223 in breast and prostate cancer cells, and that inhibiting miR-223 could further reduce the living cells in celastrol-treated cancer cell lines. We thus provide a novel way to increase celastrol's anti-cancer effects.


Assuntos
Neoplasias da Mama/genética , MicroRNAs/biossíntese , Neoplasias da Próstata/genética , Triterpenos/administração & dosagem , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Masculino , MicroRNAs/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Triterpenos Pentacíclicos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Transdução de Sinais/efeitos dos fármacos
11.
J Neuroimmune Pharmacol ; 10(3): 506-16, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25773257

RESUMO

Multiple sclerosis (MS) is the prototypical inflammatory demyelinating disease of the central nervous system (CNS), and MS results in physical and cognitive impairments, such as fatigue, pain, depression and bladder dysfunction. Though many therapies for MS have been developed, the safety profile and effectiveness of these therapies still need to be defined. Thus, new therapies for MS must be explored. Celastrol, a quinonemethide triterpene, is a pharmacologically active compound present in Thunder God Vine root extracts used to treat inflammatory and autoimmune diseases. Molecular studies have identified several molecular targets, which are mostly centered on the inhibition of IKK-NF-κB signaling. The animal model of experimental autoimmune encephalomyelitis (EAE) has been widely used in MS studies; thus, we tried to explore the role of celastrol in EAE development in this study. We demonstrated that the intraperitoneal injection of celastrol significantly attenuated EAE disease. Th17 cell responses in the peripheral lymph nodes in EAE mice were also inhibited by celastrol. We determined that celastroldownregulated cytokine production in bone-marrow derived dendritic cells (BMDCs). Accordingly, T cells that were co-cultured with either BMDCs pre-treated with celastrolor splenic DCs and then collected on day 7 after EAE immunizationshowed that Th17 cell polarization is suppressed in the above two situations. Moreover, celastrol was required for tissue-infiltrating DCs to sustain Th17 responses in the central nervous system (CNS). Taken together, the results of our study demonstrate that celastrol ameliorates EAE development by suppressing pathogenic Th17 responses; this finding offers a better understanding of the role of celastrol in EAE development as well as new proposals for clinical interventions.


Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Sistema Nervoso Periférico/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B , Triterpenos Pentacíclicos , Triterpenos/administração & dosagem
12.
Chin J Physiol ; 47(3): 137-42, 2004 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-15612531

RESUMO

The present experiments were performed to study the actions of cyclopiazonic acid on triggered activities generated in vitro in ventricular papillary muscle and cardiomyocytes isolated from the hearts of healthy male Syrian hamsters (Biobreeders F1B). Action potentials (APs) of ventricular muscle with a diameter around 1.5 mm were recorded using a microelectrode technique and force was recorded using a transducer. Ventricular preparations were driven at 2 Hz in high [Ca]o (9 mM)-low [K]o (1 mM) solution to induce delayed after depolarizations (DADs). Triggered activities were induced on resumption of electrical stimulation after a rest period of 20 sec. Effects of cyclopiazonic acid (3-10 microM) on steady-state rhythms and post-rest triggered activities were determined. Results revealed that cyclopiazonic acid initially enhanced the amplitude of DADs and induced post-rest triggered rhythms. However, after several minutes of cyclopiazonic acid exposure, AP duration (APD) was prolonged and DADs were significantly depressed. The effects on APD and DADs were reversible after washout of cyclopiazonic acid, but the diastolic potential during rest period oscillated and was able to generate high-frequency spontaneous APs at a reduced potential level. In ventricular myocytes isolated enzymatically, ionic currents were measured using of whole-cell patch-clamp techniques. In a high [Ca]o-low [K]o solution, a series of oscillatory transient inward currents (I(ti)) were obtained on repolarization to the holding potential (-45 mV) after a depolarizing pulse to the test potential of +20 mV for 1.2 sec. Cyclopiazonic acid (10 microM) reduced significantly the magnitude of I(ti). The present results in hamster ventricular cells suggested that cyclopiazonic acid by inhibiting the sarcoplasmic reticulum (SR)-Ca2+ pump would gradually deplete the amount of Ca2+ within the SR. The consequent reduction in the amount of Ca2+ released into the cytoplasm by cyclopiazonic acid might inhibit triggered arrhythmia through a reduction of DADs and I(ti).


Assuntos
Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Músculos Papilares/efeitos dos fármacos , Músculos Papilares/fisiologia , Função Ventricular/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Cricetinae , Eletrofisiologia , Homeostase , Canais Iônicos/efeitos dos fármacos , Canais Iônicos/fisiologia , Masculino , Mesocricetus , Tempo de Reação/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...