Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 373
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Hepatol ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38670321

RESUMO

BACKGROUND & AIMS: The precise pathomechanisms underlying the development of non-alcoholic steatohepatitis (NASH, also known as metabolic dysfunction-associated steatohepatitis [MASH]) remain incompletely understood. In this study, we investigated the potential role of EF-hand domain family member D2 (EFHD2), a novel molecule specific to immune cells, in the pathogenesis of NASH. METHODS: Hepatic EFHD2 expression was characterized in patients with NASH and two diet-induced NASH mouse models. Single-cell RNA sequencing (scRNA-seq) and double-immunohistochemistry were employed to explore EFHD2 expression patterns in NASH livers. The effects of global and myeloid-specific EFHD2 deletion on NASH and NASH-related hepatocellular carcinoma were assessed. Molecular mechanisms underlying EFHD2 function were investigated, while chemical and genetic investigations were performed to assess its potential as a therapeutic target. RESULTS: EFHD2 expression was significantly elevated in hepatic macrophages/monocytes in both patients with NASH and mice. Deletion of EFHD2, either globally or specifically in myeloid cells, improved hepatic steatosis, reduced immune cell infiltration, inhibited lipid peroxidation-induced ferroptosis, and attenuated fibrosis in NASH. Additionally, it hindered the development of NASH-related hepatocellular carcinoma. Specifically, deletion of myeloid EFHD2 prevented the replacement of TIM4+ resident Kupffer cells by infiltrated monocytes and reversed the decreases in patrolling monocytes and CD4+/CD8+ T cell ratio in NASH. Mechanistically, our investigation revealed that EFHD2 in myeloid cells interacts with cytosolic YWHAZ (14-3-3ζ), facilitating the translocation of IFNγR2 (interferon-γ receptor-2) onto the plasma membrane. This interaction mediates interferon-γ signaling, which triggers immune and inflammatory responses in macrophages during NASH. Finally, a novel stapled α-helical peptide targeting EFHD2 was shown to be effective in protecting against NASH pathology in mice. CONCLUSION: Our study reveals a pivotal immunomodulatory and inflammatory role of EFHD2 in NASH, underscoring EFHD2 as a promising druggable target for NASH treatment. IMPACT AND IMPLICATIONS: Non-alcoholic steatohepatitis (NASH) represents an advanced stage of non-alcoholic fatty liver disease (NAFLD); however, not all patients with NAFLD progress to NASH. A key challenge is identifying the factors that trigger inflammation, which propels the transition from simple fatty liver to NASH. Our research pinpointed EFHD2 as a pivotal driver of NASH, orchestrating the over-activation of interferon-γ signaling within the liver during NASH progression. A stapled peptide designed to target EFHD2 exhibited therapeutic promise in NASH mice. These findings support the potential of EFHD2 as a therapeutic target in NASH.

2.
Nat Mater ; 22(1): 84-91, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36175521

RESUMO

Landau band crossings typically stem from the intra-band evolution of electronic states in magnetic fields and enhance the interaction effect in their vicinity. Here in the extreme quantum limit of topological insulator HfTe5, we report the observation of a topological Lifshitz transition from inter-band Landau level crossings using magneto-infrared spectroscopy. By tracking the Landau level transitions, we demonstrate that band inversion drives the zeroth Landau bands to cross with each other after 4.5 T and forms a one-dimensional Weyl mode with the fundamental gap persistently closed. The unusual reduction of the zeroth Landau level transition activity suggests a topological Lifshitz transition at 21 T, which shifts the Weyl mode close to the Fermi level. As a result, a broad and asymmetric absorption feature emerges due to the Pauli blocking effect in one dimension, along with a distinctive negative magneto-resistivity. Our results provide a strategy for realizing one-dimensional Weyl quasiparticles in bulk crystals.

3.
BMC Cancer ; 24(1): 576, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730348

RESUMO

OBJECTIVE: Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with special biological features. Controversies exist regarding the treatment approach and prognostic factors in the IMRT era. This study aimed to evaluate the long-term outcomes and management approaches in NACC. METHODS: Fifty patients with NACC at our institution between 2010 and 2020 were reviewed. Sixteen patients received primary radiotherapy (RT), and 34 patients underwent primary surgery. RESULTS: Between January 2010 and October 2020, a total of 50 patients with pathologically proven NACC were included in our analysis. The median follow-up time was 58.5 months (range: 6.0-151.0 months). The 5-year overall survival rate (OS) and progression-free survival rate (PFS) were 83.9% and 67.5%, respectively. The 5-year OS rates of patients whose primary treatment was surgery and RT were 90.0% and 67.3%, respectively (log-rank P = 0.028). The 5-year PFS rates of patients whose primary treatment was surgery or RT were 80.8% and 40.7%, respectively (log-rank P = 0.024). Multivariate analyses showed that nerve invasion and the pattern of primary treatment were independent factors associated with PFS. CONCLUSIONS: Due to the relative insensitivity to radiation, primary surgery seemed to provide a better chance of disease control and improved survival in NACC. Meanwhile, postoperative radiotherapy should be performed for advanced stage or residual tumours. Cranial nerve invasion and treatment pattern might be important factors affecting the prognosis of patients with NACC.


Assuntos
Carcinoma Adenoide Cístico , Neoplasias Nasofaríngeas , Radioterapia de Intensidade Modulada , Humanos , Carcinoma Adenoide Cístico/radioterapia , Carcinoma Adenoide Cístico/mortalidade , Carcinoma Adenoide Cístico/patologia , Carcinoma Adenoide Cístico/cirurgia , Masculino , Feminino , Radioterapia de Intensidade Modulada/métodos , Pessoa de Meia-Idade , Adulto , Neoplasias Nasofaríngeas/radioterapia , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Idoso , Estudos Retrospectivos , Carcinoma Nasofaríngeo/radioterapia , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/patologia , Adulto Jovem , Prognóstico , Taxa de Sobrevida , Resultado do Tratamento , Seguimentos , Adolescente , Intervalo Livre de Progressão
4.
BMC Geriatr ; 24(1): 341, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622502

RESUMO

BACKGROUND: Malnutrition is a common geriatric syndrome that is closely associated with adverse clinical outcomes and poses significant harm to older adults. Early assessment of nutritional status plays a crucial role in preventing and intervening in cases of malnutrition. However, there is currently a lack of measurable methods and biomarkers to evaluate malnutrition in older adults accurately. The aim of this study is to investigate the independent correlation between serum levels of amino acids and malnutrition in older adults, and to identify effective metabolomics biomarkers that can aid in the early detection of geriatric malnutrition. METHODS: A total of 254 geriatric medical examination participants from Beijing Hospital were included in the study, consisting of 182 individuals with normal nutritional status (Normal group) and 72 patients at risk of malnutrition or already malnourished (MN group). Malnutrition was assessed using the Mini-Nutritional Assessment Short-Form (MNA-SF). Demographic data were collected, and muscle-related and lipid indexes were determined. Serum amino acid concentrations were measured using isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). The correlation between serum amino acid levels and malnutrition was analyzed using non-parametric tests, partial correlation analysis, linear regression, and logistic regression. RESULTS: The geriatric MN group exhibited significantly lower serum aromatic amino acid levels (P < 0.05) compared to the normal group. A positive correlation was observed between serum aromatic amino acid levels and the MNA-SF score (P = 0.002), as well as with known biomarkers of malnutrition such as body mass index (BMI) (P < 0.001) and hemoglobin (HGB) (P = 0.005). Multivariable logistic or linear regression analyses showed that aromatic amino acid levels were negatively correlated with MN and positively correlated with the MNA-SF score, after adjusting for some confounding factors, such as age, gender, BMI, smoking status, history of dyslipidemia, diabetes mellitus and frailty. Stratified analyses revealed that these trends were more pronounced in individuals without a history of frailty compared to those with a history of frailty, and there was an interaction between aromatic amino acid levels and frailty history (P = 0.004). CONCLUSION: Our study suggests that serum aromatic amino acids are independently associated with malnutrition in older adults. These results have important implications for identifying potential biomarkers to predict geriatric malnutrition or monitor its progression and severity, as malnutrition can result in poor clinical outcomes.


Assuntos
Fragilidade , Desnutrição , Humanos , Idoso , Fragilidade/diagnóstico , Cromatografia Líquida , Espectrometria de Massas em Tandem , Desnutrição/diagnóstico , Desnutrição/complicações , Estado Nutricional , Avaliação Nutricional , Biomarcadores , Aminoácidos , Aminoácidos Aromáticos , Avaliação Geriátrica/métodos
5.
J Adv Nurs ; 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38402452

RESUMO

OBJECTIVES: To develop an instrument to facilitate the risk assessment of falls in older outpatients. DESIGN: A quantitative methodological study using the cross-sectional data. METHODS: This study enrolled 1988 older participants who underwent comprehensive geriatric assessment (CGA) in an outpatient clinic from May 2020 to November 2022. The history of any falls (≥1 falls in a year) and recurrent falls (≥2 falls in a year) were investigated. Potential risk factors of falls were selected by stepwise logistic regression, and a screening tool was constructed based on nomogram. The tool performance was compared with two reference tools (Fried Frailty Phenotype; CGA with 10 items, CGA-10) by using receiver operating curves, sensitivity (Sen), specificity (Spe), and area under the curve (AUC). RESULTS: Age, unintentional weight loss, depression measured by the Patient Health Questionnaire-2, muscle strength measured by the five times sit-to-stand test, and stand balance measured by semi- and full-tandem standing were the most important risk factors for falls. A fall risk screening tool was constructed with the six measurements (FRST-6). FRST-6 showed the best AUC (Sen, Spe) of 0.75 (Sen = 0.72, Spe = 0.69) for recurrent falls and 0.65 (Sen = 0.74, Spe = 0.48) for any falls. FRST-6 was comparable to CGA-10 and outperformed FFP in performance. CONCLUSIONS: Age, depression, weight loss, gait, and balance were important risk factors of falls. The FRST-6 tool based on these factors showed acceptable performance in risk stratification. IMPACT: Performing a multifactorial assessment in primary care clinics is urgent for falls prevention. The FRST-6 provides a simple and practical way for falls risk screening. With this tool, healthcare professionals can efficiently identify patients at risk of falling and make appropriate recommendations in resource-limited settings. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution was received, due to our study design.

6.
Int J Mol Sci ; 25(10)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38791596

RESUMO

Ovarian follicular fluid (FF) has a direct impact on oocyte quality, playing key roles in fertilization, implantation, and early embryo development. In our recent study, we found FF thromboxane (TX) to be a novel factor inversely correlated with oocyte maturation and identified thrombin, transforming growth factor ß (TGFß), TNF-α, and follicular granulosa cells (GCs) as possible contributors to FF TX production. Therefore, this study sought to investigate the role of TGFß3 in regulating TX generation in human ovarian follicular GCs. TGFß3 was differentially and significantly present in the FF of large and small follicles obtained from IVF patients with average concentrations of 68.58 ± 12.38 and 112.55 ± 14.82 pg/mL, respectively, and its levels were correlated with oocyte maturity. In an in vitro study, TGFß3 induced TX generation/secretion and the converting enzyme-COX-2 protein/mRNA expression both in human HO23 and primary cultured ovarian follicular GCs. While TGFßRI and Smad2/3 signaling was mainly required for COX-2 induction, ERK1/2 appeared to regulate TX secretion. The participation of Smad2/3 and COX-2 in TGFß3-induced TX generation/secretion could be further supported by the observations that Smad2/3 phosphorylation and nuclear translocation and siRNA knockdown of COX-2 expression compromised TX secretion in GCs challenged with TGFß3. Taken together, the results presented here first demonstrated that FF TGFß3 levels differ significantly in IVF patients' large preovulatory and small mid-antral follicles and are positively associated with oocyte maturation. TGFß3 can provoke TX generation by induction of COX-2 mRNA/protein via a TGFßR-related canonical Smad2/3 signaling pathway, and TX secretion possibly by ERK1/2. These imply that TGFß3 is one of the inducers for yielding FF TX in vivo, which may play a role in folliculogenesis and oocyte maturation.


Assuntos
Ciclo-Oxigenase 2 , Líquido Folicular , Células da Granulosa , Transdução de Sinais , Proteína Smad2 , Proteína Smad3 , Fator de Crescimento Transformador beta3 , Humanos , Feminino , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/genética , Células da Granulosa/metabolismo , Proteína Smad2/metabolismo , Proteína Smad2/genética , Proteína Smad3/metabolismo , Proteína Smad3/genética , Líquido Folicular/metabolismo , Fator de Crescimento Transformador beta3/metabolismo , Fator de Crescimento Transformador beta3/genética , Adulto , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/genética , Folículo Ovariano/metabolismo , Oócitos/metabolismo , Células Cultivadas
7.
J Cell Mol Med ; 27(8): 1131-1143, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36965158

RESUMO

During exogenous bone-graft-mediated bone defect repair, macrophage inflammation dictates angiogenesis and bone regeneration. Exosomes from different human cells have shown macrophage immunomodulation-mediated bone regeneration potential. However, the effect of human serum-derived exosomes (serum-Exo) on macrophage immunomodulation-mediated angiogenesis during bone defect repair has not been investigated yet. In this study, we explored the effects of serum-Exo on macrophage inflammation regulation-mediated angiogenesis during bone defect repair and preliminarily elucidated the mechanism. Healthy serum-Exo was isolated by ultracentrifugation. The effect of serum-Exo on LPS-induced M1 macrophage inflammation was analysed in vitro. The conditioned medium of serum-Exo-treated LPS-induced M1 macrophage (serum-Exo-treated M1 macrophage-CM) was used to culture human umbilical vein endothelial cells (HUVEC), and the effect on angiogenesis was analysed by western blot, qRT-PCR, etc. mRNA-sequencing of HUVECs was performed to identify deferentially expressed genes. Finally, the rat mandibular defect model was established and treated with Bio-Oss and Bio-Oss + Exo. The effect of the Bio-Oss + Exo combination on mandibular bone regeneration was observed by micro-computed tomography (micro-CT), haematoxylin and eosin (HE) staining, Masson staining, and immunohistochemical staining. Serum-Exo promoted the proliferation of RAW264.7 macrophages and reduced the expression of M1-related genes such as IL-6, IL-1ß, iNOS, and CD86. Serum-Exo-treated M1 macrophage-CM induced the proliferation, migration, and angiogenic differentiation of HUVEC, as well as the expression of H-type blood vessel markers CD31 and endomucin (EMCN), compared with M1 macrophage-CM. Moreover, higher expression of vascular endothelial adhesion factor 1 (VCAM1) in HUVEC cultured with serum-Exo-treated M1 macrophage-CM compared with M1 macrophages-CM. Inhibition of VCAM1 signalling abrogated the pro-angiogenic effect of serum-Exo-treated M1 macrophage-CM on HUVEC. Local administration of serum-Exo during mandibular bone defect repair reduced the number of M1 macrophages and promoted angiogenesis and osteogenesis. Collectively, our results demonstrate the macrophage inflammation regulation-mediated pro-angiogenic potential of serum-Exo during bone defect repair possibly via upregulation of VCAM1 signalling in HUVEC.


Assuntos
Exossomos , Humanos , Ratos , Animais , Exossomos/metabolismo , Lipopolissacarídeos/metabolismo , Microtomografia por Raio-X , Regeneração Óssea/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Inflamação/genética , Inflamação/metabolismo , Macrófagos
8.
J Exp Bot ; 74(15): 4628-4641, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37129574

RESUMO

Abiotic stresses can affect the outcome of plant-pathogen interactions, mostly by predisposing the host plant to infection; however, the crosstalk between pathogens and plants related to such predisposition remains unclear. Here, we investigated the predisposition of Carya cathayensis to infection by the fungal pathogen Botryosphaeria dothidea (Bd) caused by drought in the host plant. High levels of drought stress resulted in a significant increase in plant susceptibility to Bd. Drought significantly induced the accumulation of H2O2 and the free amino acids Pro, Leu, and Ile, and in the phloem tissues of plants, and decreased the content of non-structural carbohydrates. In vitro assays showed that Bd was sensitive to H2O2; however, Pro played a protective role against exogenous H2O2. Leu, Ile, and Pro induced asexual reproduction of Bd. Our results provide the first analysis of how drought predisposes C. cathayensis to Botrysphaeria canker via amino acid accumulation in the host plant, and we propose a model that integrates the plant-pathogen interactions involved.


Assuntos
Aminoácidos , Carya , Secas , Peróxido de Hidrogênio
9.
Mol Cell Biochem ; 478(10): 2191-2206, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36640256

RESUMO

The study aims to explore the role of the ERK signaling pathway in the crosstalk between Dkk-1 and TNF-α in MC3T3E1 pre-osteoblasts under cyclic tensile/compressive stress. A forced four-point bending system was used to apply cyclic uniaxial tensile/compressive strain (2000 µ, 0.5 Hz) to MC3T3E1 cells. Dkk-1 and TNF-α expression were upregulated in MC3T3E1 cells under compressive strain. Cell proliferation, the cell cycle, osteogenesis-related gene (Wnt5a, Runx2, Osterix) expression, ß-catenin expression, and the p-ERK/ERK ratio were significantly enhanced, whereas apoptosis, the RANKL/OPG ratio, and TNF-α expression were significantly attenuated, by Dkk-1 silencing. Dkk-1 expression increased and the effects of Dkk-1 silencing were reversed when exogenous TNF-α was added. Mechanically, TNF-α crosstalked with Dkk-1 through ERK signaling in MC3T3E1 cells. ERK signaling blockade impaired Dkk-1-induced TNF-α expression and TNF-α-mediated Dkk-1 expression. Dkk-1 and TNF-α crosstalked, partially through ERK signaling, in MC3T3E1 cells under compressive/tensile strain, synergistically modulating various biological behaviors of the cells. These findings not only provide mechanical insight into the cellular events and molecular regulation of orthodontic tooth movement (OTM), but also aid the development of novel strategies to accelerate OTM.


Assuntos
Transdução de Sinais , Fator de Necrose Tumoral alfa , Diferenciação Celular , Proliferação de Células , Osteoblastos/metabolismo , Osteogênese , Estresse Mecânico , Fator de Necrose Tumoral alfa/metabolismo , Animais , Camundongos
10.
J Appl Microbiol ; 134(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36597783

RESUMO

Acinetobacter baumannii is a strictly aerobic, nonmotile, nonfermenting, gram-negative bacillus. It is a highly infectious and invasive pathogen with high mortality and morbidity rates among immunodeficient patients. Due to increasing levels of drug resistance and the inefficiency of existing antimicrobial treatments, it is crucial to develop novel agents to control this pathogen. Several recent studies have investigated virulence factors that are associated with the pathogenesis of A. baumannii, and could thus serve as novel therapeutic targets. The present review comprehensively summarizes the current understanding of these virulence factors and their mechanisms in A. baumannii. We also highlight factors that could be potential therapeutic targets, as well as list candidate virulence factors for future researchers and clinical practitioners.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Anti-Infecciosos , Humanos , Fatores de Virulência/genética , Virulência , Infecções por Acinetobacter/tratamento farmacológico , Anti-Infecciosos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla
11.
Eur Heart J ; 43(43): 4579-4595, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-35929617

RESUMO

AIMS: Exercise confers protection against cardiovascular ageing, but the mechanisms remain largely unknown. This study sought to investigate the role of fibronectin type-III domain-containing protein 5 (FNDC5)/irisin, an exercise-associated hormone, in vascular ageing. Moreover, the existence of FNDC5/irisin in circulating extracellular vesicles (EVs) and their biological functions was explored. METHODS AND RESULTS: FNDC5/irisin was reduced in natural ageing, senescence, and angiotensin II (Ang II)-treated conditions. The deletion of FNDC5 shortened lifespan in mice. Additionally, FNDC5 deficiency aggravated vascular stiffness, senescence, oxidative stress, inflammation, and endothelial dysfunction in 24-month-old naturally aged and Ang II-treated mice. Conversely, treatment of recombinant irisin alleviated Ang II-induced vascular stiffness and senescence in mice and vascular smooth muscle cells. FNDC5 was triggered by exercise, while FNDC5 knockout abrogated exercise-induced protection against Ang II-induced vascular stiffness and senescence. Intriguingly, FNDC5 was detected in human and mouse blood-derived EVs, and exercise-induced FNDC5/irisin-enriched EVs showed potent anti-stiffness and anti-senescence effects in vivo and in vitro. Adeno-associated virus-mediated rescue of FNDC5 specifically in muscle but not liver in FNDC5 knockout mice, promoted the release of FNDC5/irisin-enriched EVs into circulation in response to exercise, which ameliorated vascular stiffness, senescence, and inflammation. Mechanistically, irisin activated DnaJb3/Hsp40 chaperone system to stabilize SIRT6 protein in an Hsp70-dependent manner. Finally, plasma irisin concentrations were positively associated with exercise time but negatively associated with arterial stiffness in a proof-of-concept human study. CONCLUSION: FNDC5/irisin-enriched EVs contribute to exercise-induced protection against vascular ageing. These findings indicate that the exerkine FNDC5/irisin may be a potential target for ageing-related vascular comorbidities.


Assuntos
Vesículas Extracelulares , Sirtuínas , Humanos , Camundongos , Animais , Idoso , Pré-Escolar , Fibronectinas/metabolismo , Fatores de Transcrição/metabolismo , Camundongos Knockout , Envelhecimento , Angiotensina II/farmacologia , Inflamação/metabolismo , Músculo Esquelético/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo
12.
Nano Lett ; 22(11): 4459-4467, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35608193

RESUMO

Multimodal sensor with high sensitivity, accurate sensing resolution, and stimuli discriminability is very desirable for human physiological state monitoring. A dual-sensing aerogel is fabricated with independent pyro-piezoresistive behavior by leveraging MXene and semicrystalline polymer to assemble shrinkable nanochannel structures inside multilevel cellular walls of aerogel for discriminable temperature and pressure sensing. The shrinkable nanochannels, controlled by the melt flow-triggered volume change of semicrystalline polymer, act as thermoresponsive conductive channels to endow the pyroresistive aerogel with negative temperature coefficient of resistance of -10.0% °C-1 and high accuracy within 0.2 °C in human physiological temperature range of 30-40 °C. The flexible cellular walls, working as pressure-responsive conductive channels, enable the piezoresistive aerogel to exhibit a pressure sensitivity up to 777 kPa-1 with a detectable pressure limit of 0.05 Pa. The pyro-piezoresistive aerogel can detect the temperature-dependent characteristics of pulse pressure waveforms from artery vessels under different human body temperature states.


Assuntos
Polímeros , Condutividade Elétrica , Humanos , Monitorização Fisiológica , Temperatura
13.
Nano Lett ; 22(18): 7328-7335, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36067249

RESUMO

Here, using various substrates, we demonstrate that the in-plane uniaxial strain engineering can enhance the Jahn-Teller distortions and promote selective orbital occupancy to induce an emergent antiferromagnetic insulating (AFI) phase at x = 1/3 of La1-xCaxMnO3. Such an AFI phase depends not only on the magnitude of epitaxial strain but also on the symmetry of the substrates. Using the large uniaxial strain imparted by DyScO3(001) substrate, the AFI ground state is achieved in a wide range of doping levels (0 ≤ x ≤ 1/2), leaving an extended AFI phase diagram. Moreover, it is found that hydrostatic pressure can tune the AFI phase back to a hidden ferromagnetic metallic phase, accompanied by the formation of accommodation strain. The coaction of the accommodation strain, uniaxial strain, and hydrostatic pressure produces complex phase competition and evolution, and the result may shed light on phase space control of other functional perovskites with the competing magnetic interactions.

14.
Int J Mol Sci ; 24(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36834541

RESUMO

Tobacco smoke exposure is a major environmental risk factor that facilitates the development and progression of asthma. Our previous study showed that CpG oligodeoxynucleotide (CpG-ODN) inhibits thymic stromal lymphopoietin (TSLP)-dendritic cells (DCs) to reduce Th2/Th17-related inflammatory response in smoke-related asthma. However, the mechanism underlying CpG-ODN -downregulated TSLP remains unclear. A combined house dust mite (HDM)/cigarette smoke extract (CSE) model was used to assess the effects of CpG-ODN on airway inflammation, Th2/Th17 immune response, and amount of IL-33/ST2 and TSLP in mice with smoke-related asthma induced by adoptive transfer of bone-marrow-derived dendritic cells (BMDCs) and in the cultured human bronchial epithelium (HBE) cells administered anti-ST2, HDM, and/or CSE. In vivo, compared to the HDM alone model, the combined HDM/CSE model had aggravated inflammatory responses, while CpG-ODN attenuated airway inflammation, airway collagen deposition, and goblet cell hyperplasia and reduced the levels of IL-33/ST2, TSLP, and Th2/Th17-cytokines in the combined model. In vitro, IL-33/ST2 pathway activation promoted TSLP production in HBE cells, which could be inhibited by CpG-ODN. CpG-ODN administration alleviated Th2/Th17 inflammatory response, decreased the infiltration of inflammatory cells into the airway, and improved the remodeling of smoke-related asthma. The underlying mechanism may be that CpG-ODN inhibits the TSLP-DCs pathway by downregulating the IL-33/ST2 axis.


Assuntos
Asma , Interleucina-33 , Animais , Humanos , Camundongos , Transferência Adotiva , Alérgenos , Asma/metabolismo , Citocinas/metabolismo , Células Dendríticas , Inflamação , Interleucina-33/metabolismo , Camundongos Endogâmicos BALB C , Oligodesoxirribonucleotídeos/farmacologia , Células Th2 , Linfopoietina do Estroma do Timo , Células Th17
15.
Int J Mol Sci ; 24(20)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37894811

RESUMO

In this study, we confirmed that thrombin significantly increases the production of COX-2 and PGE2 in human tracheal smooth muscle cells (HTSMCs), leading to inflammation in the airways and lungs. These molecules are well-known contributors to various inflammatory diseases. Here, we investigated in detail the involved signaling pathways using specific inhibitors and small interfering RNAs (siRNAs). Our results demonstrated that inhibitors targeting proteins such as protein kinase C (PKC)δ, proline-rich tyrosine kinase 2 (Pyk2), c-Src, epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), or activator protein-1 (AP-1) effectively reduced thrombin-induced COX-2 and PGE2 production. Additionally, transfection with siRNAs against PKCδ, Pyk2, c-Src, EGFR, protein kinase B (Akt), or c-Jun mitigated these responses. Furthermore, our observations revealed that thrombin stimulated the phosphorylation of key components of the signaling cascade, including PKCδ, Pyk2, c-Src, EGFR, Akt, and c-Jun. Thrombin activated COX-2 promoter activity through AP-1 activation, a process that was disrupted by a point-mutated AP-1 site within the COX-2 promoter. Finally, resveratrol (one of the most researched natural polyphenols) was found to effectively inhibit thrombin-induced COX-2 expression and PGE2 release in HTSMCs through blocking the activation of Pyk2, c-Src, EGFR, Akt, and c-Jun. In summary, our findings demonstrate that thrombin-induced COX-2 and PGE2 generation involves a PKCδ/Pyk2/c-Src/EGFR/PI3K/Akt-dependent AP-1 activation pathway. This study also suggests the potential use of resveratrol as an intervention for managing airway inflammation.


Assuntos
Proteínas Proto-Oncogênicas c-akt , Fator de Transcrição AP-1 , Humanos , Proteína Tirosina Quinase CSK/metabolismo , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Quinase 2 de Adesão Focal/genética , Quinase 2 de Adesão Focal/metabolismo , Inflamação/metabolismo , Miócitos de Músculo Liso/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Resveratrol/farmacologia , Resveratrol/metabolismo , Quinases da Família src/metabolismo , Trombina/metabolismo , Fator de Transcrição AP-1/metabolismo
16.
Molecules ; 28(12)2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37375258

RESUMO

Photocatalytic CO2 reduction to valuable hydrocarbon solar fuel is of great significance but still challenging. Strong CO2 enrichment ability and easily adjustable structures make metal-organic frameworks (MOFs) potential photocatalysts for CO2 conversion. Even though pure MOFs have the potential for photoreduction of CO2, the efficiency is still quite low due to rapid photogenerated electron-hole recombination and other drawbacks. In this work, graphene quantum dots (GQDs) were in situ encapsulated into highly stable MOFs via a solvothermal method for this challenging task. The GQDs@PCN-222 with encapsulated GQDs showed similar Powder X-ray Diffraction (PXRD) patterns to PCN-222, indicating the retained structure. The porous structure was also retained with a Brunauer-Emmett-Teller (BET) surface area of 2066 m2/g. After incorporation of GQDs, the shape of GQDs@PCN-222 particles remained, as revealed by the scanning electron microscope (SEM). As most of the GQDs were covered by thick PCN-222, it was hard to observe those GQDs using a transmission electron microscope (TEM) and a high-resolution transmission electron microscope (HRTEM) directly, the treatment of digested GQDs@PCN-222 particles by immersion in a 1 mM aqueous KOH solution can make the incorporated GQDs visible in TEM and HRTEM. The linker, deep purple porphyrins, make MOFs a highly visible light harvester up to 800 nm. The introduction of GQDs inside PCN-222 can effectively promote the spatial separation of the photogenerated electron-hole pairs during the photocatalytic process, which was proved by the transient photocurrent plot and photoluminescence emission spectra. Compared with pure PCN-222, the obtained GQDs@PCN-222 displayed dramatically enhanced CO production derived from CO2 photoreduction with 147.8 µmol/g/h in a 10 h period under visible light irradiation with triethanolamine (TEOA) as a sacrificial agent. This study demonstrated that the combination of GQDs and high light absorption MOFs provides a new platform for photocatalytic CO2 reduction.

17.
Molecules ; 28(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36985588

RESUMO

A total of 39 novel cyclotryptamine alkaloid derivatives were prepared from 2-(1H-indol-3-yl) acetonitrile. The prepared compounds were evaluated against six plant pathogen fungi. Bioassay results revealed that most of the compounds displayed higher in vitro antifungal activities than the positive control. Notably, compound b2 displayed the broadest and most effective activity among the tested cyclotryptamine alkaloid derivatives and might be a novel potential leading compound for further development as an antifungal agent.


Assuntos
Alcaloides , Antifúngicos , Antifúngicos/farmacologia , Relação Estrutura-Atividade , Fungos , Alcaloides/farmacologia , Estrutura Molecular
18.
Angew Chem Int Ed Engl ; 62(3): e202212893, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36170553

RESUMO

Direct C-H bond functionalization is a useful strategy for the straightforward formation of C-C and C-Heteroatom bonds. In the present work, a unique approach for the challenging electrophilic Au-catalyzed α-C-H bond functionalization of tertiary amines is presented. Electronic, steric and conformational synergistic effects exerted by the use of a malonate unit in the substrate were key to the success of this transformation. This new reactivity was applied to the synthesis of tetrahydro-γ-carboline products which, under oxidative conditions, could be converted into valuable structural motifs found in bioactive alkaloid natural products.


Assuntos
Aminas , Ouro , Estrutura Molecular , Catálise , Conformação Molecular , Aminas/química
19.
J Cell Physiol ; 237(3): 1871-1887, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34897684

RESUMO

A higher expression level of mitogenic fibroblast growth factor-2 (FGF-2) has been reported in human nasal mucus of both chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). Meanwhile, we have shown that long pentraxin 3 (PTX3), an essential component of humoral innate immunity that is produced at sites of infection and inflammation, was overproduced in human nasal mucosae and secretions of CRSsNP. Therefore, this study was aimed to investigate how FGF-2 regulates PTX3 expression in human CRSsNP nasal mucosa-derived fibroblast cells (hNMDFs). The FGF-2 treatment caused ptx3 mRNA expression and PTX3 protein induction and secretion. In parallel, a differential expression of FGF receptor (FGFR)-1 to FGFR-4 was observed in hNMDFs and human nasal tissues. While conventionally known PI3K/Akt/mTOR and AP-1 pathways following FGFR activation were shown to be involved, the protein kinase Cδ (PKCδ) and cAMP response element-binding protein (CREB) were also found to be as critical signaling molecules in FGF-2-induced PTX3 induction. The PKCδ and CREB activation could be detected in total cells and in the cell nucleus. Accordingly, a novel CREB binding sequence was detected in the human ptx3 promoter region and could interact with activated CREB in cells challenged with FGF-2. Surprisingly, the phospholipase D (PLD), but not phosphoinositide- and phosphatidylcholine-phospholipase C, was necessarily required for PKCδ and CREB activation. Therefore, we demonstrated here for the first time that FGF-2 mediates PTX3 production not only through PI-3K/Akt/mTOR and AP-1 activation, but also through a novel FGFR-PLD-PKCδ-CREB cellular signaling pathway.


Assuntos
Pólipos Nasais , Fosfolipase D , Sinusite , Humanos , Proteína C-Reativa , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fibroblastos/metabolismo , Pólipos Nasais/genética , Pólipos Nasais/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfolipase D/genética , Fosfolipase D/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Componente Amiloide P Sérico , Sinusite/genética , Sinusite/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo
20.
Langmuir ; 38(47): 14485-14496, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36378259

RESUMO

A peculiar heterogeneous metal sandwich fragment {(Ge9)2[η6-Ge(PdPPh3)3]}4- anion cluster was synthesized for the first time by Xu et al. (Xu, H. L.; Tkachenko, N. V.; Wang, Z. C.; Chen, W. X.; Qiao, L.; Munoz-Castro, A.; Boldyrev, A. I.; Sun, Z. M. Nat. Commun.2020, 11, 5286). In this work, novel analogous sandwich compounds ({(E9)2[η6-E(PdPH3)3]}4- (E = Si (1), Ge (2), Sn (3)) were studied using quantum chemical calculations and wave function analysis to determine the geometry, bonding nature, aromaticity, active sites, and hydrogen storage. Structural analysis revealed that the clusters were compounds formed by the coordination of two E92- (E = Si, Ge, Sn) Zintl clusters with a central E@Pd3 (E = Si, Ge, Sn) interlayer. The steric hindrance at both ends is small, facilitating facile attachment to other molecules. The valence states of the central atom E (E = Si, Ge, Sn) are close to zero, indicating that they are stable novel heterometallic sandwich compounds, and the Zintl ligands at both ends are negative, thus they can react with Lewis acids. Bonding analysis showed that the E92- (E = Si, Ge, Sn) cluster has a delocalized framework bonding mode. For aromaticity analysis, we used AdNDP, ELF, LOL, ICSS, and NICS to qualitatively and quantitatively clarify that these clusters possess the characteristics of overall delocalization, σ aromaticity, and remarkable stability. By analyzing the unique structure and predicting the reaction sites, we concluded that the E92- ligand reacts with Lewis acids. Finally, through the adsorption of hydrogen molecules, the average adsorption energies of 1-3 were 0.387, 0.374, and 0.325 eV per H2 molecule, respectively, meeting the physical adsorption standard, with the adsorption effect of 3 being slightly more superior than that of 1 and 2. Our study represents a substantial step forward in the study of high-density materials for volumetric H2 storage applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA