Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Materials (Basel) ; 17(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38673130

RESUMO

This study experimentally investigated electrically assisted (EA) stress relief annealing for cold-coiled commercial automotive springs. In EA stress relief annealing, the temperature of a spring is rapidly increased to the annealing temperature (400 °C) and is held constant for a specified time using a pulsed electric current. Experimental findings show that the effectiveness of the EA stress relief annealing is superior to that of the conventional stress relief annealing, especially in terms of process time. The present study suggests that EA stress relief annealing, with properly selected process parameters, can effectively substitute for time-consuming conventional stress relief annealing using a furnace for cold-coiled automotive springs.

2.
Front Cell Neurosci ; 16: 895750, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36246521

RESUMO

The stimulation of autophagy or lysosomes has been considered therapeutic for neurodegenerative disorders because the accumulation of misfolded proteins is commonly observed in the brains of individuals with these diseases. Although zinc is known to play critical roles in the functions of lysosomes and autophagy, the mechanism behind this regulatory relationship remains unclear. Therefore, in this study, we examined which mechanism is involved in zinc-mediated activation of autophagy and lysosome. Exposure to zinc at a sub-lethal concentration activated autophagy in a concentration-dependent manner in mRFP-GFP-LC3-expressing H4 glioma cells. Zinc also rescued the blocking of autophagic flux arrested by pharmaceutical de-acidification. Co-treatment with zinc attenuated the chloroquine (CQ)-induced increase in the number and size of mRFP-GFP-LC3 puncta in H4 cells and accumulation of p62 by CQ or ammonium chloride in both H4 and mouse cerebrocortical cultures. Zinc rapidly induced the expression of cathepsin B (CTSB) and cathepsin D (CTSD), representative lysosomal proteases in neurons, which appeared likely to be mediated by transcription factor EB (TFEB). We observed the translocation of TFEB from neurite to nucleus and the dephosphorylation of TFEB by zinc. The addition of cycloheximide, a chemical inhibitor of protein synthesis, inhibited the activity of CTSB and CTSD at 8 h after zinc exposure but not at 1 h, indicating that only late lysosomal activation was dependent on the synthesis of CTSB and CTSD proteins. At the very early time point, the activation of cathepsins was mediated by an increased assembly of V-ATPase on lysosomes and resultant lysosomal acidification. Finally, considering that P301L mutation in tau protein causes frontotemporal dementia through aggressive tau accumulation, we investigated whether zinc reduces the accumulation of protein aggregates in SK-N-BE(2)-C neuroblastoma cells expressing wild-type tau or mutant P301L-tau. Zinc markedly attenuated the levels of phosphorylated tau and total tau as well as p62 in both wild-type and mutant tau-overexpressing cells. We also observed that zinc was more effective than rapamycin at inducing TFEB-dependent CTSB and CTSD expression and V-ATPase-dependent lysosomal acidification and CTSB/CTSD activation. These results suggest that the regulation of zinc homeostasis could be a new approach for developing treatments for neurodegenerative diseases, including Alzheimer's and Parkinson's.

3.
Sci Rep ; 12(1): 3537, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35241735

RESUMO

A multiple receptor tyrosine kinase inhibitor, sunitinib, is a first-line therapy for clear cell renal cell carcinoma (CCRCC). Unfortunately, it has the major challenges of low initial response rate and resistance after about one year of treatment. Here we evaluated a microRNA (miRNA) and its target responsible for sunitinib resistance. Using miRNA profiling, we identified miR-96-5p upregulation in tumors from sunitinib-resistant CCRCC patients. By bioinformatic analysis, PTEN was selected as a potential target of miR-96-5p, which showed low levels in tumors from sunitinib-resistant CCRCC patients. Furthermore, PTEN and miR-96-5p levels were negatively correlated in a large The Cancer Genome Atlas kidney renal clear cell carcinoma cohort and high miR-96 and low PTEN represented poor prognosis in this cohort. Additionally, four-week sunitinib treatment increased miR-96-5p and decreased PTEN only in tumors from a sunitinib-resistant patient-derived xenograft model. We found a novel miR-96-5p binding site in the PTEN 3' UTR and confirmed direct repression by luciferase reporter assay. Furthermore, we demonstrated that repression of PTEN by miR-96-5p increased cell proliferation and migration in sunitinib-treated cell lines. These results highlight the direct suppression of PTEN by miR-96-5p and that high miR-96-5p and low PTEN are partially responsible for sunitinib resistance and poor prognosis in CCRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , MicroRNAs , PTEN Fosfo-Hidrolase , Sunitinibe , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , MicroRNAs/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Sunitinibe/farmacologia , Sunitinibe/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Bioorg Chem ; 113: 105027, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34098398

RESUMO

Psiguadial B (8), and its fluoro- (8a), chloro- (8b), and bromo- (8c) derivatives were synthesized using a sodium acetate-catalyzed single step coupling of three components: ß-caryophyllene (5), diformylphloroglucinol (11), and benzaldehyde (12). These compounds efficiently and dose-dependently decreased H2O2-induced cell death, a quantitative marker of cell death, in primary cultures of mouse cortical neurons. Psiguadial B also decreased neuronal death and accumulation of ROS induced by FeCl2 in cortical cultures. The in vitro effects of these compounds in lipopolysaccharide (LPS)-induced expression of nitric oxide (NO), and TNF-α and IL-6 by suppressing the NF-κB pathway in immune cells demonstrated their antioxidative and anti-inflammatory activity. The present findings warrant further research on the development of psiguadial B-based neuroprotective agents for the treatment of neurodegenerative diseases, acute brain injuries and immunological disorders.


Assuntos
Anti-Inflamatórios/química , Antioxidantes/química , Fármacos Neuroprotetores/química , Terpenos/química , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Compostos Ferrosos/farmacologia , Halogenação , Peróxido de Hidrogênio/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos ICR , NF-kappa B/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/farmacologia , Óxido Nítrico/metabolismo , Psidium/química , Psidium/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA