Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Traffic ; 25(1): e12920, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37886910

RESUMO

Wilson disease (WD) is caused by mutations in the ATP7B gene that encodes a copper (Cu) transporting ATPase whose trafficking from the Golgi to endo-lysosomal compartments drives sequestration of excess Cu and its further excretion from hepatocytes into the bile. Loss of ATP7B function leads to toxic Cu overload in the liver and subsequently in the brain, causing fatal hepatic and neurological abnormalities. The limitations of existing WD therapies call for the development of new therapeutic approaches, which require an amenable animal model system for screening and validation of drugs and molecular targets. To achieve this objective, we generated a mutant Caenorhabditis elegans strain with a substitution of a conserved histidine (H828Q) in the ATP7B ortholog cua-1 corresponding to the most common ATP7B variant (H1069Q) that causes WD. cua-1 mutant animals exhibited very poor resistance to Cu compared to the wild-type strain. This manifested in a strong delay in larval development, a shorter lifespan, impaired motility, oxidative stress pathway activation, and mitochondrial damage. In addition, morphological analysis revealed several neuronal abnormalities in cua-1 mutant animals exposed to Cu. Further investigation suggested that mutant CUA-1 is retained and degraded in the endoplasmic reticulum, similarly to human ATP7B-H1069Q. As a consequence, the mutant protein does not allow animals to counteract Cu toxicity. Notably, pharmacological correctors of ATP7B-H1069Q reduced Cu toxicity in cua-1 mutants indicating that similar pathogenic molecular pathways might be activated by the H/Q substitution and, therefore, targeted for rescue of ATP7B/CUA-1 function. Taken together, our findings suggest that the newly generated cua-1 mutant strain represents an excellent model for Cu toxicity studies in WD.


Assuntos
Degeneração Hepatolenticular , Animais , Humanos , Degeneração Hepatolenticular/genética , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/metabolismo , Cobre/toxicidade , Cobre/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , ATPases Transportadoras de Cobre/genética , ATPases Transportadoras de Cobre/metabolismo , Hepatócitos/metabolismo
2.
Molecules ; 29(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38276617

RESUMO

Most hydrophobes easily diffuse into yeast cells, where they experience reduced evaporation and protection from oxidation, thus allowing inherently biocompatible encapsulation processes. Despite a long-standing industrial interest, the effect of parameters such as how is yeast pre-treated (extraction with ethanol, plasmolysis with hypertonic NaCl, depletion to cell walls), the polarity of the hydrophobes and the process conditions are still not fully understood. Here, we have developed thorough analytical protocols to assess how the effects of the above on S. cerevisiae's morphology, permeability, and encapsulation efficiency, using three differently polar hydrophobes (linalool, 1,6-dihydrocarvone, limonene) and three separate processes (hydrophobes as pure 'oils', water dispersions, or acetone solutions). The harsher the pre-treatment (depleted > plasmolyzed/extracted > untreated cells), the easier the diffusion into yeast became, and the lower both encapsulation efficiency and protection from evaporation, possibly due to denaturation/removal of lipid-associated (membrane) proteins. More hydrophobic terpenes performed worst in encapsulation as pure 'oils' or in water dispersion, but much less of a difference existed in acetone. This indicates the specific advantage of solvents/dispersants for 'difficult' compounds, which was confirmed by principal component analysis; furthering this concept, we have used combinations of hydrophobes (e.g., linalool and α-tocopherol), with one acting as solvent/enhancer for the other. Our results thus indicate advantages in using untreated yeast and-if necessary-processes based on solvents/secondary hydrophobes.


Assuntos
Acetona , Monoterpenos Acíclicos , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Acetona/metabolismo , Alérgenos/metabolismo , Solventes , Água/metabolismo
3.
Proc Natl Acad Sci U S A ; 117(51): 32453-32463, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33288711

RESUMO

Pathogenic mutations in the copper transporter ATP7B have been hypothesized to affect its protein interaction landscape contributing to loss of function and, thereby, to hepatic copper toxicosis in Wilson disease. Although targeting mutant interactomes was proposed as a therapeutic strategy, druggable interactors for rescue of ATP7B mutants remain elusive. Using proteomics, we found that the frequent H1069Q substitution promotes ATP7B interaction with HSP70, thus accelerating endoplasmic reticulum (ER) degradation of the mutant protein and consequent copper accumulation in hepatic cells. This prompted us to use an HSP70 inhibitor as bait in a bioinformatics search for structurally similar Food and Drug Administration-approved drugs. Among the hits, domperidone emerged as an effective corrector that recovered trafficking and function of ATP7B-H1069Q by impairing its exposure to the HSP70 proteostatic network. Our findings suggest that HSP70-mediated degradation can be safely targeted with domperidone to rescue ER-retained ATP7B mutants and, hence, to counter the onset of Wilson disease.


Assuntos
ATPases Transportadoras de Cobre/genética , ATPases Transportadoras de Cobre/metabolismo , Domperidona/farmacologia , Proteínas de Choque Térmico HSP70/metabolismo , Degeneração Hepatolenticular/genética , Benzimidazóis/química , Benzimidazóis/farmacologia , Células Cultivadas , Cobre/metabolismo , Domperidona/química , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Células Hep G2 , Hepatócitos/metabolismo , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/metabolismo , Degeneração Hepatolenticular/patologia , Humanos , Mutação de Sentido Incorreto , Ácidos Nipecóticos/química , Ácidos Nipecóticos/farmacologia , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/genética , Proteômica/métodos
4.
Angew Chem Int Ed Engl ; 62(51): e202312517, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-37924230

RESUMO

DNA repair protein RAD51 is a key player in the homologous recombination pathway. Upon DNA damage, RAD51 is transported into the nucleus by BRCA2, where it can repair DNA double-strand breaks. Due to the structural complexity and dynamics, researchers have not yet clarified the mechanistic details of every step of RAD51 recruitment and DNA repair. RAD51 possesses an intrinsic tendency to form oligomeric structures, which make it challenging to conduct biochemical and biophysical investigations. Here, for the first time, we report on the isolation and characterization of a human monomeric RAD51 recombinant form, obtained through a double mutation, which preserves the protein's integrity and functionality. We investigated different buffers to identify the most suitable condition needed to definitively stabilize the monomer. The monomer of human RAD51 provides the community with a unique biological tool for investigating RAD51-mediated homologous recombination, and paves the way for more reliable structural, mechanistic, and drug discovery studies.


Assuntos
Recombinação Homóloga , Neoplasias , Rad51 Recombinase , Proteínas Recombinantes , Humanos , Dano ao DNA , Reparo do DNA , Neoplasias/genética , Rad51 Recombinase/química , Rad51 Recombinase/genética , Rad51 Recombinase/isolamento & purificação , Mutação , Estabilidade Proteica , Domínios Proteicos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação
5.
Am J Orthod Dentofacial Orthop ; 162(3): 297-306, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35688724

RESUMO

INTRODUCTION: This double in vitro study and randomized clinical trial aimed to investigate the bonding failure rates of orthodontic brackets after enamel pretreatment with agents showing different particle sizes. METHODS: For the in vitro study, 80 bovine teeth were randomly divided into 4 groups according to the pretreating method used and their particle sizes: erythritol (14 µm), glycine (18-22 µm), sodium bicarbonate (70 µm), and no pretreatment. Scanning electron microscopy microphotographs were performed after pretreatment. Then, brackets were bonded, and shear bond strength was calculated. For the clinical study, agents with low (erythritol) and high (sodium bicarbonate) particle sizes were chosen. Twenty consecutive patients willing to start fixed orthodontic treatment with vestibular stainless steel brackets were enrolled. Patients were randomly divided into 2 groups following a split-mouth design. Group A underwent a 5-second enamel pretreatment procedure with erythritol for teeth belonging to maxillary left and mandibular right quadrants, whereas the remaining quadrants were pretreated for 5 seconds with sodium bicarbonate powder. In group B, quadrants were inverted. Then, brackets were bonded on the vestibular surfaces of teeth, and patients were visited monthly for 12 months to assess bond failures. Periodontal evaluation of probing pocket depth, bleeding on probing, plaque index, and papilla bleeding index was conducted before bonding and after 1, 3, 6, and 12 months. RESULTS: The in vitro study showed that erythritol and control presented significantly higher shear bond strength values for other agents. Bicarbonate showed the lowest values. In the clinical study, 20 patients (aged 16.4 ± 3.9 years) were enrolled, and all completed the study. Erythritol showed a significantly lower failure rate (3%) than sodium bicarbonate (7.5%). Kaplan-Meier survival plots showed statistically significant differences in risk of failure between the 2 groups during the 12-month follow-up. CONCLUSIONS: Enamel pretreatment with erythritol can be a viable technique to reduce failure rates of orthodontic brackets. REGISTRATION: The trial was not registered. PROTOCOL: The protocol was not published before trial commencement. FUNDING: No funding or grant was received for this research.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Animais , Bovinos , Esmalte Dentário , Eritritol , Humanos , Teste de Materiais , Cimentos de Resina/química , Cimentos de Resina/uso terapêutico , Resistência ao Cisalhamento , Bicarbonato de Sódio/farmacologia , Bicarbonato de Sódio/uso terapêutico , Propriedades de Superfície , Taxa de Sobrevida
6.
Small ; 11(24): 2919-28, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-25689227

RESUMO

The results of a systematic investigation of the role of serum proteins on the interaction of silica nanoparticles (NP) doped in their bulk with fluorescent molecules (IRIS Dots, 50 nm in size), with human mesenchymal stem cells (hMSCs) are reported. The suspension of IRIS Dots in bare Dulbecco-modified Eagle's medium results in the formation of large agglomerates (≈1.5 µm, by dynamic light scattering), which become progressively smaller, down to ≈300 nm in size, by progressively increasing the fetal bovine serum (FBS) content of the solutions along the series 1.0%, 2.5%, 6.0%, and 10.0% v/v. Such difference in NP dispersion is maintained in the external cellular microenvironment, as observed by confocal microscopy and transmission electron microscopy. As a consequence of the limited diffusion of proteins in the inter-NP spaces, the surface of NP agglomerates is coated by a protein corona independently of the agglomerate size/FBS concentration conditions (ζ-potential and UV circular dichroism measurements). The protein corona appears not to be particularly relevant for the uptake of IRIS Dots by hMSCs, whereas the main role in determining the internalization rate is played by the absence/presence of serum proteins in the extracellular media.


Assuntos
Proteínas Sanguíneas/metabolismo , Endocitose , Células-Tronco Mesenquimais/metabolismo , Nanopartículas Metálicas/química , Dióxido de Silício/metabolismo , Adsorção , Dicroísmo Circular , Citometria de Fluxo , Corantes Fluorescentes/química , Humanos , Hidrodinâmica , Cinética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/ultraestrutura , Espectrofotometria Ultravioleta , Temperatura
7.
Chem Res Toxicol ; 28(1): 87-91, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25564874

RESUMO

In the course of studies of the interaction of proteins with TiO2 nanoparticles, we have investigated the role of the medium employed in cellular tests, by measuring the variation of ζ-potential vs pH in the range 2-9 and bovine serum albumin adsorption on TiO2 P25 in the presence of either HEPES or PBS as buffers, both mimicking the physiological pH, but with different chemical nature. The two buffers yield remarkably dissimilar surface charges and protein uptake, i.e., they impart different surface characteristics to the particles which could affect the contact with cells or tissues. This may account for dissimilar toxicological outcomes among in vitro tests and particularly between in vitro vs in vivo tests, considering the high amount of phosphate ions present in body fluids.


Assuntos
HEPES/química , Nanopartículas/química , Fosfatos/química , Soroalbumina Bovina/química , Titânio/química , Testes de Toxicidade/métodos , Adsorção , Soluções Tampão , Técnicas de Cultura de Células , Concentração de Íons de Hidrogênio , Nanopartículas/toxicidade , Propriedades de Superfície , Titânio/toxicidade
8.
J Nanobiotechnology ; 13: 77, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26510588

RESUMO

BACKGROUND: Treatment of myocardial infarction with mesenchymal stem cells (MSCs) has proven beneficial effects in both animal and clinical studies. Engineered silica nanoparticles (SiO2-NPs) have been extensively used as contrast agents in regenerative medicine, due to their resistance to degradation and ease of functionalization. However, there are still controversies on their effective biosafety on cellular systems. In this perspective, the aims of the present study are: 1) to deeply investigate the impact of amorphous 50 nm SiO2-NPs on viability and function of human bone marrow-derived MSCs (hMSCs); 2) to optimize a protocol of harmless hMSCs labelling and test its feasibility in a beating heart model. RESULTS: Optimal cell labelling is obtained after 16 h exposure of hMSCs to fluorescent 50 nm SiO2-NPs (50 µg mL(-1)); interestingly, lysosomal activation consequent to NPs storage is not associated to oxidative stress. During prolonged culture hMSCs do not undergo cyto- or genotoxicity, preserve their proliferative potential and their stemness/differentiation properties. Finally, the bright fluorescence emitted by internalized SiO2-NPs allows both clear visualization of hMSCs in normal and infarcted rat hearts and ultrastructural analysis of cell engraftment inside myocardial tissue. CONCLUSIONS: Overall, 50 nm SiO2-NPs display elevated compatibility with hMSCs in terms of lack of cyto- and genotoxicity and maintenance of important features of these cells. The demonstrated biosafety, combined with proper cell labelling and visualization in histological sections, make these SiO2-NPs optimal candidates for the purpose of stem cell tracking inside heart tissue.


Assuntos
Corantes/metabolismo , Coração/fisiologia , Células-Tronco Mesenquimais/citologia , Nanopartículas/química , Dióxido de Silício/metabolismo , Coloração e Rotulagem , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Dano ao DNA , Endocitose , Humanos , Lisossomos/metabolismo , Células-Tronco Mesenquimais/ultraestrutura , Imagem Molecular , Estresse Oxidativo
9.
Biomed Pharmacother ; 175: 116677, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38701570

RESUMO

The current pharmacological approaches to multiple sclerosis (MS) target its inflammatory and autoimmune components, but effective treatments to foster remyelination and axonal repair are still lacking. We therefore selected two targets known to be involved in MS pathogenesis: N-acylethanolamine-hydrolyzing acid amidase (NAAA) and glycogen synthase kinase-3ß (GSK-3ß). We tested whether inhibiting these targets exerted a therapeutic effect against experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The combined inhibition of NAAA and GSK-3ß by two selected small-molecule compounds, ARN16186 (an NAAA inhibitor) and AF3581 (a GSK-3ß inhibitor), effectively mitigated disease progression, rescuing the animals from paralysis and preventing a worsening of the pathology. The complementary activity of the two inhibitors reduced the infiltration of immune cells into the spinal cord and led to the formation of thin myelin sheaths around the axons post-demyelination. Specifically, the inhibition of NAAA and GSK-3ß modulated the over-activation of NF-kB and STAT3 transcription factors in the EAE-affected mice and induced the nuclear translocation of ß-catenin, reducing the inflammatory insult and promoting the remyelination process. Overall, this work demonstrates that the dual-targeting of key aspects responsible for MS progression could be an innovative pharmacological approach to tackle the pathology.


Assuntos
Amidoidrolases , Encefalomielite Autoimune Experimental , Glicogênio Sintase Quinase 3 beta , Camundongos Endogâmicos C57BL , Esclerose Múltipla , Animais , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Encefalomielite Autoimune Experimental/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/metabolismo , Camundongos , Amidoidrolases/antagonistas & inibidores , Amidoidrolases/metabolismo , Feminino , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Medula Espinal/patologia , NF-kappa B/metabolismo , Inibidores Enzimáticos/farmacologia , Bainha de Mielina/metabolismo , Bainha de Mielina/efeitos dos fármacos
10.
Int J Pharm ; : 124404, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945464

RESUMO

Vaccines based on protein antigens have numerous advantages over inactivated pathogens, including easier manufacturing and improved safety. However, purified antigens are weakly immunogenic, as they lack the spatial organization and the associated 'danger signals' of the pathogen. Formulating vaccines as nanoparticles enhances the recognition by antigen presenting cells, boosting the cell-mediated immune response. This study describes a nano-precipitation method to obtain stable protein nanoaggregates with uniform size distribution without using covalent cross-linkers. Nanoaggregates were formed via microfluidic mixing of ovalbumin (OVA) and lipids in the presence of high methanol concentrations. A purification protocol was set up to separate the nanoaggregates from OVA and liposomes, obtained as byproducts of the mixing. The nanoaggregates were characterized in terms of morphology, ζ-potential and protein content, and their interaction with immune cells was assessed in vitro. Antigen-specific T cell activation was over 6-fold higher for nanoaggregates compared to OVA, due in part to the enhanced uptake by immune cells. Lastly, a two-dose immunization with nanoaggregates in mice induced a significant increase in OVA-specific CD8+ T splenocytes compared to soluble OVA. Overall, this work presents for the first time the microfluidic production of lipid-stabilized protein nanoaggregates and provides a proof-of-concept of their potential for vaccination.

11.
Sci Adv ; 10(9): eadk8123, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38427732

RESUMO

Besides recent advances in neonatal care, preterm newborns still develop sex-biased behavioral alterations. Preterms fail to receive placental insulin-like growth factor-1 (IGF-1), a major fetal growth hormone in utero, and low IGF-1 serum levels correlate with preterm poor neurodevelopmental outcomes. Here, we mimicked IGF-1 deficiency of preterm newborns in mice by perinatal administration of an IGF-1 receptor antagonist. This resulted in sex-biased brain microstructural, functional, and behavioral alterations, resembling those of ex-preterm children, which we characterized performing parallel mouse/human behavioral tests. Pharmacological enhancement of GABAergic tonic inhibition by the U.S. Food and Drug Administration-approved drug ganaxolone rescued functional/behavioral alterations in mice. Establishing an unprecedented mouse model of prematurity, our work dissects the mechanisms at the core of abnormal behaviors and identifies a readily translatable therapeutic strategy for preterm brain disorders.


Assuntos
Encefalopatias , Fator de Crescimento Insulin-Like I , Estados Unidos , Criança , Humanos , Recém-Nascido , Gravidez , Feminino , Animais , Camundongos , Receptor IGF Tipo 1 , Placenta , Recém-Nascido Prematuro , Encefalopatias/tratamento farmacológico
12.
ACS Appl Mater Interfaces ; 15(3): 3882-3893, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36629473

RESUMO

The catalytic and antioxidant properties of platinum nanoparticles (PtNPs) make them promising candidates for several applications in nanomedicine. However, an open issue, still shared among most nanomaterials, is the understanding on how internalized PtNPs, which are confined within endo-lysosomal compartments, can exert their activities. To address this problem, here we study the protective effect of 5 nm PtNPs on a human hepatic (HepG2) cell line exposed to dichlorodiphenylethylene (DDE) as a model of oxidative stress. Our results indicate that PtNPs are very efficient to reduce DDE-induced damage in HepG2 cells, in an extent that depends on DDE dose. PtNPs can contrast the unbalance of mitochondrial dynamics induced by DDE and increase the expression of the SOD2 mitochondrial enzyme that recovers cells from oxidative stress. Interestingly, in cells treated with PtNPs─alone or in combination with DDE─mitochondria form contact sites with a rough endoplasmic reticulum and endo-lysosomes containing nanoparticles. These findings indicate that the protective capability of PtNPs, through their intrinsic antioxidant properties and modulating mitochondrial functionality, is mediated by an inter-organelle crosstalk. This study sheds new light about the protective action mechanisms of PtNPs and discloses a novel nano-biointeraction mechanism at the intracellular level, modulated by inter-organelle communication and signaling.


Assuntos
Antioxidantes , Nanopartículas Metálicas , Humanos , Antioxidantes/farmacologia , Platina/farmacologia , Transdução de Sinais , Mitocôndrias/metabolismo
13.
Int J Pharm ; 631: 122479, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36509224

RESUMO

After two decades of research in the field of nanomedicine, nanoscale delivery systems for biologicals are becoming clinically relevant tools. Microfluidic-based fabrication processes are replacing conventional techniques based on precipitation, emulsion, and homogenization. Here, the focus is on solid lipid nanoparticles (SLNs) for the encapsulation and delivery of lysozyme (LZ) as a model biologic. A thorough analysis was conducted to compare conventional versus microfluidic-based production techniques, using a 3D-printed device. The efficiency of the microfluidic technique in producing LZ-loaded SLNs (LZ SLNs) was demonstrated: LZ SLNs were found to have a lower size (158.05 ± 4.86 nm vs 180.21 ± 7.46 nm) and higher encapsulation efficacy (70.15 ± 1.65 % vs 53.58 ± 1.13 %) as compared to particles obtained with conventional methods. Cryo-EM studies highlighted a peculiar turtle-like structure on the surface of LZ SLNs. In vitro studies demonstrated that LZ SLNs were suitable to achieve a sustained release over time (7 days). Enzymatic activity of LZ entrapped into SLNs was challenged on Micrococcus lysodeikticus cultures, confirming the stability and potency of the biologic. This systematic analysis demonstrates that microfluidic production of SLNs can be efficiently used for encapsulation and delivery of complex biological molecules.


Assuntos
Produtos Biológicos , Nanopartículas , Portadores de Fármacos/química , Lipídeos/química , Microfluídica , Muramidase , Nanopartículas/química , Tamanho da Partícula
14.
ACS Appl Mater Interfaces ; 15(19): 22999-23011, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37132437

RESUMO

CuFeS2 chalcopyrite nanoparticles (NPs) can generate heat under exposure to near-infrared laser irradiation. Here, we develop a protocol to decorate the surface of CuFeS2 NPs (13 nm) with a thermoresponsive (TR) polymer based on poly(ethylene glycol methacrylate) to combine heat-mediated drug delivery and photothermal heat damage. The resulting TR-CuFeS2 NPs feature a small hydrodynamic size (∼75 nm), along with high colloidal stability and a TR transition temperature of 41 °C in physiological conditions. Remarkably, TR-CuFeS2 NPs, when exposed to a laser beam (in the range of 0.5 and 1.5 W/cm2) at NP concentrations as low as 40-50 µg Cu/mL, exhibit a high heating performance with a rise in the solution temperature to hyperthermia therapeutic values (42-45 °C). Furthermore, TR-CuFeS2 NPs worked as nanocarriers, being able to load an appreciable amount of doxorubicin (90 µg DOXO/mg Cu), a chemotherapeutic agent whose release could then be triggered by exposing the NPs to a laser beam (through which a hyperthermia temperature above 42 °C could be reached). In an in vitro study performed on U87 human glioblastoma cells, bare TR-CuFeS2 NPs were proven to be nontoxic at a Cu concentration up to 40 µg/mL, while at the same low dose, the drug-loaded TR-CuFeS2-DOXO NPs displayed synergistic cytotoxic effects due to the combination of direct heat damage and DOXO chemotherapy, under photo-irradiation by a 808 nm laser (1.2 W/cm2). Finally, under a 808 nm laser, the TR-CuFeS2 NPs generated a tunable amount of reactive oxygen species depending on the applied power density and NP concentration.


Assuntos
Hipertermia Induzida , Nanopartículas , Humanos , Polímeros , Hipertermia Induzida/métodos , Sistemas de Liberação de Medicamentos , Fototerapia , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Linhagem Celular Tumoral
15.
ACS Appl Mater Interfaces ; 15(50): 58260-58273, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38051559

RESUMO

Microglial cells play a critical role in glioblastoma multiforme (GBM) progression, which is considered a highly malignant brain cancer. The activation of microglia can either promote or inhibit GBM growth depending on the stage of the tumor development and on the microenvironment conditions. The current treatments for GBM have limited efficacy; therefore, there is an urgent need to develop novel and efficient strategies for drug delivery and targeting: in this context, a promising strategy consists of using nanoplatforms. This study investigates the microglial response and the therapeutic efficacy of dual-cell membrane-coated and doxorubicin-loaded hexagonal boron nitride nanoflakes tested on human microglia and GBM cells. Obtained results show promising therapeutic effects on glioma cells and an M2 microglia polarization, which refers to a specific phenotype or activation state that is associated with anti-inflammatory and tissue repair functions, highlighted through proteomic analysis.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Microglia , Proteômica , Glioblastoma/patologia , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Neoplasias Encefálicas/patologia , Membrana Celular/patologia , Microambiente Tumoral/fisiologia , Linhagem Celular Tumoral
16.
Cell Rep ; 42(2): 112104, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36787220

RESUMO

Microglia reactivity entails a large-scale remodeling of cellular geometry, but the behavior of the microtubule cytoskeleton during these changes remains unexplored. Here we show that activated microglia provide an example of microtubule reorganization from a non-centrosomal array of parallel and stable microtubules to a radial array of more dynamic microtubules. While in the homeostatic state, microglia nucleate microtubules at Golgi outposts, and activating signaling induces recruitment of nucleating material nearby the centrosome, a process inhibited by microtubule stabilization. Our results demonstrate that a hallmark of microglia reactivity is a striking remodeling of the microtubule cytoskeleton and suggest that while pericentrosomal microtubule nucleation may serve as a distinct marker of microglia activation, inhibition of microtubule dynamics may provide a different strategy to reduce microglia reactivity in inflammatory disease.


Assuntos
Microglia , Microtúbulos , Centrossomo , Citoesqueleto , Complexo de Golgi , Tubulina (Proteína)
17.
Small ; 8(20): 3192-200, 2012 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-22821625

RESUMO

Highly bright and photostable cyanine dye-doped silica nanoparticles, IRIS Dots, are developed, which can efficiently label human mesenchymal stem cells (hMSCs). The application procedure used to label hMSCs is fast (2 h), the concentration of IRIS Dots for efficient labeling is low (20 µg mL(-1) ), and the labeled cells can be visualized by flow cytometry, confocal microscopy, and transmission electron microscopy. Labeled hMSCs are unaffected in their viability and proliferation, as well as stemness surface marker expression and differentiation capability into osteocytes. Moreover, this is the first report that shows nonfunctionalized IRIS Dots can discriminate between live and early-stage apoptotic stem cells (both mesenchymal and embryonic) through a distinct external cell surface distribution. On the basis of biocompatibility, efficient labeling, and apoptotic discrimination potential, it is suggested that IRIS Dots can serve as a promising stem cell tracking agent.


Assuntos
Nanopartículas/química , Imagem Óptica/métodos , Dióxido de Silício/química , Células-Tronco , Apoptose/fisiologia , Células Cultivadas , Citometria de Fluxo , Humanos , Microscopia Confocal
18.
Cells ; 11(2)2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35053335

RESUMO

ATP7B is a hepato-specific Golgi-located ATPase, which plays a key role in the regulation of copper (Cu) homeostasis and signaling. In response to elevated Cu levels, ATP7B traffics from the Golgi to endo-lysosomal structures, where it sequesters excess copper and further promotes its excretion to the bile at the apical surface of hepatocytes. In addition to liver, high ATP7B expression has been reported in tumors with elevated resistance to platinum (Pt)-based chemotherapy. Chemoresistance to Pt drugs represents the current major obstacle for the treatment of large cohorts of cancer patients. Although the mechanisms underlying Pt-tolerance are still ambiguous, accumulating evidence suggests that lysosomal sequestration of Pt drugs by ion transporters (including ATP7B) might significantly contribute to drug resistance development. In this context, signaling mechanisms regulating the expression of transporters such as ATP7B are of great importance. Considering this notion, we investigated whether ATP7B expression in Pt-resistant cells might be driven by transcription factor EB (TFEB), a master regulator of lysosomal gene transcription. Using resistant ovarian cancer IGROV-CP20 cells, we found that TFEB directly binds to the predicted coordinated lysosomal expression and regulation (CLEAR) sites in the proximal promoter and first intron region of ATP7B upon Pt exposure. This binding accelerates transcription of luciferase reporters containing ATP7B CLEAR regions, while suppression of TFEB inhibits ATP7B expression and stimulates cisplatin toxicity in resistant cells. Thus, these data have uncovered a Pt-dependent transcriptional mechanism that contributes to cancer chemoresistance and might be further explored for therapeutic purposes.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , ATPases Transportadoras de Cobre/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Ovarianas/genética , Platina/farmacologia , Sequência de Bases , Linhagem Celular Tumoral , ATPases Transportadoras de Cobre/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Platina/toxicidade , Transcrição Gênica/efeitos dos fármacos
19.
J Colloid Interface Sci ; 607(Pt 1): 34-44, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34492351

RESUMO

Among the strategies to fight cancer, multi-therapeutic approaches are considered as a wise choice to put in place multiple weapons to suppress tumors. In this work, to combine chemotherapeutic effects to magnetic hyperthermia when using biocompatible scaffolds, we have established an electrospinning method to produce nanofibers of polycaprolactone loaded with magnetic nanoparticles as heat mediators to be selectively activated under alternating magnetic field and doxorubicin as a chemotherapeutic drug. Production of the fibers was investigated with iron oxide nanoparticles of peculiar cubic shape (at 15 and 23 nm in cube edges) as they provide benchmark heat performance under clinical magnetic hyperthermia conditions. With 23 nm nanocubes when included into the fibers, an arrangement in chains was obtained. This linear configuration of magnetic nanoparticles resemble that of the magnetosomes, produced by magnetotactic bacteria, and our magnetic fibers exhibited remarkable heating effects as the magnetosomes. Magnetic fiber scaffolds showed excellent biocompatibility on fibroblast cells when missing the chemotherapeutic agent and when not exposed to magnetic hyperthermia as shown by viability assays. On the contrary, the fibers containing both magnetic nanocubes and doxorubicin showed significant cytotoxic effects on cervical cancer cells following the exposure to magnetic hyperthermia. Notably, these tests were conducted at magnetic hyperthermia field conditions of clinical use. As here shown, on the doxorubicin sensitive cervical cancer cells, the combination of heat damage by magnetic hyperthermia with enhanced diffusion of doxorubicin at therapeutic temperature are responsible for a more effective oncotherapy.


Assuntos
Hipertermia Induzida , Nanopartículas de Magnetita , Neoplasias , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Compostos Férricos , Campos Magnéticos , Poliésteres
20.
Colloids Surf B Biointerfaces ; 188: 110780, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32004906

RESUMO

High-resolution transmission electron microscopy, ζ-potential and in-situ IR spectroscopy of adsorbed CO were combined for elucidating the ratio between {011¯0}_ Ca-rich: {011¯0}_ P-rich terminations of {011¯0} facets, i.e. the surfaces with the highest morphological importance, in two nanohydroxyapatite samples. Bovine serum albumin was found to form at least a monolayer on the surface left accessible to protein molecules by the agglomeration of nanoparticles when suspended in the buffered incubation medium. Noticeably, the conformation of adsorbed proteins appeared sensitive to the ratio between the two types of {011¯0} terminations, also resulting in a difference in the surface exposed toward the exterior by the adsorbed protein layer(s).


Assuntos
Durapatita/química , Nanopartículas/química , Soroalbumina Bovina/química , Adsorção , Animais , Bovinos , Tamanho da Partícula , Conformação Proteica , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA